An unusual double patella: a case report.

Double patella following a 'sleeve fracture' in the lower pole of the patellar is rare and even more so after surgical treatment to the original injury. We report such a case in a boy injured at the age of 10, and presenting 3 years later with weakness and effusion. The management is described, including the technique of excision of the accessory patella and the lowering of the larger patella to a normal level. We believe that this is the first such case to be reported after surgical treatment of the primary fracture.