Surgical treatment of the spinal stenosis with an interspinous distraction device: do we really restore the foraminal height?

Abstract

The aim of implantation of interspinous device is to unload the facet joints, restore foraminal height and provide stability in order to improve the clinical outcome of surgery. After microsurgical decompression, Coflex™ device was applied. Patients were evaluated at a month after surgery and last follow-up using the visual analogue scale (VAS) and Oswestry Disability Index (ODI). Foraminal height and lumbar lordosis angle were recorded. The mean preoperative VAS was 7.85 and fell to 1.7 a month after surgery (p < 0.0001). At the last follow-up the mean VAS score was 1.65 (p < 0.0001). The mean foraminal heights were measured 19.95 mm preoperatively and 25.05 mm a month after surgery (p < 0.0001). The mean foraminal height was 21.60 mm at the last follow-up (p=0.002). The mean lumbar lordosis were measured 32.05 and 34.3 degrees at preoperative and a month after surgery respectively (p=0.155). The mean lumbar lordosis was 32 (±5.99) degrees at the last follow-up (p=0.974). Using the Coflex device is a minimal invasive, effective and safe procedure. Restoration of the foraminal height may not be a responsible factor for clinical improvement. We think microsurgical decompression looks responsible of the good clinical outcome and using interspinous device is unnecessary. Comparative clinical studies can be informative.