What is Mallet Finger (Baseball Finger)?
Signs & Symptoms Of
Mallet Finger
Mallet finger causes the fingertip to droop and prevents it from straightening. Initial symptoms may resemble a jammed finger, but can escalate.
- Drooping of the fingertip.
- Inability to straighten the fingertip.
- Pain and swelling.
- Bruising around the fingertip.
- Bump below the nail on the back of the finger.
- Blood beneath the nail (subungual hematoma).
- Possible detachment of the nail at the base.
- In cases of open mallet finger, symptoms may include a visible laceration affecting the tendon and bone.
Causes of Mallet Finger
Mallet finger occurs due to an injury to the extensor tendon responsible for straightening the fingertip. There are two main types:
Tendon Rupture: This injury can happen suddenly, such as when a finger is jammed or cut, or gradually due to arthritis, which weakens the tendon over time.
Bony Avulsion: This occurs when the bone at the tendon’s attachment site breaks, preventing the tendon from effectively pulling on the bone. In children, fractures may occur at the growth plate of the distal phalanx.
Mallet finger commonly results from an object striking the fingertip—like a baseball—or from forceful bending of the joint during activities such as lifting heavy objects. It can also arise from deep cuts that sever the tendon. These injuries highlight the vulnerability of the finger during both recreational and everyday tasks.
Diagnosis of Mallet Finger
Medical attention should be sought promptly after injury, particularly if there is blood beneath the nail or if the nail is detached, as these may indicate a nail bed injury or an open fracture.
X-rays are essential for identifying fractures that may be causing the finger deformity. In some cases, ultrasound or CT scans may be utilized to assess more complex fractures, especially if multiple fragments are present. In children, fractures may occur at the growth plate, which requires careful evaluation to avoid complications like chronic infection or abnormal growth.
Prompt diagnosis and treatment are crucial, as untreated mallet finger can lead to chronic pain, dysfunction, and the potential for arthritis due to misalignment. Proper alignment of bone fragments is vital for optimal healing and function.
Treatment of Mallet Finger
The vast majority of mallet fingers can be treated with immobilization in a splint. Even when completely torn, the extensor tendon at this location does not retract away. The torn ends of the tendon can be brought back together by splinting the joint in full extension. Typically, over a period of 8-12 weeks the body lays down scar tissue to repair the tear. A physician, sometimes with the help of a Hand Therapist, chooses from a variety of splints to keep the DIP immobilized during healing. The key to proper healing is maintaining the splinted position without interruption, especially in the first six weeks. Allowing the joint to bend during this critical period causes the healing tissue to stretch or tear, prolonging the healing time and sometimes leading to persistent drooping.
In a minority of cases, simple splinting is not sufficient to keep the finger properly aligned. Surgery is occasionally considered to repair or tighten the torn tendon or to realign an associated bone fragment. This is done in an outpatient setting, usually without the need for general anesthesia.
Mallet Finger FAQ
How can I determine if my Mallet Finger has healed completely?
You can tell mallet finger has healed when you regain full range of motion, the pain subsides, and the fingertip can be straightened without discomfort. A follow-up with a provider can confirm proper healing.
How should I properly splint Mallet Finger?
Use a stack splint to keep the fingertip straight and immobilized. Ensure the splint extends from the fingertip to just above the joint, and wear it continuously for about 6 to 8 weeks for optimal healing.
Can Mallet Finger be treated after several years?
Yes, mallet finger can be treated after several years, though it may be more complex. Treatment options, including surgery, can help restore function and alignment.