RETINAL DETACHMENT
SIGNS AND SYMPTOMS
There are three forms of retinal detachment:
1. Rhegmatogenous retinal detachment (RRD), which results from a retinal break. The vast majority of rhegmatogenous detachments are symptomatic, with patients reporting photopsiae, floating spots, peripheral visual field loss, central blurring of vision or metamorphopsia.
2. Exudative or serous retinal detachment (ERD), which results from fluid accumulation under the sensory retina without a retinal break. Exudative detachments do not generally present with photopsiae but may be associated with moderate vision loss, metamorphopsia or a visual field deficit.
3. Tractional retinal detachment (TRD), which results from the pull of proliferative fibrovascular vitreal strands. Tractional detachments are typically asymptomatic unless central vision is threatened, in which case the patient can suffer severe and abrupt vision loss.
In cases of extensive unilateral retinal detachment, you may observe a relative afferent pupillary defect. Intraocular pressure may be reduced in eyes with acute retinal detachment.
Ophthalmoscopy in cases of RRD usually reveals a clumping of pigment cells within the anterior vitreous (Shaffer's sign). There may be an area of white or grayish elevated retina adjacent to the instigating retinal break. If a significant area of the retina is involved, you may note a milky, lackluster appearance with undulating retinal folds.
A rhegmatogenous detachment will not change position with changes in body posture, however it may shift and then return to its original orientation with quick eye movements. Associated findings may include posterior vitreous detachment and preretinal or vitreal hemorrhage. Retinal pigment epithelial hyperplasia may be noted in cases of long-standing retinal detachment (pigment demarcation line), and is a good prognostic feature.
ERD appears clinically as a focal, serous elevation of the retina, which shifts position with changes in posture and eye movement. The subretinal fluid obeys gravity, always affecting the lowest aspect of the eye. Ophthalmoscopy reveals a smooth, translucent, dome-shaped protrusion of the retina. There are usually no hemorrhages, except in cases of associated retinal vasculopathy.
TRD is always associated with vitreal strands and membranes. It appears as a concave, smooth-surfaced detachment with marginal fibrovascular bands emanating into the vitreous body. It is sometimes difficult to assess where the necrotic retina ends and the vitreal membranes begin. Very often, this area encircles an intact posterior pole, resulting in a retinal "pseudo-hole." TRDs are dense and immobile. This motility lends itself well to ancillary testing with ultrasonography.
PATHOPHYSIOLOGY
All retinal detachments involve the sensory retina dissecting from the underlying pigment epithelial layer by subretinal fluid. In rhegmatogenous detachments, this fluid is liquefied vitreous, which accesses the subretinal space via a retinal break. In exudative detachments, the fluid is derived from the choroid, passing through a defective Bruch's membrane. The origin of the subretinal fluid in tractional detachments is unknown. Both passive and active movement of subretinal fluid induce progression of retinal detachments, leading to partial or total loss of vision in some patients.
Retinal breaks are the predisposing factor in patients with rhegmatogenous detachment. These may result from preexisting conditions or ocular trauma. Some of the more common entities associated with RRD include lattice degeneration, flap tears, atrophic holes, operculated retinal breaks, and acquired retinoschisis with both inner and outer holes. As the retinal tissue loses its connection to the RPE, it becomes edematous and dysfunctional. Without surgical intervention, death of this tissue occurs within 48 to 72 hours.
Exudative detachments are relatively rare, occurring in association with subretinal disorders that damage the RPE layer. These may include choroidal neoplasms, Vogt-Koyanagi-Harada syndrome, posterior scleritis, congenital optic disc anomalies (optic pits, morning glory syndrome, etc.), Coat's disease and uveal effusion syndrome.
Transudation of fluid through the RPE defects causes detachment of the otherwise normal sensory retina. As the fluid shifts with eye and head movements, the involved portion of the retina changes. This explains why most patients with ERDs suffer significantly less devastating visual compromise than those with RRDs or TRDs.
Tractional detachments occur only in proliferative vitreoretinopathies. The most common of these is proliferative diabetic retinopathy, but many TRDs are associated with ischemic retinal vein occlusions, sickle cell retinopathy, retinopathy of prematurity, toxocariasis and trauma.
The etiology of TRD involves fibrotic scaffolding of the vitreous along proliferative vascular networks which induce strong anterior tractional forces through vitreal shrinkage. These forces induce the sensory retina to separate from the underlying RPE.
Unlike rhegmatogenous or exudative detachments which tend to be abrupt, TRDs are often slow and insidious, progressing at the same rate as the associated fibrovascular proliferation. Peripheral TRDs are therefore rarely if ever noticed by the patient. Macular TRDs, on the other hand, tend to be symptomatic, unless the underlying disease process has already compromised visual acuity.
Showing posts with label diagnosis. Show all posts
Showing posts with label diagnosis. Show all posts
Friday, November 11, 2011
RETINITIS PIGMENTOSA
SIGNS AND SYMPTOMS
Patients with retinitis pigmentosa (RP) may present with varying symptoms. The onset is often gradual and insidious, and many patients fail to recognize the manifestations of this condition until it has progressed significantly. When patients do report symptoms, they commonly include difficulty with night vision (nyctalopia) as well as loss of peripheral vision.
Many patients with RP also experience photopsiae as the disorder progresses; typically they report small flashes of light or a twinkling, shimmering sensation in the midperipheral or peripheral field. These are believed to represent aberrant electrical impulses from the degenerating retina.
Central visual acuity is generally not affected until the very late stages of RP, although variants have been encountered that cause devastating macular compromise early in the disease course (e.g., X-linked recessive RP). Color vision is typically remains intact as long as visual acuity is better than 20/40.
Attenuation of the retinal arterioles is the earliest observable sign in RP. Retinal pigmentary changes occur in the form of fine mottling or granularity with surrounding areas of atrophy. Later, stellate pigment hyperplasia may be noted at perivascular locations in the midperipheral retina. These hyperplastic formations are often referred to as "bone spicules."
As the disorder progresses, general atrophy of the RPE and choriocapillaris ensues, exposing the larger choroidal vessels. The optic nerve head is often normal in early RP, but may demonstrate a waxy yellow or pale appearance later. RP has a strong correlation with acquired optic disc drusen. The macula, like the optic nerve, is usually unaffected in the early stages, but in some forms of RP may demonstrate preretinal gliosis ("cellophane maculopathy"), cystoid macular edema or focal RPE defects. Additional findings in RP include pigment cells in the vitreous ("tobacco dust sign"), posterior vitreous detachment and posterior subcapsular cataracts.
Most patients with retinitis pigmentosa are myopic, and many have keratoconus as well. Electrodiagnostic testing in RP shows a significantly diminished scotopic ERG as well as an abnormal EOG and dark adaptometry.
PATHOPHYSIOLOGY
Retinitis pigmentosa is believed to stem from a genetic defect, which leads to a disturbance in the retinal pigment epithelium (RPE) and the breakdown of the photoreceptors' outer segment disc membranes. The resultant accumulation of metabolic by-products disrupts retinal function, and manifests as lipofuscin deposition, retinal gliosis, photoreceptor loss, choriocapillaris occlusion and RPE hyperplasia. These RPE changes compromise the blood-retina barrier, resulting in subretinal leakage and macular edema in later stages. Because the affected photoreceptor cells in most cases are rods, the patient typically experiences visual difficulty under dark conditions, as well as peripheral field constriction.
There are many forms of retinitis pigmentosa, and while most present with similar findings and outcome, some presentations are atypical. RP may be classified on the basis of inheritance pattern (autosomal dominant, autosomal recessive, X-linked, simplex, multiplex), age of onset (congenital, childhood onset, juvenile onset, adult onset), predominant photoreceptor involvement (rod-cone, cone-rod), or location of retinal involvement (central, pericentral, sectoral, peripheral).
MANAGEMENT
Since there is no known treatment for retinitis pigmentosa, management calls for prompt diagnosis and subsequent counseling to maintain quality of life.
Always obtain visual fields and electrodiagnostic testing to confirm the diagnosis of RP; order serology if the diagnosis is unclear or other disorders are suspected.
Most experts recommend a pedigree analysis of patients once RP has been diagnosed. This is critical to determine the exact inheritance pattern of the patient's condition. Individuals should know the risk for their progeny or other family members developing the disease.
Recommend genetic counseling to help the patient deal with these issues. Implement low-vision services as the disorder begins to affect visual function. Field-expansion devices, infrared blocking sun lenses and contrast enhancing filters may be helpful. Periodic optometric follow-up is also important. Perform visual fields several times a year, and evaluate for cataract or macular edema at least annually.
CLINICAL PEARLS
Most patients with RP are diagnosed in the second or third generation of life. Because of the insidious nature of the disorder, the earliest indicators are often objective findings rather than subjective complaints. Some presentations are extremely subtle, particularly in the early stages. Perform a critical evaluation on all patients presenting with complaints of nyctalopia or peripheral field loss.
The diagnosis of RP is often based upon appearance, but many "masqueraders" exist, including rubella retinopathy, syphilitic retinopathy, CMV retinopathy, toxoplasmosis, cancer-associated retinopathy, retinal drug toxicity secondary to thioridazine, chlorpromazine or chloroquine, pigmented paravenous retinochoroidal atrophy, and traumatic retinopathy.
Understandably, the untreatable progressive nature of retinitis pigmentosa is extremely unsettling for the patient and their loved ones; it is often beneficial to recommend psychological or family counseling early in the disease.
Impress upon these patien
Patients with retinitis pigmentosa (RP) may present with varying symptoms. The onset is often gradual and insidious, and many patients fail to recognize the manifestations of this condition until it has progressed significantly. When patients do report symptoms, they commonly include difficulty with night vision (nyctalopia) as well as loss of peripheral vision.
Many patients with RP also experience photopsiae as the disorder progresses; typically they report small flashes of light or a twinkling, shimmering sensation in the midperipheral or peripheral field. These are believed to represent aberrant electrical impulses from the degenerating retina.
Central visual acuity is generally not affected until the very late stages of RP, although variants have been encountered that cause devastating macular compromise early in the disease course (e.g., X-linked recessive RP). Color vision is typically remains intact as long as visual acuity is better than 20/40.
Attenuation of the retinal arterioles is the earliest observable sign in RP. Retinal pigmentary changes occur in the form of fine mottling or granularity with surrounding areas of atrophy. Later, stellate pigment hyperplasia may be noted at perivascular locations in the midperipheral retina. These hyperplastic formations are often referred to as "bone spicules."
As the disorder progresses, general atrophy of the RPE and choriocapillaris ensues, exposing the larger choroidal vessels. The optic nerve head is often normal in early RP, but may demonstrate a waxy yellow or pale appearance later. RP has a strong correlation with acquired optic disc drusen. The macula, like the optic nerve, is usually unaffected in the early stages, but in some forms of RP may demonstrate preretinal gliosis ("cellophane maculopathy"), cystoid macular edema or focal RPE defects. Additional findings in RP include pigment cells in the vitreous ("tobacco dust sign"), posterior vitreous detachment and posterior subcapsular cataracts.
Most patients with retinitis pigmentosa are myopic, and many have keratoconus as well. Electrodiagnostic testing in RP shows a significantly diminished scotopic ERG as well as an abnormal EOG and dark adaptometry.
PATHOPHYSIOLOGY
Retinitis pigmentosa is believed to stem from a genetic defect, which leads to a disturbance in the retinal pigment epithelium (RPE) and the breakdown of the photoreceptors' outer segment disc membranes. The resultant accumulation of metabolic by-products disrupts retinal function, and manifests as lipofuscin deposition, retinal gliosis, photoreceptor loss, choriocapillaris occlusion and RPE hyperplasia. These RPE changes compromise the blood-retina barrier, resulting in subretinal leakage and macular edema in later stages. Because the affected photoreceptor cells in most cases are rods, the patient typically experiences visual difficulty under dark conditions, as well as peripheral field constriction.
There are many forms of retinitis pigmentosa, and while most present with similar findings and outcome, some presentations are atypical. RP may be classified on the basis of inheritance pattern (autosomal dominant, autosomal recessive, X-linked, simplex, multiplex), age of onset (congenital, childhood onset, juvenile onset, adult onset), predominant photoreceptor involvement (rod-cone, cone-rod), or location of retinal involvement (central, pericentral, sectoral, peripheral).
MANAGEMENT
Since there is no known treatment for retinitis pigmentosa, management calls for prompt diagnosis and subsequent counseling to maintain quality of life.
Always obtain visual fields and electrodiagnostic testing to confirm the diagnosis of RP; order serology if the diagnosis is unclear or other disorders are suspected.
Most experts recommend a pedigree analysis of patients once RP has been diagnosed. This is critical to determine the exact inheritance pattern of the patient's condition. Individuals should know the risk for their progeny or other family members developing the disease.
Recommend genetic counseling to help the patient deal with these issues. Implement low-vision services as the disorder begins to affect visual function. Field-expansion devices, infrared blocking sun lenses and contrast enhancing filters may be helpful. Periodic optometric follow-up is also important. Perform visual fields several times a year, and evaluate for cataract or macular edema at least annually.
CLINICAL PEARLS
Most patients with RP are diagnosed in the second or third generation of life. Because of the insidious nature of the disorder, the earliest indicators are often objective findings rather than subjective complaints. Some presentations are extremely subtle, particularly in the early stages. Perform a critical evaluation on all patients presenting with complaints of nyctalopia or peripheral field loss.
The diagnosis of RP is often based upon appearance, but many "masqueraders" exist, including rubella retinopathy, syphilitic retinopathy, CMV retinopathy, toxoplasmosis, cancer-associated retinopathy, retinal drug toxicity secondary to thioridazine, chlorpromazine or chloroquine, pigmented paravenous retinochoroidal atrophy, and traumatic retinopathy.
Understandably, the untreatable progressive nature of retinitis pigmentosa is extremely unsettling for the patient and their loved ones; it is often beneficial to recommend psychological or family counseling early in the disease.
Impress upon these patien
RETINAL MACROANEURYSM
SIGNS AND SYMPTOMS
The patient typically is in the 50 to 80 age range, and most commonly female. Approximately 50 percent of patients have concurrent systemic arterial hypertension. These patients also have an increased incidence of cardiovascular disease and arteriosclerosis.
Ophthalmoscopy reveals an isolated dilatation of a major arterial (or, rarely, venous) branch, which is unilateral in 90 percent of cases but may be multifocal. Most often, by the time the patient presents, the aneurysm has leaked significantly with exudate and extensive intra-retina and/or subretinal hemorrhage. Occasionally, you may note spontaneous pulsation of the aneurysm.
When there is extensive hemorrhage, you may have difficulty assessing retinal macroaneurysm as the cause; neovascularization is often misdiagnosed as the cause. If the focal dilatation is not apparent on ophthalmoscopy, use fluorescein angiography. With fluorescein angiography, the aneurysm hyperfluoresces early in the angiogram with a characteristic balloon appearance with later-phase leakage.
Frequently, the patient is asymptomatic. However, if the macula is involved, the patient will present with reduced acuity and field. In these cases, permanent vision reduction is possible.
PATHOPHYSIOLOGY
An idiopathic weakening of the vessel wall leads to focal outpouching and aneurysm formation. Leakage occurs in extreme cases. However, there is no microvasculopathy as seen in diabetic retinopathy. Retinal macroaneurysm is strongly associated with hypertension, which may contribute to the vessel wall changes. Retinal macroaneurysm is also strongly associated with arteriosclerosis, retinal emboli and cardiovascular disease. Occasionally, retinal macroaneurysms occur within areas of retinal vein occlusions.
MANAGEMENT
Spontaneous sclerosis and occlusion typically occurs with macroaneurysms, particularly after hemorrhaging. Monitor asymptomatic non-leaking macroaneurysms at four- to six-month intervals. If leakage takes the form of exudation and/or hemorrhage that does not threaten the macula, then monitor every one to three months.
However, if hemorrhage threatens or involves the macula, or if there is persistent macular edema, photocoagulation is indicated. In these cases, moderately intense photocoagulation should be applied directly to the macroaneurysm so as not to produce complete occlusion of the involved artery. Venous macroaneurysms should be treated in the same manner. Also, if you observe a non-hemorrhagic macroaneurysm spontaneously pulsate, then direct photocoagulation should be used since rupture is likely.
CLINICAL PEARLS
In cases of unexplained intra- or subretinal hemorrhage, consider retinal macroaneurysm as the cause. If you don't readily observe the characteristic balloon ophthalmoscopically, use fluorescein angiography to identify the aneurysm.
Due to cardiovascular disease, these patients have a high rate of five-year mortality. Refer these patients to a cardiologist for evaluation. At the very least, order a fasting blood glucose, complete blood count with differential, fasting lipid profile and blood pressure evaluation.
The patient typically is in the 50 to 80 age range, and most commonly female. Approximately 50 percent of patients have concurrent systemic arterial hypertension. These patients also have an increased incidence of cardiovascular disease and arteriosclerosis.
Ophthalmoscopy reveals an isolated dilatation of a major arterial (or, rarely, venous) branch, which is unilateral in 90 percent of cases but may be multifocal. Most often, by the time the patient presents, the aneurysm has leaked significantly with exudate and extensive intra-retina and/or subretinal hemorrhage. Occasionally, you may note spontaneous pulsation of the aneurysm.
When there is extensive hemorrhage, you may have difficulty assessing retinal macroaneurysm as the cause; neovascularization is often misdiagnosed as the cause. If the focal dilatation is not apparent on ophthalmoscopy, use fluorescein angiography. With fluorescein angiography, the aneurysm hyperfluoresces early in the angiogram with a characteristic balloon appearance with later-phase leakage.
Frequently, the patient is asymptomatic. However, if the macula is involved, the patient will present with reduced acuity and field. In these cases, permanent vision reduction is possible.
PATHOPHYSIOLOGY
An idiopathic weakening of the vessel wall leads to focal outpouching and aneurysm formation. Leakage occurs in extreme cases. However, there is no microvasculopathy as seen in diabetic retinopathy. Retinal macroaneurysm is strongly associated with hypertension, which may contribute to the vessel wall changes. Retinal macroaneurysm is also strongly associated with arteriosclerosis, retinal emboli and cardiovascular disease. Occasionally, retinal macroaneurysms occur within areas of retinal vein occlusions.
MANAGEMENT
Spontaneous sclerosis and occlusion typically occurs with macroaneurysms, particularly after hemorrhaging. Monitor asymptomatic non-leaking macroaneurysms at four- to six-month intervals. If leakage takes the form of exudation and/or hemorrhage that does not threaten the macula, then monitor every one to three months.
However, if hemorrhage threatens or involves the macula, or if there is persistent macular edema, photocoagulation is indicated. In these cases, moderately intense photocoagulation should be applied directly to the macroaneurysm so as not to produce complete occlusion of the involved artery. Venous macroaneurysms should be treated in the same manner. Also, if you observe a non-hemorrhagic macroaneurysm spontaneously pulsate, then direct photocoagulation should be used since rupture is likely.
CLINICAL PEARLS
In cases of unexplained intra- or subretinal hemorrhage, consider retinal macroaneurysm as the cause. If you don't readily observe the characteristic balloon ophthalmoscopically, use fluorescein angiography to identify the aneurysm.
Due to cardiovascular disease, these patients have a high rate of five-year mortality. Refer these patients to a cardiologist for evaluation. At the very least, order a fasting blood glucose, complete blood count with differential, fasting lipid profile and blood pressure evaluation.
PRESUMED OCULAR HISTOPLASMOSIS SYNDROME
SIGNS AND SYMPTOMS
Presumed ocular histoplasmosis syndrome (POHS) is characterized by the triad of:
1. Disseminated midperipheral choroiditis, consisting of infiltrates and scarring which appears as yellow-white punched-out lesions.
2. A macular or parafoveal subretinal neovascular membrane which appears as a grayish-green patch beneath the retina in the peripapillary and foveal areas, with or without subretinal blood, exudate or disciform scarring.
3. Atrophy or scarring adjacent to the optic disc, which appears as a flat, whitish-brown lesion; the presentation varies depending on the amount of retinal pigmentary epithelial hyperplasia next to the optic disc.
POHS occurs bilaterally in 60 percent of cases. Patients are usually age 20-50. The eye remains remarkably quiet with virtually no aqueous or vitreous cells and minimal flare. In fact, most patients are asymptomatic until a choroiditis or subretinal neovascular membrane develops around the fovea. Optic disc edema is an occasional finding in active disease.
PATHOPHYSIOLOGY
Presumed ocular histoplamosis syndrome is a dimorphic fungal disease endemic to river valley climates. The designation "presumed" ocular histoplasmosis syndrome is used because researchers have not been able to isolate the Histoplasma Capsulatum organism in ocular tissue.
POHS probably results from infection by the blood-borne pathogen H. Capsulatum. This organism has an affinity for choroidal tissue and disseminates there following a systemic infection. The primary route of infection is through the lungs following an encounter with contaminated molds found in soil or from yeasts found in animals. During the initial infection, the patient may complain of fever, chills and malaise.
H. Capsulatum or its by-products produce a lymphocytic infiltration within the choroid. This results in the formation of granulomatous inflammatory masses that disrupt Bruch's membrane and the retinal pigment epithelium and compromise the outer layers of the retina. In most cases, the resulting peripheral choroidopathies are mild, producing only subtly observable clinical signs that heal without complications within a few weeks. Macular lesions possess serious ocular sequelae and progress through stages. Their presentation can lag behind the systemic infection by 30 years. Stress or immunocompromise increases the risk of macular involvement and POHS reactivation.
Stage 1 POHS maculopathy is marked by active choroiditis near the macula appearing as a yellow focus with fuzzy white borders.
Stage 2 POHS is characterized by SRNVM growth through compromised Bruch's membrane, serous sensory retinal detachment and RPE hyperplasia. Here, the RPE attempts to confine and envelop the SRNVM. This stage may abort and resolve leaving only a small residual scotoma.
Stages 3 and 4 consist of continued SRNVM progression, with sub-RPE hemorrhage and exudation.
Stage 5 is considered the end stage and is marked by maculopathy of more than two years and disciform scarring.
.
MANAGEMENT
The key to successful management of POHS and SRNVM is early detection. Laboratory tests are of no value in diagnosing POHS. Make the diagnosis via the history and clinical observation. Patient education along with Amsler grid and home monitoring of visual acuity help uncover reactivated or macular disease.
Early asymptomatic active retinal lesions are sometimes treated with oral or depot injections of steroids to reduce inflammation and the risk of macular disease. This is controversial given a lack of firm evidence that steroid or antifungal therapies are beneficial.
Numerous studies demonstrate the benefit of photocoagulation in cases with macular involvement. If you suspect an SRNVM, order fluorescein angiography. If angiography reveals an SRNVM, refer the patient for laser treatment. Follow-up care is critical due to the high incidence of recurrence following treatment of SRNVM.
CLINICAL PEARLS
The differential diagnosis of POHS includes both inflammatory and noninflammatory chorioretinal diseases. Consider diagnoses such as angioid streaks, toxoplasmosis, toxocariasis, recurrent multifocal choroiditis, birdshot choroiditis, punctate inner choroidopathy, acute posterior multifocal placoid pigment epitheliopathy, serpiginous choroidopathy and diffuse unilateral subacute neuroretinitis.
If one eye has a disciform scar, there is a 30 percent chance the fellow eye will develop an SRNVM.
Patients who have POHS frequently have a history of exposure to pigeons or chickens. It is frequently thought that avian fecal matter is a vector of spreading disease.
Presumed ocular histoplasmosis syndrome (POHS) is characterized by the triad of:
1. Disseminated midperipheral choroiditis, consisting of infiltrates and scarring which appears as yellow-white punched-out lesions.
2. A macular or parafoveal subretinal neovascular membrane which appears as a grayish-green patch beneath the retina in the peripapillary and foveal areas, with or without subretinal blood, exudate or disciform scarring.
3. Atrophy or scarring adjacent to the optic disc, which appears as a flat, whitish-brown lesion; the presentation varies depending on the amount of retinal pigmentary epithelial hyperplasia next to the optic disc.
POHS occurs bilaterally in 60 percent of cases. Patients are usually age 20-50. The eye remains remarkably quiet with virtually no aqueous or vitreous cells and minimal flare. In fact, most patients are asymptomatic until a choroiditis or subretinal neovascular membrane develops around the fovea. Optic disc edema is an occasional finding in active disease.
PATHOPHYSIOLOGY
Presumed ocular histoplamosis syndrome is a dimorphic fungal disease endemic to river valley climates. The designation "presumed" ocular histoplasmosis syndrome is used because researchers have not been able to isolate the Histoplasma Capsulatum organism in ocular tissue.
POHS probably results from infection by the blood-borne pathogen H. Capsulatum. This organism has an affinity for choroidal tissue and disseminates there following a systemic infection. The primary route of infection is through the lungs following an encounter with contaminated molds found in soil or from yeasts found in animals. During the initial infection, the patient may complain of fever, chills and malaise.
H. Capsulatum or its by-products produce a lymphocytic infiltration within the choroid. This results in the formation of granulomatous inflammatory masses that disrupt Bruch's membrane and the retinal pigment epithelium and compromise the outer layers of the retina. In most cases, the resulting peripheral choroidopathies are mild, producing only subtly observable clinical signs that heal without complications within a few weeks. Macular lesions possess serious ocular sequelae and progress through stages. Their presentation can lag behind the systemic infection by 30 years. Stress or immunocompromise increases the risk of macular involvement and POHS reactivation.
Stage 1 POHS maculopathy is marked by active choroiditis near the macula appearing as a yellow focus with fuzzy white borders.
Stage 2 POHS is characterized by SRNVM growth through compromised Bruch's membrane, serous sensory retinal detachment and RPE hyperplasia. Here, the RPE attempts to confine and envelop the SRNVM. This stage may abort and resolve leaving only a small residual scotoma.
Stages 3 and 4 consist of continued SRNVM progression, with sub-RPE hemorrhage and exudation.
Stage 5 is considered the end stage and is marked by maculopathy of more than two years and disciform scarring.
.
MANAGEMENT
The key to successful management of POHS and SRNVM is early detection. Laboratory tests are of no value in diagnosing POHS. Make the diagnosis via the history and clinical observation. Patient education along with Amsler grid and home monitoring of visual acuity help uncover reactivated or macular disease.
Early asymptomatic active retinal lesions are sometimes treated with oral or depot injections of steroids to reduce inflammation and the risk of macular disease. This is controversial given a lack of firm evidence that steroid or antifungal therapies are beneficial.
Numerous studies demonstrate the benefit of photocoagulation in cases with macular involvement. If you suspect an SRNVM, order fluorescein angiography. If angiography reveals an SRNVM, refer the patient for laser treatment. Follow-up care is critical due to the high incidence of recurrence following treatment of SRNVM.
CLINICAL PEARLS
The differential diagnosis of POHS includes both inflammatory and noninflammatory chorioretinal diseases. Consider diagnoses such as angioid streaks, toxoplasmosis, toxocariasis, recurrent multifocal choroiditis, birdshot choroiditis, punctate inner choroidopathy, acute posterior multifocal placoid pigment epitheliopathy, serpiginous choroidopathy and diffuse unilateral subacute neuroretinitis.
If one eye has a disciform scar, there is a 30 percent chance the fellow eye will develop an SRNVM.
Patients who have POHS frequently have a history of exposure to pigeons or chickens. It is frequently thought that avian fecal matter is a vector of spreading disease.
MACULAR HOLE
SIGNS AND SYMPTOMS
Idiopathic or senile macular holes are typically encountered in patients older than 60, and slightly more often in women than in men. Presenting symptoms include decreased central acuity, a central scotoma and/or metamorphopsia.
Macular holes develop in stages, including: foveal detachments (stage I), partial-thickness holes (stage II), and full-thickness holes (stage III). A stage IV macular hole is an advanced full-thickness hole, with vitreous separation from the optic disc and macula. Depending on the stage, vision may range from 20/20 to <20/400; however, in full-thickness macular holes, the acuity is generally 20/80 to 20/200.
Patients usually report a rather abrupt loss of central vision. A full-thickness macular hole clinically appears as a round, brick-colored lesion in the center of the macula, usually one-third to two-thirds of a disc diameter.
The surrounding retinal tissue appears gray and elevated, and often there are small yellow deposits within the hole, reminiscent of drusen. Foveal detachments and partial-thickness holes do not appear red, but rather present as a loss of the foveolar depression with the development of a central yellow spot or ring. Stage II holes are accompanied by a red, crescent-shaped retinal break at the lesion's edge. Fluorescein angiography reveals an RPE "window defect" with early-stage hyperfluorescence.
PATHOPHYSIOLOGY
Controversy surrounds the etiology of idiopathic macular holes. Diverse mechanisms have been proposed, including systemic vascular disease, hormonal variations, cystic retinal degeneration, anterior vitreoretinal traction, and tangential vitreoretinal tractional forces.
Currently, the most widely held theory proposes that pre-foveal vitreal shrinkage induces tangential traction on the fovea, eventually promoting hole formation. As contraction ensues, the tangential tugging at the fovea induces a separation of the sensory retina from the underlying RPE. The foveal retina, without a firm attachment to the RPE, suffers a compromised nutrient supply and loses its ability to eliminate waste.
Ultimately, the sensory retina atrophies, forming a break and progressing to a full-thickness hole. Macular holes may also result from chronic macular edema, solar retinopathy and blunt ocular trauma.
MANAGEMENT
In the past, the only management for macular holes was patient education, periodic observation in the affected and fellow eye, and the use of protective eyewear.
More recently, research has shown some benefit to surgical excision of the macular vitreoretinal adhesions in eyes at risk for full-thickness holes. The procedure involves pars plana vitrectomy, excision of the attached cortical vitreous and gas/fluid exchange. Growth factors such as transforming growth factor-b2 have been used to induce regeneration of the macular tissue. This procedure has achieved moderate success. Candidates for surgical intervention must have 20/50 visual acuity or worse, and a stage III or IV macular hole in at least one eye.
For cases that do not lend themselves to surgical intervention, consider low vision services.
CLINICAL PEARLS
Idiopathic macular holes affect the elderly. The astute clinician must consider this entity in the differential diagnosis of older patients who present with reduced visual acuity and a seemingly unremarkable examination.
The best way to observe the macula involves a contact fundus lens, be it a standard Goldmann three-mirror goniolens or any of the newer, more compact funduscopy lenses.
For suspected macular holes that appear equivocal or do not lend themselves to observation, consider the Watzke-Allen test. A vertical beam of light is presented to the fovea, using a Maddox rod, slit lamp beam with a fundus lens or a direct ophthalmoscope. Ask the patient if the line is uniform or broken in the center-patients with macular compromise report a broken line.
Macular holes are rarely, if ever, self-limiting. It is your obligation to educate the patient about the nature of the condition, and make the appropriate referrals necessary to ensure maximal visual function.
Other important facts:
50 percent of Stage I holes will progress to Stage II or worse.
70 percent of Stage II holes will progress to Stage III.
Retinal consultation is advisable in Stage I and II holes.
Vitrectomy may be helpful in Stage I holes to prevent progression to Stage II; it may also improve vision.
Vitrectomy is helpful in Stage II holes to preserve vision.
Idiopathic or senile macular holes are typically encountered in patients older than 60, and slightly more often in women than in men. Presenting symptoms include decreased central acuity, a central scotoma and/or metamorphopsia.
Macular holes develop in stages, including: foveal detachments (stage I), partial-thickness holes (stage II), and full-thickness holes (stage III). A stage IV macular hole is an advanced full-thickness hole, with vitreous separation from the optic disc and macula. Depending on the stage, vision may range from 20/20 to <20/400; however, in full-thickness macular holes, the acuity is generally 20/80 to 20/200.
Patients usually report a rather abrupt loss of central vision. A full-thickness macular hole clinically appears as a round, brick-colored lesion in the center of the macula, usually one-third to two-thirds of a disc diameter.
The surrounding retinal tissue appears gray and elevated, and often there are small yellow deposits within the hole, reminiscent of drusen. Foveal detachments and partial-thickness holes do not appear red, but rather present as a loss of the foveolar depression with the development of a central yellow spot or ring. Stage II holes are accompanied by a red, crescent-shaped retinal break at the lesion's edge. Fluorescein angiography reveals an RPE "window defect" with early-stage hyperfluorescence.
PATHOPHYSIOLOGY
Controversy surrounds the etiology of idiopathic macular holes. Diverse mechanisms have been proposed, including systemic vascular disease, hormonal variations, cystic retinal degeneration, anterior vitreoretinal traction, and tangential vitreoretinal tractional forces.
Currently, the most widely held theory proposes that pre-foveal vitreal shrinkage induces tangential traction on the fovea, eventually promoting hole formation. As contraction ensues, the tangential tugging at the fovea induces a separation of the sensory retina from the underlying RPE. The foveal retina, without a firm attachment to the RPE, suffers a compromised nutrient supply and loses its ability to eliminate waste.
Ultimately, the sensory retina atrophies, forming a break and progressing to a full-thickness hole. Macular holes may also result from chronic macular edema, solar retinopathy and blunt ocular trauma.
MANAGEMENT
In the past, the only management for macular holes was patient education, periodic observation in the affected and fellow eye, and the use of protective eyewear.
More recently, research has shown some benefit to surgical excision of the macular vitreoretinal adhesions in eyes at risk for full-thickness holes. The procedure involves pars plana vitrectomy, excision of the attached cortical vitreous and gas/fluid exchange. Growth factors such as transforming growth factor-b2 have been used to induce regeneration of the macular tissue. This procedure has achieved moderate success. Candidates for surgical intervention must have 20/50 visual acuity or worse, and a stage III or IV macular hole in at least one eye.
For cases that do not lend themselves to surgical intervention, consider low vision services.
CLINICAL PEARLS
Idiopathic macular holes affect the elderly. The astute clinician must consider this entity in the differential diagnosis of older patients who present with reduced visual acuity and a seemingly unremarkable examination.
The best way to observe the macula involves a contact fundus lens, be it a standard Goldmann three-mirror goniolens or any of the newer, more compact funduscopy lenses.
For suspected macular holes that appear equivocal or do not lend themselves to observation, consider the Watzke-Allen test. A vertical beam of light is presented to the fovea, using a Maddox rod, slit lamp beam with a fundus lens or a direct ophthalmoscope. Ask the patient if the line is uniform or broken in the center-patients with macular compromise report a broken line.
Macular holes are rarely, if ever, self-limiting. It is your obligation to educate the patient about the nature of the condition, and make the appropriate referrals necessary to ensure maximal visual function.
Other important facts:
50 percent of Stage I holes will progress to Stage II or worse.
70 percent of Stage II holes will progress to Stage III.
Retinal consultation is advisable in Stage I and II holes.
Vitrectomy may be helpful in Stage I holes to prevent progression to Stage II; it may also improve vision.
Vitrectomy is helpful in Stage II holes to preserve vision.
IDIOPATHIC CENTRAL SEROUS CHORIORETINOPATHY
SIGNS AND SYMPTOMS
Patients with idiopathic central serous chorioretinopathy (ICSC) usually present with complaints of sudden onset, unilateral distortion or blurring of central vision. They may report metamorphopsia, decreased color perception, or even a relative central scotoma. There is typically no pain and no history of recent trauma.
Evaluation reveals no external signs of disease nor inflammation, although a hyperopic refractive shift is often noted in the affected eye. Funduscopic examination shows a serous elevation of the macula with a loss of the foveal light reflex. There may also be an underlying area of RPE detachment. Patients with ICSC are typically young, with most cases occurring in the early to mid-thirties; white males appear to be the most commonly affected group. Those individuals with "Type A" personalities seem to be particularly predisposed to this condition.
PATHOPHYSIOLOGY
Although the true etiology of ICSC is unknown, emotional stress or anxiety appears to be a common element. It is believed that, in certain individuals, vasomotor instability from sympathetic nervous stimulation may induce local weaknesses in Bruch's membrane. Such weaknesses allow serous fluid to extravasate from the choriocapillaris under the macula (through a defect in the RPE), creating a focal detachment of the sensory retina. In most instances, the fluid eventually resolves, but the condition may be recurrent in as many as 50 percent of affected individuals. In these patients, cystic yellow lesions known as "lemon drops" and areas of mild RPE hyperplasia are often seen.
MANAGEMENT
Most cases of ICSC are self-limiting, and resolve spontaneously over a period of weeks to months. The prognosis for visual recovery is excellent-up to 60 percent can expect to regain 20/20 acuity. While many cases of ICSC require no intervention, recent studies have supported the use of oral indomethacin to hasten the recovery time. In addition, focal laser photocoagulation may be effective in repairing the RPE at the site of the leakage. Most practitioners, however, will consider this therapy only in cases that fail to recover within a reasonable period of time, highly recurrent cases, or cases in which the patients are overtly symptomatic and insist on definitive treatment.
CLINICAL PEARLS
An experienced, astute clinician can often diagnose ICSC based solely upon the history and chief complaint-a young, anxious patient who presents with unilateral metamorphopsia of recent onset.
The classic fundus appearance is usually best seen with binocular indirect ophthalmoscopy.
In subtle or atypical cases, fluorescein angiography offers the definitive diagnosis.
Patients presenting with ICSC for the first time should be reassured, counseled as to the natural course of the condition, and monitored every three to four weeks for three to four months as resolution occurs. Failure to resolve within six months is probably an indication for more aggressive therapy, such as focal laser photocoagulation.
Longstanding ICSC may result in a "sick RPE" with permanent visual reduction.
Patients with idiopathic central serous chorioretinopathy (ICSC) usually present with complaints of sudden onset, unilateral distortion or blurring of central vision. They may report metamorphopsia, decreased color perception, or even a relative central scotoma. There is typically no pain and no history of recent trauma.
Evaluation reveals no external signs of disease nor inflammation, although a hyperopic refractive shift is often noted in the affected eye. Funduscopic examination shows a serous elevation of the macula with a loss of the foveal light reflex. There may also be an underlying area of RPE detachment. Patients with ICSC are typically young, with most cases occurring in the early to mid-thirties; white males appear to be the most commonly affected group. Those individuals with "Type A" personalities seem to be particularly predisposed to this condition.
PATHOPHYSIOLOGY
Although the true etiology of ICSC is unknown, emotional stress or anxiety appears to be a common element. It is believed that, in certain individuals, vasomotor instability from sympathetic nervous stimulation may induce local weaknesses in Bruch's membrane. Such weaknesses allow serous fluid to extravasate from the choriocapillaris under the macula (through a defect in the RPE), creating a focal detachment of the sensory retina. In most instances, the fluid eventually resolves, but the condition may be recurrent in as many as 50 percent of affected individuals. In these patients, cystic yellow lesions known as "lemon drops" and areas of mild RPE hyperplasia are often seen.
MANAGEMENT
Most cases of ICSC are self-limiting, and resolve spontaneously over a period of weeks to months. The prognosis for visual recovery is excellent-up to 60 percent can expect to regain 20/20 acuity. While many cases of ICSC require no intervention, recent studies have supported the use of oral indomethacin to hasten the recovery time. In addition, focal laser photocoagulation may be effective in repairing the RPE at the site of the leakage. Most practitioners, however, will consider this therapy only in cases that fail to recover within a reasonable period of time, highly recurrent cases, or cases in which the patients are overtly symptomatic and insist on definitive treatment.
CLINICAL PEARLS
An experienced, astute clinician can often diagnose ICSC based solely upon the history and chief complaint-a young, anxious patient who presents with unilateral metamorphopsia of recent onset.
The classic fundus appearance is usually best seen with binocular indirect ophthalmoscopy.
In subtle or atypical cases, fluorescein angiography offers the definitive diagnosis.
Patients presenting with ICSC for the first time should be reassured, counseled as to the natural course of the condition, and monitored every three to four weeks for three to four months as resolution occurs. Failure to resolve within six months is probably an indication for more aggressive therapy, such as focal laser photocoagulation.
Longstanding ICSC may result in a "sick RPE" with permanent visual reduction.
HOLLENHORST PLAQUE
SIGNS AND SYMPTOMS
The patient typically is elderly and often has concurrent history of hypertension, diabetes, carotid artery disease, peripheral vascular disease, hypercholesterolemia, hyperlipidemia, and/or atherosclerosis. The patient may be totally asymptomatic and the plaque(s) may be found on routine eye exam.
However, the patient may have previously experienced transient episodes of monocular blindness (amaurosis fugax). Rarely, the patient has experienced a transient ischemic attack with hemiparesis, paraesthesia, and/or aphasia. These episodic bouts of amaurosis fugax may be quite frequent, and may last from several seconds to several minutes. Rarely does the patient have any lasting visual deficits.
Frequently, the patient previously experiencing amaurosis fugax will not exhibit retinal emboli, but may have arteriolar narrowing and sheathing. A Hollenhorst plaque appears as a bright, glistening, refractile plaque, usually at the bifurcation of a retinal arteriole. These have the propensity to break up and move, and may not be present at subsequent visits.
PATHOPHYSIOLOGY
The Hollenhorst plaque is an embolus composed of cholesterol that forms from an ulcerated ipsilateral carotid artery plaque. The patient frequently has concurrent hypertension and elevated cholesterol levels. The stress on the arteries induced by hypertension leads to reduced elasticity of the vessels.
Cholesterol is deposited within the vessel walls and forms an atheroma, narrowing the artery. Turbulent blood flow over the atheroma can lead this plaque to ulcerate, which allows small particles to break off and flow within the blood stream. Eventually, the embolus enters a vessel whose caliber is too small to allow it to flow any further, and it lodges. Ischemia to the tissue occurs if blood flow is significantly impaired distal to the blockage. If the emboli lodges within a retinal vessel, then retinal ischemia with corresponding loss of vision occurs. The result may be a retinal artery occlusion.
In the case of cholesterol emboli, however, the blockage often quickly dislodges without permanent visual impairment. Instead, the patient experiences a brief interruption of vision and/or visual field (amaurosis fugax). Multiple bouts of amaurosis fugax may indicate multiple emboli. In cases where the patient is asymptomatic, yet a Hollenhorst plaque is visible, there is rarely permanent ischemia. This is because the cholesterol emboli are malleable and blood flow may be able to get past the emboli.
MANAGEMENT
There is no direct treatment of the visible emboli. In fact, because blood often can flow through an apparently complete blockage, direct removal is not necessary. In any case of retinal embolization, the concern must be further embolization with ensuing retinal infarct or cerebrovascular accident with permanent sequela of stroke. Survival rate decreases with the appearance of a retinal embolus. The primary cause of mortality in patients with retinal emboli is coronary artery disease and myocardial infarction.
A retinal embolus indicates significant systemic vascular disease. Refer the patient to an internist, vascular surgeon, or cardiologist for hypertension, coronary artery disease, diabetes, and carotid artery disease. A complete physical, carotid ultrasound, stress echocardiogram, fasting glucose and lipid levels, and blood chemistry with cardiac enzymes are indicated. Treatment of carotid stenosis, TIAs, and retinal emboli may include carotid endarterectomy, carotid angioplasty, or aspirin therapy, depending upon the risks of future ischemic events.
CLINICAL PEARLS
Patients with cholesterol emboli have a 15 percent mortality rate in the first year, 29 percent by the third year, and 54 percent by the seventh year. The main cause of mortality is cardiac death.
The patient, though in no apparent distress, must be referred to the proper medical specialist in order to appropriately manage the underlying systemic diseases and reduce morbidity and mortality.
The patient typically is elderly and often has concurrent history of hypertension, diabetes, carotid artery disease, peripheral vascular disease, hypercholesterolemia, hyperlipidemia, and/or atherosclerosis. The patient may be totally asymptomatic and the plaque(s) may be found on routine eye exam.
However, the patient may have previously experienced transient episodes of monocular blindness (amaurosis fugax). Rarely, the patient has experienced a transient ischemic attack with hemiparesis, paraesthesia, and/or aphasia. These episodic bouts of amaurosis fugax may be quite frequent, and may last from several seconds to several minutes. Rarely does the patient have any lasting visual deficits.
Frequently, the patient previously experiencing amaurosis fugax will not exhibit retinal emboli, but may have arteriolar narrowing and sheathing. A Hollenhorst plaque appears as a bright, glistening, refractile plaque, usually at the bifurcation of a retinal arteriole. These have the propensity to break up and move, and may not be present at subsequent visits.
PATHOPHYSIOLOGY
The Hollenhorst plaque is an embolus composed of cholesterol that forms from an ulcerated ipsilateral carotid artery plaque. The patient frequently has concurrent hypertension and elevated cholesterol levels. The stress on the arteries induced by hypertension leads to reduced elasticity of the vessels.
Cholesterol is deposited within the vessel walls and forms an atheroma, narrowing the artery. Turbulent blood flow over the atheroma can lead this plaque to ulcerate, which allows small particles to break off and flow within the blood stream. Eventually, the embolus enters a vessel whose caliber is too small to allow it to flow any further, and it lodges. Ischemia to the tissue occurs if blood flow is significantly impaired distal to the blockage. If the emboli lodges within a retinal vessel, then retinal ischemia with corresponding loss of vision occurs. The result may be a retinal artery occlusion.
In the case of cholesterol emboli, however, the blockage often quickly dislodges without permanent visual impairment. Instead, the patient experiences a brief interruption of vision and/or visual field (amaurosis fugax). Multiple bouts of amaurosis fugax may indicate multiple emboli. In cases where the patient is asymptomatic, yet a Hollenhorst plaque is visible, there is rarely permanent ischemia. This is because the cholesterol emboli are malleable and blood flow may be able to get past the emboli.
MANAGEMENT
There is no direct treatment of the visible emboli. In fact, because blood often can flow through an apparently complete blockage, direct removal is not necessary. In any case of retinal embolization, the concern must be further embolization with ensuing retinal infarct or cerebrovascular accident with permanent sequela of stroke. Survival rate decreases with the appearance of a retinal embolus. The primary cause of mortality in patients with retinal emboli is coronary artery disease and myocardial infarction.
A retinal embolus indicates significant systemic vascular disease. Refer the patient to an internist, vascular surgeon, or cardiologist for hypertension, coronary artery disease, diabetes, and carotid artery disease. A complete physical, carotid ultrasound, stress echocardiogram, fasting glucose and lipid levels, and blood chemistry with cardiac enzymes are indicated. Treatment of carotid stenosis, TIAs, and retinal emboli may include carotid endarterectomy, carotid angioplasty, or aspirin therapy, depending upon the risks of future ischemic events.
CLINICAL PEARLS
Patients with cholesterol emboli have a 15 percent mortality rate in the first year, 29 percent by the third year, and 54 percent by the seventh year. The main cause of mortality is cardiac death.
The patient, though in no apparent distress, must be referred to the proper medical specialist in order to appropriately manage the underlying systemic diseases and reduce morbidity and mortality.
ACQUIRED RETINOSCHISIS
SIGNS AND SYMPTOMS
The patient is nearly always asymptomatic. Rarely, the patient reports a sharp visual field defect corresponding to the area of the retinoschisis. Ophthalmoscopy reveals a smooth, stationary, bullous elevation of either the inferior-temporal or superior-temporal retina. The elevation may extend beyond the equator, and may rarely invade the posterior pole. The dome of the elevation is smooth and translucent. Blood vessels traverse the dome and cast shadows on the underlying structures. There is no pigmentation line unless a concurrent retinal detachment exists.
PATHOPHYSIOLOGY
Every eye over the age of eight years manifests peripheral cystic changes in the inner nuclear and outer plexiform layers of the retina. These spaces coalesce to form interlacing tunnels. If enough cystic spaces coalesce, the retina will form a retinoschisis, splitting into an inner and outer layer cavity. The superficial retinal layers comprise the inner layer, while the deeper layers of the retina and RPE represent the outer layer of the retinoschisis cavity.
There are technically two types of acquired retinoschisis. There is the typical degenerative retinoschisis, which presents as a shallow elevation of the inner retinal layers. There is also reticular degenerative retinoschisis, which presents in the traditional appearance of a bullous elevation.
In all types of acquired retinoschisis, either the inner layer or the outer layer, or both layers, may develop holes. Should holes develop in the inner layer of the retinoschisis, then liquid vitreous may flow into the fluid cavity. This doesn't change the prognosis. If there are outer layer holes as well, then liquid vitreous could enter the subretinal space and cause a rhegmatogenous retinal detachment. To this end, retinoschisis with both inner and outer layer holes has the potential to progress to rhegmatogenous retinal detachment. The risk of progression to rhegmatogenous retinal detachment in retinoschisis with double layer holes is 0.25 to 1.4 percent. The risk of detachment in retinoschisis without double layer holes is 0.024 percent. There is also potential for the splitting of the retina to continue with posterior extension of the retinoschisis.
MANAGEMENT
The risk of rhegmatogenous retinal detachment occurring in a retinoschisis (even with double layer holes) is exceedingly low, so there is no treatment beyond routine monitoring every six to 12 months. If possible, the retinoschisis should be photographed to monitor for progression. Because retinoschisis results in a sharply demarcated visual field defect, the stability can be monitored with a threshold visual field of the central 60 degrees.
CLINICAL PEARLS
While retinoschisis has the potential to enlarge and extend posteriorly and threaten the macula, its progression is extremely slow and may take months to years in order to threaten vision. Thus, a retinal consult is rarely urgent.
Because the RPE is not disrupted by retinoschisis, the RPE does not become hyperplastic and a pigment demarcation line will not form. If a pigment demarcation line is present in a retinoschisis, it should be taken as a sign that there is a concomitant retinal detachment.
The retinoschisis shows no movement or undulation upon eye movement or scleral indentation, whereas a retinal detachment does. Furthermore, scleral indentation will show preservation of the schisis cavity, as opposed to retinal detachment.
The patient is nearly always asymptomatic. Rarely, the patient reports a sharp visual field defect corresponding to the area of the retinoschisis. Ophthalmoscopy reveals a smooth, stationary, bullous elevation of either the inferior-temporal or superior-temporal retina. The elevation may extend beyond the equator, and may rarely invade the posterior pole. The dome of the elevation is smooth and translucent. Blood vessels traverse the dome and cast shadows on the underlying structures. There is no pigmentation line unless a concurrent retinal detachment exists.
PATHOPHYSIOLOGY
Every eye over the age of eight years manifests peripheral cystic changes in the inner nuclear and outer plexiform layers of the retina. These spaces coalesce to form interlacing tunnels. If enough cystic spaces coalesce, the retina will form a retinoschisis, splitting into an inner and outer layer cavity. The superficial retinal layers comprise the inner layer, while the deeper layers of the retina and RPE represent the outer layer of the retinoschisis cavity.
There are technically two types of acquired retinoschisis. There is the typical degenerative retinoschisis, which presents as a shallow elevation of the inner retinal layers. There is also reticular degenerative retinoschisis, which presents in the traditional appearance of a bullous elevation.
In all types of acquired retinoschisis, either the inner layer or the outer layer, or both layers, may develop holes. Should holes develop in the inner layer of the retinoschisis, then liquid vitreous may flow into the fluid cavity. This doesn't change the prognosis. If there are outer layer holes as well, then liquid vitreous could enter the subretinal space and cause a rhegmatogenous retinal detachment. To this end, retinoschisis with both inner and outer layer holes has the potential to progress to rhegmatogenous retinal detachment. The risk of progression to rhegmatogenous retinal detachment in retinoschisis with double layer holes is 0.25 to 1.4 percent. The risk of detachment in retinoschisis without double layer holes is 0.024 percent. There is also potential for the splitting of the retina to continue with posterior extension of the retinoschisis.
MANAGEMENT
The risk of rhegmatogenous retinal detachment occurring in a retinoschisis (even with double layer holes) is exceedingly low, so there is no treatment beyond routine monitoring every six to 12 months. If possible, the retinoschisis should be photographed to monitor for progression. Because retinoschisis results in a sharply demarcated visual field defect, the stability can be monitored with a threshold visual field of the central 60 degrees.
CLINICAL PEARLS
While retinoschisis has the potential to enlarge and extend posteriorly and threaten the macula, its progression is extremely slow and may take months to years in order to threaten vision. Thus, a retinal consult is rarely urgent.
Because the RPE is not disrupted by retinoschisis, the RPE does not become hyperplastic and a pigment demarcation line will not form. If a pigment demarcation line is present in a retinoschisis, it should be taken as a sign that there is a concomitant retinal detachment.
The retinoschisis shows no movement or undulation upon eye movement or scleral indentation, whereas a retinal detachment does. Furthermore, scleral indentation will show preservation of the schisis cavity, as opposed to retinal detachment.
CHOROIDAL MELANOMA
SIGNS AND SYMPTOMS
The benign choroidal melanoma, referred to clinically as a choroidal nevus, appears as a flat or slightly elevated slate gray lesion of the posterior fundus. The margins are typically indistinct, and often there are overlying areas of drusen noted within the nevus. In most instances, choroidal nevi remain under two disc diameters (DD) in size, although they may attain sizes of up to 5 DD in some cases.
The malignant choroidal melanoma, in contrast, appears as a mottled, often significantly elevated lesion, ranging in coloration from white to greenish-gray. As it grows, it may break through Bruch's membrane, taking on a mushroom-like appearance. Serous retinal detachments are commonly associated with this presentation. You may also observe overlying orange pigmentation known as lipofuscin. Most malignant melanomas are over 10 DD in size at the time of diagnosis. Most patients with choroidal melanomas are asymptomatic. However, should a significantly large lesion occur in proximity to the macula, the patient may present with metamorphopsia, acuity loss, visual field deficit and/or a hyperopic refractive shift.
PATHOPHYSIOLOGY
A choroidal melanoma represents a focal accumulation of melanocytes at the level of the uvea. In a choroidal nevus, these melanocytes are normal in both form and function. In malignant melanoma, the cells undergo neoplasia, reproducing at a faster rate than usual and resulting in a dysfunctional tumor mass. This tumor is capable of not only local extension but also of distant metastasis. While choroidal nevi do not typically lead to this type of damage, it is believed that they can convert to malignancy; the rate of malignant transformation over a 10-year period is estimated at 21 in 100,000.
Choroidal Nevus
MANAGEMENT
Nevi of 2 DD or less are harmless. Document the presentation with photography and, when possible, perform a B-scan and follow-up annually. Nevi between 2 and 5 DD are more suspicious. Either perform or refer for angiography to help differentiate the mass, and follow-up regularly at six-month intervals.
When the lesion is greater than 5 DD, consider it a malignant melanoma until proven otherwise. It may not require immediate treatment if relatively small and demonstrates no growth. But if the presentation suddenly changes dramatically or if sight is threatened, refer to a retinal specialist for treatment.
CLINICAL PEARLS
While a nevus is of little concern, malignant melanoma presents a potentially life-threatening situation because of its propensity toward metastasis. These tumors have been known to spread to the liver, lungs, skin and gastrointestinal tract.
Refer patients with newly detected malignant melanomas to a primary care physician for testing, which may include liver enzymes, carcinoembryonic antigen (CEA), neuroimaging, and chest CT.
The benign choroidal melanoma, referred to clinically as a choroidal nevus, appears as a flat or slightly elevated slate gray lesion of the posterior fundus. The margins are typically indistinct, and often there are overlying areas of drusen noted within the nevus. In most instances, choroidal nevi remain under two disc diameters (DD) in size, although they may attain sizes of up to 5 DD in some cases.
The malignant choroidal melanoma, in contrast, appears as a mottled, often significantly elevated lesion, ranging in coloration from white to greenish-gray. As it grows, it may break through Bruch's membrane, taking on a mushroom-like appearance. Serous retinal detachments are commonly associated with this presentation. You may also observe overlying orange pigmentation known as lipofuscin. Most malignant melanomas are over 10 DD in size at the time of diagnosis. Most patients with choroidal melanomas are asymptomatic. However, should a significantly large lesion occur in proximity to the macula, the patient may present with metamorphopsia, acuity loss, visual field deficit and/or a hyperopic refractive shift.
PATHOPHYSIOLOGY
A choroidal melanoma represents a focal accumulation of melanocytes at the level of the uvea. In a choroidal nevus, these melanocytes are normal in both form and function. In malignant melanoma, the cells undergo neoplasia, reproducing at a faster rate than usual and resulting in a dysfunctional tumor mass. This tumor is capable of not only local extension but also of distant metastasis. While choroidal nevi do not typically lead to this type of damage, it is believed that they can convert to malignancy; the rate of malignant transformation over a 10-year period is estimated at 21 in 100,000.
Choroidal Nevus
MANAGEMENT
Nevi of 2 DD or less are harmless. Document the presentation with photography and, when possible, perform a B-scan and follow-up annually. Nevi between 2 and 5 DD are more suspicious. Either perform or refer for angiography to help differentiate the mass, and follow-up regularly at six-month intervals.
When the lesion is greater than 5 DD, consider it a malignant melanoma until proven otherwise. It may not require immediate treatment if relatively small and demonstrates no growth. But if the presentation suddenly changes dramatically or if sight is threatened, refer to a retinal specialist for treatment.
CLINICAL PEARLS
While a nevus is of little concern, malignant melanoma presents a potentially life-threatening situation because of its propensity toward metastasis. These tumors have been known to spread to the liver, lungs, skin and gastrointestinal tract.
Refer patients with newly detected malignant melanomas to a primary care physician for testing, which may include liver enzymes, carcinoembryonic antigen (CEA), neuroimaging, and chest CT.
TOXOPLASMOSIS
SIGNS AND SYMPTOMS
The symptoms associated with ocular toxoplasmosis include unilateral, mild ocular pain, blurred vision and new onset of floating spots. Patients often describe their vision as hazy. Clinical findings may include granulomatous iritis, vitritis, optic disc swelling, neuroretinitis, vasculitis and retinal vein occlusion in the vicinity of the inflammation, in the actively involved eye. Funduscopically, active toxoplasmosis presents with white-yellow, choreoretinal lesions and vitreous cells. There may be old, inactive lesions in the fellow eye. Toxoplasmosis can produce cystoid macular edema and choroidal neovascularization.
PATHOPHYSIOLOGY
Toxoplasmosis is a disease provoked by the obligate intracellular protozoan Toxoplasma gondii. It is found in a variety of mammal and bird hosts. The most common intermediate host is the cat. It is one of the most frequent causes of retinochoroiditis in humans, with more than 60 percent of the United States population and up to 75 percent of the world's general population possessing some seropositive findings.
The systemic symptoms found in congenital toxoplasmosis consist of convulsions, calcification of the arterioles and choreoretinitis. In adults, toxoplasmosis is often contracted without sickness. A small percentage of individuals encounter self-limiting, flu-like symptoms at the time of inoculation.
Toxoplasma exists in humans in two forms: (1) actively motile tachyzoites and (2) encysted Toxoplasma gondii called brachyzoites. The oocysts that contain the organisms which produce infection are excreted in fecal material and may lie dormant in the soil until ingested by other animals, resulting in infection.
Human infection may occur from ingestion of contaminated or undercooked meat and dairy products, direct or indirect ingestion of cat feces and transplacental transmission from an infected mother to the fetus. Toxoplasmosis can only be transmitted to a fetus during maternal parastemia. Congenital toxoplasmosis accounts for the majority of cases encountered in clinical practice.
In most cases, the body is primed for infection or toxoplasmosis reactivation by an immune system failure. This may occur following contraction of human immunodeficiency syndrome (HIV) or with medical immunosupression following organ transplantation.
The inflammatory fundus lesions are composed of mononuclear cells, with a liberation of lymphocytes, macrophages, epithelioid and plasma cells. The resulting retinal vasculitis contributes to the breakdown of the blood-retinal barrier and leads to a compromise in retinal function, with subsequent destruction and thickening.
MANAGEMENT
The goal of management is twofold: (1) eradicate the parasite and (2) suppress the inflammatory response. The classic treatment regimen combines pyrimethamine (a 75mg loading dose, followed by 25mg PO BID administration) with sulfadiazine (2g loading dose, then 1g PO QID for 4 to 6 weeks). Both medications inhibit the folic acid metabolism necessary for toxoplasmosis to survive. Concurrent folinic acid, 3 to 5mg PO twice weekly helps to minimize any bone marrow toxicity produced by the pyramethamine.
Alternative antibiotic treatments include: (1) clindamycin, 300mg, PO QID used with sulfadiazine, for four to six weeks, (2) tetracycline, 2g loading then 250mg PO QID and sulfadiazine for four to six weeks, or (3) trimethoprim/sulfamethoxazole 160/800mg, one tablet PO BID, with or without clindamycin or prednisone, for the same duration.
In otherwise normal individuals, after beginning antibiotic therapy, add oral steroids at a dose of 20 to 80mg PO daily for four to six weeks. Periocular steroids are never indicated. Oral steroids without systemic antibiotics are expressly contraindicated.
Manage the anterior ocular inflammation with a cycloplegic that is appropriate for the disease's severity and a topical steroid Q2H/QID.
Systemic laboratory testing is indicated in active cases. The Sabin-Feldman methylene blue dye test (for Toxoplasma gondii), Serum antitoxoplasma antibody titer (for Toxoplasma gondii), Fluorescent Treponemal Antibody absorption test (for syphilis), purified protein derivative (for tuberculosis), chest x-ray (for sarcoid and TB), Toxocara Enzyme Linked Immunofluorescent Assay (for Toxocara canis) and Human Immunodefeciency Virus titer (for HIV) are among the important tests to order.
CLINICAL PEARLS
Since the organism may remain viable for up to 25 years and reactivation attacks are common, patient education is vital. If an outbreak is discovered in a community, provide education regarding the consumption of uncooked or under-cooked foods and the danger of untidy cats and/or their litter boxes.
In patients who have active infection, consider HIV/AIDS, especially if no other obvious means of immunosuppression are present. Surgical modalities, such as laser photocoagulation and cryopexy, have less value and are traditionally only recommended when the other modalities have failed.
The symptoms associated with ocular toxoplasmosis include unilateral, mild ocular pain, blurred vision and new onset of floating spots. Patients often describe their vision as hazy. Clinical findings may include granulomatous iritis, vitritis, optic disc swelling, neuroretinitis, vasculitis and retinal vein occlusion in the vicinity of the inflammation, in the actively involved eye. Funduscopically, active toxoplasmosis presents with white-yellow, choreoretinal lesions and vitreous cells. There may be old, inactive lesions in the fellow eye. Toxoplasmosis can produce cystoid macular edema and choroidal neovascularization.
PATHOPHYSIOLOGY
Toxoplasmosis is a disease provoked by the obligate intracellular protozoan Toxoplasma gondii. It is found in a variety of mammal and bird hosts. The most common intermediate host is the cat. It is one of the most frequent causes of retinochoroiditis in humans, with more than 60 percent of the United States population and up to 75 percent of the world's general population possessing some seropositive findings.
The systemic symptoms found in congenital toxoplasmosis consist of convulsions, calcification of the arterioles and choreoretinitis. In adults, toxoplasmosis is often contracted without sickness. A small percentage of individuals encounter self-limiting, flu-like symptoms at the time of inoculation.
Toxoplasma exists in humans in two forms: (1) actively motile tachyzoites and (2) encysted Toxoplasma gondii called brachyzoites. The oocysts that contain the organisms which produce infection are excreted in fecal material and may lie dormant in the soil until ingested by other animals, resulting in infection.
Human infection may occur from ingestion of contaminated or undercooked meat and dairy products, direct or indirect ingestion of cat feces and transplacental transmission from an infected mother to the fetus. Toxoplasmosis can only be transmitted to a fetus during maternal parastemia. Congenital toxoplasmosis accounts for the majority of cases encountered in clinical practice.
In most cases, the body is primed for infection or toxoplasmosis reactivation by an immune system failure. This may occur following contraction of human immunodeficiency syndrome (HIV) or with medical immunosupression following organ transplantation.
The inflammatory fundus lesions are composed of mononuclear cells, with a liberation of lymphocytes, macrophages, epithelioid and plasma cells. The resulting retinal vasculitis contributes to the breakdown of the blood-retinal barrier and leads to a compromise in retinal function, with subsequent destruction and thickening.
MANAGEMENT
The goal of management is twofold: (1) eradicate the parasite and (2) suppress the inflammatory response. The classic treatment regimen combines pyrimethamine (a 75mg loading dose, followed by 25mg PO BID administration) with sulfadiazine (2g loading dose, then 1g PO QID for 4 to 6 weeks). Both medications inhibit the folic acid metabolism necessary for toxoplasmosis to survive. Concurrent folinic acid, 3 to 5mg PO twice weekly helps to minimize any bone marrow toxicity produced by the pyramethamine.
Alternative antibiotic treatments include: (1) clindamycin, 300mg, PO QID used with sulfadiazine, for four to six weeks, (2) tetracycline, 2g loading then 250mg PO QID and sulfadiazine for four to six weeks, or (3) trimethoprim/sulfamethoxazole 160/800mg, one tablet PO BID, with or without clindamycin or prednisone, for the same duration.
In otherwise normal individuals, after beginning antibiotic therapy, add oral steroids at a dose of 20 to 80mg PO daily for four to six weeks. Periocular steroids are never indicated. Oral steroids without systemic antibiotics are expressly contraindicated.
Manage the anterior ocular inflammation with a cycloplegic that is appropriate for the disease's severity and a topical steroid Q2H/QID.
Systemic laboratory testing is indicated in active cases. The Sabin-Feldman methylene blue dye test (for Toxoplasma gondii), Serum antitoxoplasma antibody titer (for Toxoplasma gondii), Fluorescent Treponemal Antibody absorption test (for syphilis), purified protein derivative (for tuberculosis), chest x-ray (for sarcoid and TB), Toxocara Enzyme Linked Immunofluorescent Assay (for Toxocara canis) and Human Immunodefeciency Virus titer (for HIV) are among the important tests to order.
CLINICAL PEARLS
Since the organism may remain viable for up to 25 years and reactivation attacks are common, patient education is vital. If an outbreak is discovered in a community, provide education regarding the consumption of uncooked or under-cooked foods and the danger of untidy cats and/or their litter boxes.
In patients who have active infection, consider HIV/AIDS, especially if no other obvious means of immunosuppression are present. Surgical modalities, such as laser photocoagulation and cryopexy, have less value and are traditionally only recommended when the other modalities have failed.
Friday, November 12, 2010
ENTAMOEBA HISTOLYTICA
Microbiology
Enteric protozoan
Cyst: 5-20 micrometer with one to four nuclei
Trophozoite (ameba): 12-60 micrometer with a single nucleus, a centrally located nucleolus with a uniformly distributed peripheral chromatin
Many strains, differentiated by isoenzyme analysis
Epidemiology
10% of the world is infected
50,000-100,000 E. histolytica-associated deaths per year (third leading parasitic cause of death in the world)
Endemic in Mexico, India, West and South Africa and portions of Central and South America
Vast majority (90%) of patients remain asymptomatic
High risk factors for invasive diseases in North America:
recent immigration, institutionalization and homosexuality
Transmission by fecal-oral route
Clinical syndromes
Intestinal:
Asymptomatic colonization
Acute amebic colitis
Fulminant colitis
Ameboma
Extraintestinal
Hepatic abscess
Pleuropulmonary
Peritonea
Pericardial
brain abscesses
Diagnosis
Serology (generally positive after 7 days)
Cyst and parasite in stool (rapid examination after special coloration: modify Kinouyn: as trophozoites die rapidly)
Comments on treatment
Surgical drainage if abscess
Asymptomatic cyst passer:
recommended: Paromomycin or Iodoquinol
alternative: diloxanide furoate
Diarrhea
recommended: Metronidazole and (Paromomycin or Iodoquinol)
alternative: (tinidazol or ornidazole) and (Paromomycin or Iodoquinol)
Extraintestinal infection:
Metronidazole and Iodoquinol
HELICOBACTER PYLORI AND PEPTIC ULCER
Microbiology
Formerly Campylobacter pylori
Spiral-shaped gram-negative bacillus
Ability to survive the acidic pH of gastric fluids
Epidemiology
Implicated as a cause of duodenal and gastric ulcers
Infection increasing with age
Natural reservoir in humans
Transmission is fecal-oral
Clinical syndromes
Duodenal and gastric ulcers
Dyspepsia (non-ulcer)
Gastric carcinoma
Diagnosis
Urease test (breath test)
Culture
Gastric biopsy
Serology
Comments on treatment
Susceptible in vitro to a variety of antimicrobial agents: Tetracycline, Metronidazole, Amoxicillin and Clarithromycin
Resistance to these antibiotics has been described (associated with treatment failures)
Recommended: see Ulcer, Gastric & Duodenal for more details
Amoxicillin and Clarithromycin and (omeprazole or lansoprazole)
Alternative:
bismuth and Tetracycline and Metronidazole and omeprazole
Hepatitis-B
Microbiology
Outmoded designation: serum hepatitis, due to its historically recognized route of percutaneous transmission (interesting to note that most of the patients with "serum hepatitis" were not actually infected with HBV)
Partially double-stranded DNA virus member of the hepadnavirus family (hepatotropic DNA viruses)
Reverse-transcriptase activity associated with the viral DNA
HBSag
product of the S gene of HBV
major surface protein
several subtypes
anti-HBs is the protective antibody
extremely large production during an infection (500µg/ml or 10 trillions particles per ml)
HBcAg
core antigen
product of the C gene
HBeAg
soluble nucleocapsid protein
reliable marker of replication and infectivity
Epidemiology
Virus found in every body fluid of infected individuals (saliva, tears, CSF, seminal fluid, ascites, breast milk, gastric fluid, synovial fluid, pleural fluid, urine and even (rarely) feces)
Low infectivity with oral ingestion of the agent
Sexual and perinatal transmission are important routes
Carrier state in human (more than 200 millions in the world) is the main reservoir
Prevalence is 0.1 and 0.5% in normal population but as high as 20% in some high risk groups
Higher risk groups:
Down's syndrome
leprosy
leukemia
Hodgkin's
polyarteritis
IVDU
hemodialysis patients
spouse of acutely infected persons
sexually promiscuous people
people who required repeated transfusions (low risk with present-day blood products with screening
Clinical syndromes
Subclinical
Fulminant acute hepatitis
Chronic persistent hepatitis
Chronic active hepatitis
Hepatocellular carcinoma
Diagnosis
Serology
Comments on treatment
Acute: no therapy recommended
Chronic
recommended: interferon-alfa (2a or 2b) (4-6 months of treatment. 33% will respond)
alternative: lamivudine (duration not established)
Prevention (after transplantation for HBV-induced cirrhosis
HIV-AIDS
Microbiology
One of the four known pathogenic human retroviruses and a member of the Lentiviruses
Two recognized subtypes of HIV:
HIV-1 causes AIDS worldwide
HIV-2 produces an AIDS-like illness but appears to be less pathologic
Each virion has 2 identical copies of a single-stranded viral RNA genome
Goes through reverse transcription (RNA into double-stranded DNA)
Contains three essential genes for viral replication: gag (Group-specific AntiGen), pol (polymerase) and env (envelop)
Epidemiology
HIV is now the leading cause of death of men aged 25-40, the sixth leading cause of death of adolescent males 15-24 years of age, and the fourth leading cause of death in women 25-44 years of age.
By the year 2000, the World Health Organization estimates that there will be 40 million HIV-infected individuals worldwide.
Male homosexuality continues to be the most common mode of transmission, but I.V. drug use and heterosexual transmission continues to rise
HIV in women continues to rise
Minorities account for a disproportionate amount of AIDS
Clinical syndromes
Category A:
Asymptomatic HIV infection
Persistent generalized lymphadenopathy (PGL)
Acute (primary) HIV illness
Category B
Symptomatic, not A or C conditions
Examples include but not limited to:
Bacillary angiomatosis
Candidiasis, vulvovaginal: persistent >1 month, poorly responsive to therapy
Candidiasis, oropharyngeal
Cervical dysplasia, severe, or carcinoma in situ
Constitutional symptoms (eg, fever >38.5°C or diarrhea >1 month)
NB: attributed to HIV infection or have a clinical course or management complicated by HIV
Category C
Candidiasis: esophageal, trachea, bronchi
Coccidioidomycosis, extrapulmonary
Cryptococcosis, extrapulmonary
Cervical cancer, invasive
Cryptosporidiosis, chronic intestinal (>1 month)
CMV retinitis, or other than liver, spleen, nodes
HIV encephalopathy
Herpes simplex with mucocutaneous ulcer >1 month, bronchitis, pneumonia
Histoplasmosis: disseminated, extrapulmonary
Isosporiasis, chronic (>1 month)
Kaposi's sarcoma
Lymphoma: Burkitt's, immunoblastic, primary in brain
M. avium or M. kansasii, extrapulmonary
M. tuberculosis: pulmonary or extrapulmonary
Mycobacterium, other species disseminated or extrapulmonary
Pneumocystis carinii pneumonia
Pneumonia: recurrent (>2 episodes in 1 year)
Progressive multifocal leukoencephalopathy
Salmonella bacteremia, recurrent
Toxoplasmosis, cerebral
Wasting syndrome due to HIV
Diagnosis
Serology (ELISA and Western Blot)
PCR
CD4 counts
Comments on treatment
For more info see: AIDS
Primary:
PI (protease inhibitors) + 2 NRTIs (nucleoside reverse-transcriptase inhibitors)
Indinavir + ZDV + 3TC
Nelfinavir + d4T + ddI
(Sequinavir ± ritonavir) + [(ZDV + DDC) or (d4T + 3TC)
Alternative :
2 NRTIs (ZDV, ddI, DDC, d4T, 3TC) + NNRTI (delavirdine , nevirapine, efavirenz)
[(ZDV + 3TC) or (d4T + ddI) or (ZDV + DDC) or (d4T + 3TC)] +(efavirenz or delavirdine or nevirapine)
Paget's Disease of Bone
Definition
Condition characterised by high rates of bone resorption and disorganised immature new bone formation ® abnormal remodelling of bone
First described by Sir James Paget in 1876 and evidence of the disease found in Neanderthal man
Incidence
Affects more than 3% of population over 40 years of age around 2% of the population at age 40 to around 10% in the elderly (more than 80 years)
Relatively common in Anglo-Saxons, Britain, Germany and Australia
Britain has the highest recorded prevalence
In Australia the prevalence among British born immigrants is intermediate between the British rate and the native born Australians
Rare in Scandinavia, Russia, Italy, Asia, Africa and the Middle East
Affects American whites and blacks equally ® suggest environmental factor contributing to aetiology
Male : Female 7:6
Probably equal overall incidence but in younger individuals males slightly more frequent
Only occasionally presents in people under 50 years
There is evidence of a decline in incidence of the disease in Britain and USA
Aetiology
The primary abnormality is thought to lie in the osteoclasts but the precise cause remains unknown
Viral aetiology
suggested by the isolation of viral intra-nuclear inclusion bodies in osteoclasts on EM which resemble those of measles (Rebel 1976, Mills 1976)
Antigen to measles virus, simian virus 5 and human parainfluenza virus type 3 detected in abnormal osteoclasts (Basle 1985)
Measles virus not detected (Gordon 1991)
Canine distemper virus (CDV) in 41% of Pagetic osteoclasts, osteocytes and osteoblasts (Gordon 1991)
Slow virus type aetiology consistent with familial incidence
Ralston, 1994 investigated Pagets and normal bone with reverse-transcriptase and polymerase chain reaction
no difference in IL-1, IL-6, TNF-?, TNF-?, b-FGF, TGF-?, IGF-1
possibility that Pagets bone turnover is due to local elaboration of other osteotropic factors
Birch (Ralston) 1994 unable with PCR to detect measles and CDV aetiology for Pagets disease
Relationship to pets has been postulated but not substantiated
Genetic, as family history found in 15 - 20% of cases, and the site and extent of disease similar in family members (dominant inheritance with low penetrance (Sofaer 1983)
Extraordinary geographic variations in prevalence (see data on incidence)
Probably, Pagets disease is caused by infection with a common and widespread virus superimposed on genetic variation for susceptibility and perhaps severity of disease (Sofaer, 1983)
Interaction between hereditary and environmental factors
Geographical variations in the prevalence of Paget's disease remain unexplained and the viral hypothesis remains unproven
Also postulated
a disorder of hormonal secretion
vascular aetiology
autoimmune disease
monoclonal IgM
Clinically
Variable picture with the majority being discovered incidentally following X-Ray or elevated alkaline phosphatase
Only a minority of patients become symptomatic (5%)
Monostotic in 17% and polyostotic in 83% (pelvis 70%, Lumbar spine 50%, femur 50%, skull 45%, tibia 30%, humerus 30%, clavicle ® visible deformity in 13%, hand and foot 3 - 5%)
The disease may for many years be localised to part or the whole of one bone
Affected bones may remain asymptomatic or ® pain (dull constant ache) and become bent
Pain is worse at night, but rarely severe unless sarcoma or fracture supervene
Lesions detected on bone scan are usually painful whereas many lesions seen on X-Ray are not
Bone looks bent, feels warm (may be 5o warmer than unaffected side)and thick (osteitis deformans)
If generalised may ® headache, deafness (with impairment of hearing in 30 - 50% of cases), deformities, stiffness, limb pain and sometimes fracture and heart failure, occasionally pressure on the optic nerve may ® blindness
Facial and trigeminal nerves may also be affected
Spinal stenosis may occur ® root or cord problems infrequently or a vascular steal syndrome may ® spinal claudication
Features suggestive of pain of Pagetic origin in the back are non-specific low back pain without radiculopathy, normal or minimal findings on examination, vertebral sclerosis in radiographs, isolated vertebral involvement in bone scan and enlarged vertebra and neural arch, normal facet joints and no bony impingement
Canal stenosis occurs gradually as the expanding vertebral body reduces the canal diameter, may be kyphosis, and back ache and root pain is common
Cardiac failure associated with arterial calcification and calcification of heart valves and myocardium as well as being a high output state
About 20% of Pagets patients have fractures which may be complete or incomplete and as many as 40% ® delayed or non-union
Tinnitus and vertigo are common complaints
Coxa vara is also a feature with considerable antero-lateral bowing of the legs
When involves a joint may ® painful erosive arthritis due to altered stresses secondary to deformity and abnormal subchondral bone ® collapse or loss of resilience
X-Rays
Early ® osteoporosis circumscripta
Disease involvement usually seen at one end of the bone (generally proximal)
The bone as a whole is thick and bent
Density in the vascular stage is decreased and it is increased in the sclerotic stage
Trabeculae are coarse and widely separated
In vascular stage areas of porosis shape
Condition characterised by high rates of bone resorption and disorganised immature new bone formation ® abnormal remodelling of bone
First described by Sir James Paget in 1876 and evidence of the disease found in Neanderthal man
Incidence
Affects more than 3% of population over 40 years of age around 2% of the population at age 40 to around 10% in the elderly (more than 80 years)
Relatively common in Anglo-Saxons, Britain, Germany and Australia
Britain has the highest recorded prevalence
In Australia the prevalence among British born immigrants is intermediate between the British rate and the native born Australians
Rare in Scandinavia, Russia, Italy, Asia, Africa and the Middle East
Affects American whites and blacks equally ® suggest environmental factor contributing to aetiology
Male : Female 7:6
Probably equal overall incidence but in younger individuals males slightly more frequent
Only occasionally presents in people under 50 years
There is evidence of a decline in incidence of the disease in Britain and USA
Aetiology
The primary abnormality is thought to lie in the osteoclasts but the precise cause remains unknown
Viral aetiology
suggested by the isolation of viral intra-nuclear inclusion bodies in osteoclasts on EM which resemble those of measles (Rebel 1976, Mills 1976)
Antigen to measles virus, simian virus 5 and human parainfluenza virus type 3 detected in abnormal osteoclasts (Basle 1985)
Measles virus not detected (Gordon 1991)
Canine distemper virus (CDV) in 41% of Pagetic osteoclasts, osteocytes and osteoblasts (Gordon 1991)
Slow virus type aetiology consistent with familial incidence
Ralston, 1994 investigated Pagets and normal bone with reverse-transcriptase and polymerase chain reaction
no difference in IL-1, IL-6, TNF-?, TNF-?, b-FGF, TGF-?, IGF-1
possibility that Pagets bone turnover is due to local elaboration of other osteotropic factors
Birch (Ralston) 1994 unable with PCR to detect measles and CDV aetiology for Pagets disease
Relationship to pets has been postulated but not substantiated
Genetic, as family history found in 15 - 20% of cases, and the site and extent of disease similar in family members (dominant inheritance with low penetrance (Sofaer 1983)
Extraordinary geographic variations in prevalence (see data on incidence)
Probably, Pagets disease is caused by infection with a common and widespread virus superimposed on genetic variation for susceptibility and perhaps severity of disease (Sofaer, 1983)
Interaction between hereditary and environmental factors
Geographical variations in the prevalence of Paget's disease remain unexplained and the viral hypothesis remains unproven
Also postulated
a disorder of hormonal secretion
vascular aetiology
autoimmune disease
monoclonal IgM
Clinically
Variable picture with the majority being discovered incidentally following X-Ray or elevated alkaline phosphatase
Only a minority of patients become symptomatic (5%)
Monostotic in 17% and polyostotic in 83% (pelvis 70%, Lumbar spine 50%, femur 50%, skull 45%, tibia 30%, humerus 30%, clavicle ® visible deformity in 13%, hand and foot 3 - 5%)
The disease may for many years be localised to part or the whole of one bone
Affected bones may remain asymptomatic or ® pain (dull constant ache) and become bent
Pain is worse at night, but rarely severe unless sarcoma or fracture supervene
Lesions detected on bone scan are usually painful whereas many lesions seen on X-Ray are not
Bone looks bent, feels warm (may be 5o warmer than unaffected side)and thick (osteitis deformans)
If generalised may ® headache, deafness (with impairment of hearing in 30 - 50% of cases), deformities, stiffness, limb pain and sometimes fracture and heart failure, occasionally pressure on the optic nerve may ® blindness
Facial and trigeminal nerves may also be affected
Spinal stenosis may occur ® root or cord problems infrequently or a vascular steal syndrome may ® spinal claudication
Features suggestive of pain of Pagetic origin in the back are non-specific low back pain without radiculopathy, normal or minimal findings on examination, vertebral sclerosis in radiographs, isolated vertebral involvement in bone scan and enlarged vertebra and neural arch, normal facet joints and no bony impingement
Canal stenosis occurs gradually as the expanding vertebral body reduces the canal diameter, may be kyphosis, and back ache and root pain is common
Cardiac failure associated with arterial calcification and calcification of heart valves and myocardium as well as being a high output state
About 20% of Pagets patients have fractures which may be complete or incomplete and as many as 40% ® delayed or non-union
Tinnitus and vertigo are common complaints
Coxa vara is also a feature with considerable antero-lateral bowing of the legs
When involves a joint may ® painful erosive arthritis due to altered stresses secondary to deformity and abnormal subchondral bone ® collapse or loss of resilience
X-Rays
Early ® osteoporosis circumscripta
Disease involvement usually seen at one end of the bone (generally proximal)
The bone as a whole is thick and bent
Density in the vascular stage is decreased and it is increased in the sclerotic stage
Trabeculae are coarse and widely separated
In vascular stage areas of porosis shape
Bone Grafts
Indications
To provide stability (cortical bone best)
To provide linkage, ie replace missing bone
To stimulate osteogenesis
Bone grafts may be
Osteo-conduction
The graft provides a scaffold for bone deposition
Osteo-induction
Graft derived factors actually stimulate the recipient to invade the structure with osteogenic activity.
Physiology of remodelling and bone grafts
1. Activation
Local and systemic factors involved
2. Resorption
Appearance of osteoclasts from ? haematopoietic stem cell precursors or macrophage lineage. (pre osteoclasts may be endothelial cells, circulating monocytes, reticuloendothelial cells and fibroblasts)
3. New Bone Formation
Osteoblasts also from the marrow ® deposit osteoid ® mineralisation of the matrix.
Graft incorporation
Haematoma forms around implanted bone and only surface cells remain viable by diffusion.
Necrosis of graft follows ® inflammatory response and formation of a fibro vascular stroma.
Blood vessels and osteogenic precursors infiltrate the graft.
A neo vascular response results in increased porosity and decreased mass of the graft.
New bone formation follows and finally remodelling.
Cortical bone grafts are approximately 40-60% weaker than normal bone from 6 weeks to 6 months after transplantation. Returns to normal 1-2 years after transplant.
Factors adversely affecting incorporation
Vascularity
Infection
Foreign Material
Malnutrition
Drugs eg
(indocid, diphosphonates)
Types
Autografts
From the patient themselves, but most still dies
Vascularized autografts ® no resorption and either end of the transplanted segment heals in a way analogous to fracture healing.
Allografts
Transferred from one individual living or dead to another of the same species. Antigenicity altered by freezing / radiation. Radiation ® alters collagen ® depress graft incorporation. Osteochondral graft survival enhanced by immersion in glycerol.
Fresh grafts ® immunological response and less reliable incorporation
The sequence of events of incorporation is qualitatively similar to that for autografts, but it is delayed and less extensive (allografts are biologically inferior to autografts).
Xenografts
Bone taken from a different species, similar to allograft bone after freezing and irradiation.
Collection and distribution of donor bone in South Australia
Age limit for donation 16-60 years
Femoral Heads
Written consent required from the donor to use the bone and perform blood tests (HIV, HepB, VDRL)
Swabs taken of acetabulum and femoral head ® MCS
Biopsy of femoral head ® Histopathology
Head placed in 2 sterile bags, sterile container & un-sterile bag
Stored in -70oC ultra cold freezer
If sever osteoporosis identified bone is X-Rayed and decision made about keeping the bone
Exclusions
Hepatitis
Infection
Tumour
Rheumatoid
Alcohol / Drug abuse
Steroid treatment
Pre-senile dementia
Transfusion in last 6/12
All bone for re implantation receives 2.5 mrad of g irradiation and the bone marked ready for use.
Long bones
Consent form relatives
Tissue obtained under sterile conditions
Blood tests taken as for femoral heads
Dimensions of each bone recorded and computerised for later matching
Exclusions
Fresh bone must be 16 - 30 years old
Frozen bone can be up to 12 hours post death
Fresh bone need beating heart or in first few hours
Exclusion if in ICU > 72 hours (infection)
Allograft infection rate 10-12% and more than 80% of infected allografts are associated with clinical failure
Synthetic Grafts
Hydroxyapatite
Not biodegradable and is brittle but acts as an osteo-conductive medium
Tricalcium Phosphate
Biodegradable and is replaced by new bone but unpredictable rate of resorption and lengthy incorporation
These grafts can be used alone or mixed with autograft. Useful to fill defects where the intrinsic mechanical strength of the graft is unimportant.
Many drugs (chemotherapeutic agents, NSAIDs etc) negatively influence new bone formation in the intact skeleton and to some degree the repair associated with fractures.
Similar findings result from irradiation
Papineau Technique
Wound excision, open cancellous grafting which irradicates infection, encourages healing of the skin by granulation and results in solid bony union.
Swab for culture ® appropriate antibiotic pre-operatively
Tomograms or CT etc to define extent of sequestrum
Excision of infected tissue down to bleeding living tissue
Splint the bone if inadequate or deficient
Defect in bone must be saucerised
Development of granulation tissue ® base for subsequent graft
Secondary excision of areas not covered by granulation tissue
Within 2/52 operation for application of cancellous graft
Change dressings at 5/7 ® washing and daily dressing
Continue dressings 3/52 ( ® 3 colour changes)
By the end of the third month entire graft incorporated into granulation tissue
SSG applied if required
FWB allowed at 7/12 for osteomyelitis, 9/12 where some continuity has been preserved and 12/12 if part of the shaft was completely resected.
To provide stability (cortical bone best)
To provide linkage, ie replace missing bone
To stimulate osteogenesis
Bone grafts may be
Osteo-conduction
The graft provides a scaffold for bone deposition
Osteo-induction
Graft derived factors actually stimulate the recipient to invade the structure with osteogenic activity.
Physiology of remodelling and bone grafts
1. Activation
Local and systemic factors involved
2. Resorption
Appearance of osteoclasts from ? haematopoietic stem cell precursors or macrophage lineage. (pre osteoclasts may be endothelial cells, circulating monocytes, reticuloendothelial cells and fibroblasts)
3. New Bone Formation
Osteoblasts also from the marrow ® deposit osteoid ® mineralisation of the matrix.
Graft incorporation
Haematoma forms around implanted bone and only surface cells remain viable by diffusion.
Necrosis of graft follows ® inflammatory response and formation of a fibro vascular stroma.
Blood vessels and osteogenic precursors infiltrate the graft.
A neo vascular response results in increased porosity and decreased mass of the graft.
New bone formation follows and finally remodelling.
Cortical bone grafts are approximately 40-60% weaker than normal bone from 6 weeks to 6 months after transplantation. Returns to normal 1-2 years after transplant.
Factors adversely affecting incorporation
Vascularity
Infection
Foreign Material
Malnutrition
Drugs eg
(indocid, diphosphonates)
Types
Autografts
From the patient themselves, but most still dies
Vascularized autografts ® no resorption and either end of the transplanted segment heals in a way analogous to fracture healing.
Allografts
Transferred from one individual living or dead to another of the same species. Antigenicity altered by freezing / radiation. Radiation ® alters collagen ® depress graft incorporation. Osteochondral graft survival enhanced by immersion in glycerol.
Fresh grafts ® immunological response and less reliable incorporation
The sequence of events of incorporation is qualitatively similar to that for autografts, but it is delayed and less extensive (allografts are biologically inferior to autografts).
Xenografts
Bone taken from a different species, similar to allograft bone after freezing and irradiation.
Collection and distribution of donor bone in South Australia
Age limit for donation 16-60 years
Femoral Heads
Written consent required from the donor to use the bone and perform blood tests (HIV, HepB, VDRL)
Swabs taken of acetabulum and femoral head ® MCS
Biopsy of femoral head ® Histopathology
Head placed in 2 sterile bags, sterile container & un-sterile bag
Stored in -70oC ultra cold freezer
If sever osteoporosis identified bone is X-Rayed and decision made about keeping the bone
Exclusions
Hepatitis
Infection
Tumour
Rheumatoid
Alcohol / Drug abuse
Steroid treatment
Pre-senile dementia
Transfusion in last 6/12
All bone for re implantation receives 2.5 mrad of g irradiation and the bone marked ready for use.
Long bones
Consent form relatives
Tissue obtained under sterile conditions
Blood tests taken as for femoral heads
Dimensions of each bone recorded and computerised for later matching
Exclusions
Fresh bone must be 16 - 30 years old
Frozen bone can be up to 12 hours post death
Fresh bone need beating heart or in first few hours
Exclusion if in ICU > 72 hours (infection)
Allograft infection rate 10-12% and more than 80% of infected allografts are associated with clinical failure
Synthetic Grafts
Hydroxyapatite
Not biodegradable and is brittle but acts as an osteo-conductive medium
Tricalcium Phosphate
Biodegradable and is replaced by new bone but unpredictable rate of resorption and lengthy incorporation
These grafts can be used alone or mixed with autograft. Useful to fill defects where the intrinsic mechanical strength of the graft is unimportant.
Many drugs (chemotherapeutic agents, NSAIDs etc) negatively influence new bone formation in the intact skeleton and to some degree the repair associated with fractures.
Similar findings result from irradiation
Papineau Technique
Wound excision, open cancellous grafting which irradicates infection, encourages healing of the skin by granulation and results in solid bony union.
Swab for culture ® appropriate antibiotic pre-operatively
Tomograms or CT etc to define extent of sequestrum
Excision of infected tissue down to bleeding living tissue
Splint the bone if inadequate or deficient
Defect in bone must be saucerised
Development of granulation tissue ® base for subsequent graft
Secondary excision of areas not covered by granulation tissue
Within 2/52 operation for application of cancellous graft
Change dressings at 5/7 ® washing and daily dressing
Continue dressings 3/52 ( ® 3 colour changes)
By the end of the third month entire graft incorporated into granulation tissue
SSG applied if required
FWB allowed at 7/12 for osteomyelitis, 9/12 where some continuity has been preserved and 12/12 if part of the shaft was completely resected.
Traction
Introduction
Traction produces a reduction through the surrounding soft parts which align the fragments by their tension.
When the shaft of a long bone is fractured the elastic retraction of muscles surrounding the bone tends to produce over-riding of the fragments. This tendency is greater when the muscles are powerful and long bellied as in the thigh, when the fracture is imperfectly immobilised so that there is pain and therefore muscle spam and when the fracture is mechanically unstable because the fragments are not in apposition or because the fracture line is oblique.
Continuous traction generated by weights and pulleys in addition to causing reduction of a deformity will also produce a relative fixation of the fragments by the rigidity conferred by the surrounding soft tissue structures when under tension. It also enables maintenance of alignment while at the same time it is possible to devise apparatus which permit joint movement.
Traction may be applied through traction tapes attached to skin by adhesives or by direct pull by transfixing pins through or onto the skeleton.
Traction must always be apposed by counter traction or the pull exerted against a fixed object, otherwise it mealy pulls the patient down or off the bed.
Traction requires constant care and vigilance and is costly in terms of the length of hospital stay and all the hazards of prolonged bed rest - thromboembolism, decubiti, pneumonia and atelectasis must be considered when traction is used
Excessive traction which leads to distraction of the fracture is undesirable. Once the fracture is reduced a decreasing amount of weight is required to maintain a reduction once the muscle stretch reflex has been overcome and the fracture immobilised. For a femoral fracture no more than 10lbs should be used and for fractures of the tibia and upper limb less weight is required.
Skin Traction
Traction is applied to the skeleton through its attached soft tissued and in the adult should be used only as a temporary measure.
Skin is designed to bear compression forces and not shear. If much more than 8lbs is applied for any length of time it results in superficial layers of skin pulled off. Other difficulties such as migration of the bandage may occur with lower weights.
Skeletal Traction
First achieved by the use of tongs.
The application of traction applied by a pin transfixing bone was introduced by Fritz Steinmann. Now a threaded Denham pin is preferred to prevent early loosening of the device.
The threaded portion of the Denham pin is offset, closer to the end of the pin held in the drill chuck and should engage only the proximal cortex of the recipient long bone.
Traction by Gravity
Really only applies to fractures of the upper limb (hanging cast)
Definitions
Traction on a limb demands either a fixed point from which the traction may be exerted (fixed traction) or an equal counter-traction in the opposite direction (balanced traction)
Fixed Traction
The length of the limb remains constant and there is continuous diminution of traction force as the tone in the muscles diminishes and no further stimuli results in activation of the muscle stretch reflex.
Pull is exerted against a fixed point for example tapes are tied to the cross piece of a Thomas splint and the leg pulled down until the root of the limb abuts against the ring of the splint.
Pins in plaster is a form of fixed traction
Balanced Traction
In weight traction it is the tension in the apparatus which remains constant and the length depends on the amount of tearing of the intermuscular septum and fibrous tissue of the limb
The pull is exerted against an opposing force provided by the weight of the body when the foot of the bed is raised.
Combined Traction
May be used in conjunction with fixed traction where the weight takes up any slack in the tapes or cords while the splint maintains a reduction.
This combination facilitates less frequent checks and adjustment of the apparatus
Sliding Traction
First introduced by Pugh by applying traction tapes to the limb and fastening them to the raised foot of the bed which was then inclined head down.
He utilised this traction in the treatment of conditions such as Perthes where only one limb was fastened to the end of the bed enabling the pelvis on the opposite side to slide down the bed more thus creating traction and abduction.
The extent to which the patient slides down the bed is limited by the friction of the body against the mattress.
The traction was subsequently modified by Hendry using a mattress on a sliding frame which resulted in the same amount of traction with an inclination of 10o as that with that on a normal mattress at 30 - 40o inclination.
This is also really a form of balance traction where the amount of weight is determined by the inclination of the bed.
Specific Types of Traction
Thomas Splint Traction
Hugh Owen Thomas introduced his splint which he called "The Knee Appliance" in 1875.
The method of Hugh Owen Thomas uses fixed traction with the counter traction being applied against the perineum by the ring of the splint. This is in contrast to other methods using weight traction which is countered by the weight of the body.
Backward angulation of the distal fragment can never be corrected by traction in the axis of the femur which only results in elongation with persistence of the deformity.
Traction produces a reduction through the surrounding soft parts which align the fragments by their tension.
When the shaft of a long bone is fractured the elastic retraction of muscles surrounding the bone tends to produce over-riding of the fragments. This tendency is greater when the muscles are powerful and long bellied as in the thigh, when the fracture is imperfectly immobilised so that there is pain and therefore muscle spam and when the fracture is mechanically unstable because the fragments are not in apposition or because the fracture line is oblique.
Continuous traction generated by weights and pulleys in addition to causing reduction of a deformity will also produce a relative fixation of the fragments by the rigidity conferred by the surrounding soft tissue structures when under tension. It also enables maintenance of alignment while at the same time it is possible to devise apparatus which permit joint movement.
Traction may be applied through traction tapes attached to skin by adhesives or by direct pull by transfixing pins through or onto the skeleton.
Traction must always be apposed by counter traction or the pull exerted against a fixed object, otherwise it mealy pulls the patient down or off the bed.
Traction requires constant care and vigilance and is costly in terms of the length of hospital stay and all the hazards of prolonged bed rest - thromboembolism, decubiti, pneumonia and atelectasis must be considered when traction is used
Excessive traction which leads to distraction of the fracture is undesirable. Once the fracture is reduced a decreasing amount of weight is required to maintain a reduction once the muscle stretch reflex has been overcome and the fracture immobilised. For a femoral fracture no more than 10lbs should be used and for fractures of the tibia and upper limb less weight is required.
Skin Traction
Traction is applied to the skeleton through its attached soft tissued and in the adult should be used only as a temporary measure.
Skin is designed to bear compression forces and not shear. If much more than 8lbs is applied for any length of time it results in superficial layers of skin pulled off. Other difficulties such as migration of the bandage may occur with lower weights.
Skeletal Traction
First achieved by the use of tongs.
The application of traction applied by a pin transfixing bone was introduced by Fritz Steinmann. Now a threaded Denham pin is preferred to prevent early loosening of the device.
The threaded portion of the Denham pin is offset, closer to the end of the pin held in the drill chuck and should engage only the proximal cortex of the recipient long bone.
Traction by Gravity
Really only applies to fractures of the upper limb (hanging cast)
Definitions
Traction on a limb demands either a fixed point from which the traction may be exerted (fixed traction) or an equal counter-traction in the opposite direction (balanced traction)
Fixed Traction
The length of the limb remains constant and there is continuous diminution of traction force as the tone in the muscles diminishes and no further stimuli results in activation of the muscle stretch reflex.
Pull is exerted against a fixed point for example tapes are tied to the cross piece of a Thomas splint and the leg pulled down until the root of the limb abuts against the ring of the splint.
Pins in plaster is a form of fixed traction
Balanced Traction
In weight traction it is the tension in the apparatus which remains constant and the length depends on the amount of tearing of the intermuscular septum and fibrous tissue of the limb
The pull is exerted against an opposing force provided by the weight of the body when the foot of the bed is raised.
Combined Traction
May be used in conjunction with fixed traction where the weight takes up any slack in the tapes or cords while the splint maintains a reduction.
This combination facilitates less frequent checks and adjustment of the apparatus
Sliding Traction
First introduced by Pugh by applying traction tapes to the limb and fastening them to the raised foot of the bed which was then inclined head down.
He utilised this traction in the treatment of conditions such as Perthes where only one limb was fastened to the end of the bed enabling the pelvis on the opposite side to slide down the bed more thus creating traction and abduction.
The extent to which the patient slides down the bed is limited by the friction of the body against the mattress.
The traction was subsequently modified by Hendry using a mattress on a sliding frame which resulted in the same amount of traction with an inclination of 10o as that with that on a normal mattress at 30 - 40o inclination.
This is also really a form of balance traction where the amount of weight is determined by the inclination of the bed.
Specific Types of Traction
Thomas Splint Traction
Hugh Owen Thomas introduced his splint which he called "The Knee Appliance" in 1875.
The method of Hugh Owen Thomas uses fixed traction with the counter traction being applied against the perineum by the ring of the splint. This is in contrast to other methods using weight traction which is countered by the weight of the body.
Backward angulation of the distal fragment can never be corrected by traction in the axis of the femur which only results in elongation with persistence of the deformity.
Tibia Fractures
Proximal Tibial Fractures
Mechanism
young pt - high energy trauma
old pt minor fall
Classification AO
extrarticular
intraarticular, unicondylar
intraarticular, bicondylar
60% are lat plateau
15% are med plateau
25% involve both
Evaluation
assess assoc injuries, neurovasc examination
XRay: plain films, biplanar tomography, CT
Treatment
Extraarticular
CR if necessary, AKPOP or cast brace
Intraarticular
Undisplaced
AKPOP/ cast brace
Displaced
ORIF / BG/ cast brace for split depression
simple depression fracture may be amenable to elevation without plating using an arthroscopic assisted technique
type C fracture- often very comminuted, difficult to reconstruc, thus CR/cast bracing often preferable
Note association with meniscal lesions in ~20%
collateral or cruciate lig injuries in ~20%
Complications
nonunion
rare
malunion
more common with nonop treatment
Bicondylar fracture
knee instability due to either malunion or ligament injury
infection
more common in bicondylar fracture - increased op time, exposure, hardware
Prognosis
ref: Anglen and Healy "tibial plateau fractures" Orthopaedics 11:1527-1534, 1988
Undisplaced fracture 85% satisfactory with nonop treatment
Displaced fracture 78% satisfactory with ORIF, 54% with nonop treatment
Lachiewicz and Funcik "factors influencing the results of ORIF of tibial plateau fractures"
CORR 259: 210-215, 1990
44 fractures, 2.7 yr FU, 91% good or excellent, implant removal needed in 1/3 pts
Tibial Spine Fractures
Mechanism
hyper extension or hyperflexion® avulsion
Classification
Meyers and McKeever "Fractures of the intercondylar eminence of the tibia"
JBJS 52A: 1677-1684, 1970
Type 1: undisplaced
Type 2: displaced hinging posteriorly
Type 3: displaced with complete separation
Treatment
Type 1 + 2 CR with knee in extension likely to be successful- if not ORIF
Type 3 ORIF
Prognosis
good , low incidence of late instability
if malunion may get impingement in extension
Avulsion of the Tibial Tubercle
ref: Ogden etal "fractures of the tibial tuberosity in adolescents" JBJS 62A:205-215, 1980
Mechanism
usually in vigorous sports- violent contraction of quads in sudden acceleration or deceleration
Classification
Type 1 fracture
across the secondary ossification centre level with the post border of the inserting patellar tendon
Type 2 fracture
at the junction of the primary and secondary ossification centres
of the prox tibial epiphysis
Type 3
fracture propagates across the primary ossification centre= SH type 3
Treatment
ORIF , protect in extension , ROM exs
Prognosis
excellent
Tibial Shaft Fractures
Classification AO
Type A simple
a single circumferential disruption of the diaphysis - may be:
Spiral
Oblique ( angle more than 30 deg)
Transverse (angle less than 30 deg)
Type B multifragmentary: wedge
a fracture with one or more intermediate fragments in which after reduction, there is some contact bw the main fragments- may be:
Spiral wedge
Bending wedge
Fragmented wedge
Type C Multifragmentary: complex
a fracture with one or more intermediate fragments in which after reduction , there is no contact bw the main prox and distal fragments- may be:
Spiral
Segmental
Irregular
Treatment - closed injury
Nonoperative
best for fracture without significant comminution, shortening or displacement at the time of fracture. ie low energy fracture
AKPOP for 6/52, then convert to cast brace or PTB
union in approx 16 wks for simple fracture, longer for more complex injury (av 18 wks)
ref: Sarmiento etal "Tibial shaft fractures treated with functional braces: experience with 780 fractures" JBJS 71B: 602-609, 1989
90% healed with 1cm or less shortening
nonunion rate 2.5%
Operative
indicated in:
pt requires early return to work
displaced ie higher energy fracture
Failure of closed treatment
IM nailing:
ref: Hooper etal "Conservative management or closed nailing for tibial shaft fractures : a randomised prospective trial " JBJS 73B: 83-85, 1991
infection rate ~ 1-2%
angulatory deformities rare
shorter hospital stay, less OPD visits
earlier return to work
Treatment - Open Fractures
Wound management as for any compound fracture
IM Nailing
Court-Brown etal "Infection after intramedullary nailing of the tibia" JBJS 74B: 770-774, 1992
Tornetta etal " treatment of grade 3B open tibial fractures- a prospective randomised comparison of external fixation and nonreamed nailing" JBJS 76A:13-19, 1994
Grade 1
IM nailing - same figures as for closed fracture
Grade 2
infection 3.8%
Grade 3
A: infection 5.6%
B: infection 12.5%
External fixation:
Use for grade 3B and 3C
rates of infection same as nailing for grade 3B with added problem of pin tract infection, delayed union also a feature of ex fixation.
sometimes need to convert from ex fix to IM nail- risk of infection in the face of recent pin tract infection is ~ 20%, However if the ex fix is removed within 3 wks of application + wait another 2 wks,can nail with infection rate of ~ 5%
Ref: Johansen etal " Objective criteria accurately predict amputation following lower extremity trauma " J Trauma 30: 568-573, 1990
The MESS
1. Skeletal/ soft tissue injury
a. Low energy
eg simple fracture, civilian gunshot
1
b. Medium energy
eg open or multiple fractures, dislocation
2
c. High energy
eg close range shotgun, military gunshot, crush
3
d.
Mechanism
young pt - high energy trauma
old pt minor fall
Classification AO
extrarticular
intraarticular, unicondylar
intraarticular, bicondylar
60% are lat plateau
15% are med plateau
25% involve both
Evaluation
assess assoc injuries, neurovasc examination
XRay: plain films, biplanar tomography, CT
Treatment
Extraarticular
CR if necessary, AKPOP or cast brace
Intraarticular
Undisplaced
AKPOP/ cast brace
Displaced
ORIF / BG/ cast brace for split depression
simple depression fracture may be amenable to elevation without plating using an arthroscopic assisted technique
type C fracture- often very comminuted, difficult to reconstruc, thus CR/cast bracing often preferable
Note association with meniscal lesions in ~20%
collateral or cruciate lig injuries in ~20%
Complications
nonunion
rare
malunion
more common with nonop treatment
Bicondylar fracture
knee instability due to either malunion or ligament injury
infection
more common in bicondylar fracture - increased op time, exposure, hardware
Prognosis
ref: Anglen and Healy "tibial plateau fractures" Orthopaedics 11:1527-1534, 1988
Undisplaced fracture 85% satisfactory with nonop treatment
Displaced fracture 78% satisfactory with ORIF, 54% with nonop treatment
Lachiewicz and Funcik "factors influencing the results of ORIF of tibial plateau fractures"
CORR 259: 210-215, 1990
44 fractures, 2.7 yr FU, 91% good or excellent, implant removal needed in 1/3 pts
Tibial Spine Fractures
Mechanism
hyper extension or hyperflexion® avulsion
Classification
Meyers and McKeever "Fractures of the intercondylar eminence of the tibia"
JBJS 52A: 1677-1684, 1970
Type 1: undisplaced
Type 2: displaced hinging posteriorly
Type 3: displaced with complete separation
Treatment
Type 1 + 2 CR with knee in extension likely to be successful- if not ORIF
Type 3 ORIF
Prognosis
good , low incidence of late instability
if malunion may get impingement in extension
Avulsion of the Tibial Tubercle
ref: Ogden etal "fractures of the tibial tuberosity in adolescents" JBJS 62A:205-215, 1980
Mechanism
usually in vigorous sports- violent contraction of quads in sudden acceleration or deceleration
Classification
Type 1 fracture
across the secondary ossification centre level with the post border of the inserting patellar tendon
Type 2 fracture
at the junction of the primary and secondary ossification centres
of the prox tibial epiphysis
Type 3
fracture propagates across the primary ossification centre= SH type 3
Treatment
ORIF , protect in extension , ROM exs
Prognosis
excellent
Tibial Shaft Fractures
Classification AO
Type A simple
a single circumferential disruption of the diaphysis - may be:
Spiral
Oblique ( angle more than 30 deg)
Transverse (angle less than 30 deg)
Type B multifragmentary: wedge
a fracture with one or more intermediate fragments in which after reduction, there is some contact bw the main fragments- may be:
Spiral wedge
Bending wedge
Fragmented wedge
Type C Multifragmentary: complex
a fracture with one or more intermediate fragments in which after reduction , there is no contact bw the main prox and distal fragments- may be:
Spiral
Segmental
Irregular
Treatment - closed injury
Nonoperative
best for fracture without significant comminution, shortening or displacement at the time of fracture. ie low energy fracture
AKPOP for 6/52, then convert to cast brace or PTB
union in approx 16 wks for simple fracture, longer for more complex injury (av 18 wks)
ref: Sarmiento etal "Tibial shaft fractures treated with functional braces: experience with 780 fractures" JBJS 71B: 602-609, 1989
90% healed with 1cm or less shortening
nonunion rate 2.5%
Operative
indicated in:
pt requires early return to work
displaced ie higher energy fracture
Failure of closed treatment
IM nailing:
ref: Hooper etal "Conservative management or closed nailing for tibial shaft fractures : a randomised prospective trial " JBJS 73B: 83-85, 1991
infection rate ~ 1-2%
angulatory deformities rare
shorter hospital stay, less OPD visits
earlier return to work
Treatment - Open Fractures
Wound management as for any compound fracture
IM Nailing
Court-Brown etal "Infection after intramedullary nailing of the tibia" JBJS 74B: 770-774, 1992
Tornetta etal " treatment of grade 3B open tibial fractures- a prospective randomised comparison of external fixation and nonreamed nailing" JBJS 76A:13-19, 1994
Grade 1
IM nailing - same figures as for closed fracture
Grade 2
infection 3.8%
Grade 3
A: infection 5.6%
B: infection 12.5%
External fixation:
Use for grade 3B and 3C
rates of infection same as nailing for grade 3B with added problem of pin tract infection, delayed union also a feature of ex fixation.
sometimes need to convert from ex fix to IM nail- risk of infection in the face of recent pin tract infection is ~ 20%, However if the ex fix is removed within 3 wks of application + wait another 2 wks,can nail with infection rate of ~ 5%
Ref: Johansen etal " Objective criteria accurately predict amputation following lower extremity trauma " J Trauma 30: 568-573, 1990
The MESS
1. Skeletal/ soft tissue injury
a. Low energy
eg simple fracture, civilian gunshot
1
b. Medium energy
eg open or multiple fractures, dislocation
2
c. High energy
eg close range shotgun, military gunshot, crush
3
d.
Spine Fractures
Cervical Spine Fractures
Anatomy
spinal cord occupies ~ 35% of canal at the level of the Atlas and ~ 50% of the canal in the lower cervical region (C2-7) and the thoracolumbar spine
History
nature of incident
any neurological symptoms, any change in neurol status
LOC
head/ pectoral girdle injury
Examination
observe
head control
head injuries, pectoral girdle injuries: contusion
voluntary movement of all 4 limbs
Priapism
any limitation of movement of the pts head to either side
Palpate
tenderness over head + back off neck
step in spines
local haematoma
Neurological exam
Sensory
C2
back of head
C3
front of neck
C4
lat and inf over clavicles down to 2nd interspace
C5 - T1
upper limb
T2
below nipple
T10
unbilicus
L1
groin
L2- S2
lower limb
S3- S5 + coccygeal roots
perianal/ saddle
-once the sensory level is determined, examine distally for any evidence of sparing.
Sacral sparing indicates preservation of the lateral columns and recovery of lost muscle function is quite likely
Motor
after the sensory exam the diagnosis of a root lesion or cord lesion can be made and the completeness determined
Examine sequential nerve roots
C4
pt breaths diapragmatically
C5/6
biceps
C5
deltoid
C6
ECRL/ECRB
C7/8
triceps
C7
EDC
C8
FDP/FDP
T1
intrinsics
L1/2
adductors
L3/4
knee extension
L5/1
knee flexion
L4
tib ant
L5
EHL/ peronei
S1/2
ankle plantar flexion
Rectal inability of the pt to feel the finger in the rectum confirms a complete sensory lesion
If sphincter doesn't contract voluntarily about the finger + there are no other signs of voluntary motor power,complete motor paralysis is confirmed
Bulbocavernosus reflex: a squeeze on the glans, a tap on the mons or a tug on the catheter stimulating the trigone of the bladder causes reflex contraction of the anal sphincter about the gloved finger
If spinal shock is present a complete lesion cannot be diagnosed with certainty- if the bulbocavernosus has not returned in 24 hrs its absence is due to complete lesion as spinal shock resolves within 24 hrs
Spinal Cord Lesions
Spinal Shock
Wrt spinal cord injury = a spinal cord nervous tissue dysfunction based on physiologic dysfunction rather than structural disruption.
Spinal shock has resolved when the reflex arcs below the level of the injury begin to function again
Root injuries
are essentially peripheral nerve injuries , partial recovery is expected
root avulsion is rare except in plexus injury
Incomplete spinal cord lesions
any sparing distal to the injury = incomplete lesion= possible recovery
the greater the sparing the greater the prognosis
Brown- Sequard
an injury to either side of the cord (hemisection)
ipsilateral: muscle paralysis and jt position/ vibration loss
contralateral: pain and temperature loss
- good prognosis, 90% regain bladder / bowel function + walk
Central cord syndrome
most common incomplete cord injury, assoc with extension injury to Cx spine in middle aged pt
Impact direct to the central grey matter®severe flaccid LMN paralysis of the upper limbs
Damage to the central portion of the corticospinal and spinothalamic long tracts in the white matter®UMN spastic paralysis of the lower limbs and trunk
The sacral tracts are peripheral and are usually spared and the pt has sacral sparing
Prognosis
50-60% have progressive return of motor and sensory function to lower limbs- but poor recovery of hand function due to irreversible damage to the central grey matter
Anterior cord syndrome
complete motor and sensory loss apart from dorsal column sparing with deep pressure/ proprioception/ vibration as only remaining modality
prognosis
good if recovery progressive within 24 hrs
after 24 hrs prognosis poor
10-15% have recovery
Posterior cord syndrome
loss of deep pressure/ proprioception/ vibration only
Complete Cord Injuries
Frankel classification of Neurological Deficits in pts with Cord injuries
ref: Frankel etal "The value of postural reduction in the initial management of closed injuries of the spine with paraplegia and tetraplegia: Part 1."
Paraplegia 7: 179-192, 1969
Types
absent motor and sensory function
sensation present, motor function absent
sensation present, motor function present but not useful (gd 2-3/5)
sensation present motor function active and useful ( gd 4-5/5)
normal motor and sensory function
Assessment of Cx cord injuries
Plain XR
direct XR evidence of instability
Increased angulation bw spinous processes more than 11 deg than in adjacent segments
Ant or post translation of the vertebral bodies more than 3.5 mm
segmental disc space widening on lat XR
facet jt widening
malalignment of spinous processes of ant view
Rotation of the facets on lat XR
at tilt of vertebral body on ant XR
XR findings suggestive of unstable injuries
Increased retro pharyngeal space - ant to C3 normal not more than 3 mm
C4 + below- normal varies 8-10 mm
minimal compression fracture of ant vertebral bodies
Avulsion fracture at or near insertion of spinal ligs
nondisplaced fracture lines
Tomography
good for posterior elements, dens fracture
CT
assess bony encroachment on canal , best method for accurate bone definition
MRI
evaluate neural elements
disc disruption
ligamentous disruption
Stress XR's
flexion/ extension contraindicated in altered state of consciousness
Anatomy
spinal cord occupies ~ 35% of canal at the level of the Atlas and ~ 50% of the canal in the lower cervical region (C2-7) and the thoracolumbar spine
History
nature of incident
any neurological symptoms, any change in neurol status
LOC
head/ pectoral girdle injury
Examination
observe
head control
head injuries, pectoral girdle injuries: contusion
voluntary movement of all 4 limbs
Priapism
any limitation of movement of the pts head to either side
Palpate
tenderness over head + back off neck
step in spines
local haematoma
Neurological exam
Sensory
C2
back of head
C3
front of neck
C4
lat and inf over clavicles down to 2nd interspace
C5 - T1
upper limb
T2
below nipple
T10
unbilicus
L1
groin
L2- S2
lower limb
S3- S5 + coccygeal roots
perianal/ saddle
-once the sensory level is determined, examine distally for any evidence of sparing.
Sacral sparing indicates preservation of the lateral columns and recovery of lost muscle function is quite likely
Motor
after the sensory exam the diagnosis of a root lesion or cord lesion can be made and the completeness determined
Examine sequential nerve roots
C4
pt breaths diapragmatically
C5/6
biceps
C5
deltoid
C6
ECRL/ECRB
C7/8
triceps
C7
EDC
C8
FDP/FDP
T1
intrinsics
L1/2
adductors
L3/4
knee extension
L5/1
knee flexion
L4
tib ant
L5
EHL/ peronei
S1/2
ankle plantar flexion
Rectal inability of the pt to feel the finger in the rectum confirms a complete sensory lesion
If sphincter doesn't contract voluntarily about the finger + there are no other signs of voluntary motor power,complete motor paralysis is confirmed
Bulbocavernosus reflex: a squeeze on the glans, a tap on the mons or a tug on the catheter stimulating the trigone of the bladder causes reflex contraction of the anal sphincter about the gloved finger
If spinal shock is present a complete lesion cannot be diagnosed with certainty- if the bulbocavernosus has not returned in 24 hrs its absence is due to complete lesion as spinal shock resolves within 24 hrs
Spinal Cord Lesions
Spinal Shock
Wrt spinal cord injury = a spinal cord nervous tissue dysfunction based on physiologic dysfunction rather than structural disruption.
Spinal shock has resolved when the reflex arcs below the level of the injury begin to function again
Root injuries
are essentially peripheral nerve injuries , partial recovery is expected
root avulsion is rare except in plexus injury
Incomplete spinal cord lesions
any sparing distal to the injury = incomplete lesion= possible recovery
the greater the sparing the greater the prognosis
Brown- Sequard
an injury to either side of the cord (hemisection)
ipsilateral: muscle paralysis and jt position/ vibration loss
contralateral: pain and temperature loss
- good prognosis, 90% regain bladder / bowel function + walk
Central cord syndrome
most common incomplete cord injury, assoc with extension injury to Cx spine in middle aged pt
Impact direct to the central grey matter®severe flaccid LMN paralysis of the upper limbs
Damage to the central portion of the corticospinal and spinothalamic long tracts in the white matter®UMN spastic paralysis of the lower limbs and trunk
The sacral tracts are peripheral and are usually spared and the pt has sacral sparing
Prognosis
50-60% have progressive return of motor and sensory function to lower limbs- but poor recovery of hand function due to irreversible damage to the central grey matter
Anterior cord syndrome
complete motor and sensory loss apart from dorsal column sparing with deep pressure/ proprioception/ vibration as only remaining modality
prognosis
good if recovery progressive within 24 hrs
after 24 hrs prognosis poor
10-15% have recovery
Posterior cord syndrome
loss of deep pressure/ proprioception/ vibration only
Complete Cord Injuries
Frankel classification of Neurological Deficits in pts with Cord injuries
ref: Frankel etal "The value of postural reduction in the initial management of closed injuries of the spine with paraplegia and tetraplegia: Part 1."
Paraplegia 7: 179-192, 1969
Types
absent motor and sensory function
sensation present, motor function absent
sensation present, motor function present but not useful (gd 2-3/5)
sensation present motor function active and useful ( gd 4-5/5)
normal motor and sensory function
Assessment of Cx cord injuries
Plain XR
direct XR evidence of instability
Increased angulation bw spinous processes more than 11 deg than in adjacent segments
Ant or post translation of the vertebral bodies more than 3.5 mm
segmental disc space widening on lat XR
facet jt widening
malalignment of spinous processes of ant view
Rotation of the facets on lat XR
at tilt of vertebral body on ant XR
XR findings suggestive of unstable injuries
Increased retro pharyngeal space - ant to C3 normal not more than 3 mm
C4 + below- normal varies 8-10 mm
minimal compression fracture of ant vertebral bodies
Avulsion fracture at or near insertion of spinal ligs
nondisplaced fracture lines
Tomography
good for posterior elements, dens fracture
CT
assess bony encroachment on canal , best method for accurate bone definition
MRI
evaluate neural elements
disc disruption
ligamentous disruption
Stress XR's
flexion/ extension contraindicated in altered state of consciousness
Scapular and Clavicle Fractures
Sternoclavicular Joint
Anatomy
Diarthrodial jt, both jt surfaces covered by fibrocartilage
Artic surface of clavicle larger than that of the sternum, jt surfaces not congruent
Ligaments
intraarticular disc- fibrocartilage, divides jt into 2 cavities, rarely perforated
- runs from synchondral junction of 1st rib + sternum to sup + post aspect of med clavicle. Ant and post it blends with the capsule.
- acts to prevent med displacement of the med clavicle
Costoclavicular lig ( = rhomboid lig) - form the upper surface of the 1st rib and synchondral junction with the sternum to the rhomboid tubercle on the inf surface of the clavicle. Has 2 laminae - run in same pattern as the int and ext oblique muscles.
- ant fibres act to prevent upward motion of the clavicle
- post fibres act to prevent downward motion of the clavicle
Interclavicular lig - connects the superomed ends of each clavicle with the capsule and the upper sternum
- acts to prevent upward motion of the med clavicle
Capsule - thickened ant and post with the post being strongest
- prevents upward displacement of the med clavicle
Ossification
the clavicle is the 1st long bone of the body to ossify ( 5th intrauterine wk)
the med epiphysis is the last to appear (~ 18 ) and last to close ( ~ 25)
The capsule attaches to the epiphysis and the costoclavicular lig attaches to the metaphysis.
Thus in a SH 1 injury the costoclavicular lig is detached from the metaphysis or torn while the capsule and epiphysis remain intact.
In a SH 2 injury the costoclavicular lig remains attached to the distal fragment comprising the epiphysis and a piece of metaphysis
Classification
Anterior - most common, caused by lat compression with the shoulder rolling backward
Posterior - uncommon, caused by lat compression with the shoulder rolling forward
Injuries to the jt can be
sprain
acute dislocation
recurrent dislocation
unreduced dislocation
Symptoms and signs
severe pain increased by any movement of the arm ( post more painful than ant )
the affected shoulder appears shortened and thrust forward cf the normal side
Anterior
the med clavicle can be observed and palpated ant to the sternum
med clavicle may be fixed or mobile
Posterior
the med prominence of the normal clavicle is absent
the med clavicle is not palpable
may be venous congestion
breathing or swallowing difficulties
pneumothorax
shock due to damage to great vessels
XRay
AP view difficult to interpret
Hobbs view - pt seated, leans over table with arms up and head resting in hands, cassette on table ~ under pts neck, XR beam directed vertically down
Serendipity view : pt supine, 40 deg cephalic tilt view
Tomography
CT - gold standard
Treatment
Sprain: Rest, sling, gradual return to activity
Dislocation, anterior
most ant dislocations are unstable - notwithstanding -
CR - GA, pt supine, sandbag under centre of back
assistant pushes shoulders back
surgeon pushes clavicle back into place
in most cases this will not remain reduced - pt counselled that the risks of ORIF outweigh the cosmetic benefits of reduction
postreduction - if stable - clavicular rings to maintain position
if unstable - sling, gradual return to activity
NB cosmetic and functional deficit minimal if unreduced
Dislocation, posterior
once reduced are usually stable
may need to involve thoracic surgeon if mediastinal structures compromised
CR - GA, pt supine, sandbag under centre of back
gentle traction in line of clavicle, countertraction by assistant - this alone may reduce the dislocation
if not reduced, add manipulation with a towel clip - will reduce with clunk
rarely CR fails therefore ® OR
same position, free drape arm
involve thoracic surgeon
incision parallel to med 7-10 cm clavicle
reduction -
if stable treat as for CR
if unstable - excise the med 1- 1.5 cm clavicle and secure the remaining clavicle to the 1st rib with dacron tape
post op - clavicular rings 6 wks
Unreduced dislocation
Anterior
functional and cosmetic deficit minimal if any - no treatment indicated
Posterior
due to risk to mediastinal structures - OR indicated ( as above)
Clavicular Fractures
Classification
Type 1
middle 1/3 fractures ~ 80%
Type 2
distal 1/3 fractures ~ 15%
minimal displacement bw conoid and trapezoid ligs
ie both ligs intact
(a). fracture med to coracoclavicular ligs - displaced
(b). fracture bw conoid and trapezoid lig - displaced - ie conoid lig ruptured, trapezoid lig intact
intraartic fracture of AC jt - no lig disruption or displacement
Paediatric: ligaments intact attached to periosteum while prox frag displaces up through the disrupted periosteal sleeve
Comminuted with ligaments not attached prox or dist, but an inferior, comminuted fragment
Type 3 prox 1/3 fractures ~ 5%
minimal displacement
signif displacement ie ligs ruptured
intraarticular
epiphyseal separation - children and young adults
comminuted
Assoc injuries
Skeletal AC and SC dislocations
head and neck injuries
fracture 1st rib
Scapulothoracic dissociation
Lung and pleura PTX or haemothorax
tears of trachea or main bronchi
Brachial Plexus ulnar n most often involved in direct trauma
Vascular unusual - vessels protected by subclavius and deep cervical fascia
Mechanisms of injury
birth trauma clavicle compressed against maternal symphysis in a cephalic presentation or direct traction in a breech deli
Anatomy
Diarthrodial jt, both jt surfaces covered by fibrocartilage
Artic surface of clavicle larger than that of the sternum, jt surfaces not congruent
Ligaments
intraarticular disc- fibrocartilage, divides jt into 2 cavities, rarely perforated
- runs from synchondral junction of 1st rib + sternum to sup + post aspect of med clavicle. Ant and post it blends with the capsule.
- acts to prevent med displacement of the med clavicle
Costoclavicular lig ( = rhomboid lig) - form the upper surface of the 1st rib and synchondral junction with the sternum to the rhomboid tubercle on the inf surface of the clavicle. Has 2 laminae - run in same pattern as the int and ext oblique muscles.
- ant fibres act to prevent upward motion of the clavicle
- post fibres act to prevent downward motion of the clavicle
Interclavicular lig - connects the superomed ends of each clavicle with the capsule and the upper sternum
- acts to prevent upward motion of the med clavicle
Capsule - thickened ant and post with the post being strongest
- prevents upward displacement of the med clavicle
Ossification
the clavicle is the 1st long bone of the body to ossify ( 5th intrauterine wk)
the med epiphysis is the last to appear (~ 18 ) and last to close ( ~ 25)
The capsule attaches to the epiphysis and the costoclavicular lig attaches to the metaphysis.
Thus in a SH 1 injury the costoclavicular lig is detached from the metaphysis or torn while the capsule and epiphysis remain intact.
In a SH 2 injury the costoclavicular lig remains attached to the distal fragment comprising the epiphysis and a piece of metaphysis
Classification
Anterior - most common, caused by lat compression with the shoulder rolling backward
Posterior - uncommon, caused by lat compression with the shoulder rolling forward
Injuries to the jt can be
sprain
acute dislocation
recurrent dislocation
unreduced dislocation
Symptoms and signs
severe pain increased by any movement of the arm ( post more painful than ant )
the affected shoulder appears shortened and thrust forward cf the normal side
Anterior
the med clavicle can be observed and palpated ant to the sternum
med clavicle may be fixed or mobile
Posterior
the med prominence of the normal clavicle is absent
the med clavicle is not palpable
may be venous congestion
breathing or swallowing difficulties
pneumothorax
shock due to damage to great vessels
XRay
AP view difficult to interpret
Hobbs view - pt seated, leans over table with arms up and head resting in hands, cassette on table ~ under pts neck, XR beam directed vertically down
Serendipity view : pt supine, 40 deg cephalic tilt view
Tomography
CT - gold standard
Treatment
Sprain: Rest, sling, gradual return to activity
Dislocation, anterior
most ant dislocations are unstable - notwithstanding -
CR - GA, pt supine, sandbag under centre of back
assistant pushes shoulders back
surgeon pushes clavicle back into place
in most cases this will not remain reduced - pt counselled that the risks of ORIF outweigh the cosmetic benefits of reduction
postreduction - if stable - clavicular rings to maintain position
if unstable - sling, gradual return to activity
NB cosmetic and functional deficit minimal if unreduced
Dislocation, posterior
once reduced are usually stable
may need to involve thoracic surgeon if mediastinal structures compromised
CR - GA, pt supine, sandbag under centre of back
gentle traction in line of clavicle, countertraction by assistant - this alone may reduce the dislocation
if not reduced, add manipulation with a towel clip - will reduce with clunk
rarely CR fails therefore ® OR
same position, free drape arm
involve thoracic surgeon
incision parallel to med 7-10 cm clavicle
reduction -
if stable treat as for CR
if unstable - excise the med 1- 1.5 cm clavicle and secure the remaining clavicle to the 1st rib with dacron tape
post op - clavicular rings 6 wks
Unreduced dislocation
Anterior
functional and cosmetic deficit minimal if any - no treatment indicated
Posterior
due to risk to mediastinal structures - OR indicated ( as above)
Clavicular Fractures
Classification
Type 1
middle 1/3 fractures ~ 80%
Type 2
distal 1/3 fractures ~ 15%
minimal displacement bw conoid and trapezoid ligs
ie both ligs intact
(a). fracture med to coracoclavicular ligs - displaced
(b). fracture bw conoid and trapezoid lig - displaced - ie conoid lig ruptured, trapezoid lig intact
intraartic fracture of AC jt - no lig disruption or displacement
Paediatric: ligaments intact attached to periosteum while prox frag displaces up through the disrupted periosteal sleeve
Comminuted with ligaments not attached prox or dist, but an inferior, comminuted fragment
Type 3 prox 1/3 fractures ~ 5%
minimal displacement
signif displacement ie ligs ruptured
intraarticular
epiphyseal separation - children and young adults
comminuted
Assoc injuries
Skeletal AC and SC dislocations
head and neck injuries
fracture 1st rib
Scapulothoracic dissociation
Lung and pleura PTX or haemothorax
tears of trachea or main bronchi
Brachial Plexus ulnar n most often involved in direct trauma
Vascular unusual - vessels protected by subclavius and deep cervical fascia
Mechanisms of injury
birth trauma clavicle compressed against maternal symphysis in a cephalic presentation or direct traction in a breech deli
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