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AAOS American Joint Replacement Registry (AJRR)




Research Studies


Enrolled Patients

Created in 2009, the American Joint Replacement Registry (AJRR) has grown to be the world’s largest registry of hip and knee replacement data by annual procedural count. As of June 26, 2020, the Registry contains data on over 2 million procedures from hospitals, ambulatory surgery centers (ASCs), and private practice groups in all 50 states and the District of Columbia.

By collecting and reporting data, the AJRR provides actionable, evidence-based information to guide physicians and patient decision-making to improve care. It empowers health care organizations to enhance the patient experience and benchmark performance, orthopaedic surgeons to reduce complications and revision rates, and device manufacturers to strengthen post-market surveillance.


AJRR Data Elements Collected

The AJRR collects hip and knee arthroplasty procedures in three data types: procedural, post-operative, and patient-reported outcome measures (PROMs) data. Procedural data is patient-related, hospital/practice-related, surgeon-related, and procedure-related data that includes information about comorbidities, length of stay, and operative complications. Post-operative data includes 90-day readmission data and post-operative complications data. A PROM is a survey that captures a patient’s self-assessment regarding their health status and may include questions related to physical function, mental attitude, mobility, social function, and bodily pain. AJRR recommends collecting a health-related quality of life measure and a hip or knee-specific measure.




  • Name (Last, First)
  • Date of Birth
  • Social Security Number
  • Diagnosis (ICD-9/10, CPT)
  • Gender
  • Race/Ethnicity
  • Height + Weight/Body Mass Index
  • Payer Status

Site of Service

  • Name and Address (TIN, NPI)


  • Name (NPI)
  • Trainee


  • Type (ICD-9/10, CPT)
  • Date of Surgery
  • Length of Stay
  • Surgical Approach
  • Surgical Technique
  • Laterality
  • Anesthesia

Comorbidities and Complications

  • Comorbidities (ICD-9/10, CPT)
  • CJR Risk Variables
  • Height + Weight/Body Mass Index
  • Length of Stay
  • American Society of Anesthesiologists Score
  • Charlson Index
  • Operative and Post-operative Complications


Patient-reported Outcomes


  • PROMIS-10 Global
  • VR-12

Also Available:

  • SF-36 v1
  • Oxford Hip and Knee Scores
  • Knee Society Knee Scoring System
  • Harris Hip Score
  • WOMAC (Modified via HOOS and KOOS)
  • SF-12, EQ-5D, WOMAC (only accepting final scores)

Interested in viewing the Data Specifications or Data Dictionary for AJRR? These documents are proprietary and can be accessed in the Tools & Resources tab on AAOS RegistryInsights®. For more information, please contact AAOS Registry Program staff at AAOS American Joint Replacement Registry.


AJRR Data Submission

After AJRR participating sites collect the necessary data elements, they submit their data through the AAOS RegistryInsights® data upload process via a secure file transfer protocol (SFTP) or hypertext transfer protocol secure (HTTPS).

A few data submission best practices include:

  • Submitting data monthly
  • Consulting with your site’s IT team to set up automated reports
  • Monitoring data submission uploads and addressing errors
  • Utilizing an AAOS Registry Program Authorized Vendor to facilitate the data submission process

AJRR Reaches 2 million procedures

For more information about AJRR data submission, click here.


AJRR Participation Benefits

Participating in AJRR provides access to site-wide, systemwide, and nationwide data. Reuse of Registry data has value to certifying bodies, quality reporting, device surveillance, reimbursement, and quality measurement efforts.

A few top benefits of AJRR participation include:

Learn more about AJRR participation benefits here.

Learn more about the quality initiatives that AJRR can help meet here.


AJRR Leadership

The AJRR Steering Committee is comprised of stakeholders from various disciplines that are all vested in improving orthopaedic care. The 2020-2021 AJRR Steering Committee members and the organizations they represent include:

  • Bryan D. Springer, MD, FAAOS, Chair AJRR Representative
  • James I. Huddleston, III, MD, FAAOS, Vice Chair California State Registry Committee (CSRC) Representative
  • Scott M. Sporer, MD, FAAOS, Secretary AAOS Representative
  • James A. Browne, MD, FAAOS, Member The Knee Society Representative
  • Antonia Chen, MD, MBA, FAAOS, Member AAOS Representative
  • Paul J. Duwelius, MD, FAAOS, Member AAOS Representative
  • Richard L. Illgen, II, MD, FAAOS, Member AAOS Representative
  • William A. Jiranek, MD, FAAOS, FACS, Member American Association of Hip and Knee Surgeons (AAHKS) Representative
  • Robert L. Krebbs, Member Health Plan Representative, Optima Health
  • Richard F. Seiden, Esq., Member AAOS Registry Program Public Advisory Board (PAB) Representative
  • James D. Slover, MD, FAAOS, Member The Hip Society Representative
  • Jeffrey B. Stambough, MD, FAAOS, Member AAHKS Representative


Enrolling in the AJRR is Easy

Your site can join the AJRR in 5 simple steps. Learn about the enrollment process here. Visit the AAOS Registry Program FAQs page for more details about Registry Program participation. If you have additional questions about joining the AJRR, please email or call (847) 292-0530.

AAOS American Joint Replacement Registry



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