What is the cause of mallet finger?
It is usually caused by an injury to the tendons (tendons – are structures which connect muscle to bone and help in movement) which keep the last joint of the finger in a straight position. There are two opposing sets of tendons (called the flexors and extensors) at the tip of each finger. The first set on the top of the finger helps in lifting the tip (this movement is called extension and therefore this group of tendons are called extensors) and the second on the underside of the finger, help in lowering the tip of the finger (this movement is called flexion and hence this group of tendons and muscles are called flexors). His injury to the tendon that helps in lifting the finger creates an imbalance of forces. This leads to drooping of the tip of the finger. These injuries can be seen with bony fragments. The tendon involved is called the Extensor Digitorum.
What investigations are needed to diagnose mallet finger?
This is usually a clinical diagnosis and x-ray is recommended to rule out any bony injury, which may have happened as a result of the tendon being dropped out at the site of insertion on the bone. In either situation, treatment remains the same.
What is the treatment for mallet finger?
The treatment is to immobilize the tip of the affected finger in a special splint, called as the mallet splint.
The splint is made of plastic shaped like a well secured sleeve covering the tip of the finger including the last joint of the finger. It is secured by using tape. It is kept for for a period of six weeks in the first instance.
In case of the deformity persisting after six weeks of splintage, then splintage may be necessary for ten to twelve weeks. The patient is advised to remove it only after having kept his hand flat on top of a table, avoiding any bending at the tip and asking an assistant to clean the splint and change the tape at the bottom.
The patient is followed up by orthopedic doctors in the clinic. Physiotherapy is usually needed to resolve stiffness. Surgical repair is not advised as it does not usually yield good results. Mallet thumb is treated in the same way as a mallet finger.
If the finger is bent during the healing process, then recovery time is delayed.
What are the complications of mallet finger?
They include:
1. Loss of extension
2. Temporary skin problems
3. Difficult patient compliance
4. Refractory bony mallet (where there is a significant chunk of bone that has come off with the tendon) cases not responding to conservative management are treated by open surgery if needed.