title: Minimally invasive laminectomy for lumbar spinal stenosis in patients with and without preoperative spondylolisthesis: clinical outcome and reoperation rates.
abstract: OBJECTIVE
  Surgical decompression is the intervention of choice for lumbar spinal stenosis (LSS) when nonoperative treatment has failed. Standard open laminectomy is an effective procedure, but minimally invasive laminectomy through tubular retractors is an alternative. The aim of this retrospective case series was to evaluate the clinical and radiographic outcomes of this procedure in patients who underwent LSS and to compare outcomes in patients with and without preoperative spondylolisthesis.
  
  
  METHODS
  Patients with LSS without spondylolisthesis and with stable Grade I spondylolisthesis who had undergone minimally invasive tubular laminectomy between 2004 and 2011 were included in this analysis. Demographic, perioperative, and radiographic data were collected. Clinical outcome was evaluated using the Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, as well as Macnab's criteria.
  
  
  RESULTS
  Among 110 patients, preoperative spondylolisthesis at the level of spinal stenosis was present in 52.5%. At a mean follow-up of 28.8 months, scoring revealed a median improvement of 16% on the ODI, 2.75 on the VAS back, and 3 on the VAS leg, compared with the preoperative baseline (p < 0.0001). The reoperation rate requiring fusion at the same level was 3.5%. Patients with and without preoperative spondylolisthesis had no significant differences in their clinical outcome or reoperation rate.
  
  
  CONCLUSIONS
  Minimally invasive laminectomy is an effective procedure for the treatment of LSS. Reoperation rates for instability are lower than those reported after open laminectomy. Functional improvement is similar in patients with and without preoperative spondylolisthesis. This procedure can be an alternative to open laminectomy. Routine fusion may not be indicated in all patients with LSS and spondylolisthesis.
authors: Weill Cornell Brain and Spine Center, Department of Neurological Surgery, Weill Cornell Medical College, NewYork-Presbyterian Hospital, New York, New York.
authors: Marjan
authors: M
authors: Alimi
authors: Christoph P
authors: CP
authors: Hofstetter
authors: Se Young
authors: SY
authors: Pyo
authors: Danika
authors: D
authors: Paulo
authors: Roger
authors: R
authors: Härtl
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007796:Laminectomy / Q000295:instrumentation / Q000379:methods*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation / Q000379:methods*; D011183:Postoperative Complications / Q000175:diagnosis / Q000601:surgery*; D012086:Reoperation; D013130:Spinal Stenosis / Q000175:diagnosis / Q000601:surgery*; D013168:Spondylolisthesis / Q000150:complications / Q000175:diagnosis / Q000601:surgery*
keywords: BMI = body mass index; LSS = lumbar spinal stenosis; MCID = minimum clinically important difference; ODI = Oswestry Disability Index; Oswestry Disability Index; VAS = visual analog scale; lumbar spinal stenosis; minimally invasive laminectomy; reoperation; spondylolisthesis; tubular retractors; visual analog scale