title: Biomechanical comparison of traditional and minimally invasive intradural tumor exposures using finite element analysis.
abstract: BACKGROUND
  Minimally invasive approaches to intradural pathology have evolved in part in an effort to reduce approach related destabilization of the spine. No biomechanical data exist however evaluating the effects of traditional and minimally invasive exposures.
  
  
  METHODS
  A finite element model of the lumbar spine was generated, and a simulated open laminectomy and a modified hemilaminectomy at L4 were performed. Forces were applied to assess changes in flexion, extension, axial rotation, and lateral bending.
  
  
  RESULTS
  Open laminectomy produced much greater changes in extension, flexion, and axial rotation than the modified hemilaminectomy from the intact. Lateral bending was similarly unaffected for both exposures.
  
  
  CONCLUSIONS
  The results suggest that a minimally invasive hemilaminar exposure preserves the structural integrity of the lumbar spine and minimizes alterations to segmental motion postoperatively.
authors.affiliation: Department of Neurological Surgery, Columbia University, The Neurological Institute, 710 W. 168th Street, New York, NY 10032, USA. ato2@columbia.edu
authors.forename: Alfred T
authors.initials: AT
authors.lastname: Ogden
authors.forename: Lacey
authors.initials: L
authors.lastname: Bresnahan
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.forename: Raghu
authors.initials: R
authors.lastname: Natarajan
authors.forename: Richard G
authors.initials: RG
authors.lastname: Fessler
mesh_terms: D001696:Biomechanical Phenomena; D002278:Carcinoma in Situ / Q000503:physiopathology* / Q000601:surgery*; D019245:Compressive Strength; D003198:Computer Simulation; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D007796:Laminectomy / Q000379:methods*; D008159:Lumbar Vertebrae / Q000503:physiopathology* / Q000601:surgery*; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D008954:Models, Biological; D009038:Motion; D013314:Stress, Mechanical; D025321:Surgery, Computer-Assisted / Q000379:methods; D016474:Weight-Bearing