Clinical Study Of Adjacent Level Nucleus Pulposus Protrusion After Discectomy

【Objective】: To evaluate the clinical characteristics and efficacy of revision surgeryfor adjacent level nucleus pulposus protrusion after discectomy after discectomy.【Method】：15cases with adjacent level nucleus pulposus protrusion after primarydiscectomy who were treated from November2007to February2012wereretrospective reviewed. There were11males and4females with the average age of53.1years old （range，22to71years）. The mean period between primary surgeryand recurrence was73.5months （range，6months to238months）.The demographicand imaging data before and after operation were recorded. JOA score and Macnab’sstandard were used to evaluate the effect of reoperation and the related factors ofadjacent level nucleus pulposus protrusion were analyzed.【Result】：All15patients were followed up with the mean follow-up of14.6months（range，2months to54months）.The surgical approach for primary discectomyincluded fenestration in6cases，semi-laminectomy in4cases，laminectomy in2cases，PLF in1case，PLIF in1case and posterior implantation of Cage in1case;andthe revision surgical approach was discectomy in4cases，PLIF in10cases andlaminectomy internal fixation in1case.the clinical symptoms before reoperation aremore severity than primary discectomy in most patients. During the imaging databefore reoperation，all15cases developed lumbar kyphosis or decrease of lordosisand disc space narrowed，spinal sagittal imbalance and spondylolisthesis was evidentin1case and2patients showed Modic change.The average JOA score was13.67before operation and23.60after operation （P<0.05）. Macnab’s standard wasexcellent in8patients，good in5，and fair in2cases，the excellent and good rate is86.7%.【Conclusion】：The intervertebral levels higher than postoperative level are apt todevelop nucleus pulposus protrusion rather than which lower than postoperative level.And it’s apt to develop secondary spinal stenosis. Appropriate surgical approach can ensure a good outcome.