Finite element simulation of a scoliotic spine with periodic adjustments of an attached growing rod.

Early Onset Scoliosis (EOS) is a deformity of spine which occurs during growth. Spinal growing rod instrumentation is currently a procedure of early onset scoliosis management and newer technologies to treat scoliosis without fusion hold the exciting promise of a new paradigm in spinal deformity care. A Finite Element Model (FEM) of a scoliotic spine was created and enhanced to simulate spine growth after the attachment of a growing rod. Growing rod instrumentation was included utilizing FEA to accurately simulate the required 3D forces and moments to achieve the desired correction. We measured forces on the rods and the spine during adjustment periods (for correction of the spinal deformity) and during growth periods. For this study, a two-year period was simulated with adjustments at six month intervals. The FEM allowed us to collect data during growth periods from sensors which are only accessible during the surgical procedures.