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Approach to the adult with unspecified knee pain

Carlton J Covey, MD
Robert H Shmerling, MD
Section Editor
Karl B Fields, MD
Deputy Editor
Jonathan Grayzel, MD, FAAEM


The knee has the largest articulating surface of any joint. Depending on the activity, this weight-bearing joint can support two to five times a person's body weight. Chronic knee pain affects 25 percent of adults and has a deleterious effect on daily function and quality of life [1,2].

The general evaluation of the adult presenting with undifferentiated knee pain is discussed here, including details about differentiating among the causes of knee pain based upon the history and examination findings. For cases where knee pain develops following acute, low-energy trauma or chronic overuse, often in athletes or active adults, and is most likely musculoskeletal in origin, a separate in-depth discussion of how to approach such patients is provided. (See "Approach to the adult with knee pain likely of musculoskeletal origin".)


The anatomy and basic biomechanics of the knee are reviewed separately. (See "Physical examination of the knee", section on 'Anatomy'.)


History-taking for the active adult presenting with knee pain is discussed in detail separately, but several aspects of the history warrant emphasis. (See "Approach to the adult with knee pain likely of musculoskeletal origin", section on 'History'.)

First, the differential diagnosis for knee pain is complex and obtaining a clear history remains essential for diagnosis. The following flow chart provides an overview of how to approach the diagnosis of knee pain in the adult (algorithm 1). Information from the history helps the clinician to distinguish among four diagnostic categories:

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Literature review current through: Nov 2017. | This topic last updated: Feb 07, 2017.
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