Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
J Bone Joint Surg Am. 2024 Nov 6;106(21):1963-1970. doi: 10.2106/JBJS.23.01413. Epub 2024 Sep 24.
The rates of obesity among patients undergoing total knee arthroplasty (TKA) have substantially increased. In addition, obesity is a well-established risk factor for complications after TKA. The purpose of this study was to analyze trends in body mass index (BMI) and complication risk among obese patients undergoing primary TKA treated at a single institution over 3 decades.
Utilizing an institutional total joint registry, 13,919 primary TKAs performed to treat osteoarthritis between 1990 and 2019 were identified. Patients were stratified by BMI according to the World Health Organization (WHO) classification into 3 groups: non-obese (BMI, <30 kg/m 2 ), WHO Class-I and II obese (BMI, 30 to 39.9 kg/m 2 ), and WHO Class-III obese (BMI, ≥40 kg/m 2 ). Trends in BMI and survivorship free from reoperation, revision, and periprosthetic joint infection (PJI) were analyzed over time while controlling for age, sex, and the Charlson Comorbidity Index.
Over the study period, there was a 90% increase in the prevalence of Class-II obesity (13% to 25%) and a 300% increase in Class-III obesity (3% to 12%). Analysis of the entire cohort demonstrated a decrease in the 2-year risk of any reoperation, any revision, and PJI (p < 0.05 for all) with time. The risk decreased significantly over time for non-obese patients for any reoperation (p = 0.029) and any revision (p = 0.004) and for Class-III obese patients for any reoperation (p = 0.038) and any revision (p = 0.012), but it remained stable for Class-I and II obese patients. The risk of PJI decreased from 1990 to 2019 for non-obese patients (p = 0.005), but there were no significant changes in PJI risk for any obesity group.
Despite increasing rates of obesity among our patients who underwent TKA, we observed decreasing risks of reoperation, revision, and PJI over time. The risks of reoperation and revision declined among non-obese patients, remained stable for Class-I and II obese patients, and declined for Class-III obese patients. The PJI risk declined for non-obese patients over the study period, but no such decline occurred for any category of obesity. Despite the decreasing risks of reoperation and revision, further work is needed to improve PJI risk in obese patients.
Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.
接受全膝关节置换术（TKA）的患者中肥胖的发生率显著增加。此外，肥胖是 TKA 后并发症的一个明确的危险因素。本研究的目的是分析在一家机构接受初次 TKA 治疗的肥胖患者的体重指数（BMI）和并发症风险趋势，研究时间跨度为 3 个十年。
利用机构性全关节登记处，确定了 1990 年至 2019 年间因骨关节炎接受的 13919 例初次 TKA。根据世界卫生组织（WHO）分类，将患者按 BMI 分为 3 组：非肥胖组（BMI＜30kg/m2）、WHO Ⅰ类和Ⅱ类肥胖组（BMI 为 30 至 39.9kg/m2）和 WHO Ⅲ类肥胖组（BMI≥40kg/m2）。在控制年龄、性别和 Charlson 合并症指数的情况下，分析 BMI 和免于翻修、再手术和假体周围关节感染（PJI）的生存率随时间的变化趋势。
在研究期间，Ⅱ类肥胖的患病率增加了 90%（从 13%增加到 25%），Ⅲ类肥胖增加了 300%（从 3%增加到 12%）。对整个队列的分析表明，随着时间的推移，任何再手术、任何翻修和 PJI 的 2 年风险都降低（所有 p＜0.05）。非肥胖患者的任何再手术（p=0.029）和任何翻修（p=0.004）以及Ⅲ类肥胖患者的任何再手术（p=0.038）和任何翻修（p=0.012）的风险显著随时间下降，但Ⅰ类和Ⅱ类肥胖患者的风险保持稳定。非肥胖患者的 PJI 风险从 1990 年到 2019 年降低（p=0.005），但任何肥胖组的 PJI 风险均无显著变化。
尽管接受 TKA 的患者肥胖率不断上升，但我们观察到随着时间的推移，再手术、翻修和 PJI 的风险降低。非肥胖患者的再手术和翻修风险下降，Ⅰ类和Ⅱ类肥胖患者的风险保持稳定，Ⅲ类肥胖患者的风险下降。非肥胖患者的 PJI 风险在研究期间有所下降，但任何肥胖类别均未出现这种下降。尽管再手术和翻修的风险降低，但仍需要进一步努力降低肥胖患者的 PJI 风险。
治疗性 III 级。有关证据水平的完整说明，请参阅作者说明。
