Mallet injuries to finger are very common and result in a deformity where the end of the finger droops down. The injury is caused by household activities such as making a bed when the finger is trapped under a mattress. It can also result from sporting injuries like cricket when the ball hits the tip of the finger. Little and ring fingers are much more commonly affected. It is essentially an injury to the extensor tendon which is pulled off sometimes with a piece of bone attached to it.
Initially there is pain and inability to straighten the finger fully at the last joint. There is also bruising and swelling. An x-ray is done which may show a fracture (bony mallet) but more often there are no fractures but the deformity is visible. Some mallet injuries are caused by a cut caused by a sharp object (open mallet) when the tendon is cut.
Treatment starts with a mallet splint which is meant to keep the finger fully straight. It is used all the time including at night. When hand washing is necessary the splint can be carefully removed making sure that the finger is kept straight until the splint is reapplied. The splint is used for a period of 6 - 8 weeks after which finger exercise can be started. It is usually necessary to wear the splint for an additional period of 4 weeks at nights only. If there was a fracture (bony mallet) causing mallet injury then splint is required for a shorter period. In cases of an open mallet injury, you may require an operation where the cut is cleaned and tendon and skin are re-sutured. This can be done under a local anaesthetic.
The results after bony mallet and open mallet injuries are generally good. In simple mallet injuries where the tendon is often only overstretched, the result may not be entirely satisfactory despite splinting in around 30% of cases and a slight degree of bend at the end of the finger may persist. This is usually painless and causes little problem with the use of the hand (function). The cosmetic abnormality is acceptable to most. It is therefore not necessary to undertake any further intervention.
If you are not happy with the outcome because of pain or deformity or stiffness then operation is possible to improve the result and satisfaction. The best operation for these injuries is a fusion of the end joint (DIP fusion) of the finger. This results in pain relief and improved function and cosmetically more acceptable finger.
FRCS (Trauma & Orth)
Consultant Trauma and Hand Surgeon