title: Minimally invasive lumbar laminectomy via a dual-tube technique: evaluation in a cadaver model.
abstract: BACKGROUND
  Minimally invasive surgery is a promising new tool in treatment of spinal disorders. Minimally invasive laminectomy provides an efficacious means of achieving lumbar decompression. Present single-tube approaches may entail significant facet injury. We explore the feasibility of a dual-tube minimally invasive laminectomy approach in a cadaver model.
  
  
  METHODS
  We performed minimally invasive lumbar laminectomies in 8 adult cadavers. Twenty-three levels were treated. We used a dual-tube technique, undercutting the facet joints bilaterally while attempting to minimize facet injury. Crossed-tube rongeuring of individual facet joints and neural foramina mirrored open techniques. Pre- and postoperative CT scans of the cadavers were obtained; we measured the cross-sectional area of the spinal canal and neural foramina in each specimen using a CT workstation. Facet damage was assessed. We used the Medtronic Sofamor-Danek (Memphis, Tenn) X-Tube and Quadrant systems to complete individual procedures.
  
  
  RESULTS
  Increases in canal cross-sectional area were achieved in each specimen: L3-4 increased from 238.3 to 354.4 mm(2) (125.1%); L4-5, 274 to 390.9 mm(2) (142.7%); and L5-S1, 349.9 mm(2) to 458.8 mm(2) (131%). Neural foraminal diameter also increased in each specimen (L3-4 right increased 123%; left, 136.8%; L4-5, 143.5% and 145.6%; L5-S1, 124% and 116% respectively). Incidental facet injury was noted in 5 (10.9%) of a potential 46 joints.
  
  
  CONCLUSIONS
  We demonstrate that a dual-tube MIS technique can effectively complete lumbar decompressive laminectomy and foraminotomy procedures in a cadaver model, without significant facet injury. Minimally invasive surgery laminectomy techniques hold significant clinical promise.
authors.affiliation: Department of Neurosurgery, Rush University, Chicago, IL 60612, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Musacchio
authors.forename: Nimesh
authors.initials: N
authors.lastname: Patel
authors.forename: Bradley
authors.initials: B
authors.lastname: Bagan
authors.forename: Harel
authors.initials: H
authors.lastname: Deutsch
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Vaccaro
authors.forename: John
authors.initials: J
authors.lastname: Ratliff
mesh_terms: D000328:Adult; D002102:Cadaver; D019299:Decompression, Surgical / Q000009:adverse effects / Q000379:methods; D005240:Feasibility Studies; D006801:Humans; D007431:Intraoperative Complications; D007796:Laminectomy / Q000009:adverse effects / Q000379:methods*; D008159:Lumbar Vertebrae; D019060:Minimally Invasive Surgical Procedures; D021801:Zygapophyseal Joint / Q000293:injuries