Case report of a ruptured endobutton used in medial patellofemoral ligament reconstruction causing patellofemoral impingement.

The medial patellofemoral ligament (MPFL) is a key soft tissue stabilizer of the medial patella, with deficiency proven to be a key contributor to patellar dislocation. Reconstruction of this ligament has become a widely employed procedure in managing patients with recurrent patellar dislocation, and is also gaining popularity in the setting of primary dislocation. A wide variety of techniques have been described, differing in the type of graft used, sites for fixation and fixation technique. A number of complications have also been reported in the literature, including post-operative stiffness, apprehension, patellar fracture and recurrence of instability and dislocation. Here we report a case of an endobutton used in MPFL reconstruction becoming displaced after minimal trauma in a young female patient, subsequently causing patellofemoral irritation, patellar cartilaginous damage and functional limitation. This complication has not been previously reported to our knowledge and is one that surgeons must be aware of.