From the Guidelines
Mallet finger is a deformity of the finger caused by damage to the extensor tendon that straightens the fingertip, and its treatment primarily involves continuous splinting of the fingertip in a straight position for 6-8 weeks, with surgery reserved for cases with large bone fragments or joint misalignment 1. Mallet finger occurs when the tendon is either torn or stretched, or when a small piece of bone where the tendon attaches is pulled away (avulsion fracture). The most common causes include:
- Direct trauma to the fingertip, such as when a ball strikes the extended finger
- The finger being jammed against a hard surface
- Cuts that sever the tendon
- Chronic inflammation that weakens the tendon over time The condition results in the inability to straighten the end joint of the finger, causing it to droop downward.
Key Considerations for Treatment
- Continuous splinting of the fingertip in a straight position for 6-8 weeks, keeping the splint on at all times, even during bathing
- The splint must hold the DIP joint (fingertip joint) in slight hyperextension while allowing the middle joint (PIP) to bend freely
- Surgery is usually not necessary unless there's a large bone fragment, the joint is out of alignment, or if conservative treatment fails after appropriate splinting 1
- After the splinting period, nighttime splinting is often recommended for an additional 2-4 weeks
- Physical therapy exercises to restore strength and flexibility may be needed following treatment Without proper treatment, mallet finger can lead to permanent deformity and arthritis in the affected joint. It's essential to seek medical attention promptly after injury for proper diagnosis and treatment. In cases where radiographs are used to detect fracture fragments, large fragments may require open reduction and internal fixation, and involvement of more than one-third of the articular surface usually requires operative fixation 1.
From the Research
Definition and Causes of Mallet Finger
- Mallet finger is a fingertip deformity where the distal interphalangeal joint (DIPJ) of the affected digit is held in flexion, unable to extend the distal phalanx actively 2.
- The deformity is typically a consequence of traumatic disruption to the terminal extensor tendon at its insertion at the proximal portion of the distal phalanx or slightly proximally at the level of the DIPJ 2.
- Common mechanisms include sport activities causing a direct blow to the finger, low energy trauma while performing simple tasks, or crush injuries from getting the finger trapped in a door 2.
Treatment Options for Mallet Finger
- The majority of closed mallet splints are Doyle type I, which can be managed non-surgically with external splints, worn full-time to keep the fingertip straight until the tendon injury or fracture heals 2.
- Priority should always be given to conservative management of these injuries, which translates into a 6-to-8-week period of uninterrupted immobilization of the DIP joint with an external splint 3, 4.
- Surgical techniques are considered for other types of mallet injuries, including closed reduction and Kirschner wire fixation, open reduction and internal fixation, reconstruction of the terminal extensor tendon, and correction of swan neck deformity 2.
- Surgery is reserved for injuries involving fracture to greater than 30% of the articular surface, volar subluxation of the distal phalanx, avulsed fragments that fail reduction, injuries failing conservative management, and absence of full passive extension of the joint 5.
Importance of Patient Compliance and Rehabilitation
- Patient compliance is essential for the treatment of mallet finger injuries, and if not treated appropriately, the injury can lead to permanent deformity 5.
- Finger rehabilitation is an indispensable part of any method of treatment 3.
- Maintaining the DIPJ in extension during treatment is essential, and patient adherence to treatment is crucial 6.