Finger injuries: 5 cases to test your skills

The DIP joint of his right ring finger is swollen (FIGURE 4), but appears normal otherwise. When you isolate the joint, however, the patient is unable to flex it. You can palpate a stump on the volar surface of the finger.

What’s your next step?

Answer: Order an ultrasound of the football player’s finger and palm (C).

This patient has Jersey finger, caused by a traumatic avulsion of the flexor digitorum profundus (FDP) from the distal phalanx and diagnosed based on the mechanism of injury and the patient’s inability to flex the DIP joint. The injury often does not show on x-rays, and the diagnosis may be missed for several weeks.

Jersey finger, caused by a traumatic avulsion of the flexor digitorum profundus from the distal phalanx, requires surgical reattachment within 10 days.

Jersey finger usually happens in sports like football or rugby, where players tackle each other, and involves forced, passive extension of the DIP joint at a time of active flexion. Management of Jersey finger starts with splinting, with both the DIP and PIP in slight flexion. Surgical reattachment of the flexor tendon is needed, with best results when it is done within 7 to 10 days of injury.⁴

You may be able to palpate the tendon stump in the palm or along the digit; bony avulsions can be trapped at the flexor sheath. Soft tissue swelling can be misleading, however, and the point of maximal tenderness is not an accurate means of identifying the avulsed tendon stump.⁸

Ultrasound is effective in differentiating between a partial and full thickness rupture and in localizing the distal tendon stump.⁸ MRI is usually reserved for precise evaluation of the tendon edges, to aid in operative planning. If the tendon is retracted to the palm, scarring may be irreversible because of the lack of blood supply.

Athletes typically return to play 12 weeks after injury, starting with protected activity and progressing to full gripping/grasping. Physical therapy and/or occupational therapy will be needed after the surgical wound has healed.

CASE 5 A 40-year-old construction worker who smashed his left index finger with a hammer one day ago presents with severe pain in his fingertip, which he is unable to move. On examination, you find that the distal finger is swollen and there is extensive ecchymosis and swelling underneath the nail. The finger has normal sensation, but you are unable to see capillary refill due to a large hematoma.

X-rays (FIGURE 5) reveal a distal tuft fracture. The patient’s main concern is the pain, and he asks what you can do to relieve it.

What’s your next step?

Answer: Perform fenestration of the construction worker’s nail (B).

This patient has a closed fracture of the distal phalanx, called a tuft fracture, and a sub-ungual hematoma, evident from the x-ray and the physical presentation.

In some cases, the deformity associated with mallet finger may be delayed by a few hours, or a few days. Subungual hematoma requires fenestration with a needle to create small holes in the nail. If the nail bed is lacerated, the nail is removed and the injured nail bed repaired with sutures.

Tuft fractures sometimes require reduction. More often, they are stable and minimally displaced and can be managed conservatively, with splinting with a padded aluminum splint or a fingertip guard (Stax splint) for 3 to 4 weeks. Antibiotics are not indicated unless there is suspicion of an overlying or secondary infection. Referral to a hand surgeon is required for severe crush injuries, avulsion of the nail matrix, and open fractures of the distal phalanx.^5,6