Tuberculosis of patella in an immunocompetent patient--a case report.

Isolated involvement of patella as extra-pulmonary tuberculosis is very uncommon. It is the clinical presentation of the patellar osteomyelitis that makes it prone to delay in diagnosis as reported in literature. Imaging studies, especially MRI, are of great interest for the diagnosis and to assess the extent of tuberculosis. A tissue or bacterial diagnosis is essential. Early institution of anti-tuberculous drugs minimizes the spread of the diseases, decreases the patient's morbidity and gives a better knee functions. One rare case of patellar tuberculosis is discussed here with its clinical and radiological features.