Morlock Michael, Wu Yinan, Grimberg Alexander, Günther Klaus-Peter, Perka Carsten
Institute of Biomechanics, TUHH Hamburg University of Technology, Hamburg, Germany.
EPRD Deutsche Endoprothesenregister GmH, Berlin, Germany.
Bone Jt Open. 2025 Jun 1;6(6 Supple B):1-6. doi: 10.1302/2633-1462.66.BJO-2024-0201.R1.
Modular revision stem fracture is a rare but difficult complication after hip arthroplasty revision. The purpose of this German Arthroplasty Registry (EPRD)-based study was to investigate whether the overall re-revision rate and the re-revision reasons of modular revision stems compared with monobloc stems are different.
A total of 291 re-revisions occurring within five years after implantation of a revision stem (n = 2,039) documented in the EPRD were analyzed using Kaplan-Meier survival analysis and Cox regression. Stem type (modular: n = 1,026, monobloc: n = 1,013) and revision reason were investigated as independent variables, while BMI, sex, age, hospitals' annual revision volume, and Elixhauser score were treated as confounding variables. Cases with an infection at index surgery were analyzed separately.
Re-revision risk after five years was similar for either stem type (modular: 18.7% ( 95% CI 15.9 to 21.9); monobloc: 15.6% (95% CI 13.2 to 18.4); p = 0.200). One stem fracture of a modular revision stem was reported. The main reasons for re-revision were infection (modular/monobloc: 50%/60% of all revisions; p = 0.200), dislocation (19.8%/9.6%; p = 0.045), and loosening (12.2%/11.4%; p > 0.999). An Elixhauser score of 4 and above was associated with a higher hazard ratio (HR) for re-revision for either stem type (modular/monobloc: HR 2.01; p = 0.026/HR 2.44; p = 0.004), as well as a BMI category above 25/40 (modular/monobloc: HR 1.73 to 3.25; all p < 0.025/HR 3.61; p < 0.001). An infected index surgery increased the re-revision risk after one year to 26.0% (95% CI 22.2% to 30.3%) compared with 8.3% for noninfected cases (95% CI 7.0% to 9.8%) (p < 0.001) independent of stem type.
A high BMI increases the HR for revision for either stem design but not due to mechanical implant failure. Infection at the index operation increases re-revision risk significantly, and is also the dominant reason for re-revision independent of stem type.
模块化翻修柄骨折是髋关节置换翻修术后一种罕见但棘手的并发症。本基于德国关节置换登记处（EPRD）的研究旨在调查模块化翻修柄与一体式柄相比，总体再次翻修率及再次翻修原因是否存在差异。
使用Kaplan-Meier生存分析和Cox回归对EPRD中记录的翻修柄植入后五年内发生的291例再次翻修（翻修柄n = 2,039）进行分析。将柄类型（模块化：n = 1,026，一体式：n = 1,013）和翻修原因作为自变量，而将体重指数、性别、年龄、医院年度翻修量和Elixhauser评分作为混杂变量。对初次手术时感染的病例进行单独分析。
两种柄类型五年后的再次翻修风险相似（模块化：18.7%（95%CI 15.9至21.9）；一体式：15.6%（95%CI 13.2至18.4）；p = 0.200）。报告了1例模块化翻修柄骨折。再次翻修的主要原因是感染（模块化/一体式：占所有翻修的50%/60%；p = 0.200）、脱位（19.8%/9.6%；p = 0.045）和松动（12.2%/11.4%；p > 0.999）。Elixhauser评分为4及以上与两种柄类型再次翻修的较高风险比（HR）相关（模块化/一体式：HR 2.01；p = 0.026/HR 2.44；p = 0.004），以及体重指数类别高于25/40（模块化/一体式：HR 1.73至3.25；所有p < 0.025/HR 3.61；p < 0.001）。与未感染病例的8.3%（95%CI 7.0%至9.8%）相比，初次手术感染使一年后的再次翻修风险增加至26.0%（95%CI 22.2%至30.3%）（p < 0.001），且与柄类型无关。
高体重指数会增加两种柄设计的翻修风险比，但并非由于植入物机械故障。初次手术时的感染会显著增加再次翻修风险，并且也是与柄类型无关的再次翻修的主要原因。
