Histological changes in the anterior tibial muscle for canine leg lengthening with he increased daily rate of different-division distraction

Purpose. Comparative analyzing histological changes in skeletal muscle for canine leg lengthening using autodistraction daily by 3 mm for 120 and 180 times. Material and Methods. The histological changes in the anterior tibial muscle studied in the experiments on 15 dogs for leg lengthening by an autodistractor with the daily rate of 3 mm for 180 and 120 times. Results. Both modes of distraction established to be traumatic. The leading mechanisms of injury – muscle microinfarction with further focal substitutionary fibrosis, the disintegration of myons’ contractile apparatus structures not accompanied by sarcolemma integrity breach and thereby not causing tissue (inflammatory) reaction – less marked in case of “3 mm for 180 times” distraction. Conclusion. The foci of acute ischemic necrosis of muscle fibers revealed in the experimental series studied (muscle microinfarctions) don’t allow recommending the modes of «3 mm for 120 times» and «3 mm for 180 times» to be used in clinical practice. Perspectively, the further search of the optimal mode of high-division distraction with increased daily rate should be made.