Rating Systems to Assess the Outcomes After Total Knee Arthroplasty

To assess the success of a total knee arthroplasty (TKA), scoring systems have been developed to provide a straightforward method of evaluating the outcomes of patients following surgery. Fully evaluating these outcomes is a challenging and time consuming task, and these simplistic measures often do not provide a complete picture of a patient's recovery. Therefore, we evaluated different scoring systems to determine the most effective method of assessing the outcomes of patients undergoing total knee arthroplasty.

We evaluated all knee scoring systems currently available in literature, and a total of 46 questionnaires met our inclusion and exclusion criteria. We then identified all the metrics assessed in the questionnaires (n=48) and subdivided them into objective, subjective, rehabilitative, and quality of life outcome measures. We identified the three most commonly referenced questionnaires (the Knee Society Scores, the Knee Osteoarthritis and Outcomes Scores, and the Western Ontario and McMaster Score-WOMAC) and assessed multiple permutations of these with other scoring systems to identify the combinations that would most comprehensively and efficiently evaluate the outcomes of patients undergoing TKA.

Of the 48 metrics, we identified four subjective, eight objective, 20 rehabilitation, and 16 quality of life metrics. On permutation of the three most referenced scoring systems, the KSS and the KOOS together yielded the greatest coverage of the above metrics (79%). When the KSS, KOOS, and WOMAC, respectively, were combined with the Lower Extremity Function Scale (LEFS) and Short Form 36 (SF-36), they yielded 77, 73, and 60% coverage of the metrics and 35, 39, and 37% redundancy, respectively.

Surgeons and researchers have attempted to fully evaluate the outcomes of patients undergoing TKA. The proposed combinations may provide a more comprehensive way to cost-effectively evaluate outcomes. Further analysis is required before attempting to create newer knee scoring systems.