Rivière Charles, Ollivier Matthieu, Girerd Damien, Argenson Jean Noël, Parratte Sébastien
The MSK Lab, Charing Cross Hospital, Imperial College London, Fulham Palace Rd W6 8RF, London, United Kingdom.
Service de Chirurgie Orthopédique, Hôpital Sainte Marguerite, Université Aix-Marseille, 270 Boulevard de Sainte Marguerite, 13009 Marseille, France Marseille, France.
Knee. 2017 Jun;24(3):627-633. doi: 10.1016/j.knee.2017.03.001. Epub 2017 Mar 27.
A principle of TKA is to achieve a neutral standing coronal alignment of the limb (HKA angle) to reduce risks of implant loosening, reduce polyethylene wear, and optimize patellar tracking. Several long-term studies have questioned this because the relationship between alignment and implant survivorship is weaker than previously reported. We hypothesize that standing HKA poorly predicts implant failure because it does not predict dynamic HKA, dynamic adduction moment, and loading of the knee during gait. Therefore, the aim of our study is to assess the relationship between the standing and the dynamic (gait activity) HKAs.
A prospective study on a cohort of 35 patients treated with a posterior-stabilized TKA for primary osteoarthritis. Three months after surgery each patient had a long-leg radiograph and the limb was classified as neutrally aligned (17 patients), varus aligned (nine patients), or valgus aligned (four patients). Patients then performed a gait analysis for level walking.
Standing HKA has a moderate correlation with the peak dynamic varus (r=0.318, p=0.001) and the mean and peak adduction moments (r=0.31 and r=-0.352 respectively). No significant correlation between standing HKA and the mean dynamic coronal alignment (r=0.14, p=0.449). No differences were found for dynamic frontal parameters (dynamic HKA and adduction moment) between patients defined as neutrally or varus aligned.
The standing HKA after TKA was of little value to predict dynamic behaviour of the limb during gait, this may explain why standing coronal alignment after TKA may have limited influence on long-term implant fixation and wear.
全膝关节置换术（TKA）的一个原则是使肢体在站立位时达到冠状面中立对线（股胫角，HKA角），以降低植入物松动风险、减少聚乙烯磨损并优化髌骨轨迹。一些长期研究对此提出质疑，因为对线与植入物生存率之间的关系比之前报道的要弱。我们推测站立位HKA角不能很好地预测植入物失败，因为它无法预测动态HKA角、动态内收力矩以及步态期间膝关节的负荷。因此，我们研究的目的是评估站立位和动态（步态活动时）HKA角之间的关系。
对35例因原发性骨关节炎接受后稳定型TKA治疗的患者进行前瞻性研究。术后3个月，每位患者拍摄长腿X线片，肢体被分类为中立对线（17例患者）、内翻对线（9例患者）或外翻对线（4例患者）。然后患者进行平地行走的步态分析。
站立位HKA角与动态内翻峰值（r = 0.318，p = 0.001）以及平均和峰值内收力矩（分别为r = 0.31和r = -0.352）具有中等相关性。站立位HKA角与平均动态冠状面对线之间无显著相关性（r = 0.14，p = 0.449）。在定义为中立对线或内翻对线的患者之间，动态额状面参数（动态HKA角和内收力矩）没有差异。
TKA术后站立位HKA角对预测步态期间肢体的动态行为价值不大，这可能解释了为什么TKA术后冠状面对线对长期植入物固定和磨损的影响可能有限。
