Tophaceous gout in the bipartite patella with intra-osseous and intra-articular lesions: a case report.

We report a case of a 34-year-old man who had an acute gouty attack with tophi around the accessory bone of the bipartite patella with intra-osseous lesions. As the symptoms did not respond to conservative treatments, the patient was treated surgically. Arthroscopy revealed urate crystals surrounded by inflammatory synovitis on the surface of the bipartite patella. Arthrotomy exposed the abundant crystals around the accessory bone and in the intra-osseous lesion. These findings made us speculate that some pre-existing inflammatory conditions around the accessory bone induced deposition of urate crystals, and the destruction of the barrier between the deposits and the joint led to an acute arthritis. Curettage of the tophi resulted in immediate improvement of knee function. There had been no recurrence of symptoms at the 2-year follow-up.