Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
J Bone Joint Surg Am. 2019 Apr 3;101(7):620-627. doi: 10.2106/JBJS.18.00607.
Cementation of a constrained liner is a viable option for treating instability after total hip arthroplasty (THA) when the acetabular component is well fixed and well aligned. However, concerns regarding long-term mechanical failure and recurrent instability remain. The aim of this study was to evaluate the long-term survivorship, complications, and clinical and radiographic outcomes of constrained polyethylene liners cemented into well-fixed acetabular components at the time of revision THA.
We identified 125 cases in which a constrained liner of 1 design was cemented into a retained, osseointegrated acetabular component during revision THA between 1998 and 2006. The mean patient age at revision was 70 years. Mean follow-up was 7 years. Survivorship data, risk of instability, and clinical and radiographic outcomes were analyzed.
Survivorship free from revision for instability was 86% at 5 years and 81% at 10 years. Survivorship free from aseptic acetabular component revision was 78% at 5 years and 65% at 10 years, with the most common failure mechanism being dissociation of the constrained liner from the acetabular component. Survivorship free from revision for any reason was 76% at 5 years and 60% at 10 years. The most common complications were instability and periprosthetic joint infection, with cumulative incidences at 7 years of 18% and 11%, respectively. Harris hip scores did not significantly improve. Cup position did not affect implant survivorship or risk of dislocation.
Cementing a constrained liner into a retained acetabular shell at the time of revision THA has durable long-term results, with 8 in 10 patients free from instability at 10 years. Aseptic acetabular survivorship was worse (65%) at 10 years, primarily due to dissociation of the constrained liner from the acetabular component.
Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
在全髋关节置换术（THA）后出现不稳定时，如果髋臼部件固定良好且对齐良好，那么使用约束衬垫进行固定是一种可行的选择。然而，长期机械故障和再次不稳定的问题仍然存在。本研究的目的是评估在翻修 THA 时将约束型聚乙烯衬垫固定在固定良好的髋臼部件中的长期存活率、并发症以及临床和影像学结果。
我们在 1998 年至 2006 年间，共发现 125 例使用 1 种设计的约束型衬垫固定在保留的、骨整合的髋臼部件中的翻修 THA 病例。翻修时患者的平均年龄为 70 岁。平均随访时间为 7 年。分析了存活率数据、不稳定风险以及临床和影像学结果。
5 年和 10 年时无翻修不稳定的存活率分别为 86%和 81%。5 年和 10 年时无无菌性髋臼部件翻修的存活率分别为 78%和 65%，最常见的失败机制是约束衬垫与髋臼部件分离。5 年和 10 年时任何原因的翻修存活率分别为 76%和 60%。最常见的并发症是不稳定和假体周围关节感染，7 年时的累积发生率分别为 18%和 11%。Harris 髋关节评分无显著改善。杯的位置并不影响植入物的存活率或脱位风险。
在翻修 THA 时将约束衬垫固定在保留的髋臼壳中具有持久的长期结果，10 年时 8 例中有 10 例无不稳定。10 年时无菌性髋臼的存活率较差（65%），主要是由于约束衬垫与髋臼部件分离。
治疗水平 IV。有关证据水平的完整描述，请参见作者说明。
