AJRR introduces risk-adjusted revision rate model to improve accuracy in surgical benchmarking for THA and TKA

The AAOS American Joint Replacement Registry (AJRR) introduced a new risk-adjusted revision rate model in August, designed to enhance the value of its data. By accounting for patient factors such as demographics, comorbidities, and health history, the model provides orthopaedic surgeons and quality officers with more equitable and meaningful feedback on revision rates for total hip arthroplasty (THA) and total knee arthroplasty (TKA).

“AJRR is always seeking to improve the value of its data, and risk adjustment is necessary to enable surgeons to make meaningful comparisons of outcomes across surgeons, institutions, and surgeon-institution combinations,” said James I. Huddleston III, MD, FAAOS, chair of the AJRR Steering Committee. “Our hope is that this feature will encourage more regular use of the data for quality-improvement activities. By reflecting the true performance of THA and TKA surgical outcomes, the new model enables more reliable benchmarking and ultimately supports improved surgical outcomes in the future.”

AAOS developed the model in collaboration with Avant-garde Health, and biostatistician Isabella Zaniletti, PhD, MA, of IZ Statistics, LLC conducted expert review and validation. To develop the risk-adjusted model, they used AJRR data and Medicare claims data from 2012 to 2023 for patients captured in the registry.

The risk adjusters considered when developing the platform included demographics (sex, ethnicity, race, age, and BMI), care setting and geography (region and institution type — hospital, ambulatory surgery center, and private practice), and the year of the procedure. Additionally, the presence of osteoarthritis and all 17 subgroups of the Charlson Comorbidity Index were considered.

“Revision rates for TKA and THA are inherently complex,” said Porter Jones, MD, chief medical officer at Avant-garde Health. “By incorporating patient-specific factors, the model provides more reliable insights, helping surgeons distinguish true performance variation from differences driven by case mix. Risk adjustment should be the gold standard for comparing quality and outcomes, giving surgeons the confidence to use data for improving practice and guiding patient care.”

Dashboard tools and visual insights
Within the RegistryInsights^® dashboard, surgeons and other authorized users can evaluate one-year revision rates at the surgeon level, institution level, or surgeon-by-institution level. The dashboard also allows visual display metrics, such as funnel plots and filterable tables by year and procedure site. These visuals support longitudinal tracking of outcomes within a statistically adjusted framework, enabling surgeons to quickly identify performance trends, compare results with national benchmarks, and pinpoint areas for quality improvement.

“Producing one-year, risk-adjusted revision rates for primary hip and knee replacement has been an aspirational goal for AJRR for over a decade,” Dr. Huddleston said. “It is tremendously exciting to see this come to fruition, and we are planning to release two-year revision rates in the near future. Our new partnership with Epic’s Cloud-Based Community Registries will enable faster data acquisition and insights to enhance the strength of the risk-adjustment model by incorporating more orthopaedic-specific data points.”

The risk-adjusted revision rate model is now available to AJRR participants. To get involved with the AJRR, email an AAOS Registry engagement associate at RegistryEngagement@aaos.org, call 847-292-0530, or visit aaos.org/registries.

Jennifer Lefkowitz is a freelance writer for AAOS Now.