Anomalous muscle from the fascia around popliteal vessels.

Normally, the popliteal fossa contains popliteal vessels, tibial and common peroneal nerves. An occurrence of muscle in the popliteal fossa is very rare. During routine dissection classes for medical undergraduates, an anomalous muscle in the popliteal fossa was encountered. The muscle was originating from the thick fascia around the popliteal vessels. It was getting inserted to the medial head of the gastrocnemius through a narrow tendon and was supplied by a branch of tibial nerve. The muscle was observed in the right limb and was unilateral. An awareness of the possibility that such anomalous muscles can occur in the popliteal fossa is clinically essential as these may possibly entrap and compress the popliteal vessels. The muscle reported in the present case bears clinical significance since near its origin it almost completely surrounded the popliteal vessels and could pull on these vessels on contraction (Fig. 3, Ref. 14).