title: Side differences of knee joint cartilage volume, thickness, and surface area, and correlation with lower limb dominance--an MRI-based study.
abstract: OBJECTIVE
  To test the hypotheses that absolute side differences in knee joint cartilage morphology are substantially smaller than intersubject variability, and that systematic side differences are determined by (force) dominance of the lower limbs.
  
  
  METHODS
  Fifteen healthy volunteers with definite dominance of one lower limb were studied. Knees were imaged sagittally with a validated, high-resolution MR sequence. Transverse MR images of the thigh and calf were acquired with a spin echo sequence. Knee joint cartilage volume, thickness and joint surface areas, as well as muscle cross sectional areas were determined with in house post-processing software.
  
  
  RESULTS
  Absolute side differences amounted to 5.0+/-3.7% for the knee cartilage volume, 3.8+/-3.1% for cartilage thickness, and 3.4+/-1.7% for joint surface areas. The intersubject variability was 24.8%, 14.4%, and 14.1%, respectively. Volunteers with dominance of one of both lower limbs did not display significant side differences in cartilage morphology, but the side differences of the thigh musculature correlated positively with side differences of knee joint cartilage volume (r=+0.68; P< 0.01).
  
  
  CONCLUSIONS
  The results advocate the use of cartilage parameters from the contra-lateral limb for retrospectively estimating cartilage loss in patients with unilateral osteoarthritis (OA), and for determining local risk factors of OA in cross-sectional epidemiological studies, which are specific to pre-morbid cartilage morphology. Functional (force) dominance of one of both lower limbs does not explain side differences of articular cartilage morphology, but side differences are positively associated with side differences in muscle cross sectional areas.
authors.affiliation: Musculoskeletal Research Group, Institute of Anatomy, Ludwig-Maximilians-Universität München, Pettenkoferstrasse 11, 80336 München, Germany. eckstein@anat.med.uni-muenchen.de
authors.forename: F
authors.initials: F
authors.lastname: Eckstein
authors.forename: S
authors.initials: S
authors.lastname: Müller
authors.forename: S C
authors.initials: SC
authors.lastname: Faber
authors.forename: K-H
authors.initials: KH
authors.lastname: Englmeier
authors.forename: M
authors.initials: M
authors.lastname: Reiser
authors.forename: R
authors.initials: R
authors.lastname: Putz
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000033:anatomy & histology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology*; D007866:Leg / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000033:anatomy & histology; D010329:Patella / Q000033:anatomy & histology; D013977:Tibia / Q000033:anatomy & histology