Os trigonum syndrome is the result of an overuse injury of the posterior ankle caused by repetitive plantar flexion stress. It is predominantly seen in ballet dancers and soccer players and is primarily a clinical diagnosis of exacerbated posterior ankle pain while dancing on pointe or demi-pointe or while doing push-off maneuvers. Symptoms may improve with rest or activity modification. Imaging studies, including a lateral radiographic view of the ankle in maximal plantar flexion, will typically reveal the os trigonum between the posterior tibial lip and calcaneus. If an os trigonum is absent on radiography, an MRI may reveal scar tissue behind the posterior talus, a condition associated with similar symptoms. Os trigonum syndrome is often associated with pathology of the flexor hallucis longus tendon. Treatment begins with nonsurgical measures. In addition to physical therapy, symptomatic athletes may need surgical excision of os trigonum secondary to unavoidable plantar flexion associated with their sport. This surgery can be performed using open or arthroscopic approaches.
From the Department of Surgery, The Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada (Dr. Nault) and the Department of Orthopaedic Surgery, Boston Children’s Hospital, Boston, MA (Dr. Kocher and Dr. Micheli).
Dr. Nault or an immediate family member is a member of a speakers’ bureau or has made paid presentations on behalf of Smith & Nephew. Dr. Kocher or an immediate family member has received royalties from Biomet; serves as a paid consultant to Best Doctors, Biomet, Gerson Lehrman Group, and OrthoPediatrics; serves as an unpaid consultant to Smith & Nephew Endoscopy; has stock or stock options held in Fixes 4 Kids and Pivot Medical; and serves as a board member, owner, officer, or committee member of the American Academy of Orthopaedic Surgeons, the ACL Study Group, the American Orthopaedic Society for Sports Medicine, Harvard Medical School, Harvard School of Public Health, the Pediatric Orthopaedic Society of North America, PRISM, and the Steadman Philippon Research Institute. Dr. Micheli or an immediate family member serves as an unpaid consultant to Carticel; has received research or institutional support from Genzyme; and serves as a board member, owner, officer, or committee member of the International Federation of Sports Medicine.