Iliac horns and dysplastic fingernails.
An otherwise healthy patient was admitted to hospital with abdominal discomfort. Physical examination and laboratory studies were unremarkable, with the exception of nail dystrophy of the ulnar digits.
An abdominal plain film was performed revealing bilateral posterior iliac horns, pathognomonic of a rare syndrome called nail patella syndrome or osteo-onychodysplasia.
Additional radiographs showed hypoplastic patellae.
Nail patella syndrome is a rare, hereditary, autosomal dominant disorder, also called hereditary osteo-onychodysplasia and Fong's syndrome. It is characterised by dysplastic fingernails; hypoplastic or absent patellae; additional bony deformities, particularly about the pelvis and elbows; bony processes along the posterior surfaces of the iliac bones, also called iliac horns; and renal dysplasia.
Clinical manifestations are seen most frequently in the second and third decades of life. In infancy, this syndrome is identified by the iliac horns, absence or hypoplasia of the fibula and patella, asymmetric development of the femoral condyles or proteinuria.
Iliac horns are seen in 80% of cases. They are bilateral accessory outgrowths, consisting of cortex and medulla, continuous with the iliac bone. They are located at the site of attachment of the gluteus medius muscles and project posterolaterally. These smooth bony outgrowths are asymptomatic, frequently palpable, and, because they have no effect on gait, they need not be treated. Iliac horns are the pathognomonic feature of nail patella syndrome; that is, they occur in approximately 80% of cases and are observed only in this condition. The iliac crests are often flared with prominent anterior superior spines.
The patellae are absent or hypoplastic. The femoral condyles may be unusually prominent and there may be a valgus deformity. In the elbow, the head of the radius is poorly formed. In some cases the radius is abnormally long. Less frequently other bones show deformity in size and shape.
The disorder affecting the nails varies from unusual thinning and small size to a complete absence of one or more of the nails. The thumb is involved most frequently and severely.
Nail patella syndrome is also characterised by nephropathy. Skeletal defects and renal involvement might occur separately. The usual clinical presenting syndromes of the nephropathy are asymptomatic proteinuria, microscopic haematuria and sometimes nephrotic syndrome. In a considerable proportion of patients renal failure develops.
Other manifestations of this syndrome include ocular involvement, such as glaucoma and microcornea.
Nail patella syndrome
Based on the provided X-ray images of the pelvis, knee, and elbow joints, the following observations are noted:
Considering the patient’s clinically described nail abnormalities (nail dystrophy, small or missing nail plates) along with the radiographic findings such as iliac horns, these features suggest a classic presentation of Nail Patella Syndrome (NPS).
Based on imaging manifestations and clinical history, the following diagnoses are worth considering:
Taking into account the patient’s sex, age, clinical presentation (nail abnormalities, patellar issues), and the characteristic bilateral iliac horns seen on imaging, the most likely diagnosis is:
Nail Patella Syndrome (NPS).
If further assessment of renal or ocular involvement is needed, additional investigations (e.g., renal function tests, urinalysis, ophthalmologic evaluations) are recommended.
Currently, treatment for Nail Patella Syndrome focuses on symptomatic and supportive care. Surgical intervention may be considered in cases of marked joint instability or functional impairment. If renal involvement is present, management should be guided by nephrology specialists.
Rehabilitation/Exercise Prescription Suggestions (FITT-VP Principle):
Additionally, proper attention should be paid to joint stability and safety during rehabilitation. Supports such as knee braces can be considered to maintain proper alignment and avoid repetitive injury. If persistent pain or functional limitations occur, seek medical evaluation promptly.
Disclaimer: This report is a reference analysis based on available information and does not replace an in-person medical diagnosis or professional opinion. If you have concerns or your symptoms worsen, please seek medical attention or consult a relevant specialist.
Nail patella syndrome
