Management of Upper Extremities in Tetraplegia

Current Concepts

Michael S. Bednar, MD; Julie C. Woodside, MD

Disclosures

J Am Acad Orthop Surg. 2018;26(16):e333-e341. 

In This Article

Other Surgical Options

Nerve Transfers

Nerve transfers for restoration of function in patients with tetraplegia are attractive because the anatomic muscle designed for that function is reinnervated, avoiding the complications, technical challenges, and functional rehabilitation of tendon transfers. Most publications are case reports and technique articles.[29–32]

Bertelli et al[29] reported on one patient undergoing bilateral transfer of the teres minor motor branch to the long head of triceps motor branch at 9 months after injury, with M4 strength bilaterally at 14 months postoperatively.

van Zyl et al[30] reported on a patient with C6 level tetraplegia who underwent triple nerve transfer 6 months after injury with a teres minor nerve branch transfer to the long head of triceps nerve, brachialis nerve branch transfer to anterior interosseous nerve, and supinator branch transfer to posterior interosseous nerve. Results at 19 months postoperatively were M4 elbow extension, thumb and finger flexion, finger extension, and M3 thumb extension. The patient had independent thumb extension, abduction, and wrist ulnar deviation.

Functional Electrical Stimulation

In patients with spinal cord injury, the damage is to the upper motor neurons with preservation of the lower motor neuron arc below the level of the injury. At the level of the injury, the lower motor neurons are not viable and the muscles undergo atrophy from loss of the neuromuscular junctions. Below the level of the injury, the anterior horn cells are viable, the neuromuscular junctions are intact, the muscle is viable, and a reflex arc is present.[4] Functional electrical stimulation (FES) stimulates these muscles to function through an external neuroprosthesis with surface or percutaneous electrodes and an implantable prosthesis.[33,34] The electrical impulse directly stimulates the neuron, which then activates the muscle at the neuromuscular junction.

Candidates are usually patients with spinal cord injuries at the C5-6 level with no use of the hands and wrists and few options for surgical intervention (ie, ICSHT zero and 1). The FES system consists of a stimulator to activate the muscles and the input transducer/control unit in which the patient uses a signal (eg, joint movement, voice, and respiration) to start the pattern of movement.[35] Combining tendon transfers with FES will give the maximum benefit for the patient.[36] The first-generation Freehand neuroprosthesis, which is no longer manufactured, was an implantable FES to control grasp using contralateral shoulder motion.[37] All patients who received the neuroprosthesis had improved independence in one task and 78% in at least three tasks with a >90% satisfaction rate.[37] The second-generation implantable system has an increased number of channels and has been shown to be effective on restoration of bilateral hand release, pinch, and grasp in a small number of patients.[38] Future goals of research in this area include the ability to stimulate more muscles, control the degree to which they are stimulated, and integrate stimulation of multiple muscles to allow smooth complex motions, such as gentle versus strong grasp and pinch.

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