Proximal junctional acute collapse cranial to multi-level lumbar fusion: a cost analysis of prophylactic vertebral augmentation

Background context: Limited data are available regarding incidence of proximal junctional acute collapse after multilevel lumbar spine fusion. There are no data regarding the cost of prophylactic vertebral augmentation adjacent to long lumbar fusions compared with the costs of performing revision fusion surgery for patients suffering with this complication. Purpose: To perform a cost analysis of prophylactic vertebral augmentation for prevention of proximal junctional acute collapse after multilevel lumbar fusion. Study design: Retrospective chart review and cost analysis. Patient sample: All female patients older than 60 years undergoing extended lumbar fusions were reviewed to establish the incidence of proximal junctional acute collapse. Outcome measures: Cost estimates for two-level vertebroplasty, two-level kyphoplasty, and revision instrumented fusion were calculated using billing data and cost-to-charge ratios. Methods: Cost comparisons of prophylactic vertebral augmentation versus extension of fusion for patients suffering from proximal junctional acute collapse were performed. Results: Twenty-eight female patients older than 60 years underwent lumbar fusions from L5 or S1 extending to the thoracolumbar junction (T9-L2). Fifteen of the 28 patients had prophylactic vertebroplasty cranial to the fused segment. Proximal junctional acute collapse requiring revision surgery occurred in 2 of the 13 patients (15.3%) treated without prophylactic vertebroplasty. None of the 15 patients undergoing cement augmentation experienced this complication. Assuming a 15% decrease in the incidence of proximal junctional acute collapse, the estimated cost to prevent a single proximal junctional acute collapse was $46,240 using vertebroplasty and $82,172 using kyphoplasty. Inpatient costs associated with a revision instrumented fusion averaged $77,432. Conclusions: Prophylactic vertebral augmentation for the prevention of proximal junctional acute collapse may be a cost effective intervention in elderly female patients undergoing extended lumbar fusions. Further efforts are needed to determine more precisely the incidence of proximal junctional acute collapse and the effects of various risk factors on increasing this incidence, as well as methods of prevention.