This post will outline two cases of the sonographic presentation of an avulsion injury to the distal phalanx. For the first time we have had two cases presented,with thanks to Sophie Cochran for sending her case into The Ultrasound Site to contribute!
This patient in their early 30's, presented with a left 3rd metacarpal injury. She recalled falling over and feeling pain and discomfort in the distal interphalangeal joint. She also noticed an inability to extend her finger fully. On examination, she presented with a mallet finger, and no activation of DIP extension.
On ultrasound in clinic, there was disruption to the distal insertion of the extensor tendon onto the distal phalanx, with an area of cortical irregularity. The sonographic appearance and clinical presentation was suggestive of an avulsion injury of the distal phalanx.
The patient was referred for an x-ray (See below) to confirm the ultrasound images, and the report indicated:
'There is a non united avulsion fracture of the proximal segment of the distal phalanx, major finger left hand. '
This patient was subsequently seen in fracture clinic and then had ongoing hand clinic input.
A further case is illustrated below, contributed by Sophie Cochran, MSK Sonographer. The patient presented reporting a history of trauma. On Sunday morning they attended A&E and an x-ray of the hand showed no obvious bony injury – on retrospectively viewing the image you are unable to see the region of interest due to finger overlap. They were subsequently referred to the fracture clinic for review and an ultrasound demonstrated the images below of an avulsion.
Articles of interest
Feel free to comment in the feedback section at the bottom of this page as well.
If you would like to use these images please contact us to seek permission.
Feedback is always appreciated [email protected]