Nerve transfer to musculocutaneous for elbow flexion restoration in brachial plexus injury (Ulnar and/or Median vs. Intercostal): A systematic review and meta-analysis of comparative studies.

BACKGROUND

Nerve transfers are a cornerstone in the surgical management of traumatic brachial plexus injuries (BPIs) to restore elbow flexion. Common donor nerves include intraplexal sources like the ulnar and median nerves (fascicular transfers) and extraplexal sources like the intercostal nerves (ICNs). Despite the widespread use of both techniques, the optimal donor nerve remains a subject of debate. This systematic review and meta-analysis aims to compare these techniques for restoring elbow flexion in BPIs.

METHODS

A systematic search was conducted across PubMed, Embase, Cochrane Library, Scopus, and Web of Science to identify comparative studies. The quality of the studies included was assessed using the Newcastle-Ottawa Scale (NOS). Meta-analyses were performed to compare motor recovery (≥ M3), time to M3 recovery, and complication rates between the two surgical approaches.

RESULTS

The analysis included 13 studies with a total of 537 patients. In the overall cohort, which included mixed injury patterns, fascicular transfers showed a statistically significant advantage for achieving ≥ M3 recovery (RR = 0.84, 95% CI [0.75, 0.94]). However, when the analysis was restricted to patients with only upper-BPIs, there was no significant difference in achieving ≥ M3 strength between fascicular and ICN transfers (RR = 0.92, 95% CI [0.82, 1.04]). Fascicular transfers resulted in a significantly faster time to ≥ M3 recovery by approximately five months (MD = 5.25, 95% CI [2.87, 7.62]). Donor-site morbidity (18 sensory, 10 motor deficits) and wrist co-flexion were reported in fascicular transfer groups, whereas pneumothorax (4 cases) was the primary complication for ICN transfers.

CONCLUSION

In patients with upper-BPIs, fascicular and ICN transfers yield comparable elbow flexion strength. The choice of procedure is a trade-off between the faster recovery offered by fascicular transfers and the better rehabilitation course of ICN transfers.