title: Is increased joint loading detrimental to obese patients with knee osteoarthritis? A secondary data analysis from a randomized trial.
abstract: OBJECTIVE
  To investigate whether increased knee joint loading due to improved ambulatory function and walking speed following weight loss achieved over 16 weeks accelerates symptomatic and structural disease progression over a subsequent 1 year weight maintenance period in an obese population with knee osteoarthritis (OA).
  
  
  METHODS
  Data from a prospective study of weight loss in obese patients with knee OA (the CARtilage in obese knee OsteoarThritis (CAROT) study) were used to determine changes in knee joint compressive loadings (model estimated) during walking after a successful 16 week weight loss intervention. The participants were divided into 'Unloaders' (participants that reduced joint loads) and 'Loaders' (participants that increased joint loads). The primary symptomatic outcome was changes in knee symptoms, measured with the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire, during a subsequent 52 weeks weight maintenance period. The primary structural outcome was changes in tibiofemoral cartilage loss assessed semi-quantitatively (Boston Leeds Knee Osteoarthritis Score (BLOKS) from MRI after the 52 weight maintenance period.
  
  
  RESULTS
  157 participants (82% of the CAROT cohort) with medial and/or lateral knee OA were classified as Unloaders (n = 100) or Loaders (n = 57). The groups showed similar significant changes in symptoms (group difference: -2.4 KOOS points [95% CI -6.8:1.9]) and cartilage loss (group difference: -0.06 BLOKS points [95% CI -0.22:0.11) after 1 year, with no statistically significant differences between Loaders and Unloaders.
  
  
  CONCLUSIONS
  For obese patients undergoing a significant weight loss, increased knee joint loading for 1 year was not associated with accelerated symptomatic and structural disease progression compared to a similar weight loss group that had reduced ambulatory compressive knee joint loads.
  
  
  BACKGROUND
  NCT00655941.
authors.affiliation: The Parker Institute, Department of Rheumatology, Copenhagen University Hospital, Frederiksberg, Copenhagen F, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Henriksen
authors.forename: D J
authors.initials: DJ
authors.lastname: Hunter
authors.forename: E B
authors.initials: EB
authors.lastname: Dam
authors.forename: S P
authors.initials: SP
authors.lastname: Messier
authors.forename: T P
authors.initials: TP
authors.lastname: Andriacchi
authors.forename: L S
authors.initials: LS
authors.lastname: Lohmander
authors.forename: J
authors.initials: J
authors.lastname: Aaboe
authors.forename: M
authors.initials: M
authors.lastname: Boesen
authors.forename: H
authors.initials: H
authors.lastname: Gudbergsen
authors.forename: H
authors.initials: H
authors.lastname: Bliddal
authors.forename: R
authors.initials: R
authors.lastname: Christensen
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000473:pathology; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000473:pathology / Q000502:physiology / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D020370:Osteoarthritis, Knee / Q000150:complications / Q000473:pathology / Q000534:rehabilitation*; D011446:Prospective Studies; D016896:Treatment Outcome; D016138:Walking; D015431:Weight Loss / Q000502:physiology; D061217:Weight Reduction Programs; D016474:Weight-Bearing
keywords: Cartilage; Gait; Joint loading; Osteoarthritis; Weight loss