RESUMO
UNLABELLED: Symptomatic Os trigonum requires an initial conservative treatment, if clinical improvement cannot be obtained, then surgical treatment is performed with a traditional open approach. We describe an endoscopic technique: with the patient on prone position two portals are made, the first is posterolateral just at the tip of the fibula just lateral to the Achilles tendon; the second portal is posteromedial and at the same level to the first one but medial to the Achilles tendon. With the use of this technique, a wide and safe working field is obtained for the resection of the Os trigonum. We present the case of a 17 year-old classical ballet dancer with a symptomatic Os trigonum to whom an endoscopic resection of Os trigonum was done with the described technique, her clinical evolution was excellent and she could rein-corporate to her artistic activity at four weeks follow-up. CONCLUSION: The endoscopic technique described is a therapeutic option that allows the effective and safe treatment of the posterior compartment of the ankle with good functional results.