The relationship of functional return to varying methods of nerve repair

This experimental study correlated varying methods of nerve repair with the degree of functional return using the rat sciatic nerve as a model. Six groups of adult male Sprague-Dawley rats (300 to 350 g) had their left sciatic nerve crushed (Group 1), transected and not repaired (Group 6), or transected and repaired using four methods that varied the degree of axonal alignment (Groups 2, 3, 4, and 5). Functional return was evaluated weekly using the sciatic functional index (SFI) and histology. Group 1 (crush) had a significantly better functional return than the other groups (p less than .001). Group 6 (no repair) had a significantly worse functional return than the other groups (p less than .001). Groups 2, 3, 4, and 5, regardless of the precision of axonal alignment, experienced the same degree of functional return (p less than .05). In all groups, with the exception of Group 1 (crush), the degree of functional return was poor. As multiple modifications in conventional microsurgical neurorrhaphy have not resulted in a significant functional improvement, factors not addressed by current techniques apparently compromise clinical results. Further improvement in the results of neurorrhaphy will require modifications in our techniques beyond presently conventional microsurgical methods.