135 Prospective, Randomized Study of Lumbar Facet Arthroplasty versus Lumbar Interbody Fusion for Spondylolisthesis – 3 Year Outcomes

INTRODUCTION: Until recently, surgical management of degenerative lumbar spondylolisthesis with stenosis was limited to decompression with instrumented fusion or decompression alone. Lumbar facet arthroplasty represents a new treatment option following FDA approval in June 2023 of the TOPS System. This analysis examines outcomes after 3 years comparing facet arthroplasty to TLIF. METHODS: Three-hundred-two subjects were randomly assigned (2:1) to either facet arthroplasty or transforaminal lumbar interbody fusion (TLIF) at one lumbar level as part of a multi-center, prospective, randomized, Investigational Device Exemption (IDE) trial. This analysis examined patient reported outcomes among patients that achieved 3 years of follow-up. The primary clinical outcome measures included improvement in the Oswestry Disability Index (ODI) and visual analog scales (VAS) for leg and back pain after 3 years as measured by the percentage of subjects achieving substantial clinical benefit (SCB). RESULTS: A total of 142 subjects with a minimum of 3 years of follow-up were available for this analysis (TOPS=107; TLIF=35). The percentage of subjects reporting greater than 36.8% improvement in ODI were 92.5% for the TOPS group and 82.9% for the TLIF group (p=0.109). For low back pain, 90.7% of TOPS subjects reported greater than 41.4% improvement compared to 71.4% for TLIF (p=0.009). For leg pain, 94.4% of TOPS subjects reported greater than 38.8% improvement compared to 91.4% of TLIF subjects (p=0.689). CONCLUSIONS: Lumbar facet replacement appears to be a viable option for treatment of degenerative spondylolisthesis compared to fusion. Continued follow-up is required to validate these findings and evaluate differences between facet arthroplasty and fusion.