Nerve transfer surgery is a safe, effective complement to surgeries for upper limb reanimation in tetraplegia and can lead to significant functional improvement, according to study results published in The Lancet.
Researchers evaluated 16 patients with tetraplegia who had been referred to a center for upper limb reanimation and deemed eligible for nerve transfer. All patients received single or multiple nerve transfers in one or both upper limbs, with some patients also receiving tendon transfers. Patients were evaluated at 1 and 2 years after surgery. There were 3 primary outcome measures: the action research arm test, the grasp release test, and the spinal cord independence measure.
Results revealed there were significant improvements in median action research arm test total score (median score 34.0 [interquartile range 24.0-38.3] at 2 years vs 16.5 [12.0-22.0] at baseline, P <.0001) and grasp release test total score (125.2 [65.1-154.4] at 2 years vs 35.0 [21.0-52.3] at baseline, P <.0001). There were also improvements in the spinal cord independence measure score by more than the minimal detectable change and the minimal clinically important difference, which researchers largely attribute to the restoration of triceps function. Mean grasp strength at 2 years was 3.2 kg (standard deviation [SD] 1.5) in patients who received distal nerve transfers (n=5), 2.8 kg (SD 3.2) in patients who received proximal nerve transfers (n=9), and 3.9 kg (SD 2.4) in patients who received tendon transfers (n=8).
The main limitation reported in this study was varying spinal cord injury patterns as indicated by the large SDs and interquartile ranges. Additionally, patients had multiple procedures performed on both limbs and the sample size for this study was small. Both of these factors may have presented additional challenges and confounded the analysis and results.
The study investigators concluded that nerve transfer surgery can significantly improve and restore upper limb function in tetraplegia and can safely and effectively be combined with tendon transfer surgery to achieve further improvements.
van Zyl N, Hill B, Cooper C, Hahn J, Galea MP. Expanding traditional tendon-based techniques with nerve transfers for the restoration of upper limb function in tetraplegia: a prospective case series [published online July 4, 2019]. Lancet. doi: 10.1016/S0140-6736(19)31143-2