Tsukeoka Tadashi, Tsuneizumi Yoshikazu, Yoshino Kensuke
Department of Orthopaedic Surgery, Chiba Rehabilitation Center, Japan.
Department of Orthopaedic Surgery, Chiba Rehabilitation Center, Japan.
J Orthop Sci. 2017 Mar;22(2):313-317. doi: 10.1016/j.jos.2016.12.007. Epub 2016 Dec 23.
The knee flexion angle after a total knee arthroplasty is an important indicator of clinical outcome. However, there is little appropriate information about the correlation between the ligament balancing and knee flexion angle after total knee arthroplasty. The purpose of this study was to investigate the effect of the ligamentous balance in extension and flexion on knee flexion angle one year after posterior cruciate ligament sacrificing rotating platform total knee arthroplasty.
Eighty-five total knee arthroplasties in 71 patients were investigated in this study. The postoperative knee flexion angle and the percentage of improvement in the balanced group in which the difference between varus and valgus was less than 2° and the unbalanced group in extension and the rectangular group in which the asymmetry of the flexion gap was within 2° and the trapezoidal group in flexion were compared. The factors affecting postoperative knee flexion angle were also investigated in a forced entry multiple regression analysis.
The mean flexion angle improved significantly from 116.2° to 122.5° in the rectangular group. By contrast, in the trapezoidal group, no significant improvement was seen (from 115.5° to 117.4°). The statistically significant difference was found between the rectangular and trapezoidal group in flexion in terms of the improvement of the knee flexion angle while there was no difference between the balanced and unbalanced group in extension. The multiple regression analysis showed that the asymmetry of the flexion gap was a predictor of the postoperative knee flexion angle.
Asymmetric flexion gap affected negatively the postoperative knee flexion angle after posterior cruciate ligament sacrificing rotating platform total knee arthroplasty. A gap balancing technique is recommended for this type of implant.
全膝关节置换术后的膝关节屈曲角度是临床疗效的重要指标。然而，关于全膝关节置换术后韧带平衡与膝关节屈曲角度之间的相关性，几乎没有合适的信息。本研究的目的是探讨在牺牲后交叉韧带的旋转平台全膝关节置换术后一年，伸直和屈曲时韧带平衡对膝关节屈曲角度的影响。
本研究调查了71例患者的85例全膝关节置换术。比较了平衡组（内翻和外翻差异小于2°）和伸直不平衡组术后的膝关节屈曲角度以及改善百分比，以及屈曲间隙不对称在2°以内的矩形组和屈曲梯形组的情况。还通过强制进入多元回归分析研究了影响术后膝关节屈曲角度的因素。
矩形组的平均屈曲角度从116.2°显著提高到122.5°。相比之下，梯形组未见显著改善（从115.5°到117.4°）。在膝关节屈曲角度改善方面，矩形组和梯形组在屈曲时存在统计学显著差异，而伸直时平衡组和不平衡组之间无差异。多元回归分析表明，屈曲间隙不对称是术后膝关节屈曲角度的一个预测指标。
不对称的屈曲间隙对牺牲后交叉韧带的旋转平台全膝关节置换术后的膝关节屈曲角度有负面影响。对于这种类型的植入物，建议采用间隙平衡技术。
