Development of a novel surgical planning tool for high tibial osteotomy and a musculoskeletal model to determine the changes in internal knee loading

胫骨高位截骨术（HTO）是一种治疗影响一侧膝盖的骨关节炎（OA）的手术。它重新调整关节，重新分配关节负荷，减轻疼痛。一些临床医生将其作为一种有价值的关节保护干预措施，用于年龄太小而不能进行全膝关节置换术的患者。它也偶尔用于无症状患者，以防止进一步的膝关节不对齐。为了延长关节的寿命，关节对齐矫正的角度必须足以减少内侧隔室的负荷，同时不能过度负荷外侧隔室。在目前的临床实践中，矫正角度是由站立的静态x射线估计的。然而，据报道，动态步态测量，特别是膝关节内收力矩，与静态膝关节对齐测量相比，与临床结果的相关性更高。本研究旨在开发一种基于患者术前步态生物力学的最佳矫正角度量化方法。如果能找到新的计算修正角的方法来提高关节的使用寿命，那么该程序作为一种服务可能会得到更广泛的采用。本建议还旨在利用考虑肌肉力对关节的影响的模型来评估通过关节作用的力的相关变化。本研究将采用佛罗里达大学的患者特异性动态模型。该模型旨在利用术前步态数据和标准长腿x线测量的矫正角度来预测HTO手术后膝关节内收力矩的变化。这项研究将测试优化的模型，针对每个患者进行校准，是否可以使用HTO手术参数预测术后膝关节内收力矩。这将是该软件首次使用术前和术后患者数据。该软件将用于确定胫骨几何形状的变化，以产生最佳的术后膝关节内收力矩。基于患者术前步态计算最佳矫正角度的能力将成为一种新的临床工具的基础。作为拟议研究的一部分，开源软件（OpenSim）将被用于研究HTO手术后关节反作用力的变化。为此目的将采用一个模型。这将是研究HTO患者关节反应力变化的肌肉骨骼模型的首次实施，并将为进一步发展提供基础。术前计算的联合反应力及其术后变化将与健康队列进行比较。这将提供关于膝关节负荷变化的信息，从而提供HTO手术在恢复正常膝关节负荷方面的疗效。这项研究的最终成果将是一种新的工具，用于定制手术计划和详细描述HTO手术疗效的结果测量。它将增强对HTO重组的生物力学理解，并展示动态测量和肌肉骨骼建模的有用性。

High Tibial Osteotomy (HTO) surgery is performed as a treatment for people who have osteoarthritis (OA) affecting one side of their knee. It realigns the joint to redistribute joint loading and relieve pain. It is used by some clinicians as a valuable joint preserving intervention for patients who are too young for a total knee replacement. It is also occasionally used in asymptomatic patients to prevent further mal-alignment of the knee. To prolong the life of the joint, the angle of joint alignment correction must be sufficient to reduce loads on the medial compartment, whilst not excessively loading the lateral compartment. In current clinical practice, the angle of correction is estimated from standing static x-rays. However, dynamic gait measurements, in particular the knee adduction moment, are reported to be more highly related to clinical outcome than measures of static knee alignment. The proposed research aims to develop a method to quantify the optimum correction angle, based on a patients preoperative gait biomechanics. If new methods of calculating the correction angle can be found that improve longevity of the joint, the procedure as a service may be adopted more widely. This proposal also aims to evaluate associated changes in the forces acting through the joint using models that consider the effects of muscle forces on the joint. A patient specific dynamic model from the University of Florida will be employed in this research. This model was developed to predict the changes in knee adduction moment following HTO surgery using pre-operative gait data and the angles of correction measured from standard long leg x-rays. This research will test whether optimised models, calibrated to each patient, can predict post-surgery knee adduction moments using HTO surgical parameters. This will be the first implementation of this software using pre and post-operative patient data. This software will be adapted to determine the changes in tibial geometry required to produce the optimum post-operative knee adduction moment. The ability to calculate the optimum angles of correction based on a patient's pre-operative gait will form the basis of a new clinical tool.As part of the proposed research, open-source software (OpenSim) will be employed to investigate changes in joint reaction forces following HTO surgery. A model will be adapted for this purpose. This will be the first implementation of a musculoskeletal model to investigate changes in joint reaction forces for patients undergoing HTO and will provide a basis for further development. Joint reaction forces calculated pre-operatively and how they change post-operatively will be compared to a healthy cohort. This will provide information on the changes in loading in the knee and thus the efficacy of HTO surgery in restoring normal knee joint loading. The end product of this research will be a new tool for bespoke surgical planning and outcome measures detailing the efficacy of HTO surgery. It will enhance the biomechanical understanding of HTO realignment and demonstrate the usefulness of dynamic measurements and musculoskeletal modelling.