A Comparison of Two Surgical Procedures that Restore Elbow Extension

描述（由申请人提供）： 摘要随意控制伸肘能显著改善四肢瘫痪患者的功能。因此，通过肌腱转移进行肘关节伸展的手术重建被认为是一种有益于患者的“基本干预”，即使从未进行过旨在改善手部功能的其他肌腱转移。目前，有两种常见的肌腱转移手术用于恢复脊髓损伤后的肘部伸展。这些是后三角肌到三头肌（PD-TRI）转移和二头肌到三头肌（BI-TRI）转移。这两种手术都显著改善了自愿肘关节伸展，尽管患者恢复的自愿控制量存在差异。目前尚不清楚这种变异性是否与所选供体肌肉的机械性能、外科医生使用的手术或与控制转移肌肉作为肘伸肌相关的困难有关。本研究将直接比较PD-TRI和BI-TRI肌腱转移在以下方面的性能：自愿肘关节伸展力量、激活转移的能力以及与个体肌肉的自愿和非自愿控制相关的神经因素。这些比较将在功能相关的姿势中进行，并将提供基本信息，以提高对这两种手术恢复肘关节伸展能力的临床理解。该建议的基本假设是，不能最大限度地激活转移的后三角肌和转移的二头肌，这大大限制了可以产生手肘伸展力矩。我们的初步数据表明，大约只有60%的可用转移肌肉力量可以自愿招募。我们进一步假设，激活赤字与姿势的变化，这种变化的幅度和性质不同的候选人之间的转移。这样的改变可能会限制可以使用转移的肌肉的工作空间。我们的第一个目标将量化这些激活赤字在三个姿势相关的使用这些转移在典型的日常生活活动。我们的后两个目标将评估皮质和脊髓对主动激活这些肌肉的能力的贡献。总之，从这些目标的结果将提供一个更好的了解与每个潜在的供体肌肉和神经约束其作为肘伸肌使用的生物力学。这些结果将有助于理解BI-TRI和PD-TRI手术的相对优点以及限制其使用的神经限制。重要的是，神经生理学评估也有重要的意义，制定适当的有针对性的康复干预措施，旨在改善与这些重要的手术方法恢复自愿肘关节伸展的结果。 公共卫生相关性： 退伍军人健康管理局脊髓损伤和疾病项目的使命是促进脊髓损伤和疾病患者的健康、独立性、生活质量和生产力。该项目与该使命的所有层面都高度相关。改善肌腱转移的结果将导致颈椎SCI患者更强的自主运动和更大的功能独立性。积极的肘关节伸展对四肢瘫痪的患者有显著的功能益处。拟议的工作将提供所需的信息，以评估康复干预是否侧重于提高激活肌腱转移的能力，恢复肘关节伸展，可能会导致功能的进一步改善。如果是这样的话，我们的研究结果将成为制定康复干预措施以改善功能结果的基础。如果没有，我们的研究将确定两种常见手术的基本能力，并为临床决策提供所需的客观数据。

DESCRIPTION (provided by applicant): Abstract Voluntary control of elbow extension significantly improves functional abilities for individuals with tetraplegia. As a result, surgical reconstruction of elbow extension via tendon transfer is considered a "fundamental intervention" that benefits the patient, even if other tendon transfers aimed at improving hand function are never performed. Presently, there are two common tendon transfer surgeries used to restore elbow extension following spinal cord injury. These are the posterior deltoid to triceps (PD-TRI) transfer and the biceps to triceps (BI-TRI) transfer. Both surgeries significantly improve voluntary elbow extension, although there is variability in the amount of voluntary control that is restored among patients. It remains unclear if this variability is related to the mechanical properties of the selected donor muscle, the procedures used by the surgeon, or difficulties associated with controlling the transferred muscle as an elbow extensor. This study will directly compare the performance of PD-TRI and BI-TRI tendon transfers with regard to: voluntary elbow extension strength, the ability to activate the transfer, and neural factors associated with voluntary and involuntary control of individual muscles. These comparisons will be made in functionally relevant postures and will provide fundamental information that will improve clinical understanding of the capacity of each of these two procedures to restore elbow extension. The fundamental hypothesis of this proposal is that an inability to maximally activate the transferred posterior deltoid and the transferred biceps significantly limits the elbow extension moment that can be produced. Our preliminary data suggests that approximately only 60% of the available transferred muscle strength can be recruited voluntarily. We further hypothesize that activation deficits change with posture and that the magnitude and nature of this change differs between the candidate transfers. Such changes could limit the workspace in which a transferred muscle could be used. Our first aim will quantify these activation deficits across three postures relevant to the use of these transfers in typical activities of daily living. Our second two aims will assess the cortical and spinal contributions to the ability to activate these muscles voluntarily. Together, the results from these aims will provide a greater understanding of the biomechanics associated with each potential donor muscle and the neural constraints on its use as an elbow extensor. These results will facilitate an understanding of the relative merits of the BI-TRI and PD-TRI surgeries and the neural constraints limiting their use. Importantly, the neurophysiological assessments also have important implications for developing appropriately targeted rehabilitation interventions aimed at improving the outcomes associated with these important surgical approached to the restoration of voluntary elbow extension. PUBLIC HEALTH RELEVANCE: The mission of the Spinal Cord Injury and Disorders Program in the Veteran's Health Administration is to promote the health, independence, quality of life, and productivity of individuals with spinal cod injury and disorders. This project is highly relevant to all levels of that mission. Improving outcomes of tendon transfers will result in stronger voluntary movements and greater functional independence for individuals with cervical SCI. Active elbow extension has significant functional benefits for individuals with tetraplegia. The proposed work will provide information that is needed to assess whether rehabilitation interventions focused on improving the ability to activate tendon transfers that restore elbow extension could lead to additional improvements in function. If so, our results will form the basis for the development of rehab interventions to improve functional outcomes. If not, our study will define the fundamental capabilities of two common surgeries, and will provide objective data needed for clinical decision-making .