Influence of Surgery on Musculoskeletal Mechanics in Children with Crouch Gait

描述（由申请人提供）：脑瘫（CP）是一种神经系统发育障碍，在美国影响超过75万人（1）。这种疾病的常见发病原因是步态障碍，其中蹲姿步态是最常见的形式之一（3）。蹲下是一种疲劳步态（4-5），其特征是站立时膝盖过度屈曲（6-7）， 通常需要手术矫正，以允许患者在成熟时继续行走（8）。股骨远端延长截骨术联合髌腱前移（DFEO + PTA）是一种有前途的手术方法，可减少这些儿童的蹲下和恢复股四头肌力量（2，9）。虽然短期结果通常良好，但关于为什么联合手术优于单独手术以及哪些手术参数最有效，我们知之甚少。也许更重要的是，该程序对骨骼生长和软骨健康的长期影响尚不清楚（10）。本项目旨在使用肌肉骨骼建模、动态磁共振成像（MRI）和步态分析技术来研究DFEO + PTA对膝关节伸肌力学的影响。将在肌肉骨骼系统的计算机模型上进行手术模拟，以深入了解截骨和髌骨前移的程度如何影响术后肌肉力臂、肌肉操作长度和膝关节伸肌力量。一种新的动态MRI技术（11）将用于发现运动学和软骨接触的变化，这可能是由于大量的手术矫正造成的。最后，步态分析将与计算模型相结合，将手术引起的关节力学变化与功能步态表现联系起来。预期结果是对手术对肌肉骨骼系统影响的科学理解，可用于减轻短期和长期不良结果的可能性。 通过这个项目的完成，作为该奖学金的一部分，雷切尔·伦哈特将接触到实验和计算生物力学研究的许多领域。她的培训计划还包括机械和生物医学工程课程，以发展她的技术技能，以配合她的正式医疗培训。鉴于她的最终目标是成为一名成功的医生科学家，临床和沟通技能的发展也将是一个重点。通过在诊所的持续参与，持续的实践和写作和演讲能力的反馈，并与她的赞助商和咨询团队定期会议，雷切尔将准备成功都作为一个儿科骨科医生和作为一个独立的生物力学研究人员。

DESCRIPTION (provided by applicant): Cerebral palsy (CP) is a neurological disorder of development affecting more than 750,000 people in the US (1). A common source of morbidity in this condition is gait disorders, with crouch gait being one of the most common forms (3). Crouch is a fatiguing gait (4-5), characterized by excessive knee flexion during stance (6-7), that often requires surgical correction to allow patients to continue to ambulate as they mature (8). Distal femoral extension osteotomy coupled with patellar tendon advancement (DFEO + PTA) is a promising surgical approach for reducing crouch and restoring quadriceps strength in these children (2, 9). While short term outcomes are generally good, little is known about the why the coupled procedures are better than either procedure alone, and which surgical parameters are most efficacious. Perhaps more importantly, the long term implications of the procedures on skeletal growth and cartilage health are unclear (10). This project aims to use musculoskeletal modeling, dynamic magnetic resonance imaging (MRI), and gait analysis techniques to investigate the influence of DFEO + PTA on knee extensor mechanics. Surgical simulations will be performed on computer models of the musculoskeletal system to gain insights into how the degree of osteotomy and patellar advancement affects muscle moment arms, muscle operating lengths, and knee extensor strength post-surgery. A novel dynamic MRI technique (11) will then be used to discover changes in kinematics and cartilage contact that can result from the substantial surgical corrections. Finally, gait analysis will be coupled with computational models to relate surgically induced changes in joint mechanics to functional gait performance. The anticipated outcome is a scientific understanding of the surgical effects on the musculoskeletal system, which can be used to mitigate the potential for adverse outcomes in both the short- and long-term. Through the completion of this project as part of this fellowship, Rachel Lenhart will be exposed to many areas of experimental and computational biomechanics research. Her training plan also includes coursework in mechanical and biomedical engineering to develop her technical skills to compliment her formal medical training. Given that her end goal is to be a successful physician scientist, development of clinical and communication skills will also be a focus. Through consistent participation in the clinic, continual practice and feedback on writing and presentation abilities, and regular meetings with her sponsors and advisory team, Rachel will be poised for success both as a pediatric orthopedic surgeon and as an independent biomechanics researcher.