title: The efficacy of microendoscopic discectomy in reducing iatrogenic muscle injury.
abstract: OBJECTIVE
  The objective of this study was to evaluate the invasiveness of microendoscopic discectomy (MED) in comparison with microscopic discectomy (MD) by measuring serum levels of creatine phosphokinase (CPK)-MM and lactate dehydrogenase (LDH)-5, and by comparing visual analog scale (VAS) scores of postoperative pain.
  
  
  METHODS
  This study included a group of 15 patients who underwent surgery using MED and 15 patients who underwent surgery using MD, both for single-level unilateral herniated nucleus pulposus. The CPK-MM and LDH-5 levels were measured at admission and after 1, 3, and 5 days postoperatively. Pain assessment was recorded using scores raging from 0 to 10 on a subjective VAS at admission and at 1, 3, and 5 days postoperatively.
  
  
  RESULTS
  The mean CPK-MM levels were lower for the MED group than for the MD group at both 3 (576.1 +/- 286.3 IU/L compared with 968.1 +/- 377.8 IU/L) and 5 days (348.1 +/- 231.0 IU/L compared with 721.7 +/- 463.2) postoperatively (p < 0.05). The mean VAS scores for postoperative back pain were lower in the MED group than in the MD group, both at 1 (3.3 +/- 2.3 compared with 5.8 +/- 1.5) and 5 days (1.9 +/- 1.1 compared with 3.6 +/- 1.1) postoperatively (p < 0.01).
  
  
  CONCLUSIONS
  The MED procedure is less invasive than MD, and causes less muscle damage and less back pain.
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Dong Ah
authors.initials: DA
authors.lastname: Shin
authors.forename: Keung Nyun
authors.initials: KN
authors.lastname: Kim
authors.forename: Hyun Cheol
authors.initials: HC
authors.lastname: Shin
authors.forename: Do Heum
authors.initials: DH
authors.lastname: Yoon
mesh_terms: D000328:Adult; D001416:Back Pain / Q000517:prevention & control; D052283:Creatine Kinase, MM Form / Q000097:blood; D017586:Diskectomy / Q000379:methods*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007049:Iatrogenic Disease; D007405:Intervertebral Disc Displacement / Q000601:surgery; D007431:Intraoperative Complications / Q000517:prevention & control*; D007527:Isoenzymes / Q000097:blood; D007770:L-Lactate Dehydrogenase / Q000097:blood; D000080864:Lactate Dehydrogenase 5; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000201:enzymology / Q000293:injuries*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000517:prevention & control; D012447:Sacrum / Q000601:surgery
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase; D000080864:Lactate Dehydrogenase 5; D052283:Creatine Kinase, MM Form