Instability of the proximal tibiofibular joint.

Injury to the proximal tibiofibular joint is typically seen in athletes whose sports require violent twisting motions of the flexed knee. Instability of this joint may be in the anterolateral, posteromedial, or superior directions. With acute injury, patients usually complain of pain and a prominence in the lateral aspect of the knee. A closed reduction should be attempted in patients with acute dislocation. If this is unsuccessful, open reduction and stabilization of the joint with repair of the injured capsule and ligaments can be done. Patients with chronic dislocation or subluxation report lateral knee pain and instability with popping and catching, which may be confused with lateral meniscal injury. Symptoms of subluxation may be treated nonsurgically with physical therapies such as activity modification, supportive straps, and knee strengthening. For patients with chronic pain or instability, surgical options include arthrodesis, fibular head resection, and proximal tibiofibular joint capsule reconstruction.