Naili Josefine E, Wretenberg Per, Lindgren Viktor, Iversen Maura D, Hedström Margareta, Broström Eva W
Department of Women's and Children's Health, Karolinska Institutet, MotorikLab, Q2:07, Karolinska University Hospital, 171 76, Stockholm, Sweden.
Department of Orthopedics, School of Medical Sciences, Örebro University and Örebro University Hospital, Örebro, Sweden.
BMC Musculoskelet Disord. 2017 Mar 21;18(1):122. doi: 10.1186/s12891-017-1479-3.
It is not well understood why one in five patients report poor outcomes following knee arthroplasty. This study evaluated changes in knee biomechanics, and perceived pain among patients reporting either a good or a poor outcome in knee-related quality of life after total knee arthroplasty.
Twenty-eight patients (mean age 66 (SD 7) years) were included in this prospective study. Within one month of knee arthroplasty and one year after surgery, patients underwent three-dimensional (3D) gait analysis, completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), and rated perceived pain using a visual analogue scale. A "good outcome" was defined as a change greater than the minimally detectable change in the KOOS knee-related quality of life, and a "poor outcome" was defined as change below the minimally detectable change. Nineteen patients (68%) were classified as having a good outcome. Groups were analyzed separately and knee biomechanics were compared using a two-way repeated measures ANOVA. Differences in pain between groups were evaluated using Mann Whitney U test.
Patients classified as having a good outcome improved significantly in most knee gait biomechanical outcomes including increased knee flexion-extension range, reduced peak varus angle, increased peak flexion moment, and reduced peak valgus moment. The good outcome group also displayed a significant increase in walking speed, a reduction (normalization) of stance phase duration (% of gait cycle) and increased passive knee extension. Whereas, the only change in knee biomechanics, one year after surgery, for patients classified as having a poor outcome was a significant reduction in peak varus angle. No differences in pain postoperatively were found between groups.
Patients reporting a good outcome in knee-related quality of life improved in knee biomechanics during gait, while patients reporting a poor outcome, despite similar reduction in pain, remained unchanged in knee biomechanics one year after total knee arthroplasty. With regards to surgeon-controlled biomechanical factors, surgery may most successfully address frontal plane knee alignment. However, achieving a good outcome in patient-reported knee-related quality of life may be related to dynamic improvements in the sagittal plane.
五分之一的患者在膝关节置换术后报告预后不佳，其原因尚不清楚。本研究评估了全膝关节置换术后膝关节生物力学的变化，以及在膝关节相关生活质量方面报告预后良好或不佳的患者的疼痛感知情况。
本前瞻性研究纳入了28例患者（平均年龄66（标准差7）岁）。在膝关节置换术后1个月内及术后1年，患者接受三维（3D）步态分析，完成膝关节损伤和骨关节炎疗效评分（KOOS），并使用视觉模拟量表对疼痛感知进行评分。“良好预后”定义为KOOS膝关节相关生活质量的变化大于最小可检测变化，“不良预后”定义为变化低于最小可检测变化。19例患者（68%）被归类为预后良好。对两组分别进行分析，并使用双向重复测量方差分析比较膝关节生物力学。使用曼-惠特尼U检验评估两组之间的疼痛差异。
被归类为预后良好的患者在大多数膝关节步态生物力学指标上有显著改善，包括膝关节屈伸范围增加、内翻峰值角度减小、峰值屈曲力矩增加和外翻峰值力矩减小。预后良好组的步行速度也显著增加，站立期持续时间（步态周期的百分比）缩短（正常化），被动膝关节伸展增加。然而，被归类为预后不良的患者在术后1年膝关节生物力学的唯一变化是内翻峰值角度显著减小。两组术后疼痛无差异。
在膝关节相关生活质量方面报告预后良好的患者在步态期间膝关节生物力学有所改善，而报告预后不良的患者尽管疼痛程度相似降低，但在全膝关节置换术后1年膝关节生物力学仍无变化。关于外科医生控制的生物力学因素，手术可能最成功地解决膝关节额状面的对线问题。然而，在患者报告的膝关节相关生活质量方面取得良好预后可能与矢状面的动态改善有关。
