Repair of peripheral nerve defects in the upper extremity

Area of Science:

• Orthopedics
• Neurosurgery
• Regenerative Medicine

Background:

• Peripheral nerve defects in the upper extremity require surgical repair, often using end-to-end coaptation.
• Key techniques include in situ mobilization, rerouting, joint positioning, and bone shortening.
• A critical factor is managing tension during nerve elongation to bridge gap defects.

Purpose of the Study:

• To review and provide recommendations for peripheral nerve repair techniques, focusing on managing tension and mobilization.
• To analyze the impact of repair timing on nerve vascularity and tolerance to elongation.
• To establish guidelines for safe nerve mobilization distances and ratios to prevent neural ischemia.

Main Methods:

• Review of existing evidence on peripheral nerve repair techniques and outcomes.
• Analysis of factors influencing nerve elongation tolerance, including injury chronicity and vascularity.
• Examination of safe mobilization distances and ratios for peripheral nerves.

Main Results:

• Nerve elongation should be limited to 8%-10% of original length to prevent neural ischemia.
• Delayed repairs increase nerve vascularity, allowing greater elongation tolerance despite increased stiffness.
• Safe mesoneural stripping is up to 8-12 cm, with larger nerves tolerating greater mobilization (1:45 diameter:length ratio).

Conclusions:

• Optimal peripheral nerve repair balances defect bridging with minimizing tension-induced ischemia.
• Understanding the effects of injury chronicity on nerve vascularity is crucial for surgical planning.
• Recommendations are provided for safe nerve mobilization and repair strategies in acute settings.