A RARE ANATOMICAL VARIATION IN THE ORIGIN AND DISTRIBUTION OF POSTERIOR CUTANEOUS NERVE OF THIGH

Background: The posterior cutaneous nerve of the thigh (PCNT) arises independently from the sacral plexus (S1-S3). It supplies sensory innervation to the posterior region of the thigh and the gluteal region and the upper part of the centre of the calf. Variations related to it are reported minimally in literature. Case Presentation: During routine dissection classes of Anatomy, we found an unusual origin of PCNT. It was arising from sciatic nerve as a trifurcation along with the common peroneal nerve (CPN) and the tibial nerve (TN) at the superior angle of the popliteal fossa. The thickness of PCNT is less than the CPN and the TN. Running laterally over the biceps femoris muscle, at the level of the knee joint, it is divided into multiple branches, all of them being cutaneous and supplying the upper 1/3rd of midcalf. The sural nerve and the sural communicating nerve were normal in their origin and distribution. We could not observe PCNT in the gluteal region emerging from the greater sciatic foramen, travelling below the piriformis along with inferior gluteal vessels while being medial to the sciatic nerve. The knowledge of the Conclusion: cutaneous supply and its variation is important for all clinician, like- physician, surgeon, anaesthesiologist etc. These variations are considerable because most of the times, they are falsely diagnosed. This case report helps to comprehend the skills useful for nerve grafting, imaging techniques that improve early diagnosis and recovery of the same.