Are Psychosocial Factors Predictors of Pain and Functional Outcomes After Knee Arthroplasty at 6 and 12 Months After Surgery? A Systematic Review

Supplemental Digital Content is Available in the Text. Background: To perform a systematic review of the literature to investigate the influence of psychosocial factors on pain and functional outcomes after knee arthroplasty from 6 months after surgery. Methods: Studies were included if they were prospective cohort observational studies. The subjects had to be middle aged or aged (mean age: 45 years) and have undergone total or unilateral knee arthroplasty. Studies should have recorded the influence of different psychosocial factors and the surgery outcomes had to be evaluated according to pain and/or function variables regardless of the tools used to measure them. In addition, outcome measures had to be recorded in the medium term (6 months) or the long term (12 months). Two reviewers assessed independently the MEDLINE, PsycINFO, and CINAHL databases to select observational studies. Results: Twenty-two studies with a total of 7156 patients (5349 females) were included in this review and the mean age was 67.92 years. Twenty-two studies included in this review showed a good average methodological quality (mean ± SD: 7.22 ± 0.92) on the Newcastle—Ottawa Scale for cohort studies. Conclusion: The evidence suggests that catastrophizing, kinesiophobia, anxiety, self-efficacy, and mental health are predictors of postoperative functional outcomes at 6 and 12 months after surgery. There is conflicting evidence on whether or not catastrophizing, anxiety, and depression are predictors of postoperative pain at 6 and 12 months after surgery.