Background: 

The aim of this study was to investigate the relationship of obesity with all-cause revision and revision for infection, loosening, instability, and pain after total knee arthroplasty (TKA) performed in Australia.

Methods: 

Data for patients undergoing primary TKA for osteoarthritis from January 1, 2015, to December 31, 2020, were obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). The rates of all-cause revision and revision for infection, loosening, instability, and pain were compared for non-obese patients (body mass index [BMI], 18.50 to 29.99 kg/m²), class-I and II obese patients (BMI, 30.00 to 39.99 kg/m²), and class-III obese patients (BMI, ≥40.00 kg/m²). The results were adjusted for age, sex, tibial fixation, prosthesis stability, patellar component usage, and computer navigation usage.

Results: 

During the study period, 141,673 patients underwent primary TKA for osteoarthritis in Australia; of these patients, 48.0% were class-I or II obese, and 10.6% were class-III obese. The mean age was 68.2 years, and 54.7% of patients were female. The mean follow-up period was 2.8 years. Of the 2,655 revision procedures identified, the reasons for the procedures included infection in 39.7%, loosening in 14.8%, instability in 12.0%, and pain in 6.1%. Class-I and II obese patients had a higher risk of all-cause revision (hazard ratio [HR], 1.12 [95% confidence interval (CI), 1.03 to 1.22]; p = 0.007) and revision for infection (HR, 1.25 [95% CI, 1.10 to 1.43]; p = 0.001) than non-obese patients. Class-III obese patients had a higher risk of all-cause revision after 1 year (HR, 1.30 [95% CI, 1.14 to 1.52]; p < 0.001), revision for infection after 3 months (HR, 1.72 [95% CI, 1.33 to 2.17]; p < 0.001), and revision for loosening (HR, 1.39 [95% CI, 1.00 to 1.89]; p = 0.047) than non-obese patients. The risks of revision for instability and pain were similar among groups.

Conclusions: 

Obese patients with knee osteoarthritis should be counseled with regard to the increased risks associated with TKA, so they can make informed decisions about their health care. Health services and policymakers need to address the issue of obesity at a population level.

Level of Evidence: 

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

中文翻译：

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肥胖对全膝关节置换术翻修率影响的前瞻性纵向研究：澳大利亚骨科协会全国关节置换登记处的结果

背景： 

本研究的目的是调查肥胖与全因修正以及在澳大利亚进行的全膝关节置换术 (TKA) 后感染、松动、不稳定和疼痛的修正之间的关系。

方法： 

2015 年 1 月 1 日至 2020 年 12 月 31 日接受原发性 TKA 骨关节炎患者的数据来自澳大利亚骨科协会国家关节置换登记处 (AOANJRR)。比较非肥胖患者（体重指数[BMI]，18.50～29.99 kg/m ²）、Ⅰ级和Ⅱ级肥胖患者的全因翻修率和因感染、松动、不稳、疼痛而翻修的发生率。 BMI，30.00 至 39.99 kg/m ²）和 III 级肥胖患者（BMI，≥40.00 kg/m ²）。结果根据年龄、性别、胫骨固定、假体稳定性、髌骨组件使用和计算机导航使用进行了调整。

结果： 

在研究期间，澳大利亚有 141,673 名患者因骨关节炎接受了原发性全膝关节置换术；在这些患者中，48.0% 为 I 级或 II 级肥胖，10.6% 为 III 级肥胖。平均年龄为 68.2 岁，54.7% 的患者为女性。平均随访时间为 2.8 年。在确定的 2,655 例翻修手术中，手术原因包括 39.7% 的感染、14.8% 的松动、12.0% 的不稳定和 6.1% 的疼痛。I 级和 II 级肥胖患者的全因翻修（风险比 [HR]，1.12 [95% 置信区间 (CI)，1.03 至 1.22]；p = 0.007）和感染翻修（HR，1.25 [95% CI，1.10 至 1.43]；p = 0.001) 高于非肥胖患者。III 级肥胖患者 1 年后全因翻修的风险更高（HR，1.30 [95% CI，1.14 至 1.52]；p < 0.001），3 个月后感染翻修（HR，1.72 [95% CI，1.33 至 2.17]；p < 0.001）和松动翻修（HR，1.39 [95% CI，1.00 至 1.89]；p = 0.047）比非肥胖患者。各组之间因不稳定和疼痛而翻修的风险相似。

结论： 

应告知患有膝关节骨性关节炎的肥胖患者与 TKA 相关的风险增加，以便他们可以就他们的医疗保健做出明智的决定。卫生服务和政策制定者需要在人口层面解决肥胖问题。

证据等级： 

预后等级 III。有关证据级别的完整描述，请参见作者说明。