Snapping Pes Syndrome Caused by the Gracilis Tendon: Successful Selective Surgery with Specific Diagnosis by Ultrasonography

We report the case of painful snapping pes syndrome caused by the gracilis tendon. A 26-year-old man presented with acute right knee pain and restricted extension. Although snapping could not be reproduced due to severe pain, the snapping of the gracilis tendon could be specifically diagnosed using ultrasonography and lidocaine injection. Because of the failure of conservative treatment, surgery was performed. The distal attachment of the gracilis tendon was released, and the symptom disappeared quickly. There was no recurrence at the 10-month follow-up.

Snapping Pes Anserinus and the Diagnostic Utility of Dynamic Ultrasound

Snapping pes anserinus syndrome is an often encountered cause of medial knee snapping. It results from impingement and translation of the gracilis tendon or semitendinosus tendon over the osseous structures of the knee during active flexion and extension. Ultrasonography is often the diagnostic imaging test of choice in cases of mechanical snapping. We report 2 cases of painful snapping pes anserinus and highlight the value of dynamic ultrasound in making an accurate diagnosis so as to direct care.