Extra-articular synovial fluid extravasation following operative fixation of an osteochondral fracture of the patella.

Osteochondral fracture of the patella following a lateral patellar dislocation can be treated with operative and nonoperative techniques that are dictated by the clinical presentation. In the presence of large fragments following acute fractures, arthroscopic retrieval and fixation are advocated, whereas smaller displaced fragments may be removed and discarded as loose bodies. Several methods of fixation exist for osteochondral fractures of the patella, including the use of cannulated and noncannulated screws.This article describes a case of an elite competitive swimmer who sustained a lateral patellar dislocation with a large osteochondral fracture of the patella that was treated with open reduction and fixation using absorbable cannulated screws in an inside-out fashion. In the early postoperative period, the patient developed a symptomatic synovial fluid fistula through a cannulated screw to the prepatellar space. The diagnosis of this condition was made clinically and confirmed with noncontrast magnetic resonance imaging 6 weeks postoperatively. The symptoms of pain, skin erythema, and swelling were self-limited and eventually resolved with observation, allowing the athlete to return to his previous activity level. Magnetic resonance imaging 3 years postoperatively showed the complete resolution of the fluid extravasation. Extra-articular synovial fluid extravasation is as a rare complication following routine knee arthroscopy, accounting for 3.2% of the complications. This article describes a rare, self-limited complication following open fixation of an osteochondral fracture of the patella.