Table 4.

Proportion (%) of patients experiencing knee pain in specified age-groups of populations with radiographic osteoarthritis.

Study	Age Group	Radiographic View	Proportion (%)	OA Definition	Population
Lachance [13]	40–53	A/Pwb	35	K&L 2+	CA
			50		AA
Hart [18]	45–65	A/Pwb	56	K&L 2+	All
Davis [27]	45–75	A/Pwb	41(KL2)	K&L I+	All
			59(KL3)		All
Hannan [25]	51–74	A/P	47	Def Ost	All
Claessens [3]	> 45	A/Pwb	24	K&L 2+	All
Cicuttini [11]	> 45	Lateral Flexed wb	16	Def Ost	Female
		S/L	26		Female
Cicuttini [26]	> 45	A/Pwb	20	Ost	Female
		Lateral	15	JSN	Female
		S/L	23	or both	Female
Odding [14]	> 55	A/Pwb	30(KL2)	K&L 2+	All
			59(KL3)
Felson [20]	> 63	A/Pwb	40	K&L2+	All
				or JSN
Brandt [24]	> 65	A/Pwb + Lateral	22	K&L2+	All
Lethbridge [10]	19–92	A/P	30(KL2)	K&L2+	All
			64(KL3)
Williams [21]	51–80	A/P Lat Flexed	79	K&L2+	All
Lanyon [8]	40–80	A/Pwb + S/L	81	Altman	All
				≥ Grade I Ost [32]

A/P – antero-posterior

wb – weight bearing

S/L – skyline

Lat – lateral

CA – Caucasian

AA – African American

KL – Kellgren Lawrence grade

All – whole population

K&L – Kellgren & Lawrence Knee OA Grading Scale [33]

Ost – Osteophytes

Def Ost – Definite Osteophytes

JSN – Joint Space Narrowing