Table 2

Details of included MRI studies

Author, year	Additional information	Sex	Age	N (knees)	Diagnostic criteria	Isolated PF OA (%)			Combined (%)	Unclear PF OA (%)			Feature	Case definition
						Overall	Medial	Lateral	PF + TF OA	Overall	Medial	Lateral
Community-based population
Ding86 2005	<45 years	FM	<45	167	0–4 scale					16			Cartilage defect	≥2
	>45 years	FM	≥45	205						38			Cartilage defect	≥2
Gross39 2012^∗	FOA cohort	FM	64±9	985 (1159)	WORMS		50	18					Cartilage damage	≥2
Stefanik95 2013	FOA cohort	FM	64±8	970	WORMS	20			44				Cartilage damage	≥2
Wang99 2015	TASOAC cohort	FM	62±7	904	WORMS					19			BML	≥1
										40			Cartilage defect	≥2
Healthy individuals
Sharma92 2014	OAI cohort	M	60±9	375	MOAKS	25			33				Cartilage damage	>0
					WORMS	33			18				BML	>0
		F	60±9	474	MOAKS	34			30				Cartilage damage	>0
					WORMS	35			17				BML	>0
Wang100 2012		FM	42±7	38	0–4 scale					3			Cartilage defect	≥2
Knee pain or symptomatic population
Amin Baker79 2009^∗	BOKS cohort	M	68±9	154	WORMS						81	68	Maximal cartilage morphology	≥2
		F	64±9	111	WORMS						91	84	Maximal cartilage morphology	≥2
Amin Goggins80 2008^∗	Heavy lifting (BOKS cohort)	M	69±9	40	WORMS					60			Cartilage morphology	≥2
	Occupational exposures	M	64±9	47	WORMS					72			Cartilage morphology	≥2
	No heavy lifting/occupational exposures	M	70±9	98	WORMS					47			Cartilage morphology	≥2
Amin Guermazi81 2008	BOKS cohort	FM	67±9	265	WORMS					91			Cartilage morphology	≥2
Cai82 2015	Anhui osteoarthritis cohort	FM	56±12	174	0–4 scale					82			Cartilage damage	≥2
		FM			0–3 scale					52			BML	≥1
Crema84 2014		FM	58±10	163	0–3 scale					13			BML	≥1
Peterfy90 2004		FM	61±8	19	WORMS					94			Cartilage abnormality	≥1
										16			BML	≥1
										81			Osteophytes	≥1
Tsavalas97 2012	Various knee-related clinical conditions	FM	≤50	315	ICRS					5			Cartilage lesion	≥2
		FM	>50	200	ICRS					33			Cartilage lesion	≥2
Radiographic knee OA or high risk of knee OA
Gross 201239	MOST cohort	FM	62±8	1381 (1621)	WORMS		69	36					Cartilage damage	≥2
Stefanik Gross 201595 ^∗ (O&C)	MOST cohort	FM	69±8	1137	WORMS		22	13		63			BML	≥1
Stefanik Gross94 2015^† (ACR)	MOST cohort	F	66±8	653 (2594)	WORMS					51			Cartilage damage	≥2
										29			BML	≥1
		M	66±8	400 (1486)	WORMS					43			Cartilage damage	≥2
										23			BML	≥1
Runhaar91 2014		F	56±3	348 (529)	MOAKS	44	35	18					BML	≥1
				348 (467)		47	42	18					Cartilage defect	≥1
				348 (408)		33	27	25					Osteophytes	≥1
						Overall	Medial	Lateral	PF + TF OA	Overall	Medial	Lateral
Radiographic and symptomatic OA
Chan25 1991		FM	58	20	0–3 scale	0			75				Cartilage loss	≥1
						0			75				Osteophytes	≥1
Post-traumatic population
Culvenor85 2015	ACLR with or without meniscus repair	FM	30±8	111	MOAKS	12					2	3	BML	≥1
Van Meer98 2016	ACL rupture	FM	25±33	143	MOAKS					29			Osteophytes	≥1
Wang100 2012	Arthroscopic partial medial meniscectomy (2 years post)	FM	43±5	63	0–4 scale	19							Cartilage defect	≥2
General population
Gross87 2011	Framingham Heart study offsprings + spouses and people from Framingham town	FM	64±9	1094	WORMS						58		Cartilage damage	≥2
				1096								42	Cartilage damage	≥2
Hayes88 2005	With or without pain or OA	F	46±1	117 (232)	Modified Nayes arthroscopy system					66			Cartilage defect	≥IIA
Kornaat89 2005	40–70 years with familial generalised OA	FM	60 (43–77)	205	KOSS	66							Cartilage defect	≥1
Sowers93 2011	Middle-aged women	F	56±5	360 (724)						89			Cartilage defect
										45			BML
						Overall	Medial	Lateral	PF + TF OA	Overall	Medial	Lateral
Sowers93 2011	Middle-aged women	F	56±5	360 (724)						56			Osteophytes
Teng96 2015	Without no OA or isolated OA	FM	51±10	61	WORMS					46			Cartilage lesion	>1

Where possible, age is presented as mean±SD or mean (range).
∗Studies included in subgroup analyses.
†Percentage based on regions.
ACLR, ACL reconstruction; BOKS, Boston Knee Osteoarthritis Study; BML, bone marrow lesion; F, female; FM, both female and male; FOA, Framingham Osteoarthritis; ICRS, International Cartilage Repair Society; KOSS; Knee Osteoarthritis Scoring System; M, male; MOAKS, MRI Osteoarthritis Knee Score; MOST, Multicenter Knee Osteoarthritis; PF OA, patellofemoral osteoarthritis; OA, osteoarthritis; OAI, Osteoarthritis Initiative; TASOAC, Tasmanian Older Adult Cohort. WORMS, Whole-organ MRI Score.