Table 1

Characteristics of included studies (listed alphabetically by first author surname)

StudiesFeatures assessedPain assessmentStatistical analysisQuality score (%)
Cohort studies
 Hill et al12Patients with knee OA (ACR criteria). n=270 (42% women); mean age 67±9 years. BOKS, USA.Effusion/synovitisVASLinear regression68
 Kornaat et al20Generalised patients with OA. n=182 (86% women); median age 60 years (range: 43–77). GARP study, The Netherlands.BMLWOMAC painLinear mixed model64
 Pelletier et al21Patients with knee OA (ACR criteria) from outpatient rheumatology clinic, n=27 (52% women), mean age 64±9.6 years. Canada.SynovitisWOMAC and VAS painSpearman correlation36
 Raynauld et al14Patients with knee OA (ACR criteria). n=40 (88% women); mean age 62±8 years. Canada.CartilageWOMAC and VAS painSpearman correlation64
 Wluka et al16Patients with knee OA (ACR criteria). n=132 (54% women); mean age 63 years (range 41–86) Australia.CartilageWOMAC painSpearman correlation64
Cross-sectional studies
 Anandacoomarasamy et al35Obese patients with knee OA from general population (ACR criteria), n=77 (68% women), mean age: 51±12.7 years, Sydney, Australia.CartilageWOMAC painSpearman correlation67
 Amin et al22BOKS, USA. See above. n=265 (43% women); mean age 67±9 years.ACL tearVASStudent t test67
 Bhattacharyya et al18Cases: BOKS, USA. See above. n=154, mean age: 65 years. Controls: no knee pain, n=49 mean age: 67 years.Meniscal tearVASStudent t test67
 Dunn et al23Patients suspected for clinical OA. n=55 (55% women); mean age 63±3 years. USA.CartilageWOMAC painSpearman correlation22
 Felson et al24BOKS, USA. See above. n=401 (33% women in knee pain group, 48% in no pain group); mean age: 62 years (range: 22–91).BMLPresence/absence of painLogistic regression75
 Fernandez-Madrid et al25Case: patients with knee OA (ACR criteria). n=52 (67% women); mean age 55±14 years. Control: general population. n=40 (62% women), 49±15 years. Detroit, USA.Cartilage, osteophytes, subchondral lesions, effusion/synovitis, meniscal tearsPresence/absence of painχ2 test72
 Hayes et al26Four groups (each n=30, 100% women): no pain, no radiographic knee OA, mean age 45±1 years; no pain, radiographic knee OA, 46±1 years; pain, no radiographic knee OA, 47±1 years; pain, radiographic knee OA, 47±1 years. Southeast Michigan Osteoarthritis cohort, USA.Cartilage, osteophytes, subchondral cysts, BML, effusion/synovitis, meniscal tear, ACL tearPresence/absence of painFisher exact test of general association56
 Hernández-Molina et al27Patients with knee OA (K&L ≥2). n=1273 (48% women); mean age: 65±9 years. Framingham OA study cohort, Massachusetts, USA.Bone attritionPresence/absence of painχ2 test78
 Hill et al28Cases: BOKS, USA. See above. n=360, 33% women, mean age: 68 years. Controls: no knee pain. n=73, 65% with K&L ≥2 and JSN≥1, 57% men, 66 years.ACL tearPresence/absence of painχ2 test50
 Kornaat et al29GARP. See above. n=205 (80% women); median age 60 years (range: 43–77).Cartilage, osteophytes, subchondral cysts, BML, effusion, meniscal defectsPresence/absence of painLogistic regression78
 Link et al30Patients with knee OA (ACR criteria). n=50 (60% women); mean age 64±11 years.Cartilage, BML, meniscal tear, ACL tearWOMAC painWilcoxon rank sum test47
 Lo et al36Patients with knee OA (Knee pain or stiffness and osteophytes OARSI atlas score 1–3), n=160 (50% women), mean age 61±9.9. OA initiative.BML, effusion/synovitisWOMAC painLogistic regression78
 Pelletier et al31Knee OA (radiographic) from general population. Subset from clinical trial on Risendronate in North America. n=110 (64% women); mean age 62±7 years.CartilageWOMAC painSpearman correlation39
 Phan et al32Patients with knee OA (ACR criteria), n=34 and general population, n=6, 60% women, mean age: 58±16 years.Cartilage, BMLWOMAC painCorrelation not specified67
 Sengupta et al33BOKS. See above. n=217 (30% women); mean age 67 ±9 years.Osteophytes10-point pain scaleLogistic regression78
 Sowers et al34Southeast Michigan Osteoarthritis cohort, USA. See above.Cartilage, BMLVAS painWilcoxon or Maentel–Haenszel test of general association78
 Torres et al19Patients with knee OA (K&L ≥2 and ‘a little difficulty’ in one or two WOMAC physical function scale). n=143 (88% women); mean age 70±10 years.Cartilage, osteophytes, bone cysts, bone attrition, BML, synovitis, meniscal tears, ligament abnormalities (MCL, LCL and ACL)VAS painMedian quantile regression78
  • ACR clinical and radiographic criteria requires knee pain and osteophytes on radiograph.50

  • ACL, anterior cruciate ligament; ACR, American College of Rheumatology; BMI, body mass index; BML, bone marrow lesion; BOKS, Boston OA of the knee study; GARP, Genetic Arthrosis Progression Study; JSN, joint space narrowing; K&L, Kellgren and Lawrence Osteoarthritis Scoring System for knee radiographs; LCL, lateral cruciate ligament; MCL, medial cruciate ligament; n, number of study population; OA, osteoarthritis; VAS, visual analogue scale; WOMAC, Western Ontario and McMaster University.