Dataset for: Musculotendon adaptations but preservation of spinal reflex pathways following agonist-to-antagonist tendon transfer

Tendon transfer surgeries are performed to restore lost motor function, but outcomes are variable, particularly those involving agonist-to-antagonist muscles. Here, we evaluated the possibility that lack of proprioceptive feedback reorganization and musculotendon adaptations could influence outcomes. Plantaris to tibialis anterior tendon transfer along with resection of the distal third of the tibialis anterior muscle belly was performed in 8 cats. Four cats had concurrent transection of the deep peroneal nerve. After 15-20 weeks, intermuscular length and force dependent sensory feedback were examined between hindlimb muscles, and the integrity of the tendon-to-tendon connection and musculotendon adaptations were evaluated. Three of the transferred tendons tore. A common finding was the formation of new tendinous connections, which often inserted near the original location of insertion on the skeleton (e.g. connections from plantaris toward calcaneus and from tibialis anterior toward first metatarsal). The newly formed tissue connections are expected to compromise the mechanical action of the transferred muscle. We found no evidence of changes in intermuscular reflexes between transferred plantaris muscle and synergists/antagonists whether the tendon-to-tendon connection remained intact or tore, indicating no spinal reflex reorganization. We propose the lack of spinal reflex reorganization could contribute to altered task dependent temporal activation of the transferred muscle. Taken together, these findings suggest musculotendon plasticity and lack of spinal reflex circuitry reorganization could limit functional outcomes after tendon transfer surgery. Surgical planning and outcomes assessments after tendon transfer surgery should consider potential consequences of the transferred muscle’s intermuscular spinal circuit actions.肌腱转移手术旨在恢复受损的运动功能，但手术效果存在较大差异，尤其是涉及主动肌-拮抗肌转移的病例。本研究旨在探讨本体感觉反馈未发生重塑以及肌腱适应性改变是否会影响肌腱转移手术的预后效果。研究对8只家猫实施了跖肌-胫骨前肌腱转移术，同时切除胫骨前肌肌腹的远端三分之一区段；其中4只家猫同时接受了腓深神经切断术。术后15至20周，研究人员检测了家猫后肢肌肉间的长度与力依赖性感觉反馈，并评估了肌腱-肌腱连接的完整性以及肌腱适应性变化情况。本研究中共3例转移肌腱发生断裂。一项常见发现为新生腱性连接的形成，这类连接通常附着于骨骼上的原有附着点附近（例如：跖肌向跟骨形成的连接，以及胫骨前肌向第一跖骨形成的连接）。这类新生组织连接预计会削弱转移肌肉的力学功能。无论肌腱-肌腱连接是否保持完整或发生断裂，研究均未观察到转移跖肌与其协同肌/拮抗肌之间的肌间反射发生改变，这表明脊髓反射通路未发生重塑。本研究提出，脊髓反射通路未发生重塑可能会导致转移肌肉在任务依赖下的时序激活模式发生改变。综合来看，上述研究结果表明，肌腱可塑性不足以及脊髓反射通路未发生重塑，可能会限制肌腱转移手术后的功能预后效果。因此，在肌腱转移手术的术前规划与术后预后评估中，应当考虑转移肌肉的肌间脊髓环路活动可能带来的潜在影响。