Portal placement for endoscopic surgery in the deep gluteal area: a cadaveric study

Partial or complete avulsion of the insertion of the proximal hamstrings at the level of the ischial tuberosity is most often treated by open exploration and reinsertion. However, endoscopic reinsertion could be considered to minimize the soft tissue damage. In this study, we aimed to determine the most optimal location of four endoscopic portals that allow for a safe exploration of the proximal hamstring insertion site. The reference points for the portals run vertically through the center of the sciatic tuberosity and through a horizontal line which lies on the inferior edge of the tuberosity. The distance and relationship between the sciatic, the inferior gluteal and posterior femoral cutaneous nerves and the four proposed endoscopic portals was documented. Our results showed that it was best to start with the inferior portal followed by the medial and lateral portal. The inferior portal allowed for a clear visualization of the sciatic nerve and was along with the medial portal at a distance of >5 cm from any of the surrounding nerves. Care must be taken with the lateral portal, as the distance to the surrounding nerves varied between specimens. A fourth portal could be used as a viewing portal when necessary. Our study showed that the sequence and position of the proposed endoscopic portals provide a safe approach to the proximal part of the hamstrings and the ischial tuberosity. These findings can be helpful for endoscopic procedures to the ischium and the sciatic nerve in the gluteal region.