RESUMO
<p><b>OBJECTIVE</b>To evaluate mid-term clinical results of microendoscopic discectomy (MED) for the treatment of lumbar disc hermiation.</p><p><b>METHODS</b>In the study, 117 patients were reviewed,including 63 male and 54 female, ranging in age from 24 to 72 years,with an average of 50.6 years. Among the patients, 60 patients had simple lumbar disc herniation, 10 patients had simple lateral crypt stenosis, 32 patients had lumbar disc herniation combined with lateral crypt stenosis, and 15 patients were combined with calcified nucleus pulposus. Two patients had herniation in L3-L4, 56 patients in L4-L5, 48 patients in L5-S1, 11 patients in L4-L5 and L5-S1. The central type of lumbar disc herniation occurred in 22 patients and the lateral type of herniation occurred in other 95 patients. The Protrusion type of herniation occurred in 32 discs, ruptured type in 73 discs, and free type in 12 discs. Ninety-eight patients had lumbar and leg pain in one side, and 19 patients in double sides. MED was used to remove the nucleus and decompress the nerve root canal.</p><p><b>RESULTS</b>All the patients were followed up and the duration ranged from 48 to 84 months,with an average of 5.5 years. According to lumbar and leg pain evaluation criteria from spinal group of Chinese Orthopaedic Association, there were 93 patients got an excellent result, 16 good and 8 poor.</p><p><b>CONCLUSION</b>Appropriate control indications and skillful surgical techniques are the key points to decrease the complication and to improve the curative effect.</p>