The Application Of Dynamic Neutralization System Implanted Through Wiltse Approach For Treatment Of Degenerative Lumbar Diseases

Objective：A retrospective study was designed to evaluate the clinical efficacythrough Wiltse approach to implant dynamic stabilization system（Dynesys） fortreatment of degenerative spinal diseases．Methods： Thirty-nine consecutive patients （22male and17female） withdegenerative spinal diseases were treated with Dynesys through Wiltse approach fromOctober2010to October2011. Single segment was involved in31cases and doublesegments in8cases. The average age was45years old ranging from27to65.Twenty-six patients suffered from lumbar disc herniation including2of L_3-4,12ofL_4-5,5of L_5-S1,4of L_3-4 and L_4-5, and3of L_4-5 and L_5-S1. Ten patients sufferedfrom lumbar spinal stenosis including7of L_4-5,2of L_5-S1,1of L_4-5 and L_5-S1.And3patients suffered from lumbar spondylolisthesis （grade I） including2of L_4-5,1of L_5-S1. After implantation of Dynesys through Wiltse approach, decompression byfenestration or partial laminectomy was carried out. All the patients were evaluated bythe visual analogue scale（VAS），the Chinese version of the Oswestry Disability Index（ODI）, radiography and ROM before and after operation. UCLA （University ofCalifornia at Los Angeles Grading Scale） system was used to evaluate the adjacentsegment degeneration. Postoperative complications related to operation were alsorecorded.Results：The mean follow-up time was9.1months （ranging from6to19months）.The neural function of all patients were improved to different extents. The VAS scorewas6.87±1.28points preoperatively,2.16±1.28points6months after operation, and2.28±1.17points at final follow-up time respectively. The ODI score was 53.85%±10.29%preoperatively,12.74%±3.16%6months after operation,, and13.48%±3.17%at final follow-up time respectively （P<0.05）.In the neutral,hyperextensional and hyperttexional position, there was no significant difference in thepreoperative and postoperative ROM of interfered segment and adjacent segments（P>0.05）.The ROM of operated segment was8.22±1.20degrees preoperatively,5.23±1.98degrees6months after operation, and5.23±1.06degrees at final follow-uptime respectively （P<0.05）. The ROM of upper segment was5.41±1.85degreespreoperatively,5.54±2.02degrees6months after operation, and5.78±2.12degrees atfinal follow-up time respectively （P>0.05）.The ROM of lower segment was6.42±2.03degrees preoperatively,6.46±2.18degree6months after operation, and6.65±2.36degrees at final follow-up time respectively （P>0.05）. Statistical analysisshowed that there was no significant correlation in the therapeutic effect index （VASimprovement rate, ODI rate of improvement）, hospitalization time, operation time,bleeding volume in operation, and ROM changes of operation segment and adjacentsegments （P>0.05）.Conclusion: The Dynesys system instrumentation can not only preserve thestability of the stabilized segments and the integrity of anatomical structure, but also themotion of stabilized segments. Besides, it has no adverse effects on adjacent segments.There are more advantages to implant dynesys system by Wiltse approach such as lessintraoperative injuries，shorter recovery time，less myalgia resulting from paraspinalmuscles dissection and so on．...