Department of Orthopaedics, Brigham and Women's Hospital, Boston, Massachusetts.
Department of Orthopaedics, Hospital for Special Surgery, New York, New York.
J Arthroplasty. 2018 Feb;33(2):505-509. doi: 10.1016/j.arth.2017.09.029. Epub 2017 Sep 23.
Dislocation following total hip arthroplasty (THA) remains a significant clinical problem. Few studies have focused on the use of dual mobility (DM) components in the setting of first-time revision for instability following THA. Here, we investigate patient outcomes following first-time revision THA with DM components for a diagnosis of instability.
Institution-wide revision THAs using DM components performed between 2010 and 2013 were identified. Chart review identified 40 patients with average 3-year follow-up who had undergone first-time revision for instability, defined as instability after primary THA. Etiology of instability was classified by Wera type. Patient demographics, medical co-morbidities, re-dislocations, and re-revisions were recorded. Component position and leg-length discrepancy were measured on pre-operative and post-operative radiographs when available. Utilizing Student's t-test or Fisher's exact test, we analyzed differences between those who endured recurrent dislocation and those who did not.
Recurrent dislocation occurred in 2 patients (5%). Both patients underwent re-revision for recurrent instability and carried diagnoses of instability of unresolved etiology. Two patients underwent re-revision for reasons unrelated to the DM construct. All-cause re-revision rate at final follow-up was therefore 10% (4 patients). No medical, demographic, or radiographic factors were significantly associated with risk of recurrent instability (P > .05).
The use of DM components for first-time revision THA for a diagnosis of instability carried a re-dislocation rate of 5% and an all-cause re-revision rate of 10% at average 3-year follow-up. Instability of unresolved etiology was associated with re-dislocation following revision surgery.
全髋关节置换术后（THA）脱位仍然是一个严重的临床问题。很少有研究关注初次翻修时不稳定的情况下使用双动（DM）组件。在这里，我们研究了初次翻修时使用 DM 组件治疗 THA 后不稳定的患者的结果。
确定了 2010 年至 2013 年间在全机构范围内使用 DM 组件进行的翻修 THA。通过图表回顾，确定了 40 例平均随访 3 年的患者，这些患者因不稳定而接受了初次翻修，定义为初次 THA 后不稳定。不稳定的病因通过 Wera 分型进行分类。记录患者的人口统计学数据、合并症、再脱位和再翻修情况。如果有术前和术后 X 线片，测量组件位置和肢体长度差异。利用 Student's t 检验或 Fisher 确切检验，分析了那些经历复发性脱位和未经历复发性脱位的患者之间的差异。
2 例患者（5%）发生复发性脱位。这两例患者均因未解决病因的不稳定而接受再次翻修。另有 2 例患者因与 DM 结构无关的原因接受再次翻修。因此，最终随访时所有原因的再次翻修率为 10%（4 例）。没有任何医学、人口统计学或影像学因素与复发性不稳定的风险显著相关（P>0.05）。
初次翻修 THA 治疗不稳定，使用 DM 组件的复发性脱位率为 5%，平均 3 年随访时的所有原因再次翻修率为 10%。未解决病因的不稳定与翻修手术后再次脱位有关。
