Purpose: An os trigonum is a possible source of posterior ankle pain in dancers and often is associated with flexor hallucis longus (FHL) pathology. Surgical excision of os trigonum is indicated in patients in whom nonsurgical treatment fails. Options for surgical excision include open excision (posterolateral/posteromedial approach), subtalar arthroscopy, and posterior endoscopy. Excision via an open posteromedial approach in combination with FHL tenolysis/tenosynovectomy is a safe and effective method for the surgical management of a symptomatic os trigonum, allowing for the identification and management of associated FHL pathology. This video demonstrates the surgical technique for os trigonum excision via an open posteromedial approach.

Methods: This video provides background information on os trigonum syndrome and discusses how to clinically and radiographically evaluate a patient for this clinical entity. Nonsurgical and surgical treatment options for the management of painful os trigonum are discussed. The video discusses the case presentation of a 33-year-old woman who is a professional dancer and has experienced 1 year of pain in the posterior aspect of her right ankle that is exacerbated by plantar flexion and pointe work. Painful os trigonum syndrome was diagnosed, and the patient elected to undergo os trigonum excision via an open posteromedial approach in combination with FHL tenolysis.

Results: The video presents the clinical outcomes of a retrospective case series of 40 ankles in 38 dancers who underwent the procedure. The mean preoperative pain score was 7.7 (scale, 0 to 10), and the mean postoperative pain score was 0.6. Symptoms of FHL tendinitis/tenosynovitis were present in 42.5% of the patients preoperatively. The postoperative complication rate and time to return to dance are reviewed.

Conclusions: Os trigonum syndrome can be debilitating in dancers and often is associated with FHL pathology. An open posteromedial approach for excision of a symptomatic os trigonum in combination with management of any FHL pathology is a relatively safe, reliable, and effective treatment option.