A histomorphometric study of leg bone nerves for leg lengthening at the level of proximal meta-diaphysis experimentally

Purpose. A morphologic and histomorphometric study of leg bone nerves for transosseous distraction osteosynthesis of canine leg at the level of proximal meta-diaphysis. Materials and Methods. The histomorphometric study of the leg bone nerves in 7 adult mongrel dogs which underwent leg lengthening with the Ilizarov fixator at the level of proximal meta-diaphysis for 28 days by 1 mm for 4 times. Results. The changes of both compensatory-adaptive and destructive-reparative character revealed. The presence of combined antecurvation and valgus deformity of the leg (from 2° to 10°) was a factor which aggravated the alteration of leg bone nerves after the end of distraction. By a month after the fixator removal the proportion of destructively changed fibers increased to 5.5-6.4 % due to blood supply deterioration of nerve conductors. Dystrophic and destructive changes in microvessel epineurium, extensive subperineural and endoneural edemas evidenced nerve microcirculation disorders. Conclusion. The neurological complications (5-30% of cases) not infrequently occurring in clinical practice for leg lengthening at the level of proximal meta-diaphysis may be a result of not only compensatory-adaptive changes in leg bone nerves, but destructive-reparative ones as well.