Os trigonum impingement in dancers.

Sixteen patients underwent surgical excision of an impinging ossicle through a posterior lateral approach. Twelve of these patients (15 ankles) were available for followup and were retrospectively surveyed at an average of 28 months after surgery. There were 9 women and 3 men. Nine were professional ballet dancers and 3 were students of advanced ballet schools. Preoperative symptoms included pain localized to the posterior ankle, limitation of motion, weakness, swelling, or neurologic changes associated with dance activities. All patients were severely hampered in their dance participation and had failed nonsurgical therapies. Postoperatively, all patients followed an aggressive rehabilitation protocol. All had improvement in their impingement symptoms; eight (67%) still had occasional discomfort. All professional dancers returned to unrestricted dance activity. The mean time to full activity was 3 months. One patient had a superficial wound infection requiring antibiotic treatment and another suffered a transient tibial nerve neurapraxia. Both of these complications resolved without sequelae. We conclude that posterior ankle impingement in ballet dancers, caused by an os trigonum and resistant to nonsurgical therapies, is effectively treated with simple excision of the offending structure.