Mallet Finger
Mallet Finger | Denver, Colorado
A mallet finger is a specific type of finger injury that I frequently treat in my hand surgery practice in metropolitan Denver, Colorado.
A mallet finger, sometimes known as ‘baseball finger,’ occurs when the extensor tendon responsible for straightening the tip of the finger (the distal interphalangeal, or DIP, joint) is injured. It most commonly occurs from a force directed at the tip of the finger (such as being struck by a baseball), but also frequently happens after low-energy unexpected injuries as well. I’ve seen these from patients who were folding laundry or making the bedsheets!
Mallet Finger Symptoms & Diagnosis
Figure 1 - A ‘soft tissue’ mallet finger where the tendon ruptures off the last bone in your finger.
Davplast, CC, via Wikimedia Commons
Believe it or not, a mallet finger is frequently not painful. The primary symptom is an inability to extend the tip of the finger. Additionally, the finger will rest in a drooped position (see Figure 1). This is because the extensor tendon responsible for straightening the finger has ruptured. Oftentimes, some swelling and bruising will also be present in this injury.
X-rays of your finger will clarify the diagnosis. Sometimes the tendon pulls away from the bone and sometimes the tip of the bone fractures off with the tendon. This is helpful in classifying your injury and determining appropriate treatment.
Additional tests or imaging other than x-ray are not required for a mallet finger injury.
Mallet Finger Treatment
Fortunately, treatment of a mallet finger is usually without surgery. Unfortunately, it does require serious discipline and several months of healing in a splint.
Typical mallet finger treatment includes 8 weeks of 24/7 splinting of the finger. If your finger bends just one time during the 8 weeks of healing, your tendon will be disrupted and you will need to start over.
Occasionally surgery is required. This is only the case if the tendon has pulled off such a large bony fracture fragment that the finger becomes unstable. The term for this is DIP joint subluxation. If this is the case, you may benefit from surgical fixation of the fracture.
Additional Information
This is a basic overview of mallet finger injuries. If you have more specific questions about this injury, or you just want to learn more, read on below as I answer many of my patients’ most common questions. You can also reference my ‘deep dive’ articles to the right of the FAQs for even more information on mallet fingers.
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The Basics
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A mallet finger is an injury to the extensor tendon that is typically responsible for straightening the finger.
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Usually, a direct impact or eccentric force to the tip of the finger will cause a mallet. In this injury, the extensor tendon either pulls away from the distal phalanx bone, or the tendon pulls off a small fracture fragment of distal phalanx bone.
Either way, this will result in the absence of function of the extensor tendon. When this happens, the tip of the finger will droop and you will be unable to straighten it.
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A soft tissue mallet occurs when the tendon pulls off from the bone. Conversely, a bony mallet occurs when the force of the tendon pulls off a small fractured fragment of bone.
Both subtypes of this injury result in the same inability to straighten the finger.
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Individuals most at risk of having a mallet finger are those involved in athletic activities. However, this injury is seen in nearly all age groups and demographics. As I said before, I’ve seen it from something as simple as folding laundry!
Mallet fingers are rarely seen in pediatric patients.
Mallet Finger Symptoms & Diagnosis
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The main indication you have a mallet finger is a droop at the end of your finger with an inability to straighten it, no matter how hard you try. This almost always occurs after an identifiable injury.
Many of these injuries are not painful, particularly when it is a soft tissue mallet subtype. You may notice swelling and bruising in the area.
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A mallet finger is not difficult to diagnose. The appearance of the finger is obvious.
It is important to obtain an x-ray to diagnose whether you have a soft tissue or bony mallet. While rare, it is possible to have a severe bony mallet that would require surgery.
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Additional testing beyond a simple x-ray is not typically needed to diagnose a mallet finger injury.
Mallet Finger Treatment
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Absolutely. In fact, the majority of mallet fingers are treated without surgery.
That’s the good news. The bad news is successful treatment of this injury requires 24/7 splinting for 8 weeks. That means the tip of your finger cannot bend, even one time, for 8 weeks.
If you do accidentally bend your finger, your healing tendon will become torn again, and we have to start the 8 week cycle over again, often with worse outcomes.
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Yes. This injury requires 24/7 splinting for 8 weeks. This is the time it takes for the disrupted tendon to heal back together.
Remember, if you do accidentally bend your finger, your healing tendon will become torn again, and the 8-week clock starts over again.
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This depends on which splint you are using.
If approved by your certified hand therapist, some splints are made to shower in. If this is the case, be sure to follow their instructions carefully to dry the splint so your skin doesn’t break down or become irritated.
If you do not have a waterproof splint, you will need to cover the splint while showering. Because your finger cannot bend at all during the 8 week splinting period, it is critical to continue splint wear in the shower. This means covering the splint with a waterproof bag. Many pharmacies and online vendors now sell upper extremity ‘cast bags’ that will create a waterproof seal to protect your splint.
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I typically recommend having a splint made by a certified hand therapist, many of whom partner with us in our office. This will allow for the greatest comfort, easiest cleaning, and most motion while splinting for 8 weeks.
That being said, you can technically make a mallet splint with a popsicle stick and some tape. While I don’t routinely recommend or endorse this, there are plenty of examples you can find online if need be. If you do go this route, be sure to allow finger motion at the proximal interphalangeal (PIP) joint so that does not get stiff over the 8 weeks of splinting.
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A typical outcome after splinting is for the finger to return to a 0-20° droop. While it may not go back to fully straight, anywhere near straight is likely to impart full function to your hand and finger.
Many patients heal completely straight, but it is considered normal to have some mild residual droop to the finger after this injury. This occurs because the healing tendon fibers don’t heal quite as tight as the original tendon fibers you were born with.
Mallet Finger Surgery
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Surgery to fix a mallet finger is typically only necessary in severe cases. If the tendon pulls of a large fragment of bone from the distal phalanx, it can destabilize the joint, causing the intact distal phalanx to slide out of the DIP joint. We call this subluxation and it can be seen on x-ray.
In this uncommon situation, surgery is recommended. In this procedure, I do what we call a closed reduction percutaneous pinning (CRPP). To perform this surgery, I place sharp wires through the skin, across the fracture, and across the joint to stabilize the bones.
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Remember that ‘recovery’ is a subjective term. Below is the typical outline of healing following this surgery:
Surgery - 2 weeks: Wear a post-operative splint full-time
Begin 2 weeks: Removable splint made by hand therapy, begin to work on gentle finger range of motion exercises. No physical use of the hand.
4-6 weeks: I remove your pins in clinic. Continue with splinting, light range of motion exercises, and limited use of the hand.
6-8 weeks: Once bony healing is confirmed on x-ray and examination with me, progress strengthening of the hand and use the brace less and less.
3-4 months: Return to heavy activities and/or impact sports. Most patients feel 90% of their former selves by this point. Occasional aches and pains, or a bad day here or there are still expected.
9 months - 1 year: “Full” recovery, where you may have to stop and think to remember which finger you had injured.
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All surgeries have risks, many of which are generic to surgery itself. I go over these in detail with you before surgery as part of the informed consent process. Examples include bleeding, infection, damage to surrounding tendons/nerves/vessels, anesthesia risks, or failure of the procedure.
The most common risk specific to mallet finger surgery is pin site infection. The pins placed through the skin must be kept clean and dry. I remove them after 4-6 weeks to decrease the chances of infection. But if a pin does get infected, it will need to be removed earlier than scheduled and you will need antibiotic treatment.
