[An experimental study on the functional recovery of denervated muscles--effects of stump rotation in nerve suture (author's transl)].
There are many factors which affect the end result of nerve suture. Clinically it is said tht rotation of the stumps at suture site has an unfavorable effect upon functional recovery, owing to discrepancies of funicular patterns and inappropriate funicular approximation. In order to evaluate the effect of rotation of the stumps at suture sites, tibial nerves of thirty-three full grown rabbits were used. After the tibial nerve was cut at a point three cm proximal to the popliteal fossa, in one group (20 rabbits) the nerve was sutured without rotation (0 degrees group) and in another group (19 rabbits) with 180 degrees rotation of the proximal stump (180 degrees groups), using epineural technique under operating microscope. Six months later return of nerve function was evaluated electrophysiologically and histologically. Electrophysiological measurements included electromyography, motor conduction velocity and muscle strength stimulating proximal stump. Histological evaluation following weighing included H-E stain, DPN diaphorase stain for muscle and Cajal stain for axon. There were no significant differences between the two groups with regard to the passage rate of axons at the suture site, motor conduction velocity or recovery rate of muscle weight. But muscle strength of the plantaris in the 180 degrees group was significantly weaker than that of 0 degrees group, and in the 180 degrees group, recovery rate of muscle strength was lower than that of muscle weight, though they were the same in the 0 degrees group. Histochemically there was marked fibre type grouping of the reinnervated muscle in both groups. The author concluded that in the rabbits, the rotation of nerve stumps at suture site does not affect the passage rate of axons at the suture site nor maturation of the axon. However, it does impose unfavorable influence upon functional recovery. Further problems may arise for the recovery of complex functions when reconstitution of proprioceptive feed-back system is considered.
D000200:Action Potentials; D000818:Animals; D001369:Axons / Q000502:physiology; D004576:Electromyography; D009121:Muscle Denervation; D009129:Muscle Tonus; D009416:Nerve Regeneration; D011817:Rabbits; D013536:Suture Techniques; D013979:Tibial Nerve / Q000502:physiology / Q000601:surgery