title: The effect of multi-level laminoplasty and laminectomy on the biomechanics of the cervical spine: a finite element study.
abstract: Laminectomy has been regarded as a standard treatment for multi-level cervical stenosis. Concern for complications such as kyphosis has limited the indication of multi-level laminectomy; hence it is often augmented with an instrumented fusion. Laminoplasty has emerged as a motion preserving alternative. The purpose of this study was to compare the multidirectional flexibility of the cervical spine in response to a plate-only open door laminoplasty, double door laminoplasty, and laminectomy using a computational model. A validated three-dimensional finite element model of a specimen-specific intact cervical spine (C2-T1) was modified to simulate each surgical procedure at levels C3-C6. An additional goal of this work was to compare the instrumented computational model to our multi-specimen experimental findings to ensure similar trends in response to the surgical procedures. Model predictions indicate that mobility was retained following open and double door laminoplasty with a 5.4% and 20% increase in flexion, respectively, compared to the intact state. Laminectomy resulted in 57% increase in flexion as compared to the intact state, creating a concern for eventual kyphosis--a known risk/complication of multi-level laminectomy in the absence of fusion. Increased disc stresses were observed at the altered and adjacent segments post-laminectomy in flexion.
authors.affiliation: Department of Biomedical Engineering The University of Iowa, Iowa City, IA United States ; Center for Computer Aided Design The University of Iowa, Iowa City, IA United States.
authors.forename: Swathi
authors.initials: S
authors.lastname: Kode
authors.affiliation: Department of Biomedical Engineering The University of Iowa, Iowa City, IA United States ; Center for Computer Aided Design The University of Iowa, Iowa City, IA United States.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Kallemeyn
authors.affiliation: Department of Orthopaedics and Rehabilitation University of Iowa Hospitals and Clinics, The University of Iowa, Iowa City, IA United States.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Smucker
authors.affiliation: Department of Orthopaedics and Rehabilitation University of Iowa Hospitals and Clinics, The University of Iowa, Iowa City, IA United States.
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Fredericks
authors.affiliation: Department of Biomedical Engineering The University of Iowa, Iowa City, IA United States ; Department of Orthopaedics and Rehabilitation University of Iowa Hospitals and Clinics, The University of Iowa, Iowa City, IA United States ; Center for Computer Aided Design The University of Iowa, Iowa City, IA United States.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Grosland
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D002574:Cervical Vertebrae / Q000502:physiology* / Q000601:surgery*; D020342:Finite Element Analysis; D006801:Humans; D007796:Laminectomy; D065406:Laminoplasty; D008953:Models, Anatomic; D016059:Range of Motion, Articular / Q000502:physiology*
keywords: cervical spine; finite element; laminectomy; laminoplasty; miniplates; spacer