From the Guidelines
A complication of an untreated mallet finger injury is the development of a swan neck deformity, which can lead to permanent deformity and dysfunction of the finger. This occurs because the balance of forces across the finger joints becomes disrupted when the terminal extensor tendon remains torn, causing the middle joint (PIP joint) to gradually develop hyperextension while the fingertip remains flexed 1.
Key Points to Consider
- Untreated mallet finger injuries can result in permanent extensor lag and swan neck deformity, significantly impairing hand function and causing chronic pain, stiffness, and arthritis at the affected joint over time.
- The development of swan neck deformity is a direct consequence of the disrupted balance of forces across the finger joints, which can be prevented with proper treatment, such as continuous splinting of the fingertip in extension for 6-8 weeks.
- Radiographs are commonly used to assess for bone involvement and determine the need for operative fixation in extensor tendon injuries, including mallet finger 1.
- Involvement of more than one-third of the articular surface or palmar displacement of the distal phalanx usually requires operative fixation, highlighting the importance of prompt and proper treatment to prevent long-term complications 1.
Comparison of Options
- Boutonniere deformity is a different type of finger deformity that occurs when the proximal interphalangeal (PIP) joint is flexed and the distal interphalangeal (DIP) joint is hyperextended, which is not a direct complication of untreated mallet finger injury.
- Dupuytren contracture is a condition that affects the palmar fascia, leading to flexion contracture of the fingers, and is not directly related to mallet finger injury.
- Jersey finger is an injury to the flexor tendon, which is different from the extensor tendon injury seen in mallet finger.
- Swan neck deformity is the most relevant complication of untreated mallet finger injury, as it can result from the disrupted balance of forces across the finger joints.
From the Research
Complications of Untreated Mallet Finger Injury
- A complication of an untreated mallet finger injury is:
Other Options
- The following are not directly mentioned as complications of untreated mallet finger injury in the provided studies:
- Boutonniere deformity
- Dupuytren contracture
- Jersey finger
Treatment and Prevention of Complications
- Untreated mallet finger injuries can lead to chronic functional loss and stiffness of the finger, as well as swan neck deformity 6, 2, 5
- Treatment options for mallet finger injuries include non-surgical management with external splints, as well as surgical techniques such as closed reduction and Kirschner wire fixation, open reduction and internal fixation, reconstruction of the terminal extensor tendon, and correction of swan neck deformity 6, 3, 4, 5