title: The presence of meniscal lesions is a strong predictor of neuropathic pain in symptomatic knee osteoarthritis: a cross-sectional pilot study.
abstract: BACKGROUND
  Pain in osteoarthritis (OA) has been classically attributed to joint structural damage. Disparity between the degree of radiographic structural damage and the severity of symptoms implies that factors other than the joint pathology itself contribute to the pain. Peripheral and central sensitization have been suggested as two of the underlying mechanisms that contribute to pain in OA. The aim of this study was to explore in symptomatic knee OA patients, the structural changes assessed by magnetic resonance imaging (MRI) that could be used as markers of neuropathic pain (NP).
  
  
  METHODS
  This cross-sectional observational pilot study included 50 knee OA patients with moderate to severe pain (VAS ≥40) in the target knee. The presence of NP was determined based on the PainDETECT questionnaire. Among the 50 patients included, 25 had PainDETECT score ≤12 (unlikely NP), 9 had PainDETECT score between 13 and 18 (uncertain NP) and 16 had PainDETECT score ≥19 (likely NP). WOMAC, PainDETECT, and VAS pain scores as well as knee MRI were assessed.
  
  
  RESULTS
  Data showed no significant difference in demographic characteristics between the three groups. However, a positive and statistically significant association was found between the WOMAC pain (P <0.001), function (P <0.001), stiffness (P = 0.007) and total (P <0.001) scores as well as higher VAS pain score (P = 0.023), and PainDETECT scores. Although no difference was found in the cartilage volume between groups, the presence of meniscal extrusion in both medial (P = 0.006) and lateral (P = 0.023) compartments, and presence of meniscal tears in the lateral compartment (P = 0.011), were significantly associated with increasing PainDETECT score. Moreover, the presence of bone marrow lesions in the lateral plateau and the extent of the synovial membrane thickness in the lateral recess were associated with increasing PainDETECT scores (P = 0.032, P = 0.027, respectively).
  
  
  CONCLUSIONS
  In this study, meniscal lesions, particularly extrusion, were found to be among the strongest risk factors for NP in knee OA patients.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01733277. Registered 16 November 2012.
authors.forename: Camille
authors.initials: C
authors.lastname: Roubille
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Raynauld
authors.forename: François
authors.initials: F
authors.lastname: Abram
authors.forename: Patrice
authors.initials: P
authors.lastname: Paiement
authors.forename: Marc
authors.initials: M
authors.lastname: Dorais
authors.forename: Philippe
authors.initials: P
authors.lastname: Delorme
authors.forename: Louis
authors.initials: L
authors.lastname: Bessette
authors.forename: André D
authors.initials: AD
authors.lastname: Beaulieu
authors.forename: Johanne
authors.initials: J
authors.lastname: Martel-Pelletier
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Pelletier
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology*; D008875:Middle Aged; D009437:Neuralgia / Q000175:diagnosis* / Q000209:etiology*; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000175:diagnosis*; D010865:Pilot Projects; D011237:Predictive Value of Tests; D016037:Single-Blind Method