UMEM Educational Pearls

Title: Imaging of Knee OA

Keywords: knee osteoarthritis, plain film (PubMed Search)

Posted: 2/26/2022 by Brian Corwell, MD (Updated: 12/26/2024)
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The knee is one of the most commonly affected joints from osteoarthritis (OA).

Patients will complain of knee pain, swelling and stiffness.

This leads to disability as it interferes with walking, using stairs at home and getting in and out of chairs and the bath without assistance.

Increasing incidence due to aging of the general population and rising rates of obesity.

Patients frequently present to the ED for knee pain and imaging is often obtained.

Diagnosis of knee OA can be made with an appropriate history and imaging that shows osteophytes and joint space narrowing.

The best views for knee OA include 1) PA weight-bearing & 2) 45 degree of knee flexion

https://d3i71xaburhd42.cloudfront.net/6f8ce215fb4bcd153a478187c9a6a2ae652a5fc4/250px/1-FigureI-1.png

Note: Weight-bearing radiographs will demonstrate greater joint space narrowing than non-weight-bearing radiographs

Of the 3 compartments of the knee, the medial tibiofemoral compartment is most commonly affected > patellofemoral compartment > lateral tibiofemoral compartment.

Examples of knee OA

https://roberthowells.com.au/wp-content/uploads/2016/04/A00212F02.jpg

https://orthoinfo.aaos.org/link/e7e6933819db4020bc2f3822c45c538f.aspx