Nerve and Free Gracilis Muscle Transfers for Thumb and Finger Extension Reconstruction in Long-standing Tetraplegia.
OBJECTIVE
With spinal cord injuries, muscles below the level of the lesion remain innervated despite the absence of volitional control. This persistent innervation protects against denervation atrophy and may allow for nerve transfers to treat long-standing lesions within the spinal cord. We tested the hypothesis that in chronic spinal cord lesions, muscles remained viable for reinnervation.


METHODS
To test this hypothesis, we operated on 7 patients with tetraplegia to reconstruct thumb and finger extension after a mean interval of 5 years since injury. During surgery, if electrical stimulation of the posterior interosseous nerve (PIN) produced muscle contraction, the nerve to the supinator (NS) was transferred to the PIN. If no contractions were demonstrated, the muscles of the extensor compartment of the forearm were replaced via a free gracilis transfer with innervation supplied by the NS.


RESULTS
After an average of 26 months, M3 recovery of thumb and finger extension was observed in the 3 upper limbs from the 2 youngest patients who underwent a nerve transfer. None of the free gracilis-treated patients achieved scores above M2.


CONCLUSIONS
In our youngest patients aged 27 and 34 years, who were operated on 6 years after spinal cord injury, transfer of the NS to the PIN partially restored hand span.


METHODS
Therapeutic V.
Center of Biological and Health Sciences, Department of Neurosurgery, University of the South of Santa Catarina (Unisul), Tubarão, Santa Catarina, Brazil; Department of Orthopedic Surgery, Governador Celso Ramos Hospital, Florianópolis, Santa Catarina, Brazil. Electronic address: drbertelli@gmail.com.
Jayme Augusto
JA
Bertelli
Center of Biological and Health Sciences, Department of Neurosurgery, University of the South of Santa Catarina (Unisul), Tubarão, Santa Catarina, Brazil.
Marcos Flávio
MF
Ghizoni
D000328:Adult; D005385:Fingers / Q000294:innervation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation / Q000637:transplantation*; D016067:Nerve Transfer; D011782:Quadriplegia / Q000209:etiology / Q000601:surgery*; D013119:Spinal Cord Injuries / Q000150:complications; D013933:Thumb / Q000294:innervation
Nerve transfer; free muscle transfer; spinal cord injury; tetraplegia