One- and 2-year outcomes of lumbar facet arthroplasty versus spinal fusion in young (

Abstract

Facet arthroplasty, an alternative to lumbar fusion, offers stabilization and preserves range of motion. This subanalysis of the TOPS IDE trial (FDA #G160168) compared facet arthroplasty, using the TOPS device, with a standard single-level transforaminal lumbar interbody fusion (TLIF) in patients stratified by age (<65 and ≥65 years) with symptomatic grade 1 degenerative spondylolisthesis with moderate to severe spinal stenosis at L2-5. Patient-reported outcomes (PROMS), including Oswestry disability index (ODI), visual analog pain scales (VAS), and Zurich claudication questionnaires (ZCQ), were assessed at baseline and multiple postoperative timepoints. Radiographic evaluation of flexion/extension range of motion (ROM) occurred at baseline, 12 months, and 24 months. Data were analyzed following an intention-to-treat model. Significance was defined as p<.05. About 299 patients were included (TOPS=206, TLIF=93). The groups were similar at baseline. At 2 years, the TOPS group had a greater proportion of patients report ≥15-point improvement for ODI (93.8% versus 77.1%, p=.011) and ≥20-point improvement for VAS back (84.4% versus 61.8%, p=.014). At 1 year, TOPS group had a greater proportion of patients report clinically significant improvements in all ZCQ categories (91.6% versus 78.5%, p=.012). In patients <65 years, the TOPS group had improved PROMS compared to TLIF at 2 years; however, these differences were less pronounced in patients ≥65 years old. The TOPS groups preserved more ROM at 12 (2.8° 95%CI [1.87; 3.74], p<.0001) and 24 (2.99° 95%CI [1.82; 4.15], p<.0001) months compared to TLIF. ROM was similarly preserved in patients aged <65 and ≥65. The rate of adverse events did not differ significantly between treatment groups. Facet arthroplasty preserves more ROM in all ages and leads to improved PROMS compared to TLIF, particularly in younger patients.