With the mallet deformity, the end of the finger is bent and cannot be straightened voluntarily. The distal interphalangeal (DIP) joint (tip of the finger) can be straightened easily with help from the other hand. If the DIP joint gets stuck in a bent position and the proximal interphalangeal (PIP) joint (middle knuckle) extends, the finger may develop a deformity that is shaped like a swan’s neck. This is what is meant by a swan neck deformity.
Treatment for mallet finger is usually nonsurgical. If there is no fracture, then the assumption is that the end of the tendon has been ruptured, allowing the end of the finger to droop. Usually continuous splinting for six weeks followed by six weeks of nighttime splinting will result in satisfactory healing and allow the finger to extend.
The key is continuous splinting for the first six weeks. The splint holds the tip of the finger (the distal interphalangeal or DIP joint) in full extension and allows the ends of the tendon to move as close together as possible. As healing occurs, scar formation repairs the tendon. If the splint is removed and the finger is allowed to bend, the process is disrupted and must start all over again. The splint must remain on at all times, even in the shower.
While a simple homemade splint will work, there are many splints that have been designed to make it easier to wear at all times. In some extreme cases where the patient has to use the hands to continue working (such as a surgeon), a metal pin can be placed inside the bone across the DIP joint to act as an internal splint and allow the person to continue to use the hand. The pin is removed at six weeks.
Splinting may even work when the injury is quite old. Most doctors will splint the finger for eight to 12 weeks to see if the drooping lessens to a tolerable amount before considering surgery.
Surgical treatment is reserved for unique cases. The first is when the result of nonsurgical treatment is intolerable. If the finger droops too much, the tip of the finger gets caught as you try to put your hand in a pocket. This can be quite a nuisance. If this occurs, the tendon can be repaired surgically, or the joint can be fixed in place. A surgical pin acts like an internal cast to keep the DIP joint from moving so the tendon can heal. The pin is removed after six to eight weeks.
If the damage cannot be repaired using pin fixation, finger joint fusion may be needed. Joint fusion is a procedure that binds the two joint surfaces of the finger together, keeping them from rubbing on one another. Fusing the two joint surfaces together eases pain, makes the joint stable, and prevents additional joint deformity.
It sounds like you may be a young adult so conservative care without drastic surgical intervention (such as joint fusion) would be advised. There is also another surgical technique known as the Thompson procedure that might be helpful for patients who have chronic mallet finger.
The Thompson procedure uses a graft from the palmaris longus tendon. The graft tendon is split, spiraled under and over the middle bone of the finger, and then tied over the skin with an external button. The procedure makes it possible for motion of both the distal and proximal interphalangeal joints (DIP and PIP) to work together creating coordinated flexion and extension of the finger.
The biggest benefit of the Thompson procedure is that it corrects the extension lag of the tip of the finger (when you can’t fully extend the finger tip) while also addressing the swan neck deformity. And it does so without scarring the extensor tendon (which would restrict finger extension) or preventing flexion of the proximal interphalangeal (PIP) joint. The goal is to get smooth finger flexion and extension of both the DIP and the PIP joints.
Your best bet is to make an appointment with a hand surgeon and find out what might work for you. The information here will give you some understanding of the conservative (nonoperative) and surgical treatment options when discussing your situation with the surgeon.