Early supraclavicular nerve grafting or distal nerve transfer for restoration of elbow flexion in incomplete adult traumatic brachial plexus injuries.

Introduction: Restoration of elbow flexion is the primary treatment goal in adults with supra-clavicular traumatic brachial plexus injuries (ATBPI). To date, many nerve surgeons will initially await spontaneous recovery when dealing with an incomplete brachial plexus injury to allow sufficient recovery in the median and ulnar nerves to enable distal fascicular nerve transfers (DFNT). An alternative strategy is reconstruction by supraclavicular nerve grafting, which should be performed as early as possible after trauma to minimize denervation time. Research question: Does early supraclavicular grafting yield equivalent elbow flexion power to DFNT in adults with incomplete ATBPI? Methods: A retrospective single-centre cohort included adults with C5-C6, C5-C7 or C5-C8 traction lesions treated surgically within 12 months of injury (2009-2021). Lesion extent was defined by clinical, radiological, and intra-operative findings. Patients underwent nerve reconstruction aiming at biceps reconstruction with either nerve grafting or transfer; the reconstruction strategy considered patient age, delay, gap length and stump quality. The primary outcome was biceps strength at ≥2-year follow-up or earlier when a biceps MRC grade 4 was reached. Results: A total of 164 consecutive surgically treated ATBPI patients were identified, of which 84 met inclusion criteria (C5-C6 n = 30, C5-C7 n = 26, C5-C8 n = 28). Nerve grafting was performed in 21 and DFNT in 52 patients; 11 received other reconstructions. All supraclavicularly explored lesions showed root avulsions or Sunderland grade IV-V damage. DFNT produced MRC 4 outcomes, but the proportion achieving at least useful elbow flexion (MRC 3-4) was similar between DFNT and grafting. Lesion extent influenced both treatment choice and outcome, with DFNT used mainly in C5-C6/C5-C7 injuries and grafting favoured in more extensive C5-C8 lesions. In the grafting group, each additional month of delay reduced the odds of a better MRC category by about 50% (OR 0.49, 95%CI 0.29-0.83); for DFNT, timing was not significantly associated with outcome. Conclusions: Early supraclavicular grafting, typically used in more extensive lesions, yields lower proportion of MRC 4 biceps strength than DFNT, yet comparable rates of useful elbow flexion (≥MRC 3). Nerve grafting should be performed early, as it is more time-sensitive than DFNT, but offers reconstructive advantages in extended upper trunk injuries.