Search terms for design  1     clinical trial.mp or exp Clinical Trials  2     randomised controlled trial.mp. 3     clinical trial*.af. 4     random*.af. 5    placebo.af. 6     (randomised controlled trial or controlled clinical trial) .af. or trial .ti. 7     1 or 2 or 3 or 4 or 5 or 6 or 7 8     limit 7 to human

Search terms for population  9      exp Ankle/ 10    ankle.af. or ankle joint.af. 11    9 or 10 12     exp Arthritis/ 13     (osteoarthritis or arthritis or arthrosis or osteoarthrosis or (degenerative ˜ (arthr* or disease))).af. 14    12 or 13 or 14 15    11 and 15

Combining terms  16    8 and 15