Sunday, April 11, 2010

Ecclesiastes and an Ankle Fracture

Photo by jimforest

"What has been will be again, what has been done will be done again; there is nothing new under the sun."

This is perhaps the most famous quote from Ecclesiastes, one of the books of the Bible, and it certainly rings true. Although there are many exciting new developments in medicine every year, patients still
contract the same illnesses and undergo the same injuries they did long ago.

24 year-old male with a history of a twisting injury to the foot:

(A) Sagittal T2 fatsat and (B) sagittal T1 images reveal an avulsion fracture (red arrows) of the extensor digitorum brevis (EDB) tendon, at its origin from the calcaneus.

A small flake of bone can be seen on a conventional radiograph:

(A) Oblique axial intermediate and (B) oblique axial T2 fatsat images also show avulsed bone fragment (red arrows):

This injury was described by Norfray et al. in 1980 (AJR 134:119-123, 1980), who described the distinctive conventional radiographic findings of this injury. Radiographs of 100 consecutive emergency room patients with clinically suspected ankle fractures occurring during the winter of 1978-79 were reviewed. Most resulted from slipping on ice, or falling over snow-covered obstacles. The avulsion fracture was identified in 10 of 100 patients. Clinically, the point of maximum tenderness was similar to the area of maximum tenderness in fractures of the anterior process of the calcaneus. Thus, these fractures of the anterior process of the calcaneus and EDB avulsion fractures cannot be differentiated clinically, but only by imaging.

Avulsion fractures of the calcaneus can occur at multiple sites, including the attachment of the Achilles tendon, bifurcate ligament, plantar fascia, and the abductor hallucis (Pelletier and Kanat, J Foot Surg, 29:268-271, 1990). All of these injuries can be identified by MRI.

Avulsion fractures were common thirty years ago, and were usually found on x-rays. Avulsion fractures are still common today; there truly is nothing new under the sun. The only thing that is different is that some of these patients will have MRI scans, and the radiologist must be able to recognize these injuries.

Vic David MD