Introduction
A mallet finger injury occurs when the fingertip or thumb is subjected to a forceful downward bend, damaging the tendon responsible for straightening the fingertip joint. This type of injury is commonly known as a "baseball finger" due to its frequent occurrence in baseball.
In a mallet finger injury, individuals may experience pain, swelling, and a noticeable droop at the fingertip joint. Most cases are managed through splinting; however, surgical intervention may be necessary if there is a fracture or misalignment.
Anatomy
The human fingers consist of three bones, called phalanges, which are divided by two joints. The distal interphalangeal (DIP) joints are located closest to the fingertips, while the proximal interphalangeal (PIP) joints are situated in the middle of the fingers.
Attached to the phalanges are extensor tendons that form the extensor mechanism, which enables finger extension (straightening).
Causes
A mallet finger injury occurs when significant force bends the fingertip down, resulting in a tear of the extensor tendon attached to the distal phalanx. This can often happen in sports, particularly baseball. If the force is strong enough, the tendon may remain intact, but a small fragment of bone can be pulled away from where it attaches to the phalanx, leading to an avulsion fracture. Additionally, mallet finger can occur if the extensor tendon is severed.
Symptoms
Symptoms of a mallet finger injury include pain and swelling around the DIP joint. Affected individuals will be unable to straighten the fingertip, which will appear drooped.
Diagnosis
A physician can diagnose a mallet finger injury through a physical examination and by discussing the circumstances of the injury. X-rays may be performed to identify any avulsion fractures, joint misalignment, or other injuries.
Treatment
Most mallet finger injuries are treated with splinting. Patients are typically required to wear a finger splint continuously for about six weeks, without removing it at any time, including during showers. If the splint is removed prematurely, it may disrupt the healing process, necessitating a restart of the treatment. Following the initial six weeks, a part-time splinting regimen is generally advised for an additional three to four weeks.
When the splint is removed, it should be done carefully to monitor and care for the skin, while keeping the finger extended by resting it on a flat surface.
Surgery
In cases where mallet finger injuries involve fractures or joint misalignment, surgery may be necessary. Surgical procedures may involve the use of pins, wires, or screws to secure the bones during the healing process. In rare instances, the extensor tendon might require tightening or reconstruction using a graft.
Recovery
Post-treatment, whether through splinting or surgery, patients often undergo hand therapy rehabilitation. A hand therapist will guide them through exercises aimed at stretching and strengthening the joints. It's important to note that stiffness in adjacent finger joints can also benefit from therapy. Full recovery from a mallet finger injury can take several months, and healing times can vary significantly among individuals. Your doctor will provide guidance on what to expect during recovery.
Prevention
If a mallet finger injury occurs, it's advised to elevate the hand above heart level and apply ice intermittently until medical attention is received. Seek immediate care if there is bleeding beneath the fingernail. Prompt treatment of mallet finger injuries tends to yield better outcomes.
