FUNCTIONAL INDEXES FOR SCIATIC, PERONEAL, AND POSTERIOR TIBIAL NERVE LESIONS IN THE MOUSE

The sciatic functional index previously described in rats has proven t o be a reliable index of functional recovery following sciatic nerve i njury and repair. A similar functional assay of sciatic, peroneal, and posterior tibial nerve lesions was developed in a mouse model. Forty- eight C57/BL6 mice were randomly divided into 4 groups: sham surgery, sciatic nerve transection, peroneal nerve transection, and posterior t ibial nerve transection. Preoperative and postoperative (48 hours) wal king tracks were obtained. The pawprints were analyzed in a blinded fa shion for measurements of print length (PL), toe spread (TS), intermed iate toe spread (IT), and the orthogonal distance from the toe of one paw to the hind pad of the opposite paw (TOF). Multiple linear regress ion analysis was performed using these measurements to determine their significance and appropriate weighted contribution to the index formu la for each nerve lesion. For the sciatic functional index, changes in the PL (P = 0.0092) and TS (P = 0.0008) were significant, resulting i n an R-2 value of 0.88. For the peroneal functional index, only TS (P < 0.0001) was significant with R-2 = 0.83. For the posterior tibial in dex, only PL (P < 0.0001) was significant with R-2 = 0.89. Formulas fo r a sciatic, peroneal, and posterior tibial functional index were crea ted based on the coefficients derived from the multiple linear regress ion analysis. The indices that were developed will allow investigators to assess functional recovery following specific nerve lesions in mic e. (C) 1998 Wiley-Liss, Inc.