Fig. 4

Mechanical sensation was reduced immediately after the operation, and patients often reported “no sensation at all.” Thereafter mechanical sensitivity thresholds slightly improved, but never reached values measured at the non-operated side (a). VAS scores remained constant over time on both non-operated and operated feet (b). Vibrotactile sensation was slightly reduced after surgery (ns). In time, vibrotactile sensation recovered, but remained reduced compared to the non-operated foot (c). Blunt sensation returned quite rapid after surgery; by 1 MPO slight touch with the 10 g filament elicited in more than 50% of the patients a positive response (d). Sharp sensation recovered slower; only in the last month there was a clear improvement in the majority of patients detectable (e). Cold sensation showed a slower recovery in time, and even after 12 MPO the majority of patients were unable to sense the cold metal tip (f). Data of a–c represent mean ± SEM where */**/*** represent p < 0.05/0.01/0.001 operated vs non-operated, ^### represents p < 0.001 preoperative vs post-surgery, + represents p < 0.05 post-surgery compared to immediately after surgery (0 MPO). Graphs d–f represent percentages of total