Anterolateral impingement of the ankle.

Anterolateral impingement syndrome of the ankle is caused by entrapment of the hypertrophic soft tissue in the lateral gutter. The impingement process begins when an inversion sprain tears the anterior talofibular, and/or the calcaneofibular ligament. The ligamentous injury is not severe enough to cause chronic instability; however, inadequate immobilization and rehabilitation may lead to chronic inflammation in the ligament, resulting in formation of scar tissue. This tissue then becomes trapped between the talus and the lateral malleolus, causing irritation, pain, and further synovitis. The end result is chronic lateral ankle pain. Initial treatment involves physical therapy modalities and nonsteroidal anti-inflammatory medications. Those patients refractory to conservative treatment require arthroscopic debridement. A recent study has shown that arthroscopic debridement is successful in relieving pain and disability in high percentages of patients. Most patients were able to return to their previous levels of work and sports. Successful treatment of anterolateral impingement requires an accurate diagnosis with a clinical evaluation that excludes other causes of chronic ankle pain.