This study is a secondary analysis of 12-month follow-ups from two parallel, randomised controlled trials (RCT) in painful knee osteoarthritis patients. RCT1: Total knee replacement (TKR) followed by non-surgical treatment compared with non-surgical treatment. RCT2: Non-surgical treatment compared with usual care. The aims were to investigate 1) possible predictors of treatment outcome after TKR and non-surgical interventions at 12 months, 2) associations between pain intensity and pressure pain thresholds (PPTs) (pain sensitisation) at baseline and after 12 months, and 3) possible gender differences.