3D geometrical analysis of the CTM brace effect on scoliotic patient

The effect of the braces or instrumentation was studied using stereoradiogr aphy or axial tomography. The CTM brace was only studied clinically using f rontal radiography. This study addresses a 3D analysis of the immediate eff ect of initial CTM brace wearing on the scoliotic spine using an MRI method developed previously. The MRI examination had been performed on eight scol iotic children wearing a first CTM brace. The MRI protocol was performed fi rst with the brace and then without the brace. Using an in house processing software SIP and the pre and post processor Patran, two geometrical models of the vertebral bodies and intervertebral discs, with and without brace, were obtained. Different geometrical parameters for CTM brace effect analys is were computed. Seven braces decrease the scoliosis, transforming a C sha pe in the top view into a S or I shape and correcting the maximum deformity plane. One brace do not correct the scoliosis and aggravated this plane. T hree braces aggravated and five corrected the maximum deviation plane. The intervertebral disc shift forward is corrected by the brace. Three braces r otated the apical vertebra and translated the end vertebrae. Two braces tra nslated the apical vertebra and rotated the end vertebrae. Two braces trans lated the three vertebrae, One brace translated and rotated the three verte brae. The method developed using MRI gave quantitative and qualitative data for understanding the CTM brace effect on the scoliotic spine. Our results show that the CTM brace has a local and global three dimensional action. T his method is limited to small curvatures and to braces only worn at night, In the future, double curvatures will be analysed and the brace effect sim ulated using mechanical modelling.