Steelman Kevin R, Cheslik Thomas G, Green Cody C, Haidukewych George J
Department of Orthopaedics, Orlando Health-Orlando Regional Medical Center, Orlando, Florida.
J Arthroplasty. 2025 Aug;40(8S1):S285-S290. doi: 10.1016/j.arth.2025.03.054. Epub 2025 Mar 24.
Instability after total hip arthroplasty (THA) remains a challenging problem. Component revision or bearing exchange can be successful; however, constraints may be necessary. This study evaluated the results of revision THA for instability that required constrained liners (CLs) to determine whether revising or retaining the acetabular component is preferred.
This single-surgeon retrospective study included 50 consecutive patients who required a CL during acetabular revision for instability. Indications for constraint included the absence of functioning abductors and failed previous CL or dual mobility liner. A CL was used in existing cups if the cup position was deemed acceptable with a reasonable impingement-free arc of motion. If unacceptable, it was revised, or, if the internal diameter allowed, a CL was cemented into the existing cup in a "face changing" position to minimize impingement. All patients had a minimum 2-year follow-up. Recurrent instability occurred in 15 of 50 patients overall (30%). Results were analyzed, and patients were separated into the following two groups based on whether the cup/liner position was changed: group 1, cup revision or cemented CL with "face change" (FC) (n = 28), and group 2, CL implanted into existing cup without FC (n = 22).
Group 1 had recurrent instability in four of 28 cases (14%), whereas group 2 had instability in 11 of 22 (50%) cases (P = 0.012). Cemented liners with FC failed in four of 16 cases. Cup revision had the lowest rate of recurrent instability (zero of 12) versus 15 of 38 (39%) when the cup was retained (P = 0.01).
This study demonstrated significantly lower rates of recurrent instability when CLs can be positioned to minimize impingement, either by revising the cup or cementing the liner independent of the existing cup: a so-called "FC." Cup revision demonstrated the lowest rate of recurrent instability with predictable osteointegration at the mean 4-year follow-up.
全髋关节置换术（THA）后的不稳定仍然是一个具有挑战性的问题。组件翻修或轴承更换可能会成功；然而，可能需要使用限制装置。本研究评估了因不稳定而需要使用限制衬垫（CL）进行翻修THA的结果，以确定翻修或保留髋臼组件哪种更可取。
这项单术者回顾性研究纳入了50例连续的患者，这些患者在因不稳定进行髋臼翻修时需要使用CL。使用限制装置的指征包括外展肌功能缺失以及先前的CL或双动衬垫失败。如果髋臼杯位置被认为可接受且具有合理的无撞击活动弧，则在现有的髋臼杯中使用CL。如果不可接受，则对其进行翻修，或者，如果内径允许，则将CL以“换面”位置固定在现有的髋臼杯中，以尽量减少撞击。所有患者均进行了至少2年的随访。50例患者中共有15例（30%）出现复发性不稳定。对结果进行分析，并根据髋臼杯/衬垫位置是否改变将患者分为以下两组：第1组，髋臼杯翻修或采用“换面”（FC）的固定CL（n = 28），第2组，将CL植入现有的髋臼杯中且未进行FC（n = 22）。
第1组28例中有4例（14%）出现复发性不稳定，而第2组22例中有11例（50%）出现不稳定（P = 0.012）。16例采用FC的固定衬垫中有4例失败。髋臼杯翻修的复发性不稳定率最低（12例中为零），而保留髋臼杯时38例中有15例（39%）出现复发性不稳定（P = 0.01）。
本研究表明，当通过翻修髋臼杯或独立于现有髋臼杯固定衬垫（即所谓的“FC”）将CL放置在可尽量减少撞击的位置时，复发性不稳定的发生率显著降低。在平均4年的随访中，髋臼杯翻修的复发性不稳定率最低，且骨整合可预测。
