Pathologic patellar fracture at the site of an old Sinding-Larsen-Johansson lesion: a case report of a 33-year-old male.

A Sinding-Larsen-Johansson lesion is considered to be a self-limited process. Delayed sequelae of this disease have not previously been discussed. We present a case of a pathologic patellar fracture through a site of an old Sinding-Larsen-Johansson lesion.