ObjectiveTo investigate the effectiveness of Bernese osteotomy for the treatment of developmental dysplasia of the hip (DDH) in adults. MethodsBetween August 2012 and April 2014, 16 patients with DDH were treated with Bernese osteotomy by S-P approach, and the clinical data were retrospectively analyzed. There were 4 males and 12 females with an average age of 27.8 years (range, 18-35 years). The left side was involved in 6 cases and the right side in 10 cases. The visual analogue scale (VAS) score was 4.8±0.5, and the Harris hip score was 81.2±5.4. The lateral center edge (CE) angle (the angle between the vertical center of the femoral head and the lateral edge of the acetabulum) was (6.5±8.7)°;the horizontal tilt angle was (25.6±5.9)°;and the femoral head extrusion index was 36.5%±6.5%. According to the Tonnis osteoarthritis classification, 12 hips were rated as Grade 0, 3 hips as Grade I, and 1 hip as Grade II. ResultsThe operation time was 90-135 minutes;the intraoperative blood loss was 400-800 mL;10 cases accepted blood transfusion and the amount of blood transfusion was 200-600 mL;the postoperative drainage volume was 100-300 mL;and the hospitalization time was 7-12 days. All the cases achieved primary healing of incision with no early complications. Two cases had numb in the lateral femoral cutaneous nerve innervating area. All patients were followed up 12-26 months (mean, 20 months). The X-ray examination showed osseous healing at osteotomy site, and the healing time was 12-16 weeks (mean, 13.5 weeks). No acetabulum fracture, heterotopic ossification, osteonecrosis, and internal fixation loosening occurred during follow-up. No progression of osteoarthritis or acetabular cystic change was observed. At last follow-up, the lateral CE angle was (27.7±6.8)°;the horizontal tilt angle was (16.2±4.8)°;the femoral head extrusion index was 19.7%±5.3%;VAS score was 0.8±0.3;the Harris hip score was 96.8±6.7;and all showed significant differences when compared with preoperative ones (P<0.05). ConclusionFor DDH adults, Bernese osteotomy can effectively increase the acetabulum tolerance, improve the joint function, and slow progress in osteoarthritis, and the short-term effectiveness is satisfactory.