ABSTRACT
The goal of this study was to determine whether sensory motor nerve crossover could
alter post-denervation atrophy of skeletal muscle. Sixty adult Lewis rats were divided
into three groups: 1) unilateral transection of the tibial nerve alone; 2) unilateral
transection of the tibial nerve with immediate repair; and 3) unilateral tibial and
sural nerve transections with repair of the proximal sural nerve (sensory) to the
distal tibial nerve (motor). The unoperated hind legs acted as positive controls.
At 1 and 2 months postoperatively, posterior compartment musculature was harvested,
weighed, then fixed and stained for histologic analysis.
One month postoperatively, mean muscle weight in Group 1 animals (transection alone)
was 23.0 ± 2.6 percent of the control side; for Group 2 animals (motor-motor repair)
was 40.9 ± 42 percent; and for the sensory-protected Group 3 animals (sensory-motor
repair) was 26.7 ± 2.8 percent of controls (n = 15 per group). Two months postoperatively,
the mean weights were 14.5 ± 0.9 percent, 58.8 ±7.3 percent, and 21.1 ± 3.1 percent
of controls for Groups 1, 2, and 3, respectively (n = 5 per group). Differences between
groups were statistically significant.
Histologic analysis of Group 1 specimens revealed generalized atrophy of all muscle
fibers. In Group 2, specimens showed evidence of reinnervation and less atrophy. Group
3 specimens demonstrated an atrophic pattern with islands of non-atrophic fibers scattered
throughout.
Sensory protection was thus shown to have a significant effect on post-denervation
atrophy in rat skeletal muscle.
