STRUCTURAL PECULIARITIES OF M. QUADRICEPS OF FEMUR IN EXPERIMENTAL RATS IN THE CONDITIONS OF FEMUR DEFORMITY FORMING

Abstract

Stable posttraumatic deformities of long bones lead to changes in interrelationships in damaged segments that could cause dysfunction of muscles and ligaments, joint surface integrity and range of motion in limb joints.The goal: to investigate in experiment on rats the structural peculiarities of muscles adjacent to peak of posttraumatic femur diaphysis deformity.Methods: varus deformity on the level of middle third of femur diaphysis was simulated on 15 white mature rats (age at the beginning of study — 6 moths). Preshaped K-wire (with appropriate size and angle 35°) was inserted in the intramedullary canal after transversal osteotomy to create deformity. Euthanasia was performed 1, 3 and 6 moths after operation followed by histological investigation.Results: 1 month after deformity modeling the most severe destructive changes were noticed in muscle fibers adjacent to the peak of deformity on convex side. Tortuosity, swelling, loss of cross striation, nucleus pycnosis with their migration towards the center of fibers, edema of endomysium and perimysium were found. The severity of destructive changes decreased at the distance of the zone of deformity modeling. 3 months after operation the most severe destructive changes in muscle fibers were observed on the convex side of deformity as well. 6 months after deformity modeling on the both convex and concave sides of deformed bone the structure of muscle fibers generally corresponded to the structure of muscle structure of intact animals of appropriate age. The absence of difference in the structure of muscles on convex and concave sides of deformity on this term caused by their restructuring as a reaction to prolonged stress.Conclusions: structural-function peculiarities of the muscle of injured extremity should be taken into consideration while planning the tactics of treatment of long bones posttraumatic treatment.