Table 1.

Search strategy based on Ovid MEDLINE for systematic literature search.

No	Keywords
1	collagen
2	foam
3	sponge
4	matrix
5	por*s
6	antib*
7	antimic*
8	diabetic
9	foot
10	ulcer
11	lower extremity
12	chronic
13	wound
14	Or/2–5
15	Or/6–7
16	Or/8–13
17	1 and 14 and 15 and 16
18	Limit 17 to yr. = “2010–2020”