Department of Orthopaedic Surgery, University Hospital Carl Gustav Carus, Medical Faculty of the Technical University of Dresden, Fetscherstr 74, 01307 Dresden, Germany.
Int Orthop. 2012 Sep;36(9):1841-7. doi: 10.1007/s00264-012-1584-8. Epub 2012 May 29.
As many as 20 % of all patients following total knee arthroplasty are not satisfied with the result. Rotational alignment is one factor thought to affect clinical outcome. The purpose of this study was to assess relationships between prosthesis rotational alignment, function score and knee kinematics after TKA.
In 80 patients a cemented, unconstrained, cruciate-retaining TKA with a rotating platform was implanted. Rotational alignment was measured using CT-scans. Kinematics was assessed using fluoroscopy images.
Seventy-three patients were available for follow-up after two years. Nine patients had more than 10° rotational mismatch between the femoral and tibial component in the postoperative CT scans. These patients showed significantly worse results in the function score. While the normal patients with less than 10° rotational mismatch improved from a mean pre-operative 55 points to a mean 71 points at follow-up, the group with more than 10° mismatch deteriorated from a mean 60 points pre-operatively to a mean 57 points at follow-up. The pattern of motion during passive flexion from approximately 0° to 120° was quite different. While external rotation steadily increased with knee flexion in the normal group, there was internal rotation between 30° and 80° of flexion in the group with more than 10° rotational mismatch.
Rotational mismatch between femoral and tibial components exceeding 10° resulted in different kinematics after TKA. It might contribute to worse clinical results observed in those patients and should therefore be avoided.
全膝关节置换术后多达 20%的患者对结果不满意。旋转对线被认为是影响临床结果的一个因素。本研究的目的是评估 TKA 后假体旋转对线、功能评分和膝关节运动学之间的关系。
在 80 例接受水泥固定、无约束、保留交叉韧带的旋转平台 TKA 的患者中，使用 CT 扫描测量旋转对线。使用透视图像评估运动学。
两年后，73 例患者可进行随访。9 例患者术后 CT 扫描中股骨和胫骨组件之间存在超过 10°的旋转不匹配。这些患者的功能评分明显较差。而旋转不匹配小于 10°的正常患者从术前平均 55 分改善至随访时的平均 71 分，而旋转不匹配大于 10°的患者从术前平均 60 分恶化至随访时的平均 57 分。在被动屈曲时从大约 0°到 120°的运动模式也有很大不同。在正常组中，随着膝关节的屈曲，外旋逐渐增加，而在旋转不匹配大于 10°的组中，在屈曲 30°到 80°之间存在内旋。
股骨和胫骨组件之间的旋转不匹配超过 10°会导致 TKA 后不同的运动学。它可能导致这些患者观察到的临床结果更差，因此应予以避免。
