title: Knee malalignment is associated with an increased risk for incident and enlarging bone marrow lesions in the more loaded compartments: the MOST study.
abstract: OBJECTIVE
  To examine the relationship of knee malalignment with occurrence of incident and enlarging bone marrow lesions (BMLs) and regression of BMLs.
  
  
  METHODS
  Subjects from the Multicenter Osteoarthritis Study aged 50-79 years with or at high risk of knee osteoarthritis were studied. Full-limb radiographs were taken at baseline and hip-knee-ankle mechanical axis was measured. Baseline and 30-month magnetic resonance imaging (MRI) of knees (n = 1782) were semiquantitatively assessed for BMLs. Outcome was defined as a change in BML score in femoral/tibial condyle in medial/lateral compartments. Medial compartment in varus alignment and lateral compartment in valgus alignment were combined to form 'more loaded' compartment, while lateral compartment in valgus and medial compartment in varus were combined to form 'less loaded' compartment. Relative risk (RR) of BML score increase or decrease in relation to malalignment was estimated using a log linear regression model with the Poisson assumption, adjusting for age, gender, body mass index, physical activity scale for the elderly, race and clinic site. Further, results were stratified by ipsilateral meniscal and cartilage status at baseline.
  
  
  RESULTS
  Baseline varus alignment was associated with higher risk of BML score increase from baseline to follow-up in the medial compartment [adjusted RRs (95%CI): 1.5 (1.2-1.9)] and valgus alignment in the lateral compartment [1.4 (1.0-2.1)]. Increase in BML score was more likely in the more loaded compartments [1.7 (1.4-2.0)] in malaligned knees. Regardless of ipsilateral cartilage or meniscus status, adjusted RR for BML score increase was higher in the more loaded compartments of malaligned knees than those with neutral alignment. Decrease in BML score was less likely in the more loaded compartments in malaligned knees [0.8 (0.7-1.0)].
  
  
  CONCLUSIONS
  Knee malalignment is associated with increased risk of incident and enlarging BMLs in the more loaded compartments of the tibiofemoral joint.
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA 02118, USA. dhayashi@bu.edu
authors.forename: D
authors.initials: D
authors.lastname: Hayashi
authors.forename: M
authors.initials: M
authors.lastname: Englund
authors.forename: F W
authors.initials: FW
authors.lastname: Roemer
authors.forename: J
authors.initials: J
authors.lastname: Niu
authors.forename: L
authors.initials: L
authors.lastname: Sharma
authors.forename: D T
authors.initials: DT
authors.lastname: Felson
authors.forename: M D
authors.initials: MD
authors.lastname: Crema
authors.forename: M D
authors.initials: MD
authors.lastname: Marra
authors.forename: N A
authors.initials: NA
authors.lastname: Segal
authors.forename: C E
authors.initials: CE
authors.lastname: Lewis
authors.forename: M C
authors.initials: MC
authors.lastname: Nevitt
authors.forename: A
authors.initials: A
authors.lastname: Guermazi
mesh_terms: D000368:Aged; D017760:Bone Malalignment / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D001853:Bone Marrow / Q000473:pathology*; D001855:Bone Marrow Diseases / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D060906:Coxa Valga / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D060905:Coxa Vara / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D011859:Radiography; D012307:Risk Factors