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

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.

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.

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.

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.