Unilateral partial ossification of sacrotuberous ligament: anatomico-radiological evaluation and clinical implications.

The present study describes the topography and morphometry of a unilateral ossified sacrotuberous ligament. It aims to discuss its anatomical, radiological and clinical implications. The pudendal nerve, internal pudendal artery, nerve to obturator internus and coccygeal branch of inferior gluteal artery are all-important structures near sacrotuberous ligament. An ossified sacrotuberous ligament may be an important etiological factor in neurovascular compression syndromes and its anatomical knowledge may help in the development of new treatment for this common clinical problem. The ossified sacrotuberous ligament in the present case was 7.6 cm in length and exhibited a characteristic anterior and posterior segment. The base was at the ischial tuberosity and the apex showed numerous small bony protuberances with deep intervening grooves. The ossified STL may be important in differential diagnosis of soft tissue pain and tenderness after trauma. It may be a challenging puzzle for the present day surgeon and radiologist in interpretation of CT-scans and MRI.