Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
Department of Mechanical Engineering/Centre for Therapeutic Innovation, University of Bath, Bath, UK.
Gait Posture. 2022 May;94:144-152. doi: 10.1016/j.gaitpost.2022.02.028. Epub 2022 Feb 25.
A fully personalised combination of Gait Analysis (GA), including Ground Reaction Force (GRF), and patient-specific knee joint morphology has not yet been reported. This can provide valuable biomechanical insight in normal and pathological conditions. Abnormal knee varus results in medial knee condylar hyper-compression and osteoarthritis, which can be prevented by restoring proper condylar load distribution via High Tibial Osteotomy (HTO).
This study was aimed at reporting on an original methodology, merging GA, GRF and Computer-Tomography (CT) to depict a patient-specific representation of the knee mechanical condition during locomotion. It was hypothesised that HTO results in a lateralized pattern of GRF with respect to the tibial plateau.
Four patients selected for HTO received clinical, radiological and instrumental examinations, pre- and post-operatively at 6-month follow-up. GA was performed during level walking and more demanding motor tasks using a 9-camera motion-capture system, combined with two force platforms, and an established protocol. Additional skin markers were positioned around the tibial-plateau rim. Weight-bearing CT scans of the knee were collected while still wearing these markers. Proximal tibial and marker morphological models were reconstructed. The markers from CT reconstruction were then registered to the corresponding trajectories as tracked by GA data. Resulting registration matrices were used to report GRF vectors on the plane best matching the tibial-plateau model and the intersection paths were calculated.
The registration procedure was successfully executed, with a max registration error of about 3 mm. GRF intersection paths were found medially to the tibial plateau pre-op, and lateralized post-op, thus much closer to the knee centre, as expected after HTO. The exploitation of the present methodology offers personalised quantification of the original mechanical misalignment and of the effect of surgical correction which could enhance diagnostics and planning of HTO as well as other knee treatments.
目前尚未有报道称能够综合运用步态分析（GA）、地面反作用力（GRF）以及患者特定的膝关节形态来实现完全个性化的组合。这可以为正常和病理条件下提供有价值的生物力学见解。膝关节内翻会导致内侧膝关节髁骨过度受压和骨关节炎，通过胫骨高位截骨术（HTO）恢复适当的髁骨负荷分布可以预防这种情况。
本研究旨在报告一种原始方法，将 GA、GRF 和计算机断层扫描（CT）相结合，以描绘患者在运动过程中膝关节机械状况的特定表示。假设 HTO 会导致 GRF 相对于胫骨平台发生侧向化模式。
选择了 4 名接受 HTO 的患者，在术前、术后 6 个月的随访期间进行临床、影像学和仪器检查。GA 在水平行走和更具挑战性的运动任务中进行，使用 9 个摄像头运动捕捉系统，结合两个力台和一个既定的方案。在胫骨平台边缘周围放置额外的皮肤标记物。在仍然穿着这些标记物的情况下收集膝关节负重 CT 扫描。重建胫骨近端和标记物形态模型。然后将 CT 重建的标记物注册到 GA 数据跟踪的相应轨迹。生成的注册矩阵用于在最佳匹配胫骨平台模型的平面上报告 GRF 向量，并计算交点路径。
注册过程成功执行，最大注册误差约为 3 毫米。术前 GRF 交点路径位于胫骨平台内侧，术后发生侧向化，更接近膝关节中心，这与 HTO 后的预期结果一致。本方法的应用为个性化量化原始机械错位和手术矫正效果提供了可能，从而可以增强 HTO 以及其他膝关节治疗的诊断和规划。
