The efficacy of gradual reduction using two-stage traction for developmental dysplasia of the hip in southern China

Purpose This study aimed to report the preliminary outcome of gradual reduction (GR) utilizing two-stage traction (TST) compared with traditional traction (TT) in the treatment of developmental dysplasia of the hip (DDH) and to evaluate whether the prognosis of the TST is better than that of TT. Methods The following information on children diagnosed with DDH who underwent treatment with GR using two-stage traction or traditional traction between June 2016 and August 2017 was collected: sex, age, weight, acetabular index (AI), International Hip Dysplasia Institute (IHDI) classification, femoral head ossification, traction time, reduction quality, and labrum shape in arthrography. The AI, IHDI classification, second operation rate, and incidence of femoral head avascular necrosis (AVN) were analyzed after the final comprehensive 1-year follow-up. Results In this study, 27 cases (31 hips: 18 left and 13 right) were enrolled, with 18 hips (16 cases) assigned to the TT group and 13 hips (11 cases) assigned to the TST group, with the corresponding average age at diagnosis of 5.56 +/- 1.66 and 4.06 +/- 1 months (p < 0.001). For both TT and TST groups, the average age at operation was 6.01 +/- 1.67 and 65 +/- 0.86 months (p = 0.435), the distribution of affected left and right sides was 10/8 and 8/5 hips (p = 1), and the average initial AI was 37.11 +/- 3.26 and 36.77 +/- 4.34 (p = 0.804), respectively. IHDI classification III/IV was observed in 15/3 and 11/2 hips, respectively (p = 1). Femoral head ossification was present in 6/18 hips in the TT group and 2/13 hips in the TT group (p = 0.412). The total traction time was 13.22 +/- 2.6 days for the TT group and 49.23 +/- 25.77 days for the TST group (p < 0.001). After GR, IHDI classification III/IV was observed in 9/9 and 12/1 hips, respectively (p = 0.02). AVN was present in 5/18 hips in the TT group and 0/13 hips in the TST group (p = 0.048), while the need for a second operation was approved in 5/18 hips in the TT group and 1/13 hips in the TST group (p = 0.359) at the final follow-up. Conclusions Two-stage traction can significantly decrease the ratios of IHDI classifications III and IV and the incidence of AVN compared to traditional traction; also, it significantly reduces the total traction time.