Correlation of three sciatic functional indices with histomorphometric findings in a rat sciatic nerve allograft repair model.

Walking track analysis was used to measure global functional recovery following sciatic nerve injury. The correlation of morphologic outcome and different sciatic functional indices (SFIs) depends on different variables. The objective of this study was to compare three different SFIs and their correlation with histomorphometric findings in a sciatic nerve allograft repair model in the rat without (group I, n = 8) or with (group II, n = 8) daily intramuscular administration of 0.1 mg/kg FK 506. The correlation of SFIs with each other and with the myelin basic protein (MBP) density of nerve sections proximal, median, and distal to sciatic nerve grafts (1.5 cm) at 4, 8, 12, and 16 weeks postoperation (p.o.) was calculated, and unoperated animals served as controls (n = 8). Significant differences between SFIs calculated for experimental groups I and II at 12 and 16 weeks p.o. suggested that superior functional nerve recovery occurred in group II. However, there were significant differences between all SFIs at 16 weeks p.o. in group II, whereas only differences between SFI 1 and SFI 2 + 3 occurred in group I. SFIs of group II did not reach the values of the unoperated group. There were significant differences between the histomorphometric outcomes of groups I and II. There was no significant difference of MBP density between group II and the unoperated group, suggesting complete morphologic recovery. In conclusion, we found significant correlation between the MBP densities of groups I and II and all SFIs, suggesting a close relationship between histomorphometric and functional findings. (c) 2009 Wiley-Liss, Inc. Microsurgery, 2009.