Patient Expectations for Patient-reported Outcomes After Total Knee Arthroplasty Surpass Actual Outcomes and Correlate With Dissatisfaction

Background Unmet patient expectations are associated with dissatisfaction after total knee arthroplasty (TKA). No prior studies have quantified patient expectations using the same patient-reported outcome (PRO) metrics used to evaluate postoperative outcomes and minimal clinically important differences (MCIDs). Methods Baseline PROs were collected for 64 patients undergoing primary TKA using PROMIS Physical Function (PF), PROMIS Pain Interference (PI), Knee Injury and Osteoarthritis Outcome Score-12 (KOOS-12), and Veteran's RAND-12 Mental and Physical Component Scores (VR-12 MCS, PCS). Patients reported their expected 12-month postoperative PRO scores preoperatively. Actual 12-month PROs and satisfaction were recorded postoperatively. Expected and actual changes in PROs (ΔPROs) were compared with MCIDs and with each other. Associations between expectations, outcomes, and satisfaction were evaluated using point-biserial correlations. Results Patients (mean age 66.3 SD 9.3 years; BMI 31.1 SD 5.6; 54.7% female) expected improvements exceeding MCIDs for all PROs except VR-12 MCS ( P < .0001). Actual improvements exceeded MCID for KOOS-12, VR-12 PCS, and PROMIS PI but not for VR-12 MCS or PROMIS PF. Expected ΔPROs exceeded actual improvements for all PROs except VR-12 MCS ( P = .32). Overall satisfaction was reported by 87.5% of patients. Larger discrepancies between expected and actual improvements correlated with dissatisfaction for KOOS-12, VR-12 PCS, and PROMIS PF (r range −0.30 to −0.28; P ≤ .01). Satisfaction correlated with actual improvements in KOOS-12, VR-12 PCS, and PROMIS PI (r range −0.44 to 0.46; P ≤ .01). Conclusions Patients undergoing TKA commonly expect improvements exceeding both MCIDs and actual postoperative outcomes. Larger expectation-outcome discrepancies were associated with postoperative dissatisfaction, highlighting the importance of aligning patient expectations with realistic outcomes during preoperative counseling.