A retrospective study of 50 syndesmosis sprains in 44 football players was performed. Five patients (6 ankles) were lost to followup, allowing review of 44 injuries. Average followup was 47 months. The patients were evaluated for recurrent injury, overall ankle function, and for persistent ankle symptoms, including stiffness, pain, limping, and swelling. Follow-up radiographs of the injured ankle were obtained in 22 patients.

The average return time to full activity was 31 days. Pain with pushing-off was a major factor preventing return to activity.

At final followup, 36% of the patients complained of persistent mild to moderate stiffness of the ankle. Twenty-three percent had mild to moderate pain, usu ally with activity. One patient had a mild limp with activity, and 18% of the ankles had persistent mild to moderate swelling. Ankle function was rated as good to excellent in 86%. All patients with fair results had recurrent ankle sprains. There were no poor results.

Eleven of the 22 patients with follow-up radiographs developed heterotopic ossification within the interos seous membrane, but no patient developed a frank synostosis. The patients with heterotopic ossification required an average of 11 days more recovery time than those without ossification. There was no signifi cant difference between the 2 groups' ultimate ratings of ankle function or ankle symptoms, but the ankles with heterotopic ossification were associated with more recurrent lateral ankle sprains.

We conclude that syndesmosis sprains require a longer recovery period than other types of ankle sprains. Most of these injuries showed good to excel lent ankle function after recovery, unless there was a recurrent ankle sprain. In the absence of frank synos tosis, the results were not affected by the formation of heterotopic ossification.