The blood vessels supplying the anterior part of the iliac crest of 126 (84 males, 42 females) Chinese adult cadavers were observed. The findings are as following:1. The superficial circumflex iliac artery has an average external diameter of 1.45?0.41 mm and supplies mainly the skin and the superficial structures of the groin region and the region adjacent to the anterior superior iliac spine.2. The ascending branch of the lateral circumflex femoral artery has an average external diameter of 2.62?0.51 mm and supplies the tensor fasciae latae and the outer border of the anterior superior iliac spine.3. The deep upper branch of the superior gluteal artery has an average external diameter of 2.87?0.56 mm and supplies the glutei medius et minimus and the outer border of the anterior part of the iliac crest.4. The deep circumflex iliac artery has an average external diameter of 2.77?0.47 mm and may originate from above (18.0％), behind (41.5％), or below (40.5％) the inguinal ligament. It supplies the abdominal muscles adjacent to iliac crest and the inner border of the anterior part of the iliac crest.In this study particular attention was paid to investigating the course, branches, anastomosis of the deep circumflex iliac artery and its relationship to the anterior part of the iliac crest.5. The findings suggest that the deep circumflex iliac vessel may be used as a nutritive pedicle in free microvascular transplantation of the iliac bone.

Morphology and relationships of piriformis and its tendon,and their relations withsciatic nerve in 100 cases have been observed in order to analyse the cause of sciatica.Piriformis was divided into four types and piriformis tendon into five types.In79% of piriformis there were additional origins.In 5% of cases synovial bursa waspresent below the end of piriformis tendon.The relation between piriformis andsciatic nerve was anomalous in 38%.Sciatic nerves and their branches in 16%passed between the two tendons of piriformis,and along the anterior or posteriorsurface of a tendon.It is concluded that various anomalous relationship between piriformis tendonand sciatic nerve is an important factor giving rise to sciatic pain.