Introduction: Anatomical structures involving muscles and nerves in the gluteal region are important as any variations of Sciatic nerve (SN) and its surrounding muscles like piriformis muscle (PM) can lead to entrapment or compression of this nerve causing sciatica and piriformis syndrome.
Aim: To find out variations in the gluteal region related to piriformis muscle and the nerves surrounding it.
Materials and Methods: The study was done on 20 embalmed cadavers (total 40 gluteal regions) during routine cadaveric dissection. The anatomical relations of the piriformis and surrounding nerves i.e. sciatic nerve, its divisions and gluteal nerves were studied.
Results: The dissection was done on 40 gluteal regions. In 36 gluteal regions (90%) the sciatic nerve emerged below the piriformis as a single trunk. While in 4 gluteal regions (10%) there was a higher division of sciatic nerve. In one cadaver we observed an accessory piriformis muscle just inferior to the main piriformis muscle. The sciatic nerve was also dividing higher up into common peroneal nerve and tibial nerve in the gluteal region. The common peroneal nerve (CPN) was observed emerging between the main and the accessory piriformis muscle. Along with it the inferior gluteal nerves were also seen traversing between the main and the accessory piriformis muscle.
Conclusion: Knowledge of anatomical variations in the gluteal region is important to explain the myalgia and neuropathies in this region. This knowledge is also important in performing hip surgeries and giving intramuscular injections in the gluteal region.
Piriformis muscle, Inferior gluteal nerve, Common peroneal nerve.