Preoperative factors predicting outcome for pain, physical function and quality of life after total knee arthroplasty (TKA) have not been clearly identified.
Embase and MEDLINE were searched for relevant studies. A study was considered for inclusion if the study aimed to identify preoperative prognostic factors for pain, physical function, and/or quality of life after a follow-up period of at least 1 year; included at least 200 adults suffering from osteoarthritis and undergoing TKA; and analyzed data using multivariable modeling. The quality of the evidence per prognostic factor was determined using the Grading of Recommendations, Assessment, Development and Evaluation framework for prognosis studies.
A total of 18 studies were included. There is very low-quality evidence that preoperative more pain, presence of social support, absence of anxiety, and presence of more radiographic damage are prognostic factors for lower pain levels after TKA. There is very low-quality evidence that low preoperative physical function, less comorbidity, absence of anxiety, presence of social support, higher income, normal body mass index, and more radiographic damage are prognostic factors for better physical function. There is very low-quality evidence that female sex and less comorbidity are prognostic factors for better quality of life.
Only very low-quality evidence was found for a number of prognostic factors of long-term outcome after TKA. More studies that seek to generate understanding of the underlying process for the prognosis of outcome in TKA are needed to understand and test prognostic pathways, and it might be more valuable to look at recovery curves rather than at recovery points. Systematic review registration number: CRD42015026814.