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Age / Sex : /
Age / Sex : 22 / M
Chief complaint : both knee pain
1) What is your impression?
Two weeks later, you can see the final diagnosis with a brief discussion of this case.
* Send Application Answers to Ja-Young Choi, MD ([email protected])
Courtesy : Jong Kyu Han, MD., Soonchunhyang University College of Medicine
Diagnosis: nail-patellar syndrome
Discussion
Findings:
1. Plain radiography bilateral iliac horns *additional images: hypoplasia of the patella asymmetric development of the femoral condyles hypoplastic finger nail
2. MR hypoplasia of the patella asymmetric development of the femoral condyles hypoplasia of lateral femoral condyle
Differential Diagnosis:
Small patella syndrome, Trisomy 8, Coffin-Siris syndrome, Kuskokwin syndrome
Diagnosis: Nail-Patella syndrome(Osteo-onychodysostosis, HOOD syndrome, Fong’s syndrome)
Discussion:
Nail-patella syndrome (NPS) involves a classic clinical tetrad of changes in the nails, knees, and elbows, and the presence of iliac horns. Nail changes are the most constant feature of NPS. Nails may be absent, hypoplastic, or dystrophic; ridged longitudinally or horizontally; pitted; discolored; separated into two halves by a longitudinal cleft or ridge of skin; and thin or, less often, thickened. The patellae may be small, irregularly shaped or absent. Elbow abnormalities may include limitation of extension, pronation, and supination; cubitus valgus; and antecubital pterygia. Iliac horns are bilateral, conical, bony processes that project posteriorly and laterally from the central part of the iliac bones of the pelvis. Renal involvement, first manifest as proteinuria with or without hematuria, occurs in 30-50% of affected individuals; renal failure occurs in about 5% of affected individuals. Primary open-angle glaucoma and ocular hypertension also occur at increased frequency and at a younger age than in the general population. Clinical manifestations can become evident in a child, adolescent, or adult but are most frequently seen in the second and third decades of life. Hypoplasia or splitting of fingernails, palpable absence of the patellae, the presence of iliac protuberances, increased carrying angle of the elbow, abnormal pigmentation of the iris, and proteinuria may be recognized on initial clinical examination. Laboratory analysis can confirm the presence of more severe renal dysfunction. The radiologic changes are highly characteristic and may allow accurate diagnosis even in the absence of clinical suspicion of the disease. In infancy, the demonstration of posterior iliac horns allows identification of the dysplasia. Skeletal changes are also apparent in other regions of the body. In the knee, absence or hypoplasia of the fibula and patella, asymmetric development of the femoral condyles, and a sloping tibial plateau with a prominent tibial tubercle are indentified. These changes can lead to deformity, abnormal gait, patellar instability, and genu valgum. In the elbow, asymmetric development of the humeral condyles, hypoplasia of the capitellum, and subluxation or dislocation of the radial head are the major changes. Management of NPS includes annual monitoring for hypertension and renal disease: ACE inhibitors may slow progression of proteinuria; if necessary, renal transplantation is usually favorable. Screening for glaucoma and subsequent treatment are done as soon as a child is compliant with the examination. Orthopedic problems may be helped by analgesics, physiotherapy, splinting, bracing, or surgery. Chronic use of NSAIDs should be avoided because of their detrimental effect on kidney function.
References:
1. Tuncbilek N, Karakas HM, Okten OO. Imaging of nail-patella syndrome. Hong Kong Med J 2005;11:116-8
2. Resnick. Diagnosis of bone and joint disorders, 3rd ed. Elservier Saunders
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