110. Use of a novel allograft in single-level posterolateral lumbar spine fusion surgery: 1-year clinical and radiographic results from a prospective multicenter study with comparison to reported results for ICBG

Abstract

BACKGROUND CONTEXT Instrumented posterolateral lumbar fusion (PLF) surgery is commonly used to alleviate pain and other symptoms associated with degenerative conditions of the lumbosacral spine. Although autologous iliac crest bone graft (ICBG) remains the “gold standard” grafting material for these procedures, surgeons have sought alternatives to avoid the potential morbidity associated with ICBG harvest. OSTEOAMP is a novel allograft bone graft substitute (BGS) that has been processed to retain multiple endogenous growth factors. A prospective multicenter study was designed to enable comparison of this novel product to available data for autologous bone graft controls from large randomized controlled trials (RCTs). PURPOSE Compare 1-year outcomes from an ongoing study investigating radiographic and clinical outcomes to reported results for ICBG controls from a large RCT. STUDY DESIGN/SETTING Prospective multicenter single-arm study conducted in the United States. PATIENT SAMPLE Consenting patients, 21 to 85 years of age, scheduled for PLF surgery with a diagnosis of degenerative disc disease (DDD), degenerative spondylolisthesis, and/or mild degenerative scoliosis. OUTCOME MEASURES Bilateral radiographic fusion (blinded, multireader with adjudication) was assessed. Additional outcome measures included Oswestry Disability Index (ODI), Short Form-36 (SF-36) physical component summary (PCS) and mental component summary (MCS) scores, and improvement in leg/back pain scores. Product-related serious adverse events (SAEs) and secondary surgeries were also assessed. METHODS Forty-two patients were prospectively enrolled after obtaining IRB approval at each of 9 centers and underwent a 1-level (26 patients) or 2-level (16 patients) PLF procedure utilizing the novel BGS (67% BGS: 33% local bone graft). Clinical outcomes were measured and radiographic studies were obtained preop and postop at 1.5, 3, 6, and 12 months. Radiographic analysis included CT assessment of fusion at 12 months. One-year outcomes were available for 23 of the 26 patients who underwent a 1-level procedure and were compared to 1-year outcomes reported for ICBG controls from a large previously published RCT by estimation of novel BGS:ICBG Risk Ratios (RR) with 95% confidence intervals (CI). RESULTS One-year fusion rates and results for each of the measures (novel BGS vs ICBG) are as follows: bilateral fusion = 73.9% (17/23) vs 82.5% (151/183) with RR 0.90 (0.69, 1.15 CI); ODI (>15 improvement) = 73.9% (17/23) vs 73.9% (150/203), RR 1.00 (0.77, 1.29 CI); leg pain = 95.7% (22/23) vs 87.6% (177/202), RR 1.09 (0.99, 1.21 CI); back pain = 91.3% (21/23) vs 93.1% (180/203), RR 0.98 (0.86, 1.12 CI); SF-36 MCS = 73.9% (17/23) vs 68.7% (138/201), RR 1.08 (0.83, 1.40); SF-36 PCS = 95.7% (22/23) vs 86.6% (174/201), RR 1.10 (1.00, 1.22 CI). No statistically significant difference was found in RR between groups for all comparisons. No product-related SAEs and only one secondary surgery were observed with the novel BGS. CONCLUSIONS One-year clinical and radiographic outcomes following single-level PLF procedures with OSTEOAMP compare favorably to results reported for an ICBG control group from a large RCT. FDA DEVICE/DRUG STATUS OSTEOAMP (Approved for this indication)