This cohort study investigated the influence of psychological factors, including perception of illness, anxiety and depression on recovery and functional outcome after total knee replacement surgery. A total of 100 patients (55 male; 45 female) with a mean age of 71 (42 to 92) who underwent a primary total knee replacement for osteoarthritis were recruited into this study. In all 97 participants completed the six week and 87 the one year follow-up questionnaires. Pre-operatively patients completed the revised Illness Perception Questionnaire, Hospital Anxiety and Depression Scale and Recovery Locus of Control Scale. Function was assessed pre-operatively, at six weeks and one year using Oxford Knee Score (OKS) and the goniometer-measured range of movement (ROM). The results showed that pre-operative function had the biggest impact on post-operative outcome for ROM and OKS. In addition questionnaire variables and depression had an impact on the OKS at six weeks. Depression and anxiety were also associated with a higher (worse) knee score at one year but did not influence the ROM at either six weeks or one year. Recovery from total knee replacement can be difficult to predict. This study has identified psychological factors that play an important role in recovery from surgery and functional outcome. These should be taken into account when considering patients for total knee replacement.
Keywords: Functional outcome; Illness cognition; Knee arthroplasty; Knee replacement; Psychological distress; TKR.