Background: 

Many surgeons are reluctant to use a constrained liner at the time of acetabular component revision because of concerns that doing so might result in early acetabular component loosening related to high bone-implant interface stresses transmitted from the constrained liner. We hypothesized that, with appropriate initial implant stabilization using highly porous acetabular components with robust supplemental screw fixation, constrained liners could be safely used at the time of acetabular revision.

Methods: 

We retrospectively identified 148 revision total hip arthroplasties (THAs) in which a constrained liner of 1 design was cemented into a newly placed highly porous acetabular component fixed with supplemental screws (mean, 5 screws). The mean age at the time of revision THA was 69 years, and 68% of the patients were female. The most common indications for revision were 2-stage reimplantation (33%), recurrent dislocation (30%), and aseptic loosening of the acetabular component (22%) or both the acetabular and femoral components (9%). The mean duration of follow-up was 7 years.

Results: 

There were no failures at the bone-implant interface. No cases of acetabular metal shell loosening were identified on radiographic analysis. The 10-year survival rates with acetabular revision and any reoperation as the end points were 75% and 67%, respectively. Overall, 33 hips (22%) required revision or reoperation because of infection or wound complications (n = 12), dislocation or mechanical failure of the constrained liner (n = 11), periprosthetic femoral fracture (n = 4), femoral loosening (n = 3), or other reasons (n = 3). The 10-year survival rate with re-revision for instability as the end point was 88% overall, which was similar to the 85% 10-year survival rate with re-revision for instability as the end point among hips that were specifically revised because of instability during index revision THA (p = 0.9).

Conclusions: 

Implanting a constrained liner at the time of acetabular revision in high-risk patients resulted in no cases of aseptic metal acetabular component loosening in this large series. This finding is likely related to the fact that a highly porous acetabular component was utilized with robust supplemental screw fixation in each case. Such information is valuable as these data favor a paradigm shift when compared with some traditionally held tenets.

Level of Evidence: 

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

中文翻译：

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髋臼翻修术同时植入高度多孔的约束衬垫同时植入：令人惊讶的十年固定效果好。

背景： 

许多外科医生不愿意在髋臼组件翻修时使用受限的内衬，因为担心这样做可能导致与受限的内衬传递的高骨-植入物界面应力有关的早期髋臼组件松动。我们假设，通过使用高度多孔的髋臼组件并使用坚固的辅助螺钉固定进行适当的初始植入物稳定，可以在髋臼翻修时安全地使用受约束的衬垫。

方法： 

我们回顾性地确定了148个修订版的全髋关节置换术（THA），其中将一种设计的约束衬垫固定在新放置的高度多孔的髋臼组件中，并用辅助螺钉固定（平均5个螺钉）。修订THA时的平均年龄为69岁，其中68％为女性。翻修的最常见指征是两阶段再植入（33％），反复脱位（30％）和髋臼组件的无菌性松动（22％）或髋臼和股骨组件的无菌性松动（9％）。平均随访时间为7年。

结果： 

骨-植入物界面没有任何故障。影像学分析未发现髋臼金属壳松动的情况。以髋臼翻修和再次手术为终点的10年生存率分别为75％和67％。总体而言，由于感染或伤口并发症（n = 12），约束性内衬脱位或机械衰竭（n = 11），假体周围股骨骨折（n = 4），股骨松动（33例），需要翻修或再次手术的髋关节总数为33个（22％） n = 3）或其他原因（n = 3）。重新定为不稳定因素的10年生存率总体为88％，这与专门修订的髋关节定为不稳定因素的10年生存率总体为85％相似，因为指数修订THA期间的不稳定性（p = 0.9）。

结论： 

在高危患者中，在髋臼翻修时植入受约束的内衬不会导致大批量无菌金属髋臼组件松动的情况。该发现可能与以下事实有关：在每种情况下，都使用高度多孔的髋臼组件并使用坚固的辅助螺钉固定。这些信息非常有价值，因为与某些传统持有的原则相比，这些数据有利于范式转变。

证据级别： 

治疗级别IV。有关证据水平的完整说明，请参见《作者说明》。