title: Varus thrust during walking and the risk of incident and worsening medial tibiofemoral MRI lesions: the Multicenter Osteoarthritis Study.
abstract: To determine the association of varus thrust during walking to incident and worsening medial tibiofemoral cartilage damage and bone marrow lesions (BMLs) over 2 years in older adults with or at risk for osteoarthritis (OA).
  
  
  
  Subjects from the Multicenter Osteoarthritis Study (MOST) were studied. Varus thrust was visually assessed from high-speed videos of forward walking trials. Baseline and two-year MRIs were acquired from one knee per subject and read for cartilage loss and BMLs. Logistic regression with generalized estimating equations was used to estimate the odds of incident and worsening cartilage loss and BMLs, adjusting for age, sex, race, body mass index (BMI), and clinic site. The analysis was repeated stratified by varus, neutral, and valgus alignment.
  
  
  
  1007 participants contributed one knee each. Varus thrust was observed in 29.9% of knees. Knees with thrust had 2.17 [95% CI: 1.51, 3.11] times the odds of incident medial BML, 2.51 [1.85, 3.40] times the odds of worsening medial BML, and 1.85 [1.35, 2.55] times the odds of worsening medial cartilage loss. When stratified by alignment, varus knees also had significantly increased odds of these outcomes.
  
  
  
  Varus thrust observed during walking is associated with increased odds of incident and worsening medial BMLs and worsening medial cartilage loss. Increased odds of these outcomes persist in varus-aligned knees.
authors.affiliation: Department of Anatomy and Neurobiology, Boston University, Boston, MA, USA. Electronic address: aewink@bu.edu.
authors.forename: A E
authors.initials: AE
authors.lastname: Wink
authors.affiliation: Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, MA, USA; Department of Physical Therapy, MGH Institute of Health Professions, Boston, MA, USA. Electronic address: grossd@bu.edu.
authors.forename: K D
authors.initials: KD
authors.lastname: Gross
authors.affiliation: Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA. Electronic address: cbrown03@bu.edu.
authors.forename: C A
authors.initials: CA
authors.lastname: Brown
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA. Electronic address: guermazi@bu.edu.
authors.forename: A
authors.initials: A
authors.lastname: Guermazi
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany. Electronic address: frank.roemer@uk-erlangen.de.
authors.forename: F
authors.initials: F
authors.lastname: Roemer
authors.affiliation: Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, MA, USA. Electronic address: niujp@bu.edu.
authors.forename: J
authors.initials: J
authors.lastname: Niu
authors.affiliation: Department of Epidemiology, University of Iowa, Iowa City, IA, USA. Electronic address: james-torner@uiowa.edu.
authors.forename: J
authors.initials: J
authors.lastname: Torner
authors.affiliation: Department of Medicine, UAB, Birmingham, AL, USA. Electronic address: celewis@uabmc.edu.
authors.forename: C E
authors.initials: CE
authors.lastname: Lewis
authors.affiliation: Department of Epidemiology and Biostatistics, UCSF, San Francisco, CA, USA. Electronic address: mnevitt@psg.ucsf.edu.
authors.forename: M C
authors.initials: MC
authors.lastname: Nevitt
authors.affiliation: Department of Epidemiology and Biostatistics, UCSF, San Francisco, CA, USA. Electronic address: itolstykh@psg.ucsf.edu.
authors.forename: I
authors.initials: I
authors.lastname: Tolstykh
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. Electronic address: l-sharma@northwestern.edu.
authors.forename: L
authors.initials: L
authors.lastname: Sharma
authors.affiliation: Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, MA, USA; NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester NHS Foundation, Manchester, UK. Electronic address: dfelson@bu.edu.
authors.forename: D T
authors.initials: DT
authors.lastname: Felson
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D001853:Bone Marrow / Q000000981:diagnostic imaging; D002358:Cartilage, Articular / Q000000981:diagnostic imaging; D018450:Disease Progression; D005260:Female; D005684:Gait / Q000502:physiology*; D056305:Genu Varum / Q000503:physiopathology*; D006801:Humans; D015994:Incidence; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016138:Walking / Q000502:physiology
keywords: Bone marrow lesions; Cartilage loss; Gait; MRI; Osteoarthritis; Varus knee thrust