Dynamic Stabilization Using X-stop Versus Transpedicular Screw Fixation in the Treatment of Lumbar Canal Stenosis; Comparative Study of the Clinical Outcome

Objective: A comparative randomized prospective clinical study to compare the clinical outcome of transpedicular screw fixation and dynamic stabilization using X-stop. Background: Spinal fusion has been offered to patients who suffer from lumbar spinal stenosis or spondylolisthesis. Despite improvement in fusion it significantly alters spinal biomechanics, which causes premature disc degeneration at levels neighboring fusion. Dynamic stabilization maintains or restores intervertebral motion in a controlled fashion, whether by restricting the extremes of spinal movement or by dampening the kinetic energy involved in motion. Methods: This study included 60 patients who were divided into 2 equal groups (A and B) randomly assigned to undergo either transpedicular screw fixation (group A) or dynamic stabilization using X-stop (group B). Patients had degenerative spondylolisthesis or retrolisthesis (Grade I), lateral or central spinal stenosis. Participants were evaluated preoperatively, postoperatively at 3 weeks, and then at 6-month, 12-month, and 24-month intervals. Visual Analog Scale (VAS) was used to score both lower-limb and back pain. Patient functioning was evaluated using the Oswestry Disability Index (ODI). Results: In group A, the mean pain and function scores improved as follows: leg pain from 80.5 to 35.5, back pain from 54 to 37.5, and ODI score from 55 to 34.5%. In group B, the mean pain and function scores improved as follows: leg pain from 82.5 to 25.5, back pain from 52 to 29.5, and ODI score from 53 to 26.5%. Conclusions: The long-term outcome of dynamic stabilization is promising. The procedure is preferable to fusion because it avoids the greater tissue destruction and the morbidity of donor site problems. Adjacent-level disc degeneration after lumbar fusion has been well documented and little controversy exists as to the additional disability resulting from this proximate degenerative process.