The relation between zoledronic acid infusion and interbody fusion in patients undergoing transforaminal lumbar interbody fusion surgery

Abstract

Background Zoledronic acid (ZOL) has been shown to significantly increase bone mineral density and to decrease the incidence of osteoporotic fractures. However, its safety when used after lumbar interbody fusion surgery remains unclear. We sought to determine whether ZOL infusion 3 days after transforaminal lumbar interbody fusion (TLIF) affects the risk of nonunion. Methods This was a randomized, double-blind, placebocontrolled trial involving subjects who underwent TLIF surgery. Eighty-two subjects (=50 years of age) were randomly assigned to receive either 5 mg intravenous ZOL (N0 41) or placebo (N041) 3 days after surgery. Each patient received a lumbar computed tomography scan 6 months and 12 months postoperatively. We evaluated interbody fusion using the multiplanar reconstruction technique. Clinical outcome was evaluated with the Oswestry Disability Index. Bone turnover markers (amino terminal propeptides of type I collagen and C-telopeptide of type I collagen) were measured to investigate the biological effects of ZOL on spinal fusion. Results In the ZOL group, 7 levels (11.5%) exhibited nonunion; in the placebo group, 9 levels (14.5%) exhibited nonunion at 12 months postoperatively. This difference was not statistically significant (P00.82). The difference in ODI scores between two groups was not statistically significant at any of the follow-up times. However, ZOL decreased bone turnover markers significantly. Conclusions There was no association between ZOL treatment and nonunion of the lumbar spinal bone. Thus, undergoing lumbar interbody fusion surgery is not a valid reason to suspend or avoid treatment with ZOL. © Springer-Verlag 2012.