Are There Differences in Patient-Reported Outcomes Measurement Information System Scores After Total Knee and Total Ankle Arthroplasty in Matched Patients?

Abstract

Introduction: The purpose of this study was to evaluate Patient-Reported Outcomes Measurement Information System (PROMIS) scores, a generic patient-reported outcome measure (PROM), as a tool to compare outcomes between total knee (TKA) and total ankle arthroplasty (TAA).

Methods: Patients who underwent TKA or TAA from January 1, 2019, to December 31, 2023, with at least one year of follow-up, were reviewed retrospectively. Upon application of criteria, 2,418 TKAs and 500 TAAs were utilized for analysis. Demographics, PROMs, emergency department (ED) visits, re-admissions, and revision surgeries were collected. Propensity score matching at a 3:1 ratio of TKA to TAA patients was then done, balancing age, sex, race, body mass index (BMI), and American Society of Anesthesiologists (ASA) classification, which resulted in a final cohort of 1,256 TKAs and 470 TAAs.

Results: Preoperative PROMIS pain interference scores were similar between TKA and TAA, and both showed improvements by six weeks. Patients undergoing TAA, however, had a greater decrease in pain interference scores at one year (TKA: -10.0 [-15.0 to -5.0]) versus TAA: -11.0 [-17.0 to -6.0]; P = 0.044). Regarding PROMIS physical function, preoperative scores were also similar for TKA and TAA patients. Additionally, patients in both groups had similar improvement in physical function at one year; however, TKA patients had better physical function at six weeks (TKA: 41.0 [36.0 to 46.0] versus TAA: 37.0 [33.0 to 41.0]; P < 0.001). Preoperative PROMIS depression scores were similar between groups and showed similar improvement after surgery. Joint-specific PROMs improved in each cohort, respectively.

Conclusion: Both TKA and TAA showed improvement postoperatively in joint-specific PROMs, which concurrently resulted in PROMIS score improvement across all domains in both joints. This suggests that arthroplasties across different anatomic sites can be compared using generic PROMs. For TKA and TAA, similar improvements in PROMIS pain interference, physical function, and depression were noted one year after surgery.