[Effectiveness of proximal femur reconstruction combined with total hip arthroplasty for Crowe type Ⅳ developmental dysplasia of hip].

OBJECTIVE: To investigate the early effectiveness of proximal femur reconstruction combined with total hip arthroplasty (THA) in the treatment of adult Crowe type Ⅳ developmental dysplasia of the hip (DDH).
METHODS: Between May 2015 and March 2018, 29 cases (33 hips) suffering from Crowe type Ⅳ DDH were treated with proximal femur reconstruction combined with THA. Of the 29 cases, there were 6 males (7 hips) and 23 females (26 hips), aged from 24 to 74 years with an average age of 44.9 years. The preoperative Harris hip score was 44.0±12.0. Gait abnormalities were found in all of the 33 hips with positive Trendelenburg sign, and the lower limb discrepancy was (3.8±1.6) cm. Preoperative X-ray films and CT both indicated serious anatomical abnormalities, including complete dislocation of the affected hip with significant move-up of the greater trochanter, abnormal development of the femoral neck, abnormal anterversion angle and neck-shaft angle, dysplasia of proximal femur and dysplasia of medullary cavity. The operation time, intraoperative blood loss, transfusion rate, and complications were recorded. The Gruen and DeLee-Charnley zoning methods were used to evaluate the aseptic loosening of the prosthesis on X-ray films. The Harris score was used to evaluate hip function. The lower limb discrepancy was calculated and compared with the preoperative value.
RESULTS: The operation time ranged from 80 to 240 minutes, with an average of 124.8 minutes. The intraoperative blood loss ranged from 165 to 1 300 mL, with an average of 568.4 mL. Seventeen patients (51.5%) received blood transfusion treatment. All the incisions healed by first intention without infection or deep vein thrombosis. All patients were followed up 19-53 months, with an average of 33 months. One patient had posterior hip dislocation because of falling from the bed at 4 weeks after operation, and was treated with manual reduction and fixation with abduction brace for 4 weeks, and no dislocation occurred during next 12-month follow-up. Two patients developed sciatic nerve palsy of the affected limbs after operation and were treated with mecobalamin, and recovered completely at 12 weeks later. Trendelenburg sign was positive in 3 patients and mild claudication occurred in 4 patients after operation. X-ray films showed that all the osteotomy sites healed at 3-6 months after operation, and no wire fracture was observed during the follow-up. The Harris score was 89.8±2.8 and lower limb discrepancy was (0.6±0.4) cm at last follow-up, both improved significantly ( t=-22.917, P=0.000; t=11.958, P=0.000). The prosthesis of femur and acetabulum showed no obvious loosening and displacement, and achieved good bone ingrowth except 2 patients who had local osteolysis in the area of Gruen 1 and 7 around the femoral prosthesis, but no sign of loosening and sinking was observed.
CONCLUSION: The treatment of Crowe Ⅳ DDH with proximal femur reconstruction and THA was satisfactory in the early postoperative period. The reconstruction technique of proximal femur can effectively restore the anatomical structure of proximal femur, which is one of the effective methods to deal with the deformity of proximal femur.