Internal Neurolysis of the Common Peroneal Nerve With Lower Extremity Flexion Increases Likelihood for Direct End-End Nerve Repairs.

Introduction An understanding of common peroneal neuropathy is essential to improving current surgical techniques and overcoming limitations of permanent common peroneal nerve (CPN) damage, which negatively impacts quality of life. This study focuses on quantifying additional nerve length after CPN internal neurolysis with varying degrees of lower extremity flexion, in order to improve end-end nerve repairs in the setting of injury with a significant gap. Materials and methods Full and partial neurolysis dissections were performed on salt- and formaldehyde-perfused cadavers. For accurate measurement of additional length obtained, all dissections were palpated at the fibular head and CPNs transected proximally at the distal fascial border. We chose this site to measure the nerve length obtained because it is the common site for CPN injury and the most clinically applicable. The amount of nerve length gained from neurolysis alone was measured at the location of the common peroneal nerve passing deep to peroneus longus before and after being transected. Nerve length after neurolysis was measured in cm at 10° increments, using a protractor starting at 90° and ending at 0°. Results Both formaldehyde- and salt-perfused cadavers have a significant difference in nerve length obtained after neurolysis at each angle of measurement. This is seen for both dissection groups with p-values <0.05. Conclusions In this study, we found a direct statistically significant relationship between extent of neurolysis and increased angle of measurement, to amount of addition nerve length obtained in both neurolysis groups despite fixation type.