Long-term Effect And Changes Of Postoperative Magnetic Resonance Imagine After Posterior Lumbar Discectomy With Microendoscopic Discectomy

Objective: To investigate the long-term effect of posterior lumbar discectomy with microendoscopic discectomy(MED) as comparison with Love method .Methods: We sent 111 letters to the patients who underwent single segment lumbar discectomy. Thirty-nine patients came to the hospital, including 22 patients(12 males and 10 females, average age, of 46 years, mean follow-up period, 81 months)who underwent microendoscopic discectomy and 17 patients(15 males and 2 females, average age, of 53 years, mean follow-up period, 73 months) who underwent Love method discectomy. The pre- and postoperation conditions were evaluated by using questionnaires and JOA scores. Thirty-two patients were examined by lumbar MRI, of which 30 patients were checked with lumbar enhanced MRI. The indentation of the dura,the height of the intervertebral space were measured and the cataplasia of endplate and the signal changes of operation areas were observed from MRI.Results: The satisfaction rate , working capacity recovery rate and subjective evaluation of surgery in questionnaires were not significantly different between MED group and Love method group(p﹥0.05).The preoperation JOA scores of MED group was (10.95±5.52), Love method group's was (12.35±7.25). The postoperation JOA scores of MED group was (23.64±4.38) , Love method group's was (23.64±4.38). Pre- and postoperative JOA scores was significantly different in each group(p ﹤0.001). Pre- and postoperative difference was not significant between two groups(p﹥0.05).MED group's improvement rate was (65.66±31.00)%. Love method group's was (60.41±28.84)%.There was not significantly different between two groups(p﹥0.05). MED group's excellent rate was 81.82%. Love method group's was 76.47%.The indentation of the dura ,the height of the intervertebral space significantly reduced after surgery in each group(p﹤0.05),but there were no differences between two groups(p﹥0.05).The cataplasia of endplates were ModicⅠandⅡbefore operation, but the majority of patients'endplates were ModicⅢafter discectomy. The intervertebral space signal increased by 13 patients and 4 patients decreased in MED group. The intervertebral space signal increased by 6 patients and 9 patients decreased in Love method group. In enhanced MRI ,enhanced scar tissues were found in eight patients and enhanced nerve roots were found in two patients in MED group. Two patients had enhanced scar tissues associated with enhanced nerve roots in MED group. Enhanced scar tissues were found in ten patients and enhanced nerve roots were found in two patients in Love method group. Two patients had enhanced scar tissues associated with enhanced nerve roots in Love method group. Each group had one patient who was recurrent disc herniation. Nine patient in MED group and seven patients in Love method group had disc herniation adjacent to the operation segment. One patient hadⅠ°spondylolisthesis on operation segment in MED group and one patient hadⅠ°retrolisthesis on operation segment associated with disc herniation in Love method group. Lumbar lateral curvature was found in one patient in Love method group.Conclusions: The long-term effect of the MED had the same results as the Love method discectomy. The subjective evaluation (the satisfaction rate, working capacity recovery rate and positive judgment of surgery),the objective evaluation (JOA scores ,the improvement rate, the excellent rate), changes of postoperative MRI and complications indicate that two operation methods have the same effects.