Lewis SJ, et al. - This investigation was performed to elucidate the incidence of pseudarthrosis at the osteotomy site following three-column spinal osteotomies (3-COs) with posterior column reconstruction. Findings demonstrated that in three-column posterior-based osteotomies, there was an association between restoration of the structural integrity of the posterior column and > 95% fusion rate at the level of the osteotomy. Furthermore, pseudarthrosis at other levels was identified as the second most common reason for revision following adjacent segment disease in the long-term follow-up.