Comparison Of Wallis Interspinous Dynamic Stablization Device And Posterior Lumbar Discectomy For The Treatment Of Lumbar Disc Herniation: A Prospective Study

BACKGROUND:Traditional surgical strategy for the treatment of Lumbar disc herniation is posterior lumbar discectomy or lumbar internal fixation. In recent years, non-fusion technique for the stabilization of lumbar spine has been developed. An interspinous dynamic stabilization system—Wallis has gain more and more popularity.OBJECTIVE:To compare Wallis interspinous dynamic stabilization device and posterior lumbar discectomy for the treatment of lumbar disc herniation determining the the safety, therapeutic effect and indications of spinal non-fusion technique.METHODS:This prospective study included 60 patients with Lumbar disc herniation administrated in the Depatment of Orthopedic Surgery, Guangdong Province People's Hospital from July, 2008 to July, 2010. Thirty patients underwent posterior lumbar discectomy combined with Wallis interspinous dynamic stabilization, compared with control group including 30 patients treated with posterior lumbar discectomy alone. Clinical evaluations included VAS score, JOA score and ODI score. Disc height(DH) and the range of motion(ROM) of the operated and proximal adjacent segments and the intervertebral angle(IA) of the operated segments were evaluated by x-ray and MRI examination. All these parameters were evaluated preoperatively, 1 weeks postoperatlvely, and an average of 13.7 months postoperatively.RESULTS:The Wallis group included 15 males and 15 females with a mean age of 41.40±10.71 years, were followed up with an average of 12.27±7.42 months. The Control group included 20 males and 10 females with a mean age of 39.47±9.79 years, were followed up with an average of 15.20±5.05 months. The average duration of follow-up of two groups was 13.73±6.47 months. There were no differences in mean age, mean final follow up time, the clinical and radiological parameters preoperatively between two groups(P>0.05). Both groups had significant improvement in VAS score,JOA score and ODI score of postoperation comparing to that of preoperative level. (1) At 1 week postoperatlvely, there was no significance difference in VAS score,JOA score and ODI score between two groups(P>0.05). Disc height(DH) of operated segments improved significantly(P<0.05) in Wallis group while did not change(P>0.05) in control group. Both of the disc height(DH) of proximal adjacent segments and the intervertebral angle(IA) of operated segments did not change in both groups. (2) At final follow up postoperatively, there was significance difference in VAS score,JOA score and ODI score between two group(sP<0.05), the Wallis group has a better improvement than the Control group. In the DH of the operated segments, the Wallis group had no significant difference(P>0.05)but the control group had a significant decreas(eP<0.05)comparing to that of preoperative level. The disc height(DH) of the proximal adjacent segments and the intervertebral angle(IA) of operated segments did not change in both groups. The wallis group had a significant decrease(P<0.05) in ROM of oprerated segments while no difference(P>0.05) in ROM of proximal adjacent segments.CONCLUSIONS:Wallis interspinous dynamic stabilization system seems to be effective in correcting lumbar disc herniation by liminating pain and maintaining DH and ROM of the operated and the proximal adjacent segments in short-term follow up.