Preoperative physiotherapy and one-year patient-reported outcomes after primary total knee arthroplasty: a registry-based cohort study of 1,688 patients

OBJECTIVE: Preoperative physiotherapy in patients receiving primary total knee arthroplasty (TKA) aims to relieve pain, delay surgery, and improve postoperative recovery. This study investigates the change in PROMs and pain after primary TKA between patients who received preoperative physiotherapy (P) and those who did not (NP). DESIGN: Registry-based cohort study with data from an institutional registry. PATIENTS: 1,688 patients followed a standardized fast-track clinical pathway between August 2017 and January 2024 and were grouped in P or NP. METHODS: Primary outcome was KOOS-PS at 2 months and 1 year postoperatively. Secondary outcomes included pain, the Forgotten Joint Score, and EQ-5d-5L. Two anchor questions related to self-perceived knee function and willingness to have the surgery again at 12 months' follow-up were also evaluated. RESULTS: The model estimate demonstrated no significant between-group difference in KOOS-PS at 2 months (1.12 points; p = 0.079) or 1-year follow-up (1.25 points; p = 0.097). Visual inspection of descriptive plots showed that NP patients had higher KOOS-PS, less pain, and better joint score and quality of life at all time points. At 12 months' follow-up, both groups had similar responses to the anchor questions. CONCLUSION: After adjustment for baseline differences, no between-group differences in postoperative self-reported physical function were observed; consistently lower scores in the physiotherapy group may reflect systematic preoperative differences between groups.