Clinical Research Of Posterior Decompression Combined With Dynamic Neutralization System (Dynesys) For The Treatment Of Lumbar Degenerative Disease

Objective:To research the early and mid-term effect of posterior decompression combined with dynamic neutralization system (Dynesys) for the treatment of lumbar degenerative disease. To analyze radiographic changes of the operation secton and adjacent sgments after non-fusion internal fixation with Dynesys; To discuss the impaction on the stability of the adjacent segment and the promoting effect of the regeneration of the degeneration lumbar disc after Dynesys non-fusion fixation.Methods:Retrospectively analyse 117 cases from May 2011 to December 2014 of lumbar degenerative disease,expand posterior vertebral canal decompression,removal of nucleus pulposus combine with Dynesys system of pedicle internal fixation surgery,named Dynesys non-fusion fixation group(dynamic neutralization system, Dynesys group). Over the same period,we choose 95 cases of lumbar degenerative disease as contral group,expand posterior vertebral canal decompression and intervertbral bone graft fusion and internal fixation,named posterior lumbar interbody fusion group (PLIF group). Dynesys group has 66 cases of male patients and 51 female patients,average age (40.34±6.81).PLIF group has 53 cases of male patients and 42 female patients,average age (41.03±7.07).We used oswestry disability index(ODI)?Japan Orthopedic Association (JOA) scoring and visual analogue scale (VAS) to standard surgical treatment efficacy, and observed the postoperative complications. The following radiological parameters were measured in all patients:stabilized segments intervertebral angle, upper and lower adjacent segments intervertebral angles, Then the range of motion (ROM) was calculated. The average calibrated disc signal (CDS) of surgical level was calculated by lumbar MRI.Results:Two groups of patients were successfully completed surgery and follow-up, no recurrence of overhaul cases, no serious complications. Dynesys group follow-up 12?55 months, an average of (29.47+7.25) months. PLIF group follow-up of 12?55 months, an average of (31.54+8.71) months. The X-ray data of the lumbar spine was integrated,72 patients of Dynesys group received lumbar MRI review at the time of the last follow-up. At the time of the last follow-up, two groups of patients with lumbocrural pain VAS score and ODI index compared with preoperative were improved significantly (P< 0.05), the JOA scores were significantly increased (P< 0.05), compared to no significant statistical differences between groups (P> 0.05). Modified MacNab method to assess the two groups of postoperative curative effect was 95.72% and 93.68% respectively, there was no significant difference(P> 0.05). Dynesys group when compared with the preoperative,the last follow-up ROM of surgery segmental flexion and extension significantly reduced from 5.31°±2.60° to 3.27°±1.83° (P< 0.05),but still retain 68.37% of the preoperative ROM.There is no statistically significant defference after operation of the adjacent segment and lumbar overall ROM.The upper adjacent segmental ROM of the PLIF group obviously increased from (5.17±2.36)°to (7.25±3.57)°,the difference was statistically significant(P< 0.05).and there was no significant change to the lower adjacent segment and the lumbar overall ROM of the PLIF group.There was no significantly difference of preoperative ROM between the two groups,the upper adjacent segmental ROM of PLIF group was much bigger than Dynesys group at the last follow-up(P< 0.05).,The height of operative segment and the leading edge height of the upper segment decreased obviously(P< 0.05) of the Dynesys group.The trailing edge height of the upper segment of PLIF group decreased significantly(P< 0.05).The flange heifht of the lower adjacent segment and the lumbar lordosis angle were no significantly changed between two group after operation(P> 0.05).72 cases of Dynesys group received lumbar MRI reexamination,a total of 81 segments,their average CDS significantly improved from 39.92%±11.31% to48.37%±12.57%(P=0.004<0.01)Conclusion:Posterior decompression combined with Dynamic stabilization system for the treatment of lumbar degeneration disease has definite clinical curative effect.The Dynesys system can maintains the stability of the operation section, and can also keeps the activity of the fixed section, has realized the dynamic and stability. And what is more,it has no obvious influence on the stability of the adjacent segment. Intervertebral disc rehydration emerged after Dynesys non-fusion operation, which indicated that Dynesys may accelerated repair and regeneration of disc tissue.But due to the limitation of the observation index, it still needs further long-term follow-up studies.