Multidimensional patient-reported outcome measure for knee injury/OA.
KOOS is a self-completed questionnaire that scores knee health across five separate subscales: symptoms, pain, activities of daily living, sport and recreation function, and knee-related quality of life. Each subscale is calculated and reported independently on a 0–100 scale, with 100 representing no problems, rather than being collapsed into a single overall knee score.
Because it separates function into distinct domains, it lets you see where a patient is actually struggling — for example, good ADL scores but poor sport/rec and quality-of-life scores, which is a common and clinically meaningful pattern after ACL reconstruction. That distinction shapes conversations around return-to-sport readiness, rehab focus, and patient expectations in a way a single composite score would obscure.
Patients complete the questionnaire themselves, typically at baseline and at set follow-up intervals through rehabilitation, and each of the five subscales is scored separately rather than averaged into one figure. In ACL reconstruction and other knee ligament or cartilage trials it is commonly used alongside the IKDC and Lysholm to give a fuller picture spanning symptom burden, physical function, and psychosocial impact.
As a patient-reported measure it reflects perceived function and is influenced by expectations, pain coping, and psychological readiness, not purely physical impairment, so it shouldn't be read as an objective knee status check on its own. Comparing scores across studies or patients also requires care, since the five subscales are not meant to be averaged into a single number and different studies may emphasise or report different subscales.
This guide was auto-drafted and is pending editorial review.