Lesser Sciatic Notch On The Surface Of The Hip Bone, Medial View

Description

Lesser sciatic notch of the ischium is centered in this medial view of the hip bone, positioned inferior to the ischial spine and superior to the ischial tuberosity. Posteriorly, the notch forms the bony margin that becomes the lesser sciatic foramen when the sacrotuberous and sacrospinous ligaments bridge the gap, while anteriorly it lies adjacent to the posterior border of the body of the ischium and the acetabular region. The concavity of the notch is emphasized as a smooth indentation on the internal surface of the pelvis. Orientation is unambiguous. Clinically, this region is a high-yield landmark for the pudendal neurovascular bundle, which exits the pelvis via the greater sciatic foramen, hooks around the ischial spine near the sacrospinous ligament, and re-enters through the lesser sciatic foramen to reach the pudendal canal (Alcock canal) on the obturator internus fascia. That relationship matters in pudendal neuralgia, in targeted pudendal nerve blocks performed using the ischial spine as a palpable reference, and in fixation planning for pelvic ring injuries where fractures can encroach on the lesser sciatic notch and compromise adjacent soft tissues. Medial lighting and a tight crop on the ischial spine to notch interval support teaching of pelvic sidewall corridors without distraction from the iliac fossa or pubis. Use this illustration in pelvic anatomy labs, orthopedic and urogynecologic surgical education, and exam figures that differentiate the greater versus lesser sciatic notches and their conversion to foramina by ligaments. It also fits well in clinical atlas pages discussing pudendal nerve entrapment, posterior hip approaches, and the tendon of obturator internus as it turns around the lesser sciatic notch toward the greater trochanter. Anatomical accuracy verified by SciePro's Medical Advisory Board.