A mallet finger happens when the tendon that straightens the tip of your finger gets torn or pulled away from the bone, leaving the fingertip drooping and unable to straighten on its own. Splinting is the primary treatment, and it works well: about 75% of people treated with splinting alone achieve good or excellent outcomes. The key is keeping the fingertip held perfectly straight, without interruption, for six to eight weeks.
What’s Actually Happening in the Finger
The tendon that runs along the top of your finger and attaches at the base of your fingertip bone is responsible for straightening the last joint. When something forces that fingertip to bend sharply while the finger is extended (a ball hitting the tip is the classic example), the tendon either stretches, tears completely, or pulls a small chip of bone away with it. Without that tendon doing its job, you can’t actively straighten the last joint of the finger. It just hangs down.
If only the tendon is damaged, it’s called a soft tissue mallet finger. If a piece of bone came with it, that’s a bony mallet finger. Both types are typically treated with splinting. Surgery is rarely needed and actually has a slightly higher complication rate (53%) compared to splinting alone (45%), so conservative treatment is the standard approach for most cases.
Choosing the Right Splint
Three main types of splints are used for mallet finger, and all produce similar results:
- Stack (Stax) splints: Prefabricated plastic splints shaped like a thimble that fits over the fingertip. They hold the last joint in a slight extension and are easy to apply. They come in standard sizes.
- Aluminum foam splints: Thin aluminum strips padded with foam that you can bend and mold to your finger. They’re extremely inexpensive and produce outcomes comparable to Stack splints.
- Thermoplastic (custom-molded) splints: Made by a hand therapist using a heat-moldable material that’s shaped directly to your finger. These offer the most precise fit and allow the therapist to set the exact angle of extension.
A study comparing Stack splints to aluminum splints found no significant difference in outcomes. Stack splints produced excellent results in 62% of patients, aluminum splints in 58%. Either works. What matters far more than splint type is wearing it correctly and consistently.
How to Position and Apply the Splint
The goal is to hold the last finger joint (the one closest to your fingertip) in full extension or very slight hyperextension. This means the fingertip should be straight or angled just slightly upward. The middle joint of the finger should remain free to bend normally.
If you’re using an aluminum foam splint, cut it to length so it extends from just below the middle joint to just past the fingertip. Bend it to match the slight upward tilt you need at the fingertip. Place it along the palm side of your finger and secure it with medical tape. The splint should feel firm but not so tight that it cuts off circulation. Your fingertip should stay a normal color, not white or blue.
For a thermoplastic splint, a hand therapist will soften the material in warm water, then mold it around the palm side and sides of your finger while holding the last joint in extension. The therapist applies gentle upward pressure under the fingertip and downward pressure on the top of the middle bone to set the correct angle. Once the material cools and hardens (which takes about a minute), it’s secured with micropore tape wrapped around the finger and splint.
Whichever splint you use, it should only immobilize the last joint. Keeping the middle joint free lets you maintain grip strength and use the finger for light tasks during treatment.
How Long to Wear It
The timeline depends on whether the tendon is stretched, torn, or attached to a bone fragment:
- Stretched tendon: 4 to 6 weeks of continuous splinting, followed by 3 to 4 weeks of night-only splinting.
- Torn tendon or avulsion fracture: 6 to 8 weeks of continuous splinting, followed by 3 to 4 weeks of night-only splinting.
“Continuous” means exactly that. The splint stays on 24 hours a day, including while sleeping, showering, and working. Every time the fingertip droops or bends during the healing window, the tendon separates again and the clock resets. Even a single moment of bending can set your recovery back by weeks.
Keeping the Splint Clean Without Bending the Joint
Skin hygiene under the splint matters. Moisture trapped against the skin can cause breakdown and irritation, which is one of the most common complications. But you cannot let the fingertip bend during cleaning.
When you need to clean the splint or the skin underneath, press the finger flat against a table or use your other hand to hold the fingertip straight while you carefully slide the splint off. Keep the finger perfectly straight the entire time. Wash and dry the skin, then slide the splint back on while the finger stays extended against the flat surface. Never let the fingertip droop, not even for a second.
When showering, cover the finger and splint with a plastic bag to keep them dry. If the splint does get wet, dry it thoroughly afterward while keeping the finger straight.
What to Do During the Splinting Period
While the last joint is immobilized, you should actively move the middle joint of the injured finger and all your other fingers regularly. This prevents stiffness from spreading to joints that don’t need to be immobilized. Bend and straighten the middle joint throughout the day. Make gentle fists with the rest of your hand. The only joint that stays still is the last one on the injured finger.
Exercises After the Splint Comes Off
Once the initial immobilization period ends, recovery isn’t over. You’ll gradually rebuild range of motion in the fingertip joint over several more weeks, and the progression is slow and deliberate.
First Three Weeks of Movement
Your therapist may use angled guide boards to control exactly how far the joint bends. In the first week, you gently bend the fingertip to only about 10 degrees, hold for five seconds, then straighten fully and hold for five seconds. You repeat this five times every two hours. The second week increases to 20 degrees, and the third week to 30 degrees. Between exercise sessions, you continue wearing the protective splint.
Building Full Function
After three weeks of guided bending (around week 9 for bony injuries, week 11 for soft tissue), you can begin weaning off the daytime splint if you’re able to actively hold the fingertip straight on your own. You’ll continue wearing it at night and during activities where the finger might get knocked. At this stage, you start tendon gliding exercises: straightening all fingers fully, then making a hook fist (bending the finger joints while keeping the knuckles straight), a tabletop position (bending only at the knuckles), a flat fist, and finally a full fist. This sequence helps the repaired tendon glide smoothly through its full range.
Full return to contact sports, heavy gripping, and unrestricted use typically happens around week 13 for bony mallet injuries and week 15 for soft tissue injuries.
What Happens if Splinting Doesn’t Go Well
The biggest predictor of a less favorable outcome is how severely the fingertip was drooping at the start. Patients who begin with less than 30 degrees of droop develop residual drooping only 28% of the time. Those starting with more than 30 degrees of droop have residual drooping 72% of the time, roughly three times the risk. Some degree of residual droop (a few degrees of “extension lag”) is common even with perfect splinting and usually doesn’t affect daily function in a meaningful way.
The more serious long-term risk of an untreated or poorly treated mallet finger is swan neck deformity. When the tendon at the fingertip stays slack, the imbalance in tension gradually pulls the middle joint into hyperextension while the fingertip stays bent. This creates a characteristic S-shaped curve in the finger that can become permanent and affect hand function. Proper, consistent splinting is the best way to prevent it.