Symptomatic Tendon Sheath Ganglion at the Insertion of the Popliteus Tendon Treated With Local Cortisone Injection

Popliteus tendon sheath ganglia represent a rare and frequently overlooked cause of persistent lateral knee pain. This case report describes a patient with chronic symptoms unresponsive to conservative treatment, in whom advanced imaging revealed a ganglion at the lateral insertion of the popliteus tendon. Ultrasound-guided corticosteroid injection resulted in complete resolution of symptoms. The case highlights the importance of thorough differential diagnosis using advanced imaging and supports the effectiveness of targeted, minimally invasive interventions. Informed consent for publication was obtained.