Accelerated anterior vertebral growth resulting in kyphosis correction following posterior spinal instrumented fusion

Purpose To discuss the effect of posterior instrumented deformity correction and fusion on the progressive endochondral ossification of anterior vertebral body in a patient with congenital kyphosis secondary to type 1 vertebral anomaly. Methods A 15-year-old male patient presented with a progressively worsening congenital TL kyphosis of 52 degrees magnitude secondary to a posterior hemivertebra. His pre-operative antero-posterior vertebral height ratio (APVHR) and anterior vertebral body defect ratio (AVBDR) on CT were 38% and 49%, respectively. He underwent posterior instrumented deformity correction with multilevel type 1 Schwab osteotomies and fusion. Results Over the next 3 years, his serial imaging revealed progressive endochondral ossification and gradual increase in the dimensions of the vertebral body. At the final follow-up, there was a significant restoration of the deficient anterior vertebral body, and the final APVHR and AVBDR were 81% and 90%, respectively. Conclusions Restitution of posterior column integrity through stabilization can mitigate the compressive stresses across anterior column. Over a period of time, forces restraining the growth of anterior vertebral apophysis are alleviated, and the vertebra can potentially re-grow to near-normal dimensions in pediatric population. This phenomenon could be well-demonstrated in our patient during follow-up.