Entrapment of plantaris tendon between the tibial nerve and its branch: A case report

The plantaris muscle arises from the lateral supra condylar line and the long slender tendon of the muscle descends between the gastrocnemius and the soleus muscles. The tibial nerve, a branch of the sciatic nerve, is the nerve of the posterior compartment of the leg. The tibial nerve is related superficially to the plantaris tendon, but in the present case we report an anomalous plantaris tendon that passed between the tibial nerve and its branch to the soleus muscle. Such an entrapment of the plantaris tendon between the tibial nerve and its branch to the soleus is an extremely rare finding, which is neither reported in standard textbooks of anatomy nor in any other research report. The pull of the plantaris tendon may press upon the nerve to the soleus, thereby causing compression neuropathy. Also, surgical exploration of the thin plantaris tendon must be carefully performed, especially when it is trapped between the two nerves. Knowledge and awareness of such anomalies may be important for academic, clinical and surgical purposes.