From the Guidelines
Mallet finger is an injury to the extensor tendon of the finger, typically occurring when the tendon is damaged from a direct blow to the fingertip or forceful bending of the tip while it's straight, and is often evaluated using radiographs to detect fracture fragments or bony avulsion at the insertion of the extensor mechanism of the finger to the distal interphalangeal joint 1.
Definition and Evaluation
Mallet finger is characterized by the inability to actively extend the distal interphalangeal joint, resulting in a drooping fingertip. The injury can be caused by a variety of mechanisms, including direct trauma to the fingertip or a sudden, forceful contraction of the flexor tendon while the finger is extended. Radiographic examination is essential in evaluating mallet finger, as it can help identify associated fractures or bony avulsions that may require operative fixation 1.
Treatment and Management
Treatment of mallet finger typically involves continuous splinting of the fingertip in a straight position for 6-8 weeks, with the splint holding the fingertip slightly hyperextended to allow proper healing. Over-the-counter pain medications like acetaminophen or ibuprofen can help manage discomfort. However, if the injury includes a bone fracture or if the fingertip remains droopy after splinting, surgical repair may be necessary, particularly if there is involvement of more than one-third of the articular surface or a palmar displacement of the distal phalanx or an interfragmentary gap of >3 mm 1.
Key Considerations
- Radiographs are used to detect fracture fragments or bony avulsion at the insertion of the extensor mechanism of the finger to the distal interphalangeal joint 1.
- Involvement of more than one-third of the articular surface usually requires operative fixation 1.
- Palmar displacement of the distal phalanx or an interfragmentary gap of >3 mm is also an indication for surgery 1.
- Proper treatment is crucial to prevent permanent loss of finger extension and to minimize residual drooping or stiffness.
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 of injury 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.
Symptoms and Diagnosis
- Patients typically present with a history describing the event of injury with a typical mallet deformity 2.
- The DIPJ can be passively extended, but this extension of the joint cannot be maintained once the passive extension is stopped 2.
- Mallet finger is diagnosed clinically, but an X-ray should always be performed to rule out any bony avulsion or fracture 3.
Treatment Options
- 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.
- 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.
- A direct tendon suture technique using the distal interphalangeal (DIP) joint open approach has been shown to be effective in treating tendinous mallet finger injury 4.
- Percutaneous tenodermodesis is an office-based procedure that provides joint reduction and prevents joint movement during the immobilization period 5.
- Surgical fixation is still indicated in certain conditions, such as open injuries, avulsion fracture involving at least one third of the articular surface, and failed splinting treatment 6.