For this second update we searched the Cochrane Wounds Group Specialised Register (searched 12 August 2011); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 3); Ovid MEDLINE (1950 to August Week 1 2011); Ovid MEDLINE (In-Process & Other Non-Indexed Citations August 11, 2010); Ovid EMBASE (1980 to 2011 Week 31) and EBSCO CINAHL (1982 to 11August 2011). No date or language restrictions were applied.