Semimembranosus Tendinopathy

CONTEXT Semimembranosus tendinopathy (SMT) is an uncommon cause of chronic knee pain that is rarely described in the medical literature and may be underdiagnosed or inadequately treated owing to a lack of understanding of the condition. EVIDENCE ACQUISITION A search of the entire PubMed (MEDLINE) database using the terms knee pain semimembranosus and knee tendinitis semimembranosus, returned only 5 references about SMT-4 case series and 1 case report-and several relevant anatomical or imaging references. RESULTS The incidence of SMT is unknown in the athletic population and is probably more common in older patients. The usual presentation for SMT is aching posteromedial knee pain. Physical examination can usually localize the area of tenderness to the distal semimembranosus tendon or its insertion on the medial proximal tibia. In unclear cases, bone scan, magnetic resonance imaging, or ultrasound may distinguish SMT from other causes of posteromedial knee pain. Treatment should begin with relative rest, ice, nonsteroidal anti-inflammatory drugs, and rehabilitative exercise. In the minority of cases that persist greater than 3 months, a corticosteroid injection at the tendon insertion site may be effective. Surgery to reroute and reattach the tendon is rarely needed but may be effective. CONCLUSION SMT is an uncommon cause of knee pain, but timely diagnosis can lead to effective treatments.