Mean 5-Year Follow-Up Results of a Facet Replacement Device in the Treatment of Lumbar Spinal Stenosis and Degenerative Spondylolisthesis

OBJECTIVE: Flexible stabilization has been utilized to maintain spinal mobility in patients with early-stage lumbar spinal stenosis (LSS). Previous literature has not yet established any nonfusion solution as a viable treatment option for patients with severe posterior degeneration of the lumbar spine. This feasibility study evaluates the mean 5-year outcomes of patients treated with the Total Posterior Spine System (TOPS) facet replacement system in the surgical management of lumbar spinal stenosis and degenerative spondylolisthesis. METHODS: Ten patients (2 men, 8 women, mean age: 59.6 years) were enrolled into a non-randomized prospective clinical study. Patients were evaluated with standing anteroposterior, lateral, flexion and extension radiographs and magnetic resonance imaging scans, back and leg pain visual analog scale scores, Oswestry Disability Index, Zurich Claudication Questionnaire and the SF-36 questionnaires, preoperatively, 6 months, 1 year, 2 years, and latest follow-up at a mean of 5 years postoperatively (range: 55e74 months). Flexion and extension standing lumbar spine radiographs were obtained at 2 years to assess range of motion at the stabilized segment. RESULTS: The clinical outcome scores for the cohort improved significantly across all scoring systems. Radiographs at 2 years did not reveal any loss of position or loosening of metal work. There were 2 incidental durotomies and no failures at 5 years, with no patient requiring revision surgery. CONCLUSIONS: The TOPS implant maintains clinical improvement and motion in the surgical management of LSS and spondylolisthesis, suggesting that it can be considered an option for these indications.