A rare variation in the high division of the sciatic nerve surrounding the superior gemellus muscle.

The sciatic nerve normally leaves the pelvis by passing through the greater sciatic foramen below piriformis. However, it may divide into its common fibular and tibial nerve components within the pelvis and its relationship with piriformis is variable. In this paper, we describe a new anatomical variation in which the common fibular nerve passed superior, and the tibial nerve inferior, to the superior gemellus muscle. Anatomical variations such as these may contribute to piriformis syndrome, coccygodynia and muscle atrophy.