Psychosocial Predictors of Poor Outcomes After a Knee Arthroplasty: Prospective Observational Study.

The purpose of this study is to explore the association between the psychosocial variables: pain catastrophizing, fear of movement, coping skills, pain attitudes, anxiety and depression with postoperative outcomes (pain, health functioning, physical performance, and quality of life) after a knee arthroplasty (KA). The prevalence of KA has increased dramatically during the last two decades, its popularity can be attributed to its evident success regarding pain improvement, deformity correction and disability reduction in knee osteoarthritis subjects. However, only a third of the patients report no functional problems after surgery, the 20% of them are unsatisfied with its functional skills and around a 20% are experiencing pain, high disability degrees and a significant quality of life reduction. This results cannot be fully explained by mechanical processes, surgical procedures or surgery variations, but seems to be related to other psychological aspects. Chronic pain subjects often develop maladaptive thoughts and behaviours (i.e. pain catastrophism, kinesiophobia, activity avoidance) which contribute to make the subject suffer physically as well as emotionally, and affect on the intensity and persistency of pain.

This study is a single centre, prospective observational study of subjects undergoing primary KA. The study is designed and aimed to examine the relationship between postoperative psychosocial factors and the development of post-operative persistent pain and disability.