Table 2

Best evidence synthesis (MRI features arranged from top to bottom according to the number of studies included)

Association (sizes)Number of studies: positive/total (%)
StudiesStudy designCrudeAdjustedAdjusted confoundersAllHigh quality
Cartilage defects (level of evidence: conflicting)
 Scored using semiquantitative scores
  Pelletier et al31CSr=0.09, p=0.38NA6/12 (50%)3 (1 C, 2 CS)/6 (2 C, 3 CS) (50%)
  Phan et al32CSr Not mentioned, NSNA
  Torres et al19CSβ=1.03 (95% CI 0.6 to 1.5)0.53 (0.08 to 0.98)Age and BMI
  Hayes et al26CSPositive, p=0.001NA
  Kornaat et al29CSOR 1.12 (99% CI 0.4 to 3.2)Age, sex, BMI, intrafamily effects
  Link et al30CSpositive, p<0.05NA
 Scored quantitatively
  Raynauld et al14Cr=−0.25, NS (WOMAC), r=0.12, NS (VAS)NA
  Wluka et al16Cr=0.28, positive, p=0.002NA
  Fernandez-Madrid et al25CSNSNA
  Sowers et al34CSPositive, p<0.0001NA
  Dunn et al23CSPositive, p<0.05NA
 Scored using other methods (ie, quantitatively after giving contrast agent)
  Anandacoomarasamy et al35CSr=−0.21, p=0.07NA
Bone marrow lesion (level of evidence: moderate)
Kornaat et al20CMean difference (increasing BML)=2 (95% CI −8 to 11)Age, sex, BMI, intrafamily effects5/8 (63%)4 (CS)/5 (1 C, 4 CS) (80%)
 Hayes et al26CSPositive, p=0.001NA
Felson et al24CSOR=3.31 (95% CI 1.5 to 7.4)Age, sex, radiological and effusion score
 Link et al30CSp>0.05NA
Lo et al36CSPositive, RR BML scores versus no BML:Positive:Effusion and synovitis
p For trend=0.0009p For trend 0.006
 Phan et al32CSr Not mentioned, NSNA
Sowers et al34CS+OR=5.0 (95% CI 2.4 to 10.5)NA
Torres et al19CS+β=5.0 (95% CI 3.0 to 7.0)3.72 (1.8 to 5.7)Age and BMI
Osteophytes (level of evidence: limited)
  Fernandez-Madrid et al25CSNSNA2/6 (33%)0/2 (CS) (0%)
  Hayes et al26CSPositive, p<0.001NA
  Kornaat et al29CSOR=1.05 (99% CI 0.4 to 2.9)Age, sex, BMI, intrafamily effects
  Link et al30CSp>0.05NA
  Torres et al19)CSβ=1.2 (95% CI 0.6 to 1.7)B=0.5 (0.07 to 0.94)Age and BMI
 Signal strength
  Sengupta et al33CSPR=0.94 (0.8 to 1.1)Age, sex, BMI
Meniscal lesion (level of evidence: conflicting)
Bhattacharyya et al18CSp=0.7Age2/6 (33%)1/3 (CS) (33%)
 Fernandez-Madrid et al25CSNSNA
 Hayes et al26CSPositive, p=0.001NA
Kornaat et al29CSTears: OR=1.26 (99% CI 0.6 to 2.7), subluxation: OR=1.03 (99% CI 0.5 to 2.2)Age, sex, BMI, intrafamily effects
 Link et al30CSp>0.05NA
Torres et al19CSTears: β=3.3 (95% CI 0.9 to 5.8)Tears: 2.0 (0.6 to 3.4)Age and BMI
Subluxation: β=15.0 (95% CI −0.3 to 30.3)Subluxation: 2.22 (−6.9 to 11.3)
Effusion and synovitis (level of evidence: moderate)
Hill et al12CEffusion: OR=1.2 (95% CI −8.1 to 10.5), synovitis: OR=3.2 (95% CI 1.04 to 5.3)Age, sex, BMI, cartilage score at baseline, effusion score, BML score, change in effusion and BML score.6/8 (80 %)4 (1 C, 3 CS)/4 (1 C, 3 CS)(100%)
 Fernandez-Madrid et al25CSEffusion: positive, p<0.001NA
Synovitis: NS
 Hayes et al26CSEffusion: positive, p<0.001NA
Synovitis: positive, p<0.001
Kornaat et al29CSEffusion: OR=10.0 (99% CI 1.1 to 149)Age, sex, BMI, intrafamily effects
 Link et al27CSEffusion: p>0.05NA
Lo et al*36CS+Effusion: RR BML scores versus no BML:Synovitis and BML
p For trend<0.0001p For trend=0.0004
p For trend 0.20p For trend=0.22
Torres et al19CSβ=15.0 (95% CI −8.2 to 38.2)9.8 (0.4 to 19.3)Age and BMI
 Pelletier et al21CEffusion: r=0.07, positive, p=0.71 (WOMAC); r=0.01,positive, p=0.93 (VAS)NA
Knee ligament abnormalities (level of evidence: limited)
Amin et al22CSACL: positive, p<0.05Age, sex, BMI and cartilage scores2/5 (40%)2/2 (CS) (100%)
 Hill et al28CSACL: positive, p=0.0004NA
 Link et al30CSACL: p>0.05, MCL and LCL: p>0.05NA
Torres et al19CSβ (95% CI)Age and BMI
ACL: 5.0 (−13.0 to 23.0)ACL: 6.8 (−5.4 to 19.0)
MCL: 0 (−11.9 to 11.9)MCL: −6.10 (−14.0 to 1.7)
LCL:15.0 (95% CI −8.2 to 38.2)LCL: 29.5 (17.8 to 41.1)
 Hayes et al26CSACL and PCL: p=0.23, MCL and LCL, p=0.86NA
Subchondral cysts (level of evidence: limited)
 Hayes et al26CSPositive, p<0.001NA1/5 (20%)0/2 (CS) (0%)
Kornaat et al29CSOR=1.71 (99% CI 0.8 to 3.6)Age, sex, BMI, intrafamily effects
 Link et al27CSp>0.05NA
 Fernandez-Madrid et al22CSNSNA
Torres et al19CSβ=2.50 (95% CI −0.4 to 5.4)0.82 (−0.5 to 2.1)Age and BMI
Bone attrition (level of evidence: conflicting)
Hernández-Molina et al27CSOR=2.1 (95% CI 1.4 to 3.4)1.2 (0.7 to 2.0)Age, sex, BMI, K&L grade, presence of BML and effusion1/2 (50%)1/2 (CS) (50%)
Torres et al19CSβ=3.3 (95% CI 1.8 to 4.9)1.9 (0.7 to 3.1)Age and BMI
  • Author's name in bold indicates high-quality studies; ‘positive’ in front of p values indicates significant positive association sizes.

  • r: (Spearman's or Pearson's) correlation coefficient between MR feature of interest and pain in continuous scale (WOMAC pain subscale or VAS); in a cohort study the correlation coefficient showed the association between changes of the MRI features with the changes in pain during the follow-up. OR, odds of having pain (in cross-sectional studies) or increasing pain (in cohort studies) when a MRI feature is present or increasing comparing to the odds when MRI feature is absent. β is regression coefficient representing the increase in knee pain severity associated with increase in lesion score, PR, prevalence (odds) ratio.

  • ACL, anterior cruciate ligament; BMI, body mass index; BML, bone marrow lesion; C, cohort, CS, cross-sectional studies; K&L, Kellgren and Lawrence; LCL, lateral cruciate ligament; MCL, medial cruciate ligament; NA, not applicable; NS, not significant; PCL, posterior cruciate ligament; VAS, Visual analogue scale; WOMAC, Western Ontario and McMaster Scoring.