A Comparison of Two Surgical Procedures that Restore Elbow Extension

描述(由申请人提供)： 摘要自愿伸肘可显著改善四肢瘫痪患者的功能能力。因此，即使从未进行过旨在改善手功能的其他肌腱移植手术，通过肌腱移位重建肘部伸展也被认为是一种对患者有益的“根本性干预”。目前，有两种常见的肌腱移植手术用于恢复脊髓损伤后的肘关节伸展。这些是后三角肌到三头肌的移位(PD-TRI)和二头肌到三头肌的移位(BI-TRI)。这两种手术都显著改善了自愿伸肘，尽管患者之间恢复的自愿控制量存在差异。目前尚不清楚这种差异是否与选定供体肌肉的机械性能、外科医生使用的操作程序或作为肘部伸肌的移植肌肉控制相关的困难有关。这项研究将直接比较PD-TRI和BI-TRI肌腱移位术在以下方面的表现：自愿伸肘力量，激活移位的能力，以及与自愿和非自愿控制个别肌肉相关的神经因素。这些比较将在功能相关的体位下进行，并将提供基本信息，以提高临床对这两种手术恢复肘关节伸展能力的了解。这一建议的基本假设是，不能最大限度地激活移位的三角肌和移位的二头肌，显著限制了可以产生的肘关节伸展力矩。我们的初步数据表明，大约只有60%的可用的转移肌肉力量可以自愿招募。我们进一步假设激活赤字随着姿势的变化而变化，并且这种变化的幅度和性质在候选转移之间是不同的。这样的变化可能会限制可以使用转移的肌肉的工作空间。我们的第一个目标是通过三种姿势量化这些激活缺陷，这些姿势与这些转移在日常生活中的典型使用有关。我们的第二个两个目标将评估皮质和脊髓对自愿激活这些肌肉的能力的贡献。总而言之，这些目标的结果将使我们更好地了解与每一块潜在的供体肌肉相关的生物力学，以及将其用作肘部伸展肌的神经约束。这些结果将有助于了解BI-TRI和PD-TRI手术的相对优点以及限制其使用的神经限制因素。重要的是，神经生理学评估对于制定适当的有针对性的康复干预措施也具有重要的意义，旨在改善与这些重要的手术途径相关的结果，以恢复自愿伸肘。

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.