title: The relation of MRI-detected structural damage in the medial and lateral patellofemoral joint to knee pain: the Multicenter and Framingham Osteoarthritis Studies.
abstract: OBJECTIVE
  To examine the relation of cartilage loss and bone marrow lesions (BMLs) in the medial and lateral patellofemoral joint (PFJ) to knee pain.
  
  
  METHODS
  We categorized the location of full-thickness cartilage loss and BMLs in the PFJ on knee magnetic resonance imaging (MRIs) from the Multicenter Osteoarthritis (MOST) and Framingham Osteoarthritis (FOA) Studies as no damage, isolated medial, isolated lateral, or both medial and lateral (mixed). We determined the relation of MRI lesions in each PFJ region to prevalent knee pain. Differences in knee pain severity were compared among categories of PFJ full-thickness cartilage loss and BMLs using quantile regression.
  
  
  RESULTS
  In MOST (n = 1137 knees), compared with knees without full-thickness cartilage loss, knees with isolated lateral or mixed PFJ full-thickness cartilage loss had 1.9 (1.3, 2.8) and 1.9 (1.2, 2.9) times the odds of knee pain, respectively, while isolated medial cartilage loss had no association with knee pain. BMLs in both the medial and lateral PFJ had 1.5 (1.1, 2.0) times the odds of knee pain compared with knees without BMLs. Knee pain severity was lowest in knees with isolated medial PFJ cartilage loss or BMLs. In FOA (n = 934 knees), neither isolated medial nor lateral cartilage loss was associated with knee pain, whereas isolated BMLs in either region were associated with pain.
  
  
  CONCLUSIONS
  Results were not completely concordant but suggest that knee pain risk and severity is greatest with cartilage loss isolated to (MOST) or inclusive of (MOST and FOA) the lateral PFJ. While BMLs in either the medial or lateral PFJ are related to pain.
authors.affiliation: Department of Physical Therapy and Athletic Training, Boston University, Boston, MA, USA. Electronic address: stefanik@bu.edu.
authors.forename: J J
authors.initials: JJ
authors.lastname: Stefanik
authors.affiliation: Department of Physical Therapy, MGHIHP, Boston, MA, USA. Electronic address: grossd@bu.edu.
authors.forename: K D
authors.initials: KD
authors.lastname: Gross
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA. Electronic address: ali.guermazi@bmc.org.
authors.forename: A
authors.initials: A
authors.lastname: Guermazi
authors.affiliation: Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, MA, USA. Electronic address: dfelson@bu.edu.
authors.forename: D T
authors.initials: DT
authors.lastname: Felson
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@klinikum-augsburg.de.
authors.forename: F W
authors.initials: FW
authors.lastname: Roemer
authors.affiliation: Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, MA, USA. Electronic address: yuquing@bu.edu.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
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 Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA, USA. Electronic address: neil-segal@uiowa.edu.
authors.forename: N A
authors.initials: NA
authors.lastname: Segal
authors.affiliation: Department of Medicine, UAB, Birmingham, AB, 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
authors.initials: M
authors.lastname: Nevitt
authors.affiliation: Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, MA, USA. Electronic address: tneogi@bu.edu.
authors.forename: T
authors.initials: T
authors.lastname: Neogi
mesh_terms: D000367:Age Factors; D000368:Aged; D018771:Arthralgia / Q000453:epidemiology*; D002358:Cartilage, Articular / Q000473:pathology; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology*; D057071:Patellofemoral Joint / Q000473:pathology*; D012044:Regression Analysis; D012307:Risk Factors; D012720:Severity of Illness Index
keywords: Magnetic resonance imaging; Osteoarthritis; Pain; Patellofemoral