Effect of localized trauma and temporary splinting on immature skeletal muscle and mobility of the femorotibial joint in the dog.
The right pelvic limbs of 2 groups of dogs were splinted in extension for 2 weeks. In 1 of these groups, the dogs were anesthetized and the distal portion of the quadriceps femoris muscle was traumatized before splinting. Two groups of control dogs were also used; neither group was splinted, but 1 group was anesthetized, and their muscles were traumatized. The range of motion of the femorotibial joint was measured in all 4 groups before splinting and 3 and 9 weeks after splinting. Types I and II muscle fiber diameters and percentages were also recorded at 3 and 9 weeks in all groups. Flexion of the femorotibial joint was limited after splinting (P less than 0.001), but less so after trauma and splinting than after splinting alone (P less than 0.0001). A reversible type I fiber atrophy occurred in most restricted muscles (P less than 0.001) and early type II fiber atrophy was seen in a few muscles after trauma and splinting (P less than 0.002). Multifocal fiber necrosis was the only irreversible change seen after 3 weeks of splinting with or without concurrent muscle trauma. Relative fiber percentages did not change appreciably during splinting or recovery.
D000818:Animals; D004283:Dog Diseases / Q000209:etiology / Q000473:pathology*; D004285:Dogs; D006614:Hindlimb / Q000293:injuries*; D007103:Immobilization; D007596:Joints / Q000503:physiopathology; D009132:Muscles / Q000473:pathology; D009133:Muscular Atrophy / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D013165:Splints / Q000009:adverse effects / Q000662:veterinary*