title: Meniscal extrusion predicts increases in subchondral bone marrow lesions and bone cysts and expansion of subchondral bone in osteoarthritic knees.
abstract: OBJECTIVE
  Meniscal extrusion is often present in knees with OA, and has been associated with cartilage changes. It is unknown whether meniscal extrusion is related to subchondral bone. The aim of the study was to examine the relationship between meniscal extrusion and knee cartilage and subchondral bone, and also changes in these structures over 2 years in a cohort with mild to moderate knee OA.
  
  
  METHODS
  One hundred and seventeen subjects with knee OA entered the study and underwent MRI on their symptomatic knee at baseline and approximately 2 years later. Meniscal extrusion was assessed at baseline; tibial cartilage volume and plateau bone area, subchondral bone marrow lesions (BMLs) and bone cysts were measured at baseline and follow-up.
  
  
  RESULTS
  At baseline, meniscal extrusion was associated with reduced tibial cartilage volume, increased tibial plateau area, increased prevalence of BMLs and bone cysts in both medial and lateral tibiofemoral compartments (all P < or = 0.001). Baseline medial meniscal extrusion was associated with increased expansion of tibial plateau bone (P = 0.04), increases in BMLs (P = 0.02) and bone cysts (P = 0.003) in the medial tibiofemoral compartment over 2 years.
  
  
  CONCLUSIONS
  Meniscal extrusion predicts increases in subchondral bone lesions and tibial plateau bone expansion in patients with knee OA. These data suggest that subchondral bone changes are an early consequence of meniscal extrusion. This may reflect the impaired ability of an extruded meniscus to optimally distribute mechanical loading across the tibial plateau.
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, Australia.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Anita E
authors.initials: AE
authors.lastname: Wluka
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Pelletier
authors.forename: Johanne
authors.initials: J
authors.lastname: Martel-Pelletier
authors.forename: François
authors.initials: F
authors.lastname: Abram
authors.forename: Changhai
authors.initials: C
authors.lastname: Ding
authors.forename: Flavia M
authors.initials: FM
authors.lastname: Cicuttini
mesh_terms: D000368:Aged; D001845:Bone Cysts / Q000150:complications*; D001855:Bone Marrow Diseases / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging / Q000473:pathology*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000473:pathology*; D011237:Predictive Value of Tests; D011859:Radiography; D012307:Risk Factors