Mallet finger
A ball catches the tip of the finger, or the finger snags on a bedsheet or on a sock while getting dressed, and from that moment the last bone of the finger…
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Medicines commonly prescribed for Mallet finger
For informational purposes only. Always consult a doctor before using any medicine.
Dosage form: ORAL SOLUTION/SUSPENSION, 1 g paracetamolActive substance: paracetamolManufacturer: Pharmex Advanced Laboratories S.L.Prescription not requiredDosage form: INJECTABLE PERFUSION, 10 mg paracetamol/mlActive substance: paracetamolManufacturer: Altan Pharmaceuticals SaPrescription requiredDosage form: ORAL SOLUTION/SUSPENSION, 40 mg/mlActive substance: ibuprofenManufacturer: Laboratorios Cinfa S.A.Prescription required
A ball catches the tip of the finger, or the finger snags on a bedsheet or on a sock while getting dressed, and from that moment the last bone of the finger droops and will not lift. The pain is often so moderate that people come a week later, or a month later, calling it just a knock. In fact the tendon that straightens the fingertip has been torn off, and whether the joint stays bent for good depends on how quickly the finger is held straight. Treatment usually needs no operation at all: it needs a splint and patience.
What it looks like
The tip of the finger droops and will not lift by itself. The check is simple: put the hand palm down on a table and try to raise only the nail joint off the surface. With this injury it does not come up at all, or comes up far less than on the sound finger. If somebody else straightens the joint for you, it straightens easily and without resistance, and that is exactly what tells a torn tendon apart from a dislocation or a jammed joint.
Over the last joint there is usually swelling and tenderness, sometimes bruising; on brown and black skin redness is harder to see, so go by the swelling and by tenderness on pressing. Blood under the nail, a nail lifting away from its bed, or a small wound at the base of the nail all mean the injury has not stopped at the tendon.
The trap with this injury is how trivial it looks. The finger still bends, nothing gets in the way, so people carry on using it while the tendon heals long, and the tip stays down.
What is happening inside the finger
The extensor tendon runs along the back of the finger and attaches to the base of the last bone. When the straightened tip takes a sharp blow along the line of the finger, that joint is forced to bend and the attachment gives way. There are two possibilities: either the tendon itself tears, or it pulls away with a chip of bone, which is called the bony version of the injury.
After that it is simple mechanics. The flexor tendon on the palm side is intact and goes on pulling the tip down, and there is no longer anything to balance it. That is why the tip hangs, and why it will not straighten on its own: while the ends of the tendon are held apart they cannot knit properly. Treatment has exactly one aim, to bring them together and hold them still, and that is what a splint does.
It also explains why the finger must not be exercised. Every bend of the nail joint pulls apart whatever has begun to heal, and the count of weeks starts again.
What to do before you see a doctor
Keep the fingertip straight and do not bend it; that matters more than anything else. Until a doctor looks at it you can improvise a splint: any rigid flat strip of the right length, bandaged or taped so that the last joint stays straight. There is no need to pull on the finger or try to put anything back, because there is nothing there to reduce.
Put something cold on it through a cloth for fifteen to twenty minutes and repeat over the first day; keep the hand raised, especially in the first hours, to limit the swelling. Take rings off straight away, including from the neighbouring fingers, because within hours swelling may make that impossible. For pain, paracetamol or anti-inflammatory painkillers at the usual doses are suitable if you have no reason to avoid them.
Aim to be seen within a few days, ideally within the first forty-eight hours. A fresh injury is simpler and more predictable to treat, but even weeks later it is not too late for a splint: it helps in long-standing cases too, so "it is too late now" is a poor reason not to go.
When to be seen the same day
This injury does not usually need an ambulance, but there are signs that cannot wait. Get help the same day if:
- there is a wound over the joint, a graze that has bled, or the finger has been pierced by something sharp, because an open injury risks infection inside the joint;
- the nail is torn off, has come out of its fold, or there is a large collection of blood beneath it;
- the finger has gone pale, cold or numb;
- the finger is clearly bent sideways or shortened, or the joint looks displaced;
- the injury was caused by an animal or human bite;
- days after the injury the finger turns red, feels hot, throbs, discharges pus, or you develop a temperature.
Keep a separate eye on the skin under the splint. White, sodden or broken areas, increasing pain beneath the splint and a bad smell all mean the splint is pressing and needs to be refitted rather than endured.
How the diagnosis is made
The doctor examines the finger and tests extension: the middle joint is held steady and you are asked to lift the tip. The finger is compared with the same one on the other hand, passive straightening is assessed, sensation and circulation are checked, and the nail and skin are inspected.
An X-ray in two views, including a strict side view, is needed almost always. It answers two questions on which the treatment depends: whether a fragment of bone has been pulled off and how big it is, and whether the last bone has slipped out of line with the joint. A small fragment in good position is splinted just like a torn tendon; a large fragment or a joint that has subluxed changes the plan.
In children and teenagers there is a separate situation worth knowing about: the fracture line can run through the growth plate, and the nail bed lies right next to it. If a child with this injury has a damaged nail or a small wound at its base, that counts as an open fracture and needs to be seen urgently rather than watched.
Treatment with a splint
The splint holds the last joint straight or very slightly overstraightened and leaves the middle joint free, and that joint should be moved as usual so that it does not stiffen. The splint is worn without a break for about six to eight weeks, and then for a few more weeks at night and for heavier tasks.
The essential condition is that the finger must not bend even once during that time, including while the strapping is being changed. If it does, the clock starts again, so it is better to spend two extra minutes on a careful change than to lose three weeks of treatment.
If the tip drops again when the splint comes off, the doctor will often suggest a second course of the same length, and it frequently works. In injuries that are already weeks or months old a splint is still worth trying: the result is not as good as with a fresh injury, but in many people the droop reduces noticeably.
Looking after a finger in a splint
The skin under the splint suffers from damp, so both splint and finger are kept dry: for washing up and for showering it is easiest to put the hand inside a waterproof bag. A wet splint should be dried at once, because a finger left soaking under plastic becomes sore.
Once a day the finger and the splint need cleaning, and it is easier with someone helping. The order is this: rest the hand palm down on a table so that the finger lies straight, cut or peel off the tape and slide the splint away without lifting the finger from the surface. Wash and dry the skin and the splint and look at the pressure points. Put the splint back on, again without raising the tip, and re-tape it. The tape should not grip too hard: a finger that turns blue, goes numb or throbs has been strapped too tightly.
Bend and straighten the middle joint of the finger every day, which does not disturb healing and keeps the movement.
When an operation is needed
Surgery is needed for this injury only occasionally. It is considered when a large bony fragment has come away and takes up a noticeable part of the joint surface, when the last bone has shifted and the joint has subluxed, in open injuries with damage to the skin or the nail bed, and when after a full course of splinting the finger has still not straightened and that gets in the way at work or at home.
Usually the fragment and the joint are held with a fine wire for a few weeks. The decision is weighed carefully, because an operation carries its own risks, including infection, deformity of the nail and lasting stiffness of the joint, and on balance it does not always give a better result than a splint worn properly.
What recovery is like
The finger settles slowly. Swelling, tenderness and an over-sensitive tip last several months, and a small lump may remain on the back of the joint, becoming less noticeable with time.
A slight residual lack of extension is ordinary: in many people the tip stays a few degrees short of straight, and this has almost no effect on how the hand works. A visible deformity is less of a nuisance than people expect, but if it is a nuisance to you, that is worth discussing with a doctor. Keep a separate eye on the middle joint: if it starts to bend backwards while the tip stays down, the finger takes on a characteristic curve, and it is better to have that seen early.
Exercises begin once splinting is finished and are built up gradually, following the advice of the doctor or hand therapist. Work that involves leaning on the fingers, and ball sports, are the last things to go back to, sometimes several months later; in the meantime it is often possible to work in the splint if lighter duties can be agreed.
Online consultation
A remote appointment suits the first assessment well: the doctor will ask you to show the finger from different angles, to rest the hand on a table and try to lift the tip, and will ask exactly how the injury happened and how long ago. That is enough to tell this injury from a bruise or a dislocation, to explain how to improvise a splint straight away, and to decide whether an X-ray is needed and how urgently.
After that, being able to speak online is useful throughout treatment: showing the skin under the splint if it has started to hurt, checking that the finger is sitting correctly after a change done at home, going through the X-ray and the report, and discussing when to return to work and to sport. With an open wound, a torn-off nail or a finger that has gone pale or numb, though, a face-to-face examination the same day is needed, and a remote consultation is not enough.
This material is for information only and does not replace medical advice.
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