Discrepancy of vertebral and disc wedging between porcine scoliosis model and early onset scoliosis in humans

Abstract

Objective To compare the disc and vertebral wedging in patients with early onset scoliosis (EOS) and porcine scoliosis model.Methods Eight scoliosis pigs and 13 EOS cases (all without congenital spinal deformity) were reviewed radiographically.Each disc and vertebral wedging in the major curve was measured.The wedging angle as a proportion of the curve' s Cobb angle was then calculated.The average wedging angle of 5 vertebrae and 4 discs were calculated,including apex and two superior and two inferior vertebrae as well as 4 discs between these vertebrae.Additionally,the wedging of the 5 vertebrae and 4 discs in the apical region was also calculated as a proportion of the sum of those.Results No difference with respect to the Cobb angle was observed between the two groups (59.3° vs.54.7°,P ＞ 0.05).The wedging of both vertebrae and discs was greatest at the apex of the scoliosis deformity.Vertebral wedging played a major role in the contribution of Cobb angle in both groups.However,the wedging of the vertebra was found to be greater in porcine scoliosis than in EOS patients (P ＜ 0.01).No significant difference in the average wedging angle of the five vertebrae was found between porcine scoliosis and EOS patients (P ＞ 0.05).However,the vertebral wedging as a proportion of the apical Cobb angle of the porcine scoliosis model was larger than that of EOS patients (75.4％ vs.60.2％,P ＜0.01).Conclusion The pattern of vertebrae and discs wedging is different between porcine scoliosis and EOS patients.It should be taken into account when appling the results extracted from the porcine model to humans and exploration of new correction techniques. Key words: Scoliosis; Vertebrae ; Disc ; Pig