Abstract: Objective： To compare efficacies and complications of total hip arthroplasty (THA) with subtrochanteric osteotomy for treating patients with Hartofilakidis types C1 and C2 developmental dysplasia of the hip (DDH).Methods: Retrospective analysis was performed in 32 patients with DDH who underwent THA. These patients were divided into two groups according to Hartofilakidis classification, 17 patients in type C1 and 15 in type C2. Their HSS and WOMAC scores, leg length discrepancy (LLD), hip joint image data and complications were evaluated. Results: HSS scores in type C1 was changed from preoperative 43.7±4.6 to postoperative 87.2±7.1 (P<0.001), together with WOMAC scores 43.6±4.3 to 87.5±6.7 (P<0.001). HSS scores in type C2 was changed from preoperative 44.4±5.4 to postoperative 86.5±8.0 (P<0.001), together with WOMAC scores 44.1±4.1 to 86.7±8.1 (P<0.001). Four cases in type C2 and one case in type C1 presented intraoperative fracture which all healed during the postoperative follow-up. The postoperative X-ray films showed that the joint prosthesis location was satisfactory, the surrounding bone was not dissolved and the bone at femur osteotomy site healed with no infection. Conclusion: For unilateral high dislocation DDH patients, THA with femur osteotomy can be effective and safe. No significant differences were found between types C1 and C2, however intraoperative fracture in type C2 should be paid attention to.

Key words: Osteotomy, Arthroplasty, replacement, hip, Hip dislocation, congenital