The features of canine m. psoas minor histogenesis in the period of active growth during modeling the lumbar spine scoliosis

Abstract

Objective. To identify the features of m. psoas minor histogenesis in growing dogs under conditions of the development of spinal scoliotic deformity. Material and Methods . Experiments were performed on 16 four-month-old mongrel dogs, males and females. In animals of Series I, the deformity was created by gangliotomy at five lumbar motion segments (L 2 -L 6 ), in animals of Series II - by fixation of adjacent L 3 -L 6 vertebral bodies with nickel titanium staples possessing thermochemical shape memory effect, and in animals of Series III - by implantation of titanium plates into the subchondral zone of vertebral growth plates, together with the staples. The control series included intact age-matched dogs. The X-ray examination of animals of Series I-III was performed in dorsoventral and lateral views at days 14, 30, 60, 90, and 180 after surgery. Paraffin and semi-thin sections of m. psoas minor from concave and convex sides of the lumbar scoliotic deformity zone were studied using light microscopy in 3 and 6 months after surgery. Results . Standard signs of degenerative-dystrophic changes and reparation by restitution/substitution type characterize the histogenesis of m. psoas mino r. The most marked destructive changes in the muscles on both sides of the deformity retained in the long-term only in animals of Series III. Conclusions . The study results can be used for evaluating the adaptation and plasticity potential of paravertebral muscles, as well as for developing models of the spine scoliotic deformity.