OBJECTIVETo analyze the metaphase outcome of total hip arthroplasty with Zweymuller system and deepening acetabulum technique in treating DDH.

METHODSFrom Jan.1998 to Dec. 2004,56 patients (62 hips) with DDH (secondary osteoarthritis) were treated with total hip arthroplasty with Zweymuller system. There were 14 males (15 hips) and 42 females (47 hips) with an average age of 48.6 years,ranged from 30 to 67 years. All patients had pain of hip joint and functional disturbance before operation. Observation items included postoperative complications,imaging and function of hip joint. The function of hip joint was analyzed according to Harris scoring.

RESULTSAll patients were followed up from 5 to 11 years with an average of 6.5 years. X-rays showed that the acetabular cup was in the position of true acetabulum, which combined tightly with the peripheral bone, the abduction angle of the acetabular cup was from 35 degrees to 45 degrees, introversion and extroversion of the femoral prosthesis was within 3 degrees, operated legs were shorter with a mean of (0.5 +/- 0.2) cm. The complications were as following:deep vein thrombosis in 20 cases,which were improved after thrombolysis;hip dislocation in 1 case,which was treated with reduction and immobilization for 3 weeks; ectopic ossification in 4 patients,all were Brook II type; no found infection or nerve injury. The Harris scoring was 87.4 +/- 3.5 postoperative,which was significant higher than that preoperative (43.2 +/- 6.7).

CONCLUSIONThe metaphase outcome of total hip arthroplasty with Zweymuller system and deepening acetabulum technique in treating DDH can obtain good result.