title: Modified Marmot operation versus spinous process transverse cutting laminectomy for lumbar spinal stenosis.
abstract: METHODS
  Retrospective comparative cohort study.
  
  
  OBJECTIVE
  To compare clinical outcomes for lumbar spinal stenosis (≥3 levels) treated with posterior decompression without exposing the paravertebral muscles (PVM) with outcomes from surgery with PVM exposure.
  
  
  BACKGROUND
  Exposure of the PVM can cause muscle injury and denervation, which may induce failed back syndrome. However, it is unknown whether lumbar spinal stenosis is more likely to lead to clinical improvement after PVM preservation than the procedure involving exposure of the PVM.
  
  
  METHODS
  Fifty-three patients with lumbar spinal stenosis were divided on the basis of the timing of the surgery into 2 groups: modified split-spinous process laminotomy (Marmot operation) (MM) group (26 patients) and spinous process transverse cutting laminectomy through a unilateral approach (control) group (27 patients). The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, visual analogue scale score of low back pain, and patients' satisfaction were assessed preoperatively and 1 year postoperatively. Operation time, blood loss, and creatine phosphokinase and C-reactive protein levels were measured 7 days postoperatively. Magnetic resonance imaging changes in the PVM were evaluated at the follow-up.
  
  
  RESULTS
  The preoperative visual analogue scale and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire scores did not differ between groups. The operation time did not differ between groups, but blood loss was less in the MM group than in the control group (129 vs. 205 mL) (P < 0.05). C-reactive protein (1.1 vs. 2.8 mg/dL) and creatine phosphokinase (68 vs. 253 IU/L) levels were lower in the MM group (P < 0.05). The visual analogue scale score for low back pain and patient satisfaction did not differ between groups. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire scores for pain-related disorders, gait disturbance, and social life disturbance improved significantly in the MM group compared with the control group (P < 0.05). Nine patients in the control group showed positive changes in the PVM.
  
  
  CONCLUSIONS
  The MM operation was less invasive and produced superior clinical outcomes compared with laminectomy involving exposure of the PVM.
authors.affiliation: *Spine Care Center, Wakayama Medical University Kihoku Hospital, Wakayama, Japan †Department of Orthopaedic Surgery, Wakayama Rosai Hospital, Wakayama, Japan; and ‡Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Kawakami
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Nakao
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fukui
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Kadosaka
authors.forename: Toshiko
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001696:Biomechanical Phenomena; D016063:Blood Loss, Surgical / Q000517:prevention & control; D002097:C-Reactive Protein / Q000378:metabolism; D003402:Creatine Kinase / Q000097:blood; D019299:Decompression, Surgical / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000009:adverse effects / Q000379:methods*; D017116:Low Back Pain / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000503:physiopathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D010147:Pain Measurement; D017060:Patient Satisfaction; D011237:Predictive Value of Tests; D020127:Recovery of Function; D012189:Retrospective Studies; D013130:Spinal Stenosis / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein; D003402:Creatine Kinase