Evolving Outcome Measures in Total Knee Arthroplasty: Trends and Utilization Rates Over the Past 15 Years

Patient-reported outcome metrics and reporting are important for demonstrating value associated with total knee arthroplasty (TKA). This review studied the patient-reported outcome utilization trends as reported within the TKA literature over a 15-year period.

A PubMed search of all manuscripts related to TKA from January 2005 to December 2019 was performed. Descriptive statistics were used for individual outcome metrics as proportions of total article publications focusing on TKA outcomes. Linear regressions analysis was performed to demonstrate significant changes in utilization rates over time.

There was a significant overall increase in studies utilizing outcome metrics between 2005 and 2019 (16.1%-45.0%; P < .001; R² = 98.7%). Within joint-specific metrics (2005-2019), use of Knee Disability and Osteoarthritis Outcome score increased (0%-14.8%; P < .001); while use of Knee Society Knee Scoring System decreased (55.2%-35.4%; P = .007). Of the studies reporting general health, use of the Forgotten Joint Score-12 decreased (100%-66.7% from 2014 to 2019; P = .006), and Patient-Reported Outcome Measurement Information System Global-10 increased (0%-21.4% from 2005 to 2019; P < .001). In the quality of life subcategory (2005-2019), EuroQol 5-Dimension Health Outcome Survey increased in usage (14.3%-28.0%; P < .001), while Short Form-36 use decreased (85.7%-36.6%; P < .001).

Although utilization of outcome metrics has significantly increased over the last 15 years in the TKA literature, there still exists considerable heterogeneity of outcome metrics. This lack of consensus may impede comparisons of studies for clinical and research purposes, as well as hinder cross-walk of outcome tools over time. Further study is needed to identify ideal global and joint-specific tools, while balancing issues like ease of use and utility in specific populations such as the young and highly active.