Evaluate whether polyethylene glycol (PEG)–mediated axonal fusion improves early sensory, motor, and patient-reported outcomes versus standard neurorrhaphy after mixed (median/ulnar) Sunderland V forearm injuries.

Upper-extremity peripheral nerve injuries (UE-PNIs) constitute the majority of traumatic PNIs (~69-73), and up to 40% of cases requiring surgery fail to restore meaningful functions. PEG is a hydrophilic fusogen that may acutely re-establish axolemmal continuity, attenuate Wallerian degeneration, and preserve neuromuscular targets, potentially accelerating recovery. This study presents preliminary results from the first randomized clinical trial evaluating PEG-mediated neurorrhaphy for mixed motor and sensory nerve injuries of the distal forearm.

Eligible participants were adults 18-75 years old presenting within 72 hours with Sunderland V UE-PNIs requiring primary repair or autograft. Blinded assessors performed Semmes-Weinstein monofilament testing (SWMT), static two-point discrimination (S2PD), Medical Research Council Classification (MRCC) sensory/motor grading, and the Michigan Hand Outcomes Questionnaire (MHQ) at approximately 1 week, 1 month, 6 months, and 12 months postoperatively. Statistical analyses used mixed-effects linear regression models. 

Thirteen patients (5 non-PEG, 8 PEG) were analyzed; demographics, injury, and operative variables were balanced. By postoperative day 21, PEG showed better sensory outcomes: lower S2PD (16.6 vs. 21.7; p = 0.008), lower SWMT (5.82 vs. 7.31; p = 0.003), and higher MRCC sensory (p = 0.02); PEG also reported lower pain (p = 0.03). Mixed-effects models across visits showed PEG associated with lower estimated S2PD (−6.68 ± 2.64; p = 0.032) and SWMT (−1.89 ± 0.63; p = 0.013), higher MRCC sensory (+1.27±0.52; p = 0.039) and motor (+1.13±0.38; p = 0.013), and higher MHQ without pain (+3.38±1.42; p = 0.046). No PEG-related adverse events or synkinesis were observed.

PEG application at neurorrhaphy sites is associated with accelerated early recovery and better patient-reported function and well-being, suggesting clinical utility in mixed distal forearm nerve reconstruction.