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）是治疗单侧膝关节骨关节炎（OA）的一种方法。它重新调整关节，重新分配关节负荷，减轻疼痛。它被一些临床医生用作对于太年轻而不能进行全膝关节置换的患者的有价值的关节保留干预。它偶尔也用于无症状患者，以防止膝关节进一步对线不良。为了延长关节的寿命，关节对线矫正的角度必须足以减少内侧间室上的负荷，同时不过度加载外侧间室。在目前的临床实践中，矫正角度是根据站立静态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，与静态膝关节对线测量相比，与临床结局的相关性更高。该研究旨在开发一种基于患者术前步态生物力学来量化最佳矫正角度的方法。如果能够找到计算修正角的新方法，从而提高接头的寿命，则可以更广泛地采用该程序作为服务。该提案还旨在使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。本研究将采用来自佛罗里达大学的患者特异性动态模型。开发该模型是为了使用术前步态数据和标准长腿X线片测量的矫正角度预测HTO手术后膝关节内收力矩的变化。这项研究将测试是否优化模型，校准到每个病人，可以预测术后膝关节内收力矩使用HTO手术参数。这将是该软件使用术前和术后患者数据的首次实施。该软件将用于确定产生最佳术后膝关节内收力矩所需的胫骨几何结构变化。根据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，将采用开源软件（OpenSim）来调查HTO手术后关节反作用力的变化。将为此目的调整一个模型。这将是第一次实施肌肉骨骼模型，以调查接受HTO的患者的关节反作用力的变化，并将为进一步开发提供基础。将术前计算的关节反作用力及其术后变化与健康队列进行比较。这将提供有关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有效性。这项研究的最终产品将是一种新的工具，用于定制手术计划和结果测量，详细说明HTO手术的疗效。它将增强HTO重新排列的生物力学理解，并证明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.