[Patellar pathologic fracture secondary to aneurysmal bone cyst. A case report].

Aneurysmal bone cyst is a tumor-like lesion which accounts for about 1% of all biopsied tumors and tumor-like lesions of bone. We report an extremely rare case of aneurysmal bone cyst of the patella in an 18-year-old patient revealed by a pathological fracture. The unexpected appearance of a pathological fracture affects the whole therapeutical management. However, in the case of a well-preserved articular surface, curettage and corticocancellous grafting are considered to be successful methods of treatment for aneurysmal bone cyst of the patella, as revealed in our study.