Lumbar facet distraction and fixation in patients with lumbar spinal stenosis: Long-term clinical outcome and reoperation rates

OBJECTIVE: Symptomatic lumbar spinal stenosis (LSS) unresponsive to conservative therapy is commonly treated by surgical decompression. In this study, we compared clinical outcomes after decompressive surgery for LSS in patients implanted with interarticular spacers along with microdecompression (MD) with those receiving only MD. METHODS: A retrospective study was analyzed 40 patients (Group A) affected by LSS treated by MD and implant of interarticular spacers comparing the outcome with a homogeneous group of 40 patients with LSS treated with MD alone (Group B). Clinical outcome was evaluated using the Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, as well as Macnab's criteria. RESULTS: At 1-year follow-up, ODI improved in both groups with statistically significant differences as compared to baseline and both Groups (P < 0.05). Statistically significant differences were observed at 3-year follow-up (P < 0.05), without further variation at 5-year follow-up. At 1-year follow-up, VAS for back and leg pain scores was significantly better than that of Group B (P < 0.05). At 3-year follow-up, back and leg pain scores were no longer significantly improved (P > 0.01), resulting almost the same at 5-year follow-up. A comparison of functional outcomes between the groups showed significant improvements in Group A as compared to Group B (P < 0.05). The reoperation rate was 10% in Group A and 30% in Group B. In implanted patients, successful fusion was obtained in 90% of the cases. CONCLUSIONS: Interarticular spacers showed significant and clinically meaningful improvements in pain and disability, even in a long follow-up.