Ghomrawi Hassan M K, Kane Robert L, Eberly Lynn E, Bershadsky Boris, Saleh Khaled J
Division of Health Policy, Department of Public Health, Weill Cornell Medical College and Hospital for Special Surgery, New York, NY 10065, USA.
J Bone Joint Surg Am. 2009 Dec;91(12):2838-45. doi: 10.2106/JBJS.H.00782.
Despite the increase in the number of total knee arthroplasty revisions, outcomes of such surgery and their correlates are poorly understood. The aim of this study was to characterize patterns of functional improvement after revision total knee arthroplasty over a two-year period and to investigate factors that affect such improvement patterns.
Three hundred and eight patients in need of revision surgery were enrolled into the study, conducted at seventeen centers, and 221 (71.8%) were followed for two years. Short Form-36 (SF-36), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lower-Extremity Activity Scale (LEAS) scores were collected at baseline and every six months for two years postoperatively. A piecewise general linear mixed model, which models correlation between repeated measures and estimates separate slopes for different follow-up time periods, was employed to examine functional improvement patterns.
Separate regression slopes were estimated for the zero to twelve-month and the twelve to twenty-four-month periods. The slopes for zero to twelve months showed significant improvement in all measures in the first year. The slopes for twelve to twenty-four months showed deterioration in the scores of the WOMAC pain subscale (slope = 0.67 +/- 0.21, p < 0.01) and function subscale (slope = 1.66 +/- 0.63, p < 0.05), whereas the slopes of the other measures had plateaued. A higher number of comorbidities was consistently the strongest deterrent of functional improvement across measures. The modes of failure of the primary total knee arthroplasty were instrument-specific predictors of outcome (for example, tibial bone lysis affected only the SF-36 physical component score [coefficient = -5.46 +/- 1.91, p < 0.01], while malalignment affected both the SF-36 physical component score [coefficient = 5.41 +/- 2.35, p < 0.05] and the LEAS score [coefficient = 1.42 +/- 0.69, p < 0.05]). Factors related to the surgical technique did not predict outcomes.
The onset of worsening pain and knee-specific function in the second year following revision total knee arthroplasty indicates the need to closely monitor patients, irrespective of the mode of failure of the primary procedure or the surgical technique for the revision. This information may be especially important for patients with multiple comorbidities.
尽管全膝关节置换翻修手术的数量有所增加，但此类手术的结果及其相关因素仍知之甚少。本研究的目的是描述翻修全膝关节置换术后两年内功能改善的模式，并调查影响这种改善模式的因素。
308例需要进行翻修手术的患者纳入了这项在17个中心开展的研究，其中221例（71.8%）患者接受了为期两年的随访。在基线时以及术后两年内每六个月收集一次简明健康状况调查量表（SF-36）、西安大略和麦克马斯特大学骨关节炎指数（WOMAC）以及下肢活动量表（LEAS）评分。采用分段广义线性混合模型，该模型对重复测量之间的相关性进行建模，并估计不同随访时间段的单独斜率，以检查功能改善模式。
分别估计了0至12个月和12至24个月期间的回归斜率。0至12个月的斜率显示，所有指标在第一年都有显著改善。12至24个月的斜率显示，WOMAC疼痛子量表（斜率 = 0.67±0.21，p < 0.01）和功能子量表（斜率 = 1.66±0.63，p < 0.05）的评分出现恶化，而其他指标的斜率则趋于平稳。合并症数量较多始终是所有指标功能改善的最强阻碍因素。初次全膝关节置换术的失败模式是结果的器械特异性预测因素（例如，胫骨骨溶解仅影响SF-36身体成分评分[系数 = -5.46±1.91，p < 0.01]，而对线不良则同时影响SF-36身体成分评分[系数 = 5.41±2.35，p < 0.05]和LEAS评分[系数 = 1.42±0.69，p < 0.05]）。与手术技术相关的因素并不能预测结果。
翻修全膝关节置换术后第二年疼痛加重和膝关节特异性功能恶化表明，无论初次手术的失败模式或翻修手术技术如何，都需要密切监测患者。这些信息对于患有多种合并症的患者可能尤为重要。
