Measuring tools for functional outcomes in total knee arthroplasty

Abstract

Total knee arthroplasty has come under increasing scrutiny attributable to the fact that it is a high-volume, high-cost medical intervention in an era of increasingly scarce medical resources. Health-related quality-of-life outcomes have been developed such that healthcare providers might determine how good an intervention is and whether it is cost-effective. Total knee arthroplasty has been subjected to disease-specific, patient-specific, global health, functional capacity, and cost-to-utility outcome measures. Patient satisfaction is high (90%) after total knee arthroplasty and 93% of patients would have this operative procedure again. Large improvements in preoperative to postoperative WOMAC scores occurred (over 39 of 100 points in 82% of patients). Cost-to-quality outcomes demonstrated total knee arthroplasties are extremely cost-effective. This analysis documents total knee arthroplasty is a highly efficacious procedure that competes favorably with all medical and surgical interventions.

Fig. 1

These Ontario Joint Replacement Registry data demonstrate the preoperative to postoperative WOMAC change scores with patient satisfaction/transition change scores as outlined by Jaeschke et al. [11] (n = 3003).

Fig. 2

Patient severity at decision date as measured by WOMAC scores for TKA (n = 4437) is demonstrated [2].

Fig. 3

Patient severity 1 year postoperatively after TKA (n = 4437) is shown [2].

Fig. 4

The use of preoperative WOMAC scores to predict postoperative TKA patient outcomes based on the length of time patients waited for their surgery. Note that mild (WOMAC, 60), moderate (WOMAC, 40), and severe (WOMAC, 20) patients all did well if their surgery was performed within 100 days from the decision date [2].

Fig. 5

An example of outcomes using the patient-specific MACTAR patient preference disability questionnaire in patients undergoing THA is shown [8]. When stating the top five reasons for undergoing THA on a 10-centimeter visual analogue scale, the mean preoperative to postoperative substantially improved and remained improved up to four years postoperatively.

Fig. 6

A comparison of cost-to-utility adjusted life years (cost-to-QALY) of various medical and surgical interventions. Treatments < $20,000 are considered extremely cost-effective, those between $20,000 - $100,000 moderately so and those > $100,000 expensive. (HT = medical treatment of moderate hypertension, CAB = coronary bypass, Hemodial = hemodialysis, L. Transp = liver transplantation, HIV = medical treatment of human immune virus infections). HT = medical treatment of moderate hypertension; CAB = coronary artery bypass; Hemodial = hemodialysis; L Transp = liver transplantation; HIV = medical treatment of human immune virus infections [8].