Guntin Jonathan, Plummer Darren, Della Valle Craig, DeBenedetti Anne, Nam Denis
Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Illinois, USA.
Bone Jt Open. 2021 Oct;2(10):858-864. doi: 10.1302/2633-1462.210.BJO-2021-0124.R1.
Prior studies have identified that malseating of a modular dual mobility liner can occur, with previous reported incidences between 5.8% and 16.4%. The aim of this study was to determine the incidence of malseating in dual mobility implants at our institution, assess for risk factors for liner malseating, and investigate whether liner malseating has any impact on clinical outcomes after surgery.
We retrospectively reviewed the radiographs of 239 primary and revision total hip arthroplasties with a modular dual mobility liner. Two independent reviewers assessed radiographs for each patient twice for evidence of malseating, with a third observer acting as a tiebreaker. Univariate analysis was conducted to determine risk factors for malseating with Youden's index used to identify cut-off points. Cohen's kappa test was used to measure interobserver and intraobserver reliability.
In all, 12 liners (5.0%), including eight Stryker (6.8%) and four Zimmer Biomet (3.3%), had radiological evidence of malseating. Interobserver reliability was found to be 0.453 (95% confidence interval (CI) 0.26 to 0.64), suggesting weak inter-rater agreement, with strong agreement being greater than 0.8. We found component size of 50 mm or less to be associated with liner malseating on univariate analysis (p = 0.031). Patients with malseated liners appeared to have no associated clinical consequences, and none required revision surgery at a mean of 14 months (1.4 to 99.2) postoperatively.
The incidence of liner malseating was 5.0%, which is similar to other reports. Component size of 50 mm or smaller was identified as a risk factor for malseating. Surgeons should be aware that malseating can occur and implant design changes or changes in instrumentation should be considered to lower the risk of malseating. Although further follow-up is needed, it remains to be seen if malseating is associated with any clinical consequences. Cite this article: 2021;2(10):858-864.
先前的研究已经确定模块化双动髋臼内衬可能会出现安装不当的情况，先前报道的发生率在5.8%至16.4%之间。本研究的目的是确定在我们机构中双动植入物安装不当的发生率，评估内衬安装不当的风险因素，并调查内衬安装不当是否对手术后的临床结果有任何影响。
我们回顾性地分析了239例初次和翻修全髋关节置换术中使用模块化双动髋臼内衬的X线片。两名独立的评估人员对每位患者的X线片进行了两次评估，以寻找安装不当的证据，第三名观察者作为裁决者。进行单因素分析以确定安装不当的风险因素，使用约登指数来确定临界点。采用科恩kappa检验来衡量观察者间和观察者内的可靠性。
总共有12个内衬（5.0%）出现安装不当的影像学证据，其中包括8个史赛克内衬（6.8%）和4个捷迈邦美内衬（3.3%）。观察者间的可靠性为0.453（95%置信区间（CI）0.26至0.64），表明观察者间的一致性较弱，强一致性大于0.8。单因素分析发现，50毫米或更小的假体尺寸与内衬安装不当有关（p = 0.031）。内衬安装不当的患者似乎没有相关的临床后果，术后平均14个月（1.4至99.2个月）内无人需要翻修手术。
内衬安装不当的发生率为5.0%，与其他报道相似。50毫米或更小的假体尺寸被确定为安装不当的一个风险因素。外科医生应意识到可能会发生安装不当的情况，应考虑改变植入物设计或手术器械，以降低安装不当的风险。尽管需要进一步随访，但安装不当是否与任何临床后果相关仍有待观察。引用本文：2021；2(10):858-864。
