Experimental scoliosis in the course of unilateral surface electrostimulation of the paravertebral muscles in rabbits: effects according to stimulation period.
Scoliosis among children and adolescents is a persistent problem. Worldwide, it afflicts between 0.3 to 15.3% of the population. One of the treatment methods of this disorder is to administer lateral electrical surface stimulation (LESS) for 9 h/day; unfortunately, however, this results in side-effects. Improvements are therefore sought. The main aim of the study was to investigate the effects of the duration of LESS on scoliosis progression and to evaluate, qualitatively, any associated macroscopic effect on other internal organs. The length of the LESS period was based on the results of previous clinical trials in children. The experiment was performed on 13 developing rabbits (aged 3.5 months), divided into three groups: group 1, rabbits subsequently treated for 9 h/day (n=5); group 2, animals treated for 2 h/day (n=5); group 3, control rabbits without electrostimulation (n=3). Stimulation was carried out using an electric stimulator SCOL-2 according to the method modified by Kowalski. The animals were killed after 3 months and examined macroscopically, and their adrenal glands were dissected and weighed. The X-rays of the spine of the animals were taken to analyse spinal deformity. Macroscopic lesions in rabbits from groups 2 and 3 (control) were mostly absent. While there was considerable deviation in group 1, all the stress features were apparent. The enlargement of the adrenal glands observed in group 2 was significantly less marked than in group 1. The degree of scoliotic deformity (according to the Cobb method) ranged from 21 degrees to 410 degrees (mean, 31.2 degrees) and from 23 degrees to 330 degrees (mean, 30 degrees) in groups 1 and 2, respectively. LESS resulted in spinal deformity to a similar degree in the rabbits treated for either 9 or 2 h/day over a 3-month period. Short LESS therapy (2 h/day) significantly reduced detrimental effects associated with the treatment on internal organs of laboratory animals.