Neural mobilization combined with a polylactic acid conduit enhances functional and morphological recovery following median nerve repair.

BACKGROUND

Peripheral nerve transection repaired with a poly(lactic acid) (PLA) conduit remains associated with incomplete functional recovery. Neural mobilization (NM) may enhance nerve regeneration, but its optimal timing and effects remain unclear. This study investigated how NM timing affects nerve regeneration and functional recovery after median nerve transection and PLA conduit repair.

METHODS

Nineteen young adult female Wistar rats underwent median nerve transection and repair using a 10-mm PLA conduit to bridge an 8-mm gap. Animals were assigned to control (no mobilization) or NM groups initiated 1, 5, or 30 days after surgery. Mobilization consisted of scapular depression and forelimb movements for 10 min, three times weekly. Recovery was assessed using von Frey and grip strength tests, electrophysiological, histological, morphometric, and muscle analyses 8 weeks after surgery.

RESULTS

NM effects were time-dependent, with mobilization initiated 5 days after surgery producing the most favorable functional and electrophysiological outcomes. This timing improved grip strength, mechanical sensitivity, and CMAP amplitude without affecting latency. NM also enhanced axonal regeneration and increased the proportion of myelinated fibers, but did not significantly affect angiogenesis, myelin thickness, or muscle atrophy.

CONCLUSIONS

Initiating NM 5 days after nerve repair may represent a favorable therapeutic window following severe peripheral nerve injury. NM at this time point improved functional, electrophysiological, and structural outcomes, although it did not significantly affect muscle atrophy or myelin thickness. These findings support NM as a time-dependent therapeutic approach and provide a basis for further investigation of its translational potential future clinical studies and applications.