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What it measures:

The Knee Injury and Osteoarthritis Outcome Score, Joint Replacement (KOOS, JR) is a survey measuring overall knee health for individuals post total knee arthroplasty (TKA) by evaluating stiffness, pain, function, and activities of daily living.(1,2)

This survey was developed at the Hospital for Special Surgery by Stephen Lyman, PhD, as a relevant short version of the Knee Injury and Osteoarthritis Outcome (KOOS) for a specific population.(2)

ICF Domain(s):

  • Body Structure and Function
  • Activity

Conditions & Test Variations Included in this Summary:

The KOOS, JR is a patient-reported outcome measure designed to assess knee health of individuals following knee replacement surgery. This summary contains information on the use of this test in patients following TKA.

Variation/revision: KOOS, JR and 4 KOOS Quality of Life subscales were the basis for development of the KOOSglobal, a patient-reported outcomes measure used with patients who have had ACL reconstruction. KOOSglobal will not be further reviewed here.(3)

Taskforce Recommendations:

  • American Academy of Hip and Knee Surgeons Symposium recommends KOOS, JR as an efficient outcome assessment for total knee replacement as it meets the Center for Medicaid and Medicare requirements.(1)
  • American Academy of Orthopedic Surgeons' Quality Outcomes Data Work Group recommend KOOS, JR for patients with knee osteoarthritis.(3)
  • Clinical Orthopaedics and Related Research on Value-based Healthcare suggest using short-form instruments, such as KOOS, JR at more frequent intervals than longer instruments.(16)
  • American Association of Hip and Knee Surgeons and Technical Expert Panel, consisting of representatives from the American Association of Orthopaedic Surgeons, Hip Society, Knee Society, American Joint Replacement Registry, Centers for Medicare and Medicaid Services, Yale New Haven Health Services Corporation and the Center for Outcomes Research and Evaluation, National Committee for Quality Assurance, Mathematica, CECity, and Blue Cross Blue Shield Association suggest that the KOOS, JR should be used with patients with specific diseases, but expressed concerns regarding the validation of this instrument.(17)

Clinical Insights

KOOS JR is a valid and responsive outcome measure and only has 7 questions, but the instrument only provides meaningful data for a specific knee pathology and cannot be used for other knee-related subspecialties.(3)

KOOS, JR requires a fifth-grade reading level meeting the American Medical Association recommendations that PROMs be written at a sixth-grade level.(18) Some clinicians may find this outcome measure useful for patients 1-week and 1-month post-TKA.

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