What is mallet finger?

At the back of the fingertip, the extensor tendon attaches to the small bone of the fingertip (the distal phalanx). This tendon is what allows you to straighten the end joint of the finger. In a mallet finger injury, this attachment is disrupted, either the tendon itself ruptures, or a small flake of bone is pulled off where the tendon attaches.

The classic mechanism is a sudden forced bending of the fingertip when the finger is straight and tensed, getting hit by a ball, catching a finger in bed sheets, or pushing a finger into something hard. The result is a finger that droops at the end joint and cannot be actively straightened, although it can usually be passively pushed straight by the other hand.

Most mallet fingers are treated successfully with a simple splint worn continuously for 6-8 weeks, keeping the end joint straight while the tendon heals. The crucial rule is that the joint must never be allowed to bend during this period, even once, even briefly. If the splint comes off for any reason, the treatment clock restarts. Surgery is reserved for specific situations: large bony fragments, joint subluxation, or open injuries.

Common causes

Direct blow to the tip of an extended finger (classically ball sports)
Catching a finger on bed linen, clothing, or in a pocket
Forceful gripping with sudden release
Lacerations to the back of the fingertip
Crush injuries to the fingertip

Who is at risk? Ball sports (cricket, basketball, baseball, netball) are by far the most common cause in younger adults. Older patients can sustain the injury from very minor trauma due to age-related tendon weakening.

Symptoms

Symptoms vary depending on the severity and duration of the condition. Common symptoms include:

Inability to straighten the end joint of the finger
Drooping of the fingertip
Pain and swelling over the back of the end joint
A small bump may be felt where bone has been pulled off
Bruising under the fingernail in some cases
Pain on attempting to straighten the finger

When to seek help: See your GP, urgent care centre, or hand specialist as soon as possible, ideally within a few days, and certainly within 2 weeks. Early splinting gives the best outcome. Open injuries and lacerations need urgent assessment.

How is it diagnosed?

Your hand surgeon will take a detailed history and examine the hand and wrist. The following investigations may be arranged to confirm the diagnosis:

Clinical examination, an obvious droop of the fingertip and inability to straighten it actively
Plain X-rays in two views, assess for bony avulsion fragment and joint subluxation
Measurement of the size of the bony fragment if present
Assessment of joint subluxation, particularly important
Examination of the skin to rule out open injury

The size of any bony fragment and the presence of joint subluxation are the two factors that determine whether splinting or surgery is recommended. Fragments involving more than one third of the joint surface, with subluxation of the joint, are usually treated surgically.

Treatment pathway

Treatment is tailored to the severity of the condition, your age, activity level, and overall health. Most conditions are treated in a stepwise fashion, starting with the least invasive options.

First line, most cases

Continuous splinting

A small splint (Stack splint or similar) is worn continuously for 6-8 weeks, keeping the end joint completely straight at all times. Skin care during washing is taught carefully so that the splint can be changed briefly without ever letting the joint bend. A further 2-4 weeks of night-time splinting follows.

Surgical option

K-wire fixation

For mallet fractures with a large bony fragment and joint subluxation, the joint is reduced and held with a K-wire across the joint for 6 weeks. Sometimes a second wire is used to hold the bony fragment in place (extension block pinning).

For chronic or open injuries

Tendon reconstruction or surgical repair

Open mallet injuries (lacerations) need direct tendon repair. Chronic mallet finger (more than 8-12 weeks old) is harder to treat; options include re-splinting, tendon advancement, or fusion of the joint, depending on age and demands.

Recovery

The greatest challenge in mallet finger is adherence to splinting. The splint must never come off without keeping the end joint straight, even briefly bending it once can require restarting treatment. Most patients regain near-full extension. A small persistent droop (5-10 degrees) is common and rarely causes any functional problem.

Continuous splint: 6-8 weeks
Night splint: 2-4 weeks
Gradual return to activity: 8-12 weeks
Sport (with finger taping): 12 weeks

What results can I expect?

Good in most cases when treatment is started within 2 weeks. A small permanent extension lag of 5-15 degrees is common and usually not noticed by the patient. Late-presenting cases and those with poor splint adherence may have a more significant droop, but function is usually well preserved.

In numbers

6-8

weeks of full-time splinting[1]

continuous splinting in extension is the mainstay of treatment

Plus

further weeks at night[1]

additional night splinting once full-time wear is finished

Most

do well with splinting[1]

most closed injuries heal well without surgery if the splint is worn correctly

Lag

may remain[1]

a small permanent extensor lag is common but rarely affects function

What the evidence shows

A mallet finger is caused by rupture or avulsion of the extensor tendon insertion at the base of the distal phalanx, the fingertip droops and cannot be actively straightened[1]

The splint must hold the distal joint in full extension continuously, even a brief lapse during washing or dressing can reset the healing clock[1]

Surgery is occasionally needed for fractures involving a large portion of the joint surface, or when the joint is partially subluxed[1]

Skin maceration under the splint is the most common complication, careful splint care and brief skin checks (while keeping the joint extended) are essential[1]

Hand therapist supervision improves outcomes by ensuring correct splint fit and patient understanding[2]

When can I…?

Typical activity timelines for this condition. These are approximate and vary considerably between patients. Always follow the specific guidance given by your surgeon and hand therapist.

Activity	Typical timeline	Notes
Wear the splint	Continuously, 6-8 weeks	The splint must stay on every minute, including in the shower (use a waterproof cover). A single brief removal at the wrong time can reset the clock.[1]
Drive	When safe to grip	Most patients can drive with a small splint in place once they can grip the wheel. Discuss with insurer.[3]
Shower	With splint covered	A waterproof cover keeps the splint dry. Brief skin care during splint changes must keep the joint fully extended.[1]
Desk / light work	Day one	Splinting does not stop most office-based work. Manual or wet hand work may need to wait.[1]
Sport	Wait until healed	Avoid impact and contact sports until the splinting period (including any night-only phase) is complete.[1]
Night-only splinting	Further 2-4 weeks	After the full-time period ends, night splinting usually continues for a further few weeks to consolidate the result.[1]

Is this normal?

Common concerns from patients with this condition or recovering from treatment, and whether they are expected or worth mentioning to your team.

Yes. A small permanent "extensor lag" (a few degrees of droop) is common even after correctly treated mallet injuries. It rarely affects function and is largely cosmetic.[1]

Probably. Even a brief loss of full extension during the splinting period can mean the healing clock starts again. Discuss with your hand therapist, in many cases the splinting period is restarted from that point.[1]

Mild redness can occur but worsening skin irritation, breaks, or pressure sores need attention. Contact your hand therapist for a splint check. Skin care must always be done while keeping the joint fully extended.[2]

Yes. Stiffness after several weeks of immobilisation is expected and improves with gentle exercises under hand therapy guidance. Avoid forcing the joint.[2]

References & further reading

References are to UK clinical guidance and patient information from recognised organisations. This page is for general information and does not replace personalised advice from your own clinical team.

Mallet finger