Mallet Finger Info In-depth Evidence

What you're feeling

With a mallet finger, the end joint of your finger droops and you cannot straighten the fingertip on your own. The finger may look bent at the last joint, closest to the nail. The injury happens when the tendon that straightens that joint is torn or pulled away, sometimes with a small piece of bone.

The end joint is often tender and may be swollen or bruised, especially in the days after it happens. Pushing the fingertip straight, gripping a ball, or knocking the finger can make the pain worse. Resting the finger still, supported by a splint, usually settles it.

Day to day, the drooping tip gets in the way of fine tasks. Picking up coins, doing up small buttons, typing, or holding a pen can feel clumsy because the fingertip will not push straight. Ball sports are a common way people get this injury, and a jammed finger during a game is often how it starts.

Some fingers also develop a second problem further up the digit. When the end joint droops, the middle joint can start to over-straighten or bend backwards. If you notice that, mention it, as it changes how the finger is treated.

One thing matters more than almost anything else: timing. Getting the finger seen and splinted early, ideally within two weeks of the injury, gives the best chance of a straight, working fingertip. Waiting can lead to lasting stiffness or a joint that no longer lines up properly. If your finger has been drooping for a while, it is still worth having it looked at, as there are options for fingers that have been left untreated.

You do not need to guess how bad it is. A drooping fingertip after a knock is reason enough to have it assessed, so the right splint or treatment can be started before the joint changes.

What's actually happening

Your fingertip straightens because a thin cord of tendon, a rope of strong fibres, runs along the back of the finger and anchors onto the last bone. With a mallet finger, that cord snaps or pulls off its anchor, sometimes taking a small chip of bone with it. The end joint can no longer be pushed straight from the back, so the tendon that bends the joint pulls it down and it rests in a droop you cannot correct yourself.

Most of these injuries come from a jamming force, like the fingertip snagging on a bedsheet or a ball striking an extended finger and bending the end joint suddenly. Less often, a hard over-straightening force breaks a larger piece of bone off the base of the last bone. When that broken piece involves a third or more of the joint surface, surgery is generally advised. It is also generally advised when the last bone slips out of line towards the palm, because the joint no longer sits where it should.

The droop you noticed in the section above is the direct result of this lost anchor. Another effect can follow further up the finger: with the end joint stuck in a bent position, the balance of straightening and bending forces through the rest of the digit shifts, which is why some fingers develop that over-straight middle joint.

There are two broad patterns. In one, only the tendon is torn. In the other, a piece of bone comes away with it, and the two look much the same from the outside because the tendon goes with the fragment. Most mallet fingers, either pattern, settle with a splint that holds just the end joint straight. Surgery is kept for the larger fractures, for joints that have slipped out of line, or for fingers where earlier treatment did not work.

What we can do about it

Dr Kieran Hirpara, an upper-limb surgeon at Mater Private Hospital Rockhampton, matches the treatment to your specific injury. Patients are generally referred to our clinic by their GP; if a physiotherapist has suggested you see us, you will still need a referral from your GP in order to be eligible for the Medicare rebate. At that visit we take a history, examine the finger and arrange an X-ray if one is needed, to check whether a piece of bone has come away and whether the joint still lines up.

For most mallet fingers, the first step is a splint that holds just the end joint straight. We usually ask you to wear it for 6 to 8 weeks, keeping it on day and night, and to avoid the sport or activity that caused the injury while splinted. A hand therapist fits the splint and shows you how to wear it without irritating the skin, and can manage many of these injuries from start to finish. If the tendon has been torn for 2 to 4 weeks before you get help, splinting still works about as well as when the finger is treated in the first 2 weeks, and even a finger splinted 12 weeks after the injury can be treated much the same way as a fresh one. Some people need to keep the splint on longer than 12 weeks, and how long you continue is largely up to your comfort with it. A night splint on top of the day splint does not add anything, so we do not ask you to double up. The type of splint, custom-made or ready-made, matters less than wearing it as directed.

Pain tablets and anti-inflammatories are not a treatment for the droop itself. They may settle the soreness in the first days while the splint does its job.

Surgery is considered when a splint has not worked, when the droop is stopping you work or meeting a specific need, or when the injury involves a large piece of joint surface or the joint has slipped towards the palm. The operation repairs or reattaches the straightening tendon, or fixes the bone fragment back in place, and the finger is then held straight with a small wire and a splint while it heals. We will talk through the options with you and decide together whether surgery suits your finger and your goals.

What to expect

For most people, a mallet finger settles with treatment rather than surgery. A splint that holds just the end joint straight is the usual path, and it works for most injuries, whether the tendon alone was torn or a small piece of bone came away with it. Both splinting and surgery lead to good results, so you can expect a straight, working fingertip when the finger is treated properly.

Timing shapes how the recovery feels. When the finger is splinted within two weeks of the injury, few people are left with any lasting disability. If the tendon has been torn for 2 to 4 weeks before you get help, splinting still works about as well, and even a finger splinted 12 weeks after the injury can be treated much the same way as a fresh one. Some people need to keep the splint on longer than 12 weeks, and how long you continue is largely up to your comfort with it.

If your finger is left untreated, the droop usually stays. The end joint may stiffen in a bent position, and the middle joint can develop that over-straightening described earlier. Some neglected injuries still do well: tendinous mallet fingers left for 2 to 4 weeks have low long-term complication rates when managed without surgery, and large-fragment cases managed conservatively also have low complication rates. But waiting makes the outcome less predictable, which is why early splinting matters.

Surgery is kept for the smaller group of fingers where a splint will not do the job, such as larger fractures or a joint that has slipped out of line. It is worth knowing that surgery on these fractures carries a complication rate of 41%, partly because the straightening tendon is thin and has a poor blood supply. Surgery done later for bony mallet fingers, though, has shown minimal complications. Your surgeon will weigh these points with you rather than push one path.

There is no single splint proven better than another, custom-made or ready-made. What matters is wearing it as directed, which is the part you control.

When to see someone

A drooping fingertip after a knock is worth having checked within days, not weeks. Early splinting gives the best chance of a straight, working finger, so ask your GP for a referral to a hand surgeon as soon as you notice the droop. The same applies if the end joint is swollen, bruised or tender and will not straighten.

Some warning signs matter more than others. If a piece of bone has broken off and the joint surface is involved, the finger can slip out of line towards the palm. A larger fracture, or one seen late, raises that risk. Ask for a specialist review if the fingertip sits visibly out of place, or if the middle joint starts bending backwards while the tip droops.

Go to an emergency department if the finger is rapidly more painful, hot, red or swollen, or if you cannot move it at all after a forceful injury.

In more depth

Advanced reading: the deeper science (optional)

This section goes further than you need for your own treatment decisions. Mallet finger is worth the extra reading because the two situations that are usually treated as clear indications for surgery — a large fracture fragment, and a persistent droop after splinting, are less clearly established than the confidence with which they are stated.

Both treatments produce good results, and nobody knows where the line is

A systematic review of surgical and non-surgical management reached a conclusion that is unusually direct: both lead to good clinical outcomes, and insufficient evidence is available to determine when surgical intervention is indicated [1].

That second half is the important one. The dispute is not about whether either treatment works. It is that the threshold for choosing surgery, the point at which the fracture is judged too large, or the joint too subluxed, rests on convention rather than on comparative evidence.

Where a fragment involves more than a third of the joint surface, or the distal phalanx has subluxed, surgery is generally indicated, but a significant advantage of surgical management, even in those complicated cases, has yet to be clearly proven [2].

Splinting works, and the number that matters is how long

The orthotic evidence is more concrete. Two of three studies found a large effect size for orthotic intervention, ranging from 2.17 to 12.12, with a recommended immobilisation duration of 6 to 8 weeks, and additional weeks where a lag persists [3].

Two practical points follow. The first is that the splint must hold the fingertip straight continuously, the tendon ends are held apposed by position alone, and a few minutes of flexion while washing restarts the clock. The second is that "additional weeks where a lag persists" is part of the protocol, not a sign of failure.

Why a residual droop is often acceptable

A small permanent extension lag after treatment is common, and it is usually compatible with normal hand use. The distal joint contributes relatively little to grip, and most people adapt to a few degrees of droop without noticing it functionally.

That matters when weighing surgery for an imperfect result, because operating on this joint is not without cost: the fragment is small, the skin is thin, and pin or wire fixation of a joint this size carries risks of infection, nail deformity and joint stiffness that must be set against a cosmetic-to-mild functional gain. Given the reviews above cannot demonstrate an advantage for surgery even in the complicated cases, accepting a modest lag is an evidence-consistent choice rather than a compromise.

The deformity that is not a mallet finger

Mallet finger is one of a family of closed extensor mechanism injuries, distinguished mainly by where along the tendon the failure occurs, mallet at the fingertip, boutonnière at the middle joint, and sagittal band injury at the knuckle [4]. They are frequently confused with one another early, when swelling obscures the pattern, and each has a different splinting position. Splinting a boutonnière as though it were a mallet holds the wrong joint, which is why the diagnosis is worth confirming before six weeks of immobilisation are committed to.

Mallet Finger Info In-depth Evidence

What you're feeling

What's actually happening

What we can do about it

What to expect

When to see someone

In more depth

Both treatments produce good results, and nobody knows where the line is

Splinting works, and the number that matters is how long

Why a residual droop is often acceptable

The deformity that is not a mallet finger

Overview

Anatomy & Pathophysiology

Mechanism of Injury

Pathophysiology

Incidence and Demographics

Classification

Clinical Presentation

Investigations

Treatment

Non-Operative Management

Operative Management

Surgical Techniques and Postoperative Care

Complications

Recovery

Key Evidence

References