Clinical predictors of resilience following total knee arthroplasty: the PRIME-KNEE study

BACKGROUND: We aimed to describe recovery trajectories over 6 months in pain intensity, pain interference, lower extremity disability, and physical activity in older adults undergoing elective total knee arthroplasty (TKA), and to identify clinically feasible measures predicting recovery. METHODS: Prospective cohort study in a single academic medical center. Adults ≥60 years (n = 203) scheduled for elective TKA had preoperative assessments of physical reserve (3-min walk test, grip strength), psychological reserve (PHQ-9, Resilience Scale), social support (emotional support scale, financial resource sufficiency, education level), and cognitive reserve (3MS, Trail Making Test Part B, Digit Symbol Substitution Test, 15-item recall). Provocative tests with experimental stressors included dual-task gait speed, and functional near infrared spectroscopy (fNIRS). Outcomes were the PROMIS pain scales, the lower extremity gain scale, and average daily step counts measured at postoperative day 1-7 and months 1, 2, 4, and 6. Latent class trajectory analysis defined common recovery patterns for each outcome. RESULTS: For each outcome, 3-4 recovery trajectory groups were defined. Overall, 7% of participants were in the highest recovery group in all 4 outcomes and 20% in the lowest for all outcomes. Preoperative depression score, cognitive tests, emotional support scale, 3-min walk distance, and grip strength were significantly different across resilience groups in multiple outcomes. Provocative tests were not predictive of recovery. CONCLUSIONS: Recovery trajectories after TKA are predicted by physical, cognitive, and psychological reserve measures. Results inform future resilience research and may allow for shared decision-making and targeted preoperative optimization.