Application of Prospect Theory in decision-making for total knee arthroplasty: A retrospective study on loss aversion and patient expectations

Total knee arthroplasty (TKA) provides substantial pain relief and functional improvement in advanced knee osteoarthritis, yet up to 20% of patients remain dissatisfied despite technically successful procedures. Traditional preoperative assessments overlook psychological determinants influencing surgical decision-making and postoperative satisfaction. Prospect Theory—emphasizing loss aversion and perceived gains—offers a novel behavioral framework to explain these outcomes. A retrospective observational study included 500 patients with Kellgren–Lawrence grade III–IV osteoarthritis; 300 underwent TKA and 200 declined surgery. Preoperative and postoperative assessments included EQ-5D, Satisfaction With Life Scale (SWLS), and Global Perceived Effect (GPE). Psychological parameters were evaluated using a Prospect Theory–based model quantifying perceived gains, perceived risks, and loss aversion (α = 0.88, β = 0.88, λ = 2.25). Statistical analyses comprised t-tests, chi-square tests, correlations, and logistic regression to identify predictors of surgical decision and satisfaction. Patients who declined surgery demonstrated higher loss aversion (7.1 ± 1.9) compared to surgical patients (4.3 ± 2.1, p < 0.001). Perceived gain scores were greater in the TKA group (8.2 ± 1.4 vs. 5.9 ± 1.6, p < 0.001). Loss aversion correlated negatively with surgical acceptance (r = –0.655, p < 0.001), while perceived gain correlated positively (r = 0.746, p < 0.001). Among surgical patients, EQ-5D mobility improved from 0.41 ± 0.22 to 0.78 ± 0.19, pain decreased by –3.4 points, and anxiety/depression by –2.1 points (all p < 0.001). Logistic regression identified loss aversion (OR 0.62, 95% CI 0.51–0.74) and perceived gain (OR 1.48, 95% CI 1.28–1.71) as independent predictors of surgical acceptance. Overall satisfaction was 82% at 12 months. Psychological factors, particularly loss aversion and perceived gains, significantly influence both the decision to undergo TKA and postoperative satisfaction. The Prospect Theory–based model accurately predicted surgical acceptance and recovery trajectories, underscoring the potential of integrating behavioral economics into preoperative counseling and shared decision-making. • Up to 20% of TKA patients remain dissatisfied despite technical success. • Prospect Theory explains decision-making through loss aversion and perceived gains. • Higher loss aversion was strongly linked to declining surgery. • Perceived gains predicted surgical acceptance and postoperative satisfaction. • A Prospect Theory model accurately predicted decisions and recovery outcomes. • Integrating behavioral economics may improve counseling and reduce dissatisfaction.