Jersey Finger on ultrasound: Imaging Findings
Jersey finger is an avulsion of the flexor digitorum profundus tendon, the tendon that bends the fingertip. It is the opposite tendon-side problem from mallet finger and can require time-sensitive hand surgery assessment because the tendon may retract into the palm. X-ray looks for a bony avulsion fragment, while MRI or ultrasound can map tendon retraction when no fragment is seen.
Some signs described on this page need prompt medical care. If you have them, get care first. Reading about imaging can wait.
Common Symptoms
- Inability to actively bend the fingertip after forceful extension
- Pain or bruising on the palm side of the distal finger
- Weak grip because the DIP joint does not flex normally
- History of grabbing a jersey, rope, shirt, or equipment as it was pulled away
What We Look For on Imaging
- Volar avulsion fragment from the base of the distal phalanx
- Flexor digitorum profundus tendon discontinuity or retraction level
- Fluid or hematoma along the flexor tendon sheath after acute injury
- Relationship of the retracted tendon stump to the A2 and A4 pulleys
- Associated pulley injury, volar plate injury, or occult fracture
Frequently Asked Questions
Why is jersey finger often treated as time-sensitive?
The flexor tendon can retract and scar, making later repair harder. Imaging helps identify whether a bone fragment is attached and how far the tendon has retracted, but urgent clinical evaluation is important when the fingertip cannot actively bend.
Can an X-ray be normal with jersey finger?
Yes. If the tendon tears without pulling off a bone fragment, the X-ray may look normal. Ultrasound or MRI can show the flexor tendon gap and retraction, especially when the clinical exam strongly suggests loss of FDP function.
Sources
- Leddy JP, Packer JW. Avulsion of the profundus tendon insertion in athletes. J Hand Surg Am. 1977;2(1):66-69.
- Freilich AM. Evaluation and treatment of jersey finger and pulley injuries in athletes. Clin Sports Med. 2015;34(1):151-166.
- Shapiro LM, Kamal RN. Evaluation and treatment of flexor tendon and pulley injuries in athletes. Clin Sports Med. 2020;39(2):279-297.
- Weintraub MD, Hansford BG, Stilwill SE, et al. Avulsion injuries of the hand and wrist. Radiographics. 2020;40(1):163-180.
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