title: Prevalence and distribution of thoracic and lumbar compressive lesions in cervical spondylotic myelopathy.
abstract: METHODS
  Retrospective cross-sectional study.
  
  
  OBJECTIVE
  This study analyzed the prevalence and distribution of horacic and lumbar compressive lesions in cervical spondylotic myelopathy as well as their relationships with cervical developmental spinal canal stenosis (DCS) by using whole-spine postmyelographic computed tomography.
  
  
  BACKGROUND
  There are few studies on missed compressive lesions of the spinal cord or cauda equina at the thoracolumbar level in cervical spondylotic myelopathy. Furthermore, the relationships between DCS, and the prevalence and distribution of thoracic and lumbar compressive lesions are unknown.
  
  
  METHODS
  Eighty patients with symptomatic cervical spondylotic myelopathy were evaluated. Preoperative image data were obtained. Patients were classified as DCS or non-DCS (n=40 each) if their spinal canal longitudinal diameter was <12 mm at any level or ≥12 mm at all levels, respectively. Compressive lesions in the anterior and anteroposterior parts, ligamentum flavum ossification, posterior longitudinal ligament ossification, and spinal cord tumors at the thoracolumbar levels were analyzed.
  
  
  RESULTS
  Compressive lesions in the anterior and anteroposterior parts were observed in 13 (16.3%) and 45 (56.3%) patients, respectively. Ligamentum flavum and posterior longitudinal ligament ossification were observed in 19 (23.8%) and 3 (3.8%) patients, respectively. No spinal cord tumors were observed. Thoracic and lumbar compressive lesions of various causes tended to be more common in DCS patients than non-DCS patients, although the difference was statistically insignificant.
  
  
  CONCLUSIONS
  Surveying compressive lesions and considering the thoracic and lumbar level in cervical spondylotic myelopathy in DCS patients are important for preventing unexpected neurological deterioration and predicting accurate neurological condition after cervical surgery.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Miyazaki
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan.
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Kodera
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan.
authors.forename: Toyomi
authors.initials: T
authors.lastname: Yoshiiwa
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Kawano
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Kaku
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsumura
keywords: Cervical surgery; Lumbar spine; Tandem spinal stenosis; Thoracic spine