title: Microsurgical unilateral laminotomy for decompression of lumbar spinal stenosis: long-term results and predictive factors.
abstract: The microsurgical unilateral laminotomy (MUL) technique for bilateral decompression of lumbar spinal stenosis (LSS) is a less destabilizing alternative to laminectomy and leads to good short-term outcomes. However, little is known about the long-term results including predictive factors.
  
  
  
  Medical records of patients who underwent MUL for LSS decompression between 2005 and 2010 were reviewed, and a questionnaire was distributed to complement the long-term outcome data. The study population consisted of 176 patients including 17 patients with stable grade I spondylolisthesis. Complications and reoperations were meticulously analyzed. Clinical outcome was measured using a modified Prolo scale and was further dichotomized in good vs. poor outcome. Predictive factors were obtained from uni- and multivariate analyses.
  
  
  
  The median age of the cohort was 70.0 years and the follow-up 71.7 months. Complications occurred in 5.1 % of the patients. The overall reoperation rate was 17.0 %, including surgery, which was exclusively performed at other levels in 4.0 %. The reoperation rate for fusion was 4.5 %. Good neurogenic claudication outcome faded from 98.3 % at hospital discharge to 47.2 % at 6 years. Multivariate analysis identified previous lumbar operation as a potential independent predictor of a reoperation; potential independent predictors of poor long-term claudication outcome were older age, female gender, higher body mass index (BMI) and tobacco smoking.
  
  
  
  In our experience, the long-term reoperation rate after MUL for LSS is not negligible and higher in previously operated patients. It seems like the good initial clinical results after MUL may fade over time, and several patient-related predictive factors including potentially modifiable obesity and tobacco smoking seem to play an important role.
authors.affiliation: Department of Neurosurgery, Justus-Liebig-University Giessen, Klinikstr. 33, 35392, Giessen, Germany. karsten.schoeller@neuro.med.uni-giessen.de.
authors.forename: Karsten
authors.initials: K
authors.lastname: Schöller
authors.affiliation: Department of Neurosurgery, Justus-Liebig-University Giessen, Klinikstr. 33, 35392, Giessen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Steingrüber
authors.affiliation: Department of Neurosurgery, Justus-Liebig-University Giessen, Klinikstr. 33, 35392, Giessen, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Stein
authors.affiliation: Department of Neurosurgery, Justus-Liebig-University Giessen, Klinikstr. 33, 35392, Giessen, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Vogt
authors.affiliation: Department of Neurosurgery, Justus-Liebig-University Giessen, Klinikstr. 33, 35392, Giessen, Germany.
authors.forename: Tilman
authors.initials: T
authors.lastname: Müller
authors.affiliation: Institute for Medical Informatics, Medical Statistics Study Group, Justus-Liebig-University, Giessen, Germany.
authors.forename: Jörn
authors.initials: J
authors.lastname: Pons-Kühnemann
authors.affiliation: Department of Neurosurgery, Justus-Liebig-University Giessen, Klinikstr. 33, 35392, Giessen, Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Uhl
mesh_terms: D000368:Aged; D019299:Decompression, Surgical / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000009:adverse effects*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D012086:Reoperation / Q000706:statistics & numerical data; D013130:Spinal Stenosis / Q000601:surgery*
keywords: Long-term outcome; Microsurgical unilateral decompression; Predictors; Reoperation; lumbar spinal stenosis