Posterolateral instability of the knee following osteochondral fracture including the femoral insertion of the popliteus tendon. A case report

139 ABSTRACT Isolated injury of the tendon of the popliteus muscle is infrequent. It often forms part of multiple ligament injuries of the posterolateral complex of the knee. The diagnosis of this type of injury may pose a challenge, since the physical manifestations are sometimes subtle and rather nonspecific. Magnetic resonance imaging (MRI) is the diagnostic technique of choice. We present the case of a 30-year-old woman who suffered an accidental fall with osteochondral fracture of the external femoral condyle measuring 21 mm in diameter and affecting the insertion of the tendon of the popliteus muscle, together with a concomitant complex injury of the lateral meniscus. The patient underwent surgery due to persistent instability of the knee. Type of study: case report. Level of evidence: IV.