Sinus Tarsi Syndrome

Anatomy & Synopsis

The sinus tarsi is a small 'canal' in the bone on the outside of the ankle joint. It contains small ligament whose function is to hold part of the outside aspect of the ankle joint together. Injury to the ligaments in this space may occur during inward rolling of the ankle joint or from overuse, usually in those with 'flat feet'. Pain will be present to the front of the outside of the ankle and may be hard to locate.

Pain may worsen when changing direction during running, running in a circle on the affected side, or running on an uneven surface. It may also be painful and stiff to turn the ankle inwards (inversion) and outwards (eversion).


This condition was first described by Denis O’Connor in 1957. He also described a surgical procedure to address this problem (called the O’Connor procedure) that involves removal of all or a portion of the contents of the sinus tarsi. sometimes after a diagnosis is established conservative treatment can be initiated which is generally very effective in eliminating the problem. Treatment may include anti-inflammatories, stable shoes, period of immobilization, ankle sleeve and over-the-counter orthotics. Resistant cases may require a course of oral steroids, series of steroid injectionss, physical therapy or custom orthotics. Rarely is surgery indicated and if needed open surgery (through an incision) or closed surgery (via arthroscopy) can be considered. Excellent results should be expected but surgery is not uncommon and should be considered as a last resort.