Mallet Finger

How mallet finger happens

The extensor tendon runs along the back of the finger and attaches to the base of the last bone (distal phalanx). When the fingertip is forced to bend while the finger is held straight, the tendon can:

• stretch or tear
• pull off a small piece of bone where it attaches (bony mallet)

Common situations:

• catching or being hit by a ball (basketball, baseball, volleyball)
• jamming the finger while tucking in bed sheets or putting on socks
• a direct blow or cut over the back of the end joint

The middle, ring and little fingers of the dominant hand are most often affected.

Symptoms

• the fingertip droops and cannot straighten on its own (finger deformity)
• finger pain, swelling and bruising over the end joint
• the fingertip can be straightened passively with the other hand
• sometimes a small bump on the back of the joint

Some people have little pain and only notice the droop later.

Untreated, the imbalance can pull the middle joint backward over time, causing a swan-neck deformity.

Diagnosis

A clinician examines the finger and asks you to straighten the tip. An X-ray checks for:

• a bone fragment pulled off by the tendon (a type of finger fracture)
• the size of the fragment (as a share of the joint surface)
• whether the joint is out of alignment (subluxed)

Treatment

Splinting (most cases)

A splint holds the end joint straight, or slightly extended, while the middle joint stays free to bend.

• wear it continuously for 6 to 8 weeks, day and night
• then wear it at night and during risky activities for another 2 to 4 weeks
• do not let the fingertip bend at any time. If it bends even once, the healing tendon can pull apart and the 6-week count usually restarts
• when cleaning the skin or changing the splint, keep the fingertip supported straight on a flat surface
• check the skin for pressure sores
• bony mallet injuries without joint misalignment are also usually treated with splinting

Splinting started within the first week gives the best results, but it can help even when started weeks after the injury.

Surgery

Surgery may be considered for:

• a large bone fragment with the joint out of alignment
• open injuries where the tendon is cut
• failure of splinting or inability to wear a splint (for example, some surgeons and musicians)

Options include pinning the joint straight with a wire or fixing the bone fragment.

Recovery

• most people regain good function
• a slight droop of 5 to 10 degrees often remains but rarely affects use
• stiffness and a small bump over the joint are common
• gentle bending exercises begin after splinting, as advised
• return to sport is usually possible with taping or splinting during play

Frequently asked questions

How do I know if I have mallet finger?

After an injury to the fingertip, the tip droops and you cannot straighten it on your own, although you can push it straight with your other hand. Swelling, pain and bruising over the end joint are common.

How long does mallet finger take to heal?

The splint is usually worn continuously for 6 to 8 weeks, then at night for a further 2 to 4 weeks. Total recovery takes about 2 to 3 months, and some swelling or stiffness can persist for months.

Can I take my mallet finger splint off?

Only to clean the skin or change the splint, and always while keeping the fingertip supported straight against a flat surface. Letting the fingertip bend can disrupt healing and restart the treatment period.

Does mallet finger need surgery?

Most do not. Splinting alone heals the majority, including many with small bone fragments. Surgery is considered for large fractures with joint misalignment, cut tendons or when splinting fails.

What happens if mallet finger is not treated?

The fingertip may stay permanently drooped, and over time a swan-neck deformity can develop, with the middle joint bending backward. Treatment can still help if started weeks after the injury, so see a clinician.