Table III.

Characteristics of key epidemiology studies reporting prevalence and incidence of foot and ankle OA

Study	n	Age range (mean)	% female	Population	Country	Radiographic views	Joints assessed	Grading system	Radiographic definition	Symptomatic definition
Zoetermeer Study	6,585	19+ (NR)	53	Zoetermeer, Western Netherlands	Netherlands	NR	First to fifth MTP, TMT, PIP	KL	Grade ≥2	–
Clearwater Osteoarthritis Study	3,436	40–94 (62)	>69	Pinellas County, Florida	USA	WB AP	First MTP	KL	Grade ≥2	–
Clinical Assessment Study of the Foot	525	50–87 (65)	56	4 general practices, North Staffordshire	UK	WB AP WB lateral	First MTP, first CM, second CM, NC, TNJ	La Trobe Foot Atlas	Grade >2 for OP and/or JSN, either view	Pain in past 4 weeks in corresponding region of the foot
Johnston County Osteoarthritis Project	863	55+ (71)	68	6 communities in Johnston County, North Carolina	USA	WB AP WB lateral	First MTP, first CM, second CM, NC, TNJ	La Trobe Foot Atlas	Grade >2 for OP and/or JSN, either view	Pain, aching or stiffness in corresponding foot
Chingford Study	209	45–64 (57)	100	1 general practice, Chingford, East London	UK	Semi-WB AP	First MTP	La Trobe Foot Atlas	Grade >2 for OP and/or JSN	–

NR: not reported; KL: Kellgren and Lawrence; MTP: metatarsophalangeal; TMT: tarsometatarsal; PIP: proximal interphalangeal; CM: cuneometatatarsal; NC: navicularfirst cuneiform; TN: talonavicular; WB: weightbearing; AP: antero-posterior; OP: osteophytes; JSN: joint space narrowing.