Wise Barton L, Niu Jingbo, Felson David T, Hietpas Jean, Sadosky Alesia, Torner James, Lewis Cora E, Nevitt Michael
Center for Musculoskeletal Health, University of California, Davis School of Medicine, 4625 2nd Avenue, Suite 2000, Sacramento, CA, 95817, USA,
Clin Orthop Relat Res. 2015 Aug;473(8):2505-13. doi: 10.1007/s11999-015-4211-3.
Debilitating pain associated with knee osteoarthritis (OA) often leads patients to seek and complete total knee arthroplasty (TKA). To date, few studies have evaluated the relation of functional impairment to the risk of TKA, despite the fact that OA is associated with functional impairment.
QUESTIONS/PURPOSES: The purpose of our study was to (1) evaluate whether function as measured by WOMAC physical function subscale was associated with undergoing TKA; and (2) whether any such association varied by sex.
The National Institutes of Health-funded Multicenter Osteoarthritis Study (MOST) is an observational cohort study of persons aged 50 to 79 years with or at high risk of symptomatic knee OA who were recruited from the community. All eligible subjects with complete data were included in this analysis. Our study population sample consisted of 2946 patients with 5796 knees; 1776 (60%) of patients were women. We performed a repeated-measures analysis using baseline WOMAC physical function score to predict the risk of TKA from baseline to 30 months and WOMAC score at 30 months to predict risk of incident TKA from 30 months to 60 months. We used generalized estimating equations to account for the correlation between two knees within an individual and across the two periods. We calculated relative risk (RR) of TKA over 30 months by WOMAC function using a score of 0 to 5 as the referent in multiple binomial regressions with log link.
Those with the greatest functional impairment (WOMAC scores 40-68; 62 TKAs in 462 knee periods) had 15.5 times (95% confidence interval [CI], 7.6-31.8; p<0.001) the risk of undergoing TKA over 30 months compared with the referent group (12 TKAs in 3604 knee periods), adjusting for basic covariates, and 5.9 times (95% CI, 2.8-12.5; p<0.001) the risk after further adjusting for knee pain severity. At every level of functional limitation, the RR for TKA for women was higher than for men, but interaction with sex did not reach significance after adjustment for covariates including ipsilateral pain (p=0.138).
Baseline physical function appears to be an important element in patients considering TKA. Future studies should examine whether interventions to improve function can reduce the need for TKA.
Level III, observational cohort study.
与膝关节骨关节炎（OA）相关的衰弱性疼痛常常导致患者寻求并接受全膝关节置换术（TKA）。尽管OA与功能障碍相关，但迄今为止，很少有研究评估功能障碍与TKA风险之间的关系。
问题/目的：我们研究的目的是：（1）评估由WOMAC身体功能子量表测量的功能是否与接受TKA相关；（2）这种关联是否因性别而异。
美国国立卫生研究院资助的多中心骨关节炎研究（MOST）是一项对年龄在50至79岁、有症状性膝关节OA或有高风险的人群进行的观察性队列研究，这些人是从社区招募的。所有有完整数据的合格受试者都纳入了本分析。我们的研究人群样本包括2946例患者共5796个膝关节；1776例（60%）患者为女性。我们进行了重复测量分析，使用基线WOMAC身体功能评分来预测从基线到30个月的TKA风险，以及30个月时的WOMAC评分来预测从30个月到60个月的新发TKA风险。我们使用广义估计方程来考虑个体内两个膝关节之间以及两个时间段之间的相关性。我们在对数链接的多项二项式回归中，以0至5分作为参照，计算了30个月内WOMAC功能评分对应的TKA相对风险（RR）。
功能障碍最严重的患者（WOMAC评分40 - 68；462个膝关节时间段中有62例TKA）在30个月内接受TKA的风险是参照组（3604个膝关节时间段中有12例TKA）的15.5倍（95%置信区间[CI]，7.6 - 31.8；p < 0.001），在调整了基本协变量后，在进一步调整膝关节疼痛严重程度后风险为5.9倍（95% CI，2.8 - 12.5；p < 0.001）。在每个功能受限水平上，女性TKA的RR都高于男性，但在调整了包括同侧疼痛在内的协变量后，与性别的交互作用未达到显著水平（p = 0.138）。
基线身体功能似乎是考虑进行TKA的患者的一个重要因素。未来的研究应该探讨改善功能的干预措施是否可以减少TKA的需求。
III级，观察性队列研究。
