From the Guidelines
Mallet finger is an injury to the extensor tendon of the finger, typically occurring from a forceful blow, and is characterized by the inability to straighten the fingertip, which droops downward. This condition is often evaluated using radiographs to detect fracture fragments, as large fragments may require open reduction and internal fixation 1. The diagnosis of mallet finger involves assessing the extent of the injury, including the presence of bony avulsion at the insertion of the extensor mechanism of the finger to the distal interphalangeal joint. Some key points to consider in the evaluation and management of mallet finger include:
- Radiographs are used to detect fracture fragments and determine the need for operative fixation 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
- Treatment typically involves continuous splinting of the fingertip in a straight position for 6-8 weeks to allow proper healing
- For more severe cases involving bone fragments, surgery might be necessary to restore normal finger function. The goal of treatment is to restore normal finger function and prevent permanent deformity, highlighting the importance of prompt and proper management of mallet finger injuries.
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 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 proposed for 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.
- 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 6.