PURPOSE Dislocation and peri-prosthetic fracture (PPF) are major reasons for revision THA (total hip arthroplasty). The main advantage of dual mobility (DM) cups is to minimize the incidence of dislocation compared to single mobility (SM) cups. We hypothesized that the use of DM would lead to an increased risk of PPF because of its greater stability. In contrast, standard cups would be at higher risk of dislocation. METHODS A retrospective comparative study was performed in our institution including 126 revision THAs between January 2013 and December 2017. Collected data included gender, age, BMI, Parker score, ASA score, the etiology for primary THA, type of cup (SM or DM), cortical index, Noble index, and the stem fixation. RESULTS Overall, 53 standard and 73 DM cups were included for study. In the dislocation group, 29 had standard cups (83%) and 6 had DM cups (17%). Dislocation was 12-fold higher in SM cups (p < 0.001). In the PPF group, 24 had standard cups (26%) and 67 had DM cups (74%). PFF was 12-fold higher for DM cups (p < 0.001). A higher Parker score and a higher cortical index had a protective effect on the risk of PPF (OR = 0.76 (p = 0.03), OR = 0.57 (p = 0.048)). CONCLUSION The use of DM increased hip stability but led to a higher rate of PPF by load transfer on the femur. Further studies with larger cohort and follow-up are needed to confirm these findings and measure the incidence of these complications.

中文翻译：

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一次全髋关节置换术后双重活动度与标准杯之间脱位和假体周围骨折发生率的比较研究。

目的脱位和假体周围骨折（PPF）是修订THA（全髋关节置换术）的主要原因。双移动（DM）杯的主要优点是与单移动（SM）杯相比，可将脱位的发生率降至最低。我们假设使用DM会提高PPF的稳定性，因此会增加PPF的风险。相比之下，标准杯的位错风险更高。方法在2013年1月至2017年12月期间，我们机构进行了回顾性比较研究，包括126个修订版THA。收集的数据包括性别，年龄，BMI，Parker评分，ASA评分，原发性THA的病因，杯型（SM或DM） ，皮质指数，Noble指数和茎固定。结果总体上，包括53个标准杯和73个DM杯用于研究。在脱位组中 29杯装有标准杯（83％），6杯装有DM杯（17％）。SM杯中的脱位率高12倍（p <0.001）。在PPF组中，有24杯为标准杯（26％），有67杯为DM杯（74％）。DM杯的PFF高12倍（p <0.001）。较高的Parker评分和较高的皮质指数对PPF风险具有保护作用（OR = 0.76（p = 0.03），OR = 0.57（p = 0.048））。结论DM的使用增加了髋关节的稳定性，但通过股骨上的负荷转移导致了更高的PPF率。需要进一步的队列研究和随访研究，以证实这些发现并测量这些并发症的发生率。较高的Parker评分和较高的皮质指数对PPF风险具有保护作用（OR = 0.76（p = 0.03），OR = 0.57（p = 0.048））。结论DM的使用增加了髋关节的稳定性，但通过股骨上的负荷转移导致了更高的PPF率。需要进一步的大规模队列研究和随访，以证实这些发现并测量这些并发症的发生率。较高的Parker评分和较高的皮质指数对PPF风险具有保护作用（OR = 0.76（p = 0.03），OR = 0.57（p = 0.048））。结论DM的使用增加了髋关节的稳定性，但通过股骨上的负荷转移导致了更高的PPF率。需要进一步的队列研究和随访研究，以证实这些发现并测量这些并发症的发生率。