Minimally Invasive Decompression Versus X-stop in Lumbar Spinal Stenosis: a Randomized Controlled Multicenter Study

Study Design: Prospective randomized controlled multicenter study.

Objective: To compare the effect of X-Stop with minimally invasive decompression (MID) in patients with neurogenic intermittent claudication due to lumbar spinal stenosis.

Summary Of Background Data: Lumbar spinal stenosis is the most common indication for operative treatment in elderly. Laminectomy has been the "gold standard," but MID is now widely used. Another minimally invasive surgery option is X-Stop showing good result compared with nonoperative treatment, but showing higher reoperation rate than laminectomy.

Methods: We enrolled 96 patients aged 50 to 85 years, with symptoms of neurogenic intermittent claudication within 250-m walking distance and 1- or 2-level lumbar spinal stenosis, randomized to either MID or X-Stop. Primary outcome was Zurich Claudication Questionnaire in this intention-to-treat analysis. Secondary outcome was Oswestry Disability Index, EuroQol 5-dimensional questionnaire, numerical rating scale 11 for lower back pain and leg pain, and risk for secondary surgery and complications.

Results: No significant differences were found in Zurich Claudication Questionnaire between the groups at any follow-ups. Both groups had a statistical and clinical significant improvement at 6 weeks and throughout the 2-year observation period. The number of patients having secondary surgery due to persistent or recurrent symptoms was significantly higher in the X-Stop group, odds ratio (95% confidence interval) = 6.5 (1.3-31.9). Complication rate was similar and low, but more severe for MID.

Conclusion: Both MID and X-Stop led to significant symptom improvements. There were no significant clinical differences in effect between the methods at any of the follow-up time points. X-Stop had significant higher risk of secondary surgery. Complication was more severe for MID.