108. A novel bone graft has higher fusion rate than local autologous bone in stand-alone posterolateral fusion: a propensity score adjusted analysis

BACKGROUND CONTEXT Posterolateral fusion (PLF) is a common procedure for spinal fusion, either stand-alone or in combination with interbody fusion. Achieving solid fusion in stand-alone PLF is challenging. OSTEOAMP® is a novel allograft bone graft substitute (BGS) manufactured using a proprietary process that retains high levels of endogenous growth factors, and offers a promise of an effective solution for BGS in PLF. PURPOSE To compare radiologic and patient outcomes following stand-alone PLF that used a novel BGS vs local autologous bone (LAB). STUDY DESIGN/SETTING A propensity score-adjusted nonconcurrent multicenter prospective cohort study. PATIENT SAMPLE Patients undergoing PLF with either the novel BGS or LAB. The OSTEOAMP group underwent a 1- or 2-level procedure and the LAB group underwent a 1-level procedure. OUTCOME MEASURES Fusion, Oswestry Disability Index (ODI), back and leg pain, SF36 PCS and MCS at 12 months. METHODS Clinical and patient outcomes for PLF using OSTEOAMP (N=38 patients) or LAB (control, N=104 patients) from two prospective studies were compared utilizing a propensity score approach to reduce selection bias in baseline characteristics. After application of propensity score region, 38 OSTEOAMP and 82 LAB patients were included in the analysis. The weighted analysis was performed using propensity scores as weights. Fusion was defined as uni- or bilateral bridging bone on CT scans and an absence of angular and translational motion ( RESULTS The fusion rate was 84% and 61% in the OSTEOAMP and LAB groups, respectively (P=0.028, RR = 1.4 (95% C.I. = 1.0 to 1.9)). At 12-month follow-up, both groups showed statistically significant improvements in all outcomes. There was no difference in ODI outcomes between the groups. The average ODI at 12 months was 20.3 and 18.8 in the BGS and LAB subjects, respectively. There was a marked and significant improvement in SF 36 PCS in both groups (15.4 and 13.1 in BGS and LAB groups, respectively, n.s.). SF 36 MCS improved in both groups (7.1 and 7.6 in BGS and LAB groups, respectively). Both groups experienced similar improvements in back pain and leg pain. Safety outcomes were similar between the groups. CONCLUSIONS OSTEOAMP is a viable replacement for LAB and achieves better radiologic fusion rates and similar patient outcomes in stand-alone PLF. FDA DEVICE/DRUG STATUS OSTEOAMP® is compliant to 21 CFR 1271 and is regulated as a 361 HCT/P.