Patient factors that influence the outcome of total knee replacement: A critical review of the literature

Introduction Total knee replacement is a cost effective treatment for end-stage osteoarthritis of the knee and the rate of this procedure continues to increase, which is thought to be due to an aging society with greater functional demands. The outcome of total knee replacement is variable, however, with approximately one in five patients not being satisfied with their knee after surgery. There are multiple patient factors that are thought to affect the outcome of total knee replacement. The aim is to review the published literature and present the current evidence regarding the influence of patient factors upon the outcome of total knee replacement. Conclusion A patient’s outcome according to the Oxford knee score is not influenced by their age, socioeconomic status and mental wellbeing, but is influenced by fulfilment of their pre-operative expectations and their post-operative general physical health. In contrast to the Oxford knee score the rate of patient satisfaction is influenced by socioeconomic status, mental wellbeing, in addition to fulfilment of expectations and the post-operative general physical health of the patient. Introduction Total knee replacement (TKR) is an effective procedure for the treatment of end-stage osteoarthritis of the knee, and the rate of this procedure continues to increase year on year1. However, one in five patients undergoing TKR will not be satisfied with their knee replacement postoperatively2,3. The rate of patient satisfaction is influenced by multiple patient-dependent factors, which also influence patient-reported outcome measures (PROMs). The outcome of TKR can be measured by using numerous PROMs. The Oxford knee score4 (OKS) and the Short Form-12 (SF-12) questionnaire5 are two such PROMs that are commonly used. The OKS is a joint-specific score that enables subjective measurement of knee function and pain after surgery. The SF-12 score, in contrast, is a generic health measure of a patient’s overall physical and mental wellbeing. This critical review presents the current literature regarding the influence of patient factors, specifically age, socioeconomic status, mental health, expectation and general health, on the outcome of TKR according to PROMs and patient satisfaction.