| Mallet finger | |
| Synonyms: | Hammer finger,[1] extensor tendon injury at the DIP joint, baseball finger |
| Field: | Emergency medicine, sports medicine, plastic surgery |
| Symptoms: | Inability to extend the finger tip, pain and bruising of the finger |
| Causes: | Trauma resulting in over bending of the finger tip |
| Diagnosis: | Based on symptoms, X-rays |
| Treatment: | Splinting for 8 weeks, surgery |
| Prognosis: | 6 to 10 weeks for healing |
| Frequency: | Relatively common |
A mallet finger, also known as hammer finger or PLF finger or Hannan finger, is an extensor tendon injury at the farthest away finger joint.[2] This results in the inability to extend the finger tip without pushing it. There is generally pain and bruising at the back side of the farthest away finger joint.
A mallet finger usually results from overbending of the finger tip. Typically this occurs when a ball hits an outstretched finger and jams it. This results in either a tear of the tendon or the tendon pulling off a bit of bone. The diagnosis is generally based on symptoms and supported by X-rays.
Treatment is generally with a splint that holds the fingertip straight continuously for 8 weeks. The middle joint is allowed to move.[3] This should be begun within a week of the injury.[3] If the finger is bent during these weeks, healing may take longer.[3] If a large piece of bone has been torn off surgery may be recommended.[3] Without proper treatment, the finger may be permanently deformed.[2]
The diagnosis is generally based on symptoms and supported by X-rays.[3] The injury can be accompanied by swelling and ecchymosis.[4]
The management goal is to restore extension of the joint.[5] Treatment is generally with a splint that holds the first joint of the finger straight continuously for 8 weeks.[3] This should begin within a week of the injury.[3] The splint may be worn just at night for a few additional weeks after this.[3] The splint acts to immobilize flexing of the joint.
Surgery generally does not improve outcomes.[2] It may be required if the finger cannot be straightened by pushing on it or the break has pulled off more than 30% of the joint surface.[2] Surgery may be preferred over the use of a splint if a child is non-compliant.[5] If the problem has been present a long time surgery may also be required.[6] An open fracture may be another reason. Surgery will put the finger in a neutral position and drill a wire through the distal interphalangeal joint (DIP) to the proximal interphalangeal joint (PIP), forcing immobilization.