Durability of Suppl. Rod Constructs-SuppleMentAry Rod Technique for Long-segment Posterior Instrumented Spinal Fusions

This is a multicenter retrospective comparative cohort study. The index surgery for this study is primary or revision long-segment posterior thoracolumbar (TL) instrumented fusion using either a supplementary rod construct or a dual-rod construct. Eligible patients who already had index surgery, will be identified for enrollment through a review of medical records of the participating surgeons at the study sites.