Sciatic nerve functional index (SFI)

The plantar blotting was performed on the 7th and 14th day after operation in each group. The measurement of SFI was based on a reference [¹⁴]. SFI was measured using an apparatus as follows. The SFI apparatus was made from wood with 60 × 7 × 20 cm (L, A, H, respectively) dimensions and its floor was covered with white paper. Functional recovery was assessed at 2^nd, 4^th, 6^th, 8^th, 10^th and 12^th weeks after surgery. The lengths of the third toe to its heel (PL), the second toe to the fourth toe (IT) and the first to the fifth toe (TS) were measured on the contralateral normal side (N) and the experimental side (E). SFI was computed by the following modified formula: SFI = – 38.5 (EPL – NPL/NPL) +109.5(ETS – NTS/NTS) +13.3(EIT – NIT/NIT) – 8.8. In this study, SFI oscillates around 0 for normal nerve function, whereas around −100 SFI represents total motor sciatic nerve dysfunction.