45S5 bioglass graft decreases surgical site infection after posterior transforaminal lumbar interbody fusion reconstruction compared to alternative graft materials

Background: 45S5 bioglass synthetic bone graft is an established bone graft material with known intrinsic antimicrobial material properties well documented in the in vitro setting. However, 45S5 bioglass graft has not been studied clinically to determine if these antimicrobial properties translate to decreased surgical site infection (SSI) rates. This study sought to determine whether synthetic 45S5 bioglass graft decreases the risk of SSI in posterior transforaminal lumbar interbody fusion (TLIF) compared to other non-bioglass bone graft materials in the clinical setting.

Methods: This multi-center retrospective review included all patients undergoing open TLIF procedures from 2017–2022. The minimum follow-up period was 1-year. The final included cohort consisted of 1,376 patients (470 bioglass and 906 non-bioglass). Patient demographic, comorbidity, perioperative, and acute postoperative variables were obtained for each patient and compared between groups. The primary outcome measure was SSI at 1-year postoperatively. Multivariable regression analysis was performed to compare outcomes of interest between the groups, controlling for variables with P<0.05 on univariate analysis.

Results: The use of 45S5 bioglass synthetic graft for posterior TLIF was associated with a decreased risk of SSI within one year compared to patients who received non-bioglass grafts [0.6% vs. 2.7%, odds ratio (OR) =0.19, 95% confidence interval (CI): 0.04–0.68, P=0.02], when adjusting for covariates.

Conclusions: Results of this multicenter retrospective analysis support an association between 45S5 bioglass graft use and a reduced risk of SSI in the setting of posterior TLIF, consistent with the intrinsic antimicrobial properties of 45S5 demonstrated in prior in vitro work. Causation cannot be established from a retrospective design; prospective, randomized trials are warranted to confirm these findings. This association uniquely expands the recognized clinical properties of 3rd-generation 45S5 bioglass bone graft, which is both an established synthetic osteobiologic graft material and, in this series, associated with a significantly decreased SSI risk.