The American Academy of Orthopaedic Surgeons (AAOS) has developed a series of patient outcome reporting measures that help to measure patient function and satisfaction following the treatment (or intervention) of a specific joint.

The AAOS hip and knee questionnaire is an example of such an outcome tool. It was developed by the AAOS in 2004 to complement the Short Form Health Survey 36 (SF‐36) [2]. Therefore, this questionnaire consists of seven questions that measure stiffness, swelling, and pain in conjunction to functioning (walking on flat surfaces, going up or down stairs and ability to get around). There are no sub-scales and its recall period is one week, which makes it a very quick and efficient survey for patients to complete. AAOS scores range from 0-100 with higher scores correlating to better function.

Standardized scores from this questionnaire can be translated into normative scores using the average, standard deviation from a healthy population. As an example, patients on the normative scale scoring 50 will be above the general healthy population’s average. Meanwhile, a score under 50 means the patient is under the healthy population’s average.

Although the AAOS survey is extremely short, it doesn’t appear to have the widespread use – except in particular circumstances such as alongside use with the SF-36 or for undertaking basic assessments of hip and knee conditions and treatment improvements.

Hip PRO Tools Guide

What’s the difference between AAOS Hip and Knee Measure, HOOS Jr, and other PRO Measures?

Find out with our Hip PRO Measures Guide.


The burden of administration with this outcome tool is extremely light. With only seven questions, it can be filled out by patients in under five minutes, thereby giving it a higher completion rate than many other surveys.


The AAOS hip and knee surveys went through psychometric evaluation in 2004 but to date this is the only time it has happened. Since then, no other (published) psychometric evaluations have been carried out on this tool.

The lack of popularity of the AAOS hip and knee is its key consideration. It was developed for use in the clinic as well as in research, but it hasn’t found much traction in either field. Additionally, there’s no clear comparability to other instruments.

All of this may be due to the lack of literature that currently exists on the AAOS hip and knee, but further testing of the instrument may be warranted before it gains widespread usage [1].


No license is required to use this tool and it can be obtained freely from the American Academy of Orthopedic Surgeons website.


  1. Nilsdotter, A., & Bremander, A. (2011). Measures of hip function and symptoms: Harris hip score (HHS), hip disability and osteoarthritis outcome score (HOOS), Oxford hip score (OHS), Lequesne index of severity for osteoarthritis of the hip (LISOH), and American Academy of Orthopedic Surgeons (AAOS) hip and knee questionnaire. Arthritis care & research, 63(S11), S200-S207.
  2. The California Joint Replacement Registry Selecting a Tool for Evaluating Patient-Reported Outcomes. The executive summary.