The International Knee Documentation Committee (IKDC) is a knee-specific patient-reported outcome measure. It’s considered to be one of the most reliable outcome reporting tools in its category and was one of the instruments used in the popular MOON study. IKDC has been subjected to rigorous statistical evaluation and has proven to be a valid and responsive patient-reported outcome tool (PRO) [1].

Development of the IKDC began in 1987 and has consisted of multiple iterations of the questionnaire which has ultimately lead to the current format seen today. Originally titled the ‘Standard knee evaluation form’ it was first conceptualized to help create an industry standard document for knee-specific conditions that could be used consistently amongst all healthcare providers.

IKDC is a subjective scale that provides patients with an overall function score. The questionnaire looks at 3 categories: symptoms, sports activity, and knee function. The symptoms subscale helps to evaluate things such as pain, stiffness, swelling and giving-way of the knee. Meanwhile, the sports activity subscale focuses on functions like going up and down the stairs, rising from a chair, squatting and jumping. The knee function subscale asks patients one simple question: how is their knee at present versus how was their knee prior to injury?

Scores are obtained by summing the individual items, then transforming the crude total to a scaled number that ranges from 0 to 100. This final number is interpreted as a measure of function with higher scores representing higher levels of function.

Overall, the IKDC is a simple and straightforward reporting tool that is easy to use and requires little time to complete. It’s important to note, however, that the IKDC is a knee-specific measure of symptoms, function, and sports activity (rather than a disease-specific tool).

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The IKDC is one of the instruments most commonly used to determine results following various knee procedures including ACL reconstructions [2]. This is evidenced by the fact that it was selected for use as one of the outcome instruments in the well-publicized MOON study – a large-scale study that followed the outcomes of patients undergoing ACL reconstructions.

Because it is knee-specific and not disease specific, IKDC may also be used to measure symptoms, function, and sports activity for people with a variety of knee disorders like ligamentous and meniscal injuries, osteoarthritis, and patellofemoral dysfunction [3-].

The reliability and responsiveness of IKDC is also comparable with other widely-used patient-reported outcome measures, particularly for those suffering from articular cartilage lesions [2].

IKDC is a fast and simple outcome tool. It requires just 10 minutes for completion and uses language that is easy to understand and suitable for all patient groups.



Although used extensively, no normative data has yet been established for IKDC. As a PRO tool that was designed specifically for knee problems, it has limited value for use in patients with general leg pathology.

Overall, the IKDC is a reliable, well-known outcome tool and its simple 10-Question format makes it patient and clinician friendly.



No license is required to use the IKDC. Forms (in English and 17 other languages) can be obtained free of charge from

*English long-form version with scoring methodology can be obtained from the American Academy of Orthopedic Surgeons website by clicking here.

About CODE Technology

CODE Technology is a PRO vendor singularly focused on collecting, reporting, and benchmarking PRO data as a service. Our real life humans – not robots – will administer surveys and handle all data collection, 100% outside of the office, you won’t even know we’re there. Better yet, with CODE as your outcomes vendor, additional employees to help with all the data won’t be necessary. Just ask our client, Joe Holmbo, Clinical Director for ORA Orthopedics. “For us to be able to collect PROs without adding any additional staff, it’s well worth the investment that we’ve made with CODE.”

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  1. Assessment of Differences Between the Modified Cincinnati and International Knee Documentation Committee Patient Outcome Scores
  2. Greco, N. J., Anderson, A. F., Mann, B. J., Cole, B. J., Farr, J., Nissen, C. W., & Irrgang, J. J. (2010). Responsiveness of the International Knee Documentation Committee subjective knee form in comparison to the Western Ontario and McMaster Universities Osteoarthritis Index, modified Cincinnati Knee Rating System, and Short Form 36 in patients with focal articular cartilage defects. The American journal of sports medicine, 38(5), 891-902.