title: Operative results and learning curve: microscope-assisted tubular microsurgery for 1- and 2-level discectomies and laminectomies.
abstract: OBJECTIVE
  The authors present their clinical results and the learning curve associated with the use of tubular retractors for 1- and 2-level lumbar microscope-assisted discectomies and laminectomies.
  
  
  METHODS
  The study involves a retrospective and prospective analysis of 230 patients who underwent noninstrumented minimally invasive procedures for degenerative lumbar spinal disease between 2004 and 2007. Data on patient demographic characteristics and operative results, including length of stay, blood loss, operative times, and surgical complications were collected. Clinical outcomes were assessed based on pre- and postoperative Visual Analog Scale scores, Oswestry Disability Index values, and the Macnab outcome scale scores.
  
  
  RESULTS
  The results showed characteristic differences in blood loss and operating times between 1- and 2-level procedures and between discectomies and laminectomies. A significant learning curve was seen by a decrease in operating time for 1-level discectomies and 2-level laminectomies. Major complications were not observed.
  
  
  CONCLUSIONS
  The use of tubular retractors for microsurgical decompression of degenerative spinal disease is a safe and effective treatment modality. As with other techniques, minimally invasive procedures are associated with a significant learning curve. As surgeons become more comfortable with the procedure, its applications can be expanded to include, for example, spinal instrumentation and deformity correction.
authors.affiliation: Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York, New York 10021, USA.
authors.forename: Karishma
authors.initials: K
authors.lastname: Parikh
authors.forename: Andre
authors.initials: A
authors.lastname: Tomasino
authors.forename: Jared
authors.initials: J
authors.lastname: Knopman
authors.forename: John
authors.initials: J
authors.lastname: Boockvar
authors.forename: Roger
authors.initials: R
authors.lastname: Härtl
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D017586:Diskectomy / Q000193:education / Q000379:methods*; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000193:education / Q000379:methods*; D007858:Learning; D008159:Lumbar Vertebrae / Q000473:pathology / Q000601:surgery*; D008297:Male; D008866:Microsurgery / Q000193:education / Q000379:methods*; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000517:prevention & control; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome