Identifying patient subgroups with different trends of patient-reported outcomes (PROMs) after elective knee arthroplasty

Background: Patient-reported outcome measures (PROMs) are increasingly being used to assess the effectiveness of elective total knee arthroplasty (TKA). However, little is known about the change over time of PROMs scores in these patients. The aim of this study was to identify the trajectories of quality of life and joint functioning, and their associated demographic and clinical features in patients undergoing elective TKA. Methods We conducted a prospective, cohort study in which PROMs questionnaires (Euro Quality 5 Dimensions 3L, EQ-5D-3L, and Knee injury and Osteoarthritis Outcome Score Patient Satisfaction, KOOS-PS) were administered to patients undergoing elective TKA before surgery, and at 6 and 12 months after surgery at a single center. Latent class growth mixture models were used to analyze the patterns of change in PROMs scores over time. Multinomial logistic regression was used to investigate the association between patient characteristics and PROMs trajectories. Results A total of 564 patients were included in the study. Our analysis highlighted differential patterns of improvement after TKA. Three distinct PROMs trajectories were identified for each PROMs questionnaire, with one trajectory characterizing the best outcome. Female gender appears to be associated with a presentation to surgery with worse perceived quality of life and joint function than males, but also more rapid improvement after surgery. Having an ASA score greater than 3 is instead associated with a worse functional recovery after TKA. Conclusion Our results suggest three main PROMs trajectories in patients undergoing elective TKA. Most patients reported an increase in quality of life and joint functioning at 6 months and a stabilization afterwards, while other subgroups present more heterogeneous trajectories. Further research is needed to confirm these findings and to explore the potential clinical implications of these results.