Surgical removal of a partial ossified sacrotuberous ligament for refractory pudendal nerve entrapment syndrome

The sacrotuberous ligament (STL) extends from the sacrum, posterior iliac spine, and coccyx to the medial surface of ischial tuberosity, stabilizing the pelvis and locking the sacroiliac joint [1, 2]. Recent studies have reported the association between the STL and pudendal nerve entrapment (PNE) syndrome, described as a severe pain along the course of the pudendal nerve, the principal nerve supplying the perineum [3, 4]. Little attention has been paid to the role of the ossified STL in compression of the pudendal nerve. In a cadaveric study, Arora et al. [5] reported the topography and morphometry of a unilateral partial ossification of STL, which was identified as a potential factor for PNE syndrome. We report the case of a 77-year-old man who presented with a right refractory PNE syndrome. Computed tomography (CT) of the pelvis identified partial ossification of the right STL, which was surgically excised and attained pudendal nerve decompression. To our knowledge, this occurrence has not previously been described. Case report