OBJECTIVETo study the results of the total hip arthroplasty (THA) in the treatment of developmental dysplasia of the hip (DDH) with severe osteoarthritis in adults.

METHODSFrom March 2004 to February 2011, 29 patients (32 hips) with DDH were treated by THA with an cementless cup. There were 11 males and 18 females,with an average age of 52.6 years (ranging from 37 to 73 years). Unilateral DDH occurred in 26 patients and bilateral DDH occurred in 3 patients. Based on the Crowe classification, there were 18 hips in 17 patients of type I ,7 hips in 6 patients of type II, 4 hips in 3 patients of type III, 3 hips in 3 patients of type IV. Except for 3 patients with bilateral DDH, the other patients' ill lower limbs were 1 to 6 cm shorter than the healthy lower ones.

RESULTSAll the patients were followed up,and the duration ranged from 8 months to 5.3 years(averaged 3.7 years) without infection, dislocation, and sciatic nerves injury after the operation. One patient with proximal femoral fracture, intraoperation used wire binding, after 4 years of follow-up, fracture healed without evidence of prosthesis loosening. All grafts and subtrochanteric osteotomy healing were achieved. In 21 patients, the pain was completely relieved and the function of the hip joints was good. Five patients still had mild limping, but reduced significantly than preoperation. In 3 patients, the ill lower limbs were more than 1 cm shorter than the healthy lower ones and the other patients' ill lower limbs were less than 1 cm shorter than the healthy lower ones. Two patients' lower limbs were lengthened 4 to 5 cm. The Harris scores were 43.6 +/- 7.1 preoperatively and 86.7 +/- 5.3 postoperatively (P < 0.05).

CONCLUSIONTHA with deepening the medial wall of the acetabulum at the true acetabulum, according to different characteristics of Crowe classification, using different operation program, cementless cup in adult could obtain favorable results.