Comparison of fusion rate and clinical results between CaO-SiO₂-P₂O₅-B₂O₃ bioactive glass ceramics spacer with titanium cages in posterior lumbar interbody fusion

Background Context The CaO-SiO₂-P₂O₅-B₂O₃ glass ceramics spacer generates chemical bonding to adjacent bones with high mechanical stability to produce a union with the end plate, and ultimately stability. Purpose The authors aimed to compare the clinical efficacy and safety of CaO-SiO₂-P₂O₅-B₂O₃ glass ceramics with a titanium cage that is widely used for posterior lumbar interbody fusion (PLIF) surgery in the clinical field. Study Design/Setting This is a prospective, stratified randomized, multicenter, single-blinded, comparator-controlled non-inferiority trial. Patient Sample The present study was conducted in four hospitals and enrolled a total of 86 patients between 30 and 80 years of age who required one-level PLIF due to severe spinal stenosis, spondylolisthesis, or huge disc herniation. Outcome Measures The Oswestry Disability Index (ODI), Short Form-36 Health Survey (SF-36), and pain visual analog scale (VAS) were assessed before surgery and at 3, 6, and 12 months after surgery. The spinal fusion rate was assessed at 6 and 12 months after surgery. Methods The spinal fusion rate and the area of fusion, subsidence of each CaO-SiO₂-P₂O₅-B₂O₃ glass ceramics and titanium cage, and the extent of osteolysis were evaluated using a dynamic plain radiography and a three-dimensional computed tomography at 12 months after surgery. The present study was supported by BioAlpha, and some authors (JHL, C-KL, and B-SC) have stock ownership (<10,000 US dollars). Results From the plain radiography results, the 6-month fusion rates for the bioactive glass ceramics group and the titanium group were 89.7% and 91.4%, respectively. In addition, the 12-month fusion rates based on CT scan were 89.7% and 91.2%, respectively, showing no significant difference. However, the bone fusion area directly attached to the end plate of either bioactive glass ceramics or the titanium cage was significantly higher in the bioactive glass ceramics group than in the titanium group. The ODI, SF-36, back pain, and lower limb pain in both groups significantly improved after surgery, with no significant differences between the groups. No significant differences between the two groups were observed in the extent of subsidence and osteolysis. Conclusions In lumbar posterior interbody fusion surgery, CaO-SiO₂-P₂O₅-B₂O₃ glass ceramics spacer showed a similar fusion rates and clinical outcomes compared with titanium cage.