1     Ankle/ or Ankle Joint/ 2     ankle.af. 3     exp Osteoarthritis/ 4     exp Arthritis/ 5     (osteoarthritis or arthritis or arthrosis or osteoarthrosis or (degenerative adj (arthr$ or disease))).af. 6     1 or 2 7     or/3‐5 8     or/3‐5 9     6 and 7 10     exp Surgery/ 11     Surgery operative/ 12     surg$.tw. 13     surg$.tw. 14     10 or 11 or 12 15     11 or 12 or 13 16     9 not 14