Preoperative quadriceps muscle strength and functional ability predict performance-based outcomes 6 months after total knee arthroplasty: a systematic review

Background: One-third of individuals report limitations in activities of daily living even 6 months after total knee arthroplasty (TKA). Moderate-quality evidence exists for several sociodemographic and clinical predictors of patient-reported outcome measures of perceived functionality. Objectively measured performance-based measures (PBMs) provide a less subjective approach to informing patient treatment after TKA; however, there is a dearth of information on predictors of functionally relevant PBMs. Purpose: This systematic review synthesized the available research on preoperative predictors of PBMs after primary TKA for osteoarthritis. Data Sources: In June 2016 and January 2017, Medline, Embase, and PsycINFO databases were searched. Study Selection: Cohort studies exploring preoperative predictors of stair climbing, walking speed, and gait speed measured at least 6 months after primary TKA were included. Screening of abstracts and selection of full texts were undertaken by 2 independent reviewers. Data Extraction: Information on study design, patient characteristics, analysis, and results was extracted using pilot-tested forms. Two independent reviewers assessed risk of bias using modified Quality in Prognostic Studies criteria. Data Synthesis: Of the eligible 12 studies involving 6 prospective cohorts, 10 studies reported information on baseline predictors. Meta-analysis of predictors was not possible because of missing information on effect size or standard errors. Narrative synthesis of evidence of predictors was therefore performed. Limitations: The quality of evidence was low because of the risk of bias and heterogeneity of included studies as well as nonreporting of measures of effect. Conclusions: Low-quality evidence exists for an association of preoperative functional ability and quadriceps muscle strength with functionality at 6 months after TKA. There is a need for improving the reporting of predictor analyses to enable evidence generation for clinical management. Osteoarthritis of the knee is an age related degenerative condition leading to considerable disability.1,2 Total knee arthroplasty (TKA) is a well-established procedure for end stage osteoarthritis3 and has been shown to significantly improve pain, function, and quality of life.4,5 Evidence from systematic reviews of observational studies of patients undergoing TKA have shown improvements in walking speed,6 rates of return to work7 or sports.8 Since its inception in 1970, both the surgical procedure and the prosthesis have evolved over the years,9 leading to early recovery, greater range of motion, and longer prosthesis survival. Consequently there has been an increase in the use of this procedure across developed and developing nations10-12 with a demographic shift towards younger (less than 60 years) persons.13.