Quantifying the Impact of C7 Spinal Nerve Harvest on Spontaneous, Patient-Initiated Movement of the Donor Upper Extremity

Plast Reconstr Surg. 2025 Oct 1;156(4):534e-540e. doi: 10.1097/PRS.0000000000011825. Epub 2024 Oct 15.

Abstract

Background: Transfer of a healthy C7 spinal nerve is a tool for upper extremity reanimation in patients with severe brachial plexus injury (BPI). Its use remains controversial because of concern for neurologic injury to the donor arm. Using wearable motion-sensor technology, the authors aimed to quantify donor arm morbidity after C7 spinal nerve harvest in patients with pan-BPI, reporting both the time and magnitude of donor arm movement in a real-world setting compared with healthy controls.

Methods: Seventeen patients who underwent contralateral C7 (CC7) transfer for traumatic pan-BPI at least 2 years prior were compared with 14 healthy controls. Each participant wore an accelerometer on both arms for 7 consecutive days. The vector time (VT) (or time of movement measured in hours per day) and the vector magnitude (VM) (or magnitude of arm movement measured as a single vector magnitude per second) were collected and compared between groups. The correlation between VT and VM and time from C7 spinal nerve harvest was also calculated.

Results: At a mean of 7.7 years after C7 spinal nerve harvest, there was no difference between donor and control arms for VT (5.76 ± 1.55 versus 5.45 ± 1.22 hours; P = 0.56) or VM (2,242,236 ± 753,853 versus 1,919,223 ± 579,723 activity counts; P = 0.20), regardless of donor arm dominance. The C7 harvest cohort used the injured arm 53% of the time and with 27% of the power of the donor arm.

Conclusion: There was no significant difference in time or magnitude of arm movement between donor arms and the arms of healthy controls.

Clinical question/level of evidence: Therapeutic, IV.

MeSH terms

  • Accelerometry
  • Adult
  • Arm / innervation
  • Brachial Plexus Neuropathies* / surgery
  • Brachial Plexus* / injuries
  • Brachial Plexus* / surgery
  • Case-Control Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Movement / physiology
  • Nerve Transfer* / adverse effects
  • Nerve Transfer* / methods
  • Spinal Nerves* / transplantation
  • Tissue and Organ Harvesting* / adverse effects
  • Tissue and Organ Harvesting* / methods
  • Upper Extremity* / innervation
  • Upper Extremity* / physiology
  • Young Adult