Idiopathic chondrolysis is a condition which was initially described in Cape Town. It occurs in teenage girls and, as the name suggests, the cause is unknown. The patient presents with a stiff hip, usually held in flexion and adduction as well as x-ray changes consisting of joint space narrowing and osteopenia around the hip. The differential diagnosis includes hip sepsis, tuberculosis and juvenile idiopathic arthritis. Skin tests for tuberculosis, inflammatory markers as well as a rheumatoid screen should be performed, however, the diagnosis may remain unclear even after all these investigations have been performed. While arthroscopic- or open biopsy of the joint may be an attractive option, this often results in significant hip stiffness. It may, however, be necessary in order to avoid six weeks of unnecessary TB treatment, which may itself cause significant complications.
