What is your diagnosis?

Kohler's disease is an avascular necrosis of the navicular bone. The navicular bone on Image 1 appears sclerotic, wafer-like, and thin on X-ray. Image 2 is a normal 7 year-old foot for comparison.

Image 2. Case courtesy of Dr Aneta Kecler-Pietrzyk, Radiopaedia.org, rID: 53079. Annotation by Authors

• Pearl:  Kohler's disease occurs mainly in males around 4-7 years of age. The adult counterpart to this disease is called Mueller-Weiss syndrome

What is the cause?

The exact pathophysiology is unknown but is believed to be a compression of the navicular bone prior to ossification which compromises blood flow and results in avascular necrosis. [1]

• Pearl: The navicular blood supply is a watershed zone which makes it susceptible to avascular necrosis

What is your treatment in the ED?

Treat initially with a short-term course of NSAIDS for symptom relief. If there is significant pain with activity, a short leg cast can be used for 6-8 weeks. [2]

• Pearl: Kohler's disease is generally self-limiting but may take up to 3 years for symptom resolution. There is no long-term disability associated with this diagnosis. [1]

What is your disposition?

The patient can be discharged and follow up with an orthopedic or sports medicine physician in 2-4 weeks.