Psychological factors affecting the outcome of total hip and knee arthroplasty: a systematic review

Objectives: Recently, numerous studies have reported that psychological factors can influence the outcome of total knee arthroplasty (TKA) and total hip arthroplasty (THA). However, a systematic overview is missing. The objective of this study was to examine which psychological factors influence the outcome of TKA and THA and to what extent.

Methods: Data were obtained from the MEDLINE and EMBASE databases from inception to January 2011. Search terms included TKA and THA, outcome measures, and psychological aspects. Two reviewers independently selected the studies. Studies with a prospective before-after design with a minimum follow-up time of 6 weeks were included. One reviewer extracted the results and 2 reviewers independently conducted quality assessment. We distinguished between follow-up shorter and equal or longer than 1 year.

Results: Thirty-five of 1837 studies met the inclusion criteria and were included in this systematic review. In follow-ups shorter than 1 year, and for knee patients only, strong evidence was found that patients with pain catastrophizing reported more pain postoperatively. Furthermore, strong evidence was found that preoperative depression had no influence on postoperative functioning. In long-term follow-up, 1 year after TKA, strong evidence was found that lower preoperative mental health (measures with the SF-12 or SF-36) was associated with lower scores on function and pain. For THA, only limited, conflicting, or no evidence was found.

Conclusions: Low preoperative mental health and pain catastrophizing have an influence on outcome after TKA. With regard to the influence of other psychological factors and for hip patients, only limited, conflicting, or no evidence was found.