title: Secular changes of spinal canal dimensions in Western Switzerland: a narrowing epidemic?
abstract: METHODS
  Computed tomography-based anatomical study.
  
  
  OBJECTIVE
  To study the secular changes in lumbar spinal canal dimensions.
  
  
  BACKGROUND
  Development of symptomatic lumbar spinal stenosis, among other factors, is related to the dimensions of the bony canal. The canal reaches its adult size early on in life. Several factors, including protein intake, may influence its final dimensions. As with increases in human stature from improvements of socioeconomic conditions, we hypothesized that adult bony canal size has also grown larger in recent generations.
  
  
  METHODS
  This study analyzes computed tomographic reconstructions from 184 subjects performed for either trauma (n = 81) or abdominal pathologies (n = 103) and born either between 1940 and 1949 (n = 88) or 1970 and 1979 (n = 96). The cross-sectional area of the bony canal was digitally measured at the level of the pedicle (i.e., at a level not influenced by degenerative changes) for each lumbar vertebra. Intra- and interobserver reliability was assessed.
  
  
  RESULTS
  Intra- and interobserver measurement reliability were excellent (interclass correlation coefficient = 0.87) and good (interclass correlation coefficient = 0.61), respectively. Contrary to our hypothesis, the 1940-1949 generation patient group exhibited larger lumbar canals at all levels as compared with the 1970-1979 group. Statistically this difference was highly significant (P < 0.001) and particularly pronounced in the trauma subgroup.
  
  
  CONCLUSIONS
  Given that human stature evolution has stabilized and adult height is established during the first 2 years of long bone growth, it is possible that antenatal factors are responsible for this surprising finding. Maternal smoking and age may be possible explanations. This finding may have significant implications. An increasing number of patients may emerge with lumbar spinal stenosis as degenerative changes develop, putting a strain on health resources. Further studies in different population groups and countries will be important to further confirm this trend.
  
  
  METHODS
  3.
authors.affiliation: *Department of Orthopedics, Centre Hospitalier Universitaire Vaudois (CHUV), and the University of Lausanne, Lausanne, Switzerland and Spine Unit, Clinic Cecil, Lausanne, Switzerland †Medical School, University of Lausanne, Lausanne, Switzerland ‡Burier Gymnasium, La Tour-de-Peilz, Switzerland; and Departments of §Radiology and ¶Orthopedics, Centre Hospitalier Universitaire Vaudois (CHUV) and the University of Lausanne, Lausanne, Switzerland.
authors.forename: Constantin
authors.initials: C
authors.lastname: Schizas
authors.forename: Aline
authors.initials: A
authors.lastname: Schmit
authors.forename: Alexis
authors.initials: A
authors.lastname: Schizas
authors.forename: Fabio
authors.initials: F
authors.lastname: Becce
authors.forename: Gerit
authors.initials: G
authors.lastname: Kulik
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Pierzchała
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000473:pathology*; D008161:Lumbosacral Region / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D013115:Spinal Canal / Q000473:pathology*; D013130:Spinal Stenosis / Q000453:epidemiology*; D013557:Switzerland; D014057:Tomography, X-Ray Computed / Q000379:methods