Nerve and Tendon Transfers for Upper Extremity Reconstruction in Spinal Cord Injury Patients: A Systematic Review

Background: Spinal cord injury (SCI) often results in upper extremity paralysis, significantly limiting independence and quality of life. Surgical interventions, including nerve and tendon transfers, offer the potential to restore critical functions such as hand grasp and elbow extension. However, the utilisation of these techniques remains limited despite promising outcomes. As such, this study aimed to systematically review the literature on the clinical outcomes of nerve and tendon transfers for upper extremity reconstruction in patients with cervical SCI. Methods: A systematic search was conducted in PubMed/Medline, Scopus, Embase and Web of Science following PRISMA guidelines. Studies reporting quantitative outcomes following nerve or tendon transfer in SCI patients were included. Risk of bias was assessed using the Newcastle-Ottawa Scale, and descriptive synthesis was performed due to heterogeneity. Results: Thirty studies met the inclusion criteria: 15 focussed on nerve transfers (208 patients, 319 limbs) and 15 on tendon transfers (360 patients, 447 limbs). The most common nerve transfers were brachialis to the anterior interosseous nerve (AIN) and supinator to the posterior interosseous nerve (PIN). Tendon transfers most frequently included extensor carpi radialis longus (ECRL) to flexor digitorum profundus (FDP) and brachioradialis (BR) to flexor pollicis longus (FPL). Both techniques demonstrated significant functional gains, with nerve transfers associated with more natural biomechanics and tendon transfers with greater strength. Early rehabilitation appeared to enhance outcomes. Conclusions: Both nerve and tendon transfer techniques can substantially improve upper limb function in patients with cervical SCI. Level of Evidence: Level III (Therapeutic).