Recovery of skeletal muscle after laceration and repair.

Few data are available regarding structural and functional recovery of lacerated skeletal muscle after repair. This study used the extensor digitorum longus muscle of rabbits to document recovery after laceration and repair and a healing period of 12 weeks. Completely lacerated muscles recovered approximately 50% of their ability to produce tension but were able to shorten to 80% of normal. Partially lacerated muscle bellies recovered approximately 60% of their ability to produce tension and normal ability to shorten. Histologic specimens revealed that the lacerations did not cause necrosis of either segment. After the recovery period, histologic and histochemical sections revealed that the distal segment initially isolated from the nerve supply showed histologic changes of fiber atrophy and size variability, increased fibrosis, and nuclear centralization suggestive of denervation. Dense scar separated the two fragments. Data show that skeletal muscle can recover useful but not normal function after laceration and repair.