Objectives We aimed to show the utility of high hip center technique used in patients with Crowe II–III developmental dysplasia of the hip at the midterm follow‐up and evaluated the clinical and radiographic results between different heights of hip center. Methods From December 2003 to November 2013, we retrospectively evaluated 69 patients (85 hips) with Crowe II–III dysplasia who underwent a high hip center cementless total hip arthroplasty. The patients were divided into two groups according to the height of hip center, respectively group A (≥ 22 mm and < 28 mm) and group B (≥28 mm). The survivorship outcomes and radiographic and clinical results, including the vertical and horizontal distances of hip center, femoral offset, abductor lever arm, cup inclination, leg length discrepancy, Trendelenburg sign, and limp were evaluated. Results The mean follow‐up time was 8.9 ± 1.8 years. The mean location of the hip center from the inter‐teardrop was 25.1 ± 1.6 mm vertically and 30.0 ± 3.8 mm horizontally in group A, and 33.1 ± 4.8 mm vertically and 31.4 ± 6.1 mm horizontally in group B. Eleven hips of group B showed a lateralization over 10 mm, and the same was shown in one hip in group A (P = 0.012). There were no statistically significant differences between two groups in postoperative femoral offset, abductor lever arm, leg length discrepancy and cup inclination. At the final follow up, the mean WOMAC and Harris hip score were significantly improved in both groups. Of the 85 hips, four hips in group A and three hips in group B showed a positive Trendelenburg sign. Additionally, four patients in group A and two patients in group B presented with a limp. No significant differences were shown regarding the Harris hip score, WOMAC score, Trendelenburg sign, and limp between two groups. One hip of group A was revised by reason of dislocation at 8.3 years after surgery. One hip of group B was diagnosed with osteolysis and underwent a revision at 8.1 years after surgery. The Kaplan–Meier implants survivorship rates at the final follow‐up for all‐causes revisions in group A and group B were similar (96.7% [95% confidence interval, 90.5%–100%] and 96.2% [95% confidence interval, 89.0%–100%], respectively). Conclusions The high hip center technique is a valuable alternative to achieve excellent midterm results for Crowe II–III developmental dysplasia of the hip. Further, between the groups with differing degrees of HHC, there were no significant differences in outcomes or survivorship in our study.

The aim of the present paper was to evaluate the results of one-stage total hip arthroplasty (THA) for patients with bilateral Crowe type IV developmental dysplasia of the hip (DDH). Methods: Data for 58 patients (116 hips) with bilateral Crowe type IV DDH who had one-stage THA performed by the same surgeon during the period of April 2008 to February 2019 were retrospectively reviewed. The mean age of the patients was 37.3 years; 5 were men and 53 were women. All patients underwent THA through the posterolateral approach using the Pinnacle acetabular cup, a ceramic-on-ceramic bearing, and the modular S-ROM stem. Subtrochanteric shortening osteotomy was performed on 86/116 hips. Intraoperative conditions were recorded. Radiographic and functional outcomes were evaluated, and complications were recorded. Results: All patients were followed up for an average of 71.3 ± 37.6 months (range, 12-140). The mean operative time was 276.5 ± 57.9 min (range, 175-540). The mean intraoperative blood loss was 933.6 ± 400.8 mL (range, 300-2000). The mean transfusion requirement was 1778 ± 798.0 mL (range, 575-4550). The mean length of hospital stay was 8.6 ± 3.7 days (range, 5-22). At the final follow-up, no loosening of acetabular and femoral components was observed. No osteolysis and heterotopic ossification occurred. The mean Harris hip scores were improved from 55.4 ± 14.3 preoperatively to 91.3 ± 4.2 postoperatively (P < 0.001) In terms of complications, no perioperative deaths were recorded. Deep vein thrombosis occurred in 1 hip, with no pulmonary embolism. Intraoperative femur fracture occurred in 3 hips, nerve injury in 1 hip, and leg length discrepancy in 1 patient. Postoperative dislocation occurred in 5 hips and nonunion in 1 hip. Conclusion: Our data demonstrated that one-stage bilateral THA for bilateral Crowe type IV DDH is feasible and can effectively restore hip function.

The purpose of this study was to determine whether dislocation height can predict the use of subtrochanteric osteotomy in patients with Crowe type IV hip dysplasia. Patients and Methods: We retrospectively included 102 patients affected by unilateral Crowe type IV developmental dysplasia who underwent primary total hip arthroplasty with modular cementless stem from April 2008 to May 2019 in our institution. Based on radiographs and operative notes, we found 62 hip arthroplasties were performed with subtrochanteric osteotomy and 40 without subtrochanteric osteotomy, which were named as the (subtrochanteric osteotomy) STO group and non-STO group, respectively. The predictive values of height of greater trochanter, height of femoral head/neck junction, and distalization of greater trochanter were analyzed using receiver operating characteristic (ROC) curves. Results: The ROC curves showed that distalization of greater ntrochanter had the highest areas under the ROC curve (AUC), at 0.998. This was followed by height of greater trochanter and height of head/neck junction, which had AUCs of 0.937 and 0.935, respectively. The optimal thresholds of these three indicators were 4.84 cm, 6.05 cm, and 4.26 cm. At the last follow-up, six dislocations occurred (five in the STO group and one in the non-STO group). Four hips were treated by closed reduction and two by open reduction. Three patients (all in STO group) developed femoral nerve palsy with skin numbness on the frontal thigh or tibia and all recovered in a year. At outpatient visit, the limb length was measured. LLD was <1 cm in 83/102, 1-2 cm in 18/102, and >2 cm in 1/102. Conclusion: This study reveals that indicators of dislocation height are useful in predicting the use of subtrochanteric osteotomy during total hip arthroplasty for Crowe type IV hip dysplasia. However, a comprehensive, multivariate analysis may be required to validate these results.