['Various types of periacetabular osteotomies have been proposed to treat acetabular dysplasia for young and active patients. Acetabular dysplasia is prevalent in women and rare in men, therefore few reports exist concerning periacetabular osteotomy of male patients. The purpose of this study is to clarify the gender differences in surgical techniques, radiographic and clinical outcomes.', 'Between 1989 and 2007, we performed 530 eccentric rotational acetabular osteotomies and followed them annually for more than five years. Thirty-six male patients were investigated. As a control group, 72 female patients were matched for age and preoperative stage of osteoarthritis at the time of surgery. We evaluated operative time and blood loss, radiographic parameters, Harris Hip Score (HHS) and survival rate. We investigated the clinical and radiographic differences between men and women.', 'The mean operative time was 148 min in males and 135 min in females. The bleeding during surgery was 445 g in males and 351 g in females. HHS improved 94.1 points in males and 93.5 points in women postoperatively. The mean CE angle improved 31.7° in males and 35.1° in females. The mean AHI was 90.8% in males and 94.1% in females postoperatively. The survival rate of male patients were 92.8% and that of female patients were 98.1%.'] Does gender difference affect the outcomes of eccentric rotational acetabular osteotomy used in hip dysplasia?