Objective: To investigate revision reasons and prosthesis selection of Crowe Ⅳ developmental dysplasia of the hip (DDH) after total hip arthroplasty (THA).
Methods: A clinical data of 14 patients (15 hips) with Crowe Ⅳ DDH, who underwent a revision hip arthroplasty between January 2008 and May 2018, was retrospectively reviewed. There were 1 male (1 hip) and 13 females (14 hips). The age ranged from 27 to 63 years (mean, 45.0 years). There were 7 cases of left hip, 6 cases of right hip, and 1 case of bilateral hips. The prosthetic interfaces of primary THA were metal-on-polyethylene (MOP) in 9 hips, ceramic-on-ceramic (COC) in 4 hips, ceramic-on-polyethylene (COP) in 1 hip, and ceramic-on-metal in 1 hip. The time from primary THA to revision was 3-204 months (mean, 65.0 months). The causes of revision included aseptic loosening in 7 hips, dislocation in 3 hips, periprosthetic joint infection in 2 hips, osteolysis in 1 hip, nonunion of osteotomy in 1 hip, and a small-angle of femoral anteversion in 1 hip. Preoperative Harris score was 54.1±17.8 and the range of motion (ROM) of flexion was (92.7±20.2)°. Preoperative X-ray films showed the acetabular bone defect in 11 hips and osteolysis of femoral side in 4 hips. During the revision, the prostheses with COP and COC interfaces were used in 5 hips and 10 hips, respectively. Both acetabular and femoral revisions were performed in 11 hips and only femoral revision was performed in 4 hips.
Results: The mean operation time was 3.7 hours (range, 1.5-6.0 hours). The mean intraoperative blood loss was 940.0 mL (range, 200-2 000 mL). All patients were followed up 16-142 months (mean, 73.9 months). Postoperative X-ray films showed no difference in inclination and anteversion between primary THA and revision ( P>0.05). The height of rotation center and offset after revision were higher than those after primary THA, and the difference in offset was significant ( P<0.05). At last follow-up, the Harris score and ROM of flexion were 85.0±7.3 and (115.0±17.0)°, respectively, which were significantly higher when compared with those before revision ( t=8.909, P=0.000; t=4.911, P=0.000). Three hips underwent a re-revision operation. All protheses were fixed well and no radiolucent line, loosening, or subsidence was observed at last follow-up.
Conclusion: The most common reason for revision in patients with Crowe Ⅳ DDH after THA was aseptic loosening. Due to high activity demand of this population, the prosthesis with MOP interface should be prevented and the prosthesis with COC interface could be alternative. Metal block, cup-cage, and reinforcement ring were reasonable solutions for reconstruction of acetabulum with severe bone defects and have satisfactory effectiveness. S-ROM prosthesis should be the preferred stem for neither primary THA or revision.
目的: 探讨 Crowe Ⅳ 型髋关节发育不良（developmental dysplasia of the hip，DDH）患者人工全髋关节置换术（total hip arthroplasty，THA）翻修原因及翻修假体的选择。.
方法: 回顾分析 2008 年 1 月—2018 年 5 月行翻修术的 14 例（15 髋）Crowe Ⅳ 型 DDH 患者临床资料。男 1 例（1 髋），女 13 例（14 髋）；翻修术时年龄 27～63 岁，平均 45.0 岁。左髋 7 例，右髋 6 例；双髋 1 例。初次置换假体摩擦界面类型：金属-聚乙烯界面（metal-on-polyethylene，MOP）9 髋，陶瓷-陶瓷界面（ceramic-on-ceramic，COC）4 髋，陶瓷-聚乙烯界面（ceramic-on-polyethylene，COP）和陶瓷-金属界面各 1 髋。初次置换至翻修术时间为 3～204 个月，平均 65.0 个月。翻修原因：假体无菌性松动 7 髋，反复脱位 3 髋，感染 2 髋，骨溶解、截骨处不愈合、股骨柄前倾角偏小各 1 髋。术前髋关节 Harris 评分为（54.1±17.8）分，髋关节屈曲达（92.7±20.2）°。术前 X 线片检查显示髋臼侧骨缺损 11 髋，股骨侧骨溶解 4 髋。翻修术中假体摩擦界面 5 髋选择 COP，其余患者均采用 COC。11 髋行髋臼及股骨侧翻修，4 髋仅行股骨侧翻修。.
结果: 手术时间 1.5～6.0 h，平均 3.7 h；术中出血量为 200～2 000 mL，平均 940.0 mL。术后患者均获随访，随访时间 16～142 个月，平均 73.9 个月。X 线片复查显示，初次置换术后及翻修术后臼杯外展角及前倾角比较，差异均无统计学意义（ P>0.05）。翻修术后旋转中心高度及股骨偏心距均高于初次置换术后，其中股骨偏心距差异有统计学意义（ P<0.05）。末次随访时，Harris 评分为（85.0±7.3）分，髋关节屈曲达（115.0±17.0）°，均较术前明显提高（ t=8.909， P=0.000； t=4.911， P=0.000）。翻修术后 3 例再次进行翻修。末次随访时 15 髋假体均稳定，未观察到透亮线；股骨柄均为中立位，未发生松动或下沉。.
结论: Crowe Ⅳ 型 DDH 患者 THA 术后翻修主要原因为假体无菌性松动。由于患者均相对年轻且关节活动度大，为了延长假体使用寿命，初次置换时不应使用 MOP 界面，COC 界面更优。翻修术中使用金属垫块、加强环和 Cup-cage 均可达到良好的髋臼重建效果。S-ROM 假体应作为初次置换及翻修的首选假体。.
Keywords: Crowe Ⅳdevelopmental dysplasia of the hip; prosthesis selection; revision reason; total hip arthroplasty.