What is the treatment for Mallet Finger?

Treatment of Mallet Finger

The standard treatment for acute closed mallet finger is conservative management with continuous splinting of the distal interphalangeal joint (DIP) in slight extension for 6-8 weeks, which has been shown to be effective in approximately 77-83% of cases. 1, 2

Diagnosis

• Mallet finger is a traumatic zone I lesion of the extensor tendon with either tendon rupture or bony avulsion at the base of the distal phalanx
• Presents with inability to actively extend the DIP joint
• Always obtain standard radiographs to assess for bony avulsion fractures and joint subluxation

Classification

Tubiana's classification guides treatment:

• Type I: Tendon rupture without fracture
• Type II: Fracture of <1/3 of the articular surface
• Type III: Fracture of >1/3 of the articular surface with reducible subluxation
• Type IV: Fracture with irreducible subluxation

Treatment Algorithm

Conservative Treatment (First-line for most cases)

1. For tendinous mallet finger (Type I) and small avulsion fractures (Type II):

   • Apply dorsal or volar splint with DIP joint in slight hyperextension (for tendon injuries) or neutral position (for bony avulsions)
   • Maintain continuous splinting for 6-8 weeks
   • Some protocols extend splinting to 12 weeks full-time followed by 4 weeks of night splinting for improved outcomes 3
   • Critical: Patient must not flex the DIP joint during the entire treatment period

2. Key points for splinting:

   • Various splint designs are effective (Stack splint, custom thermoplastic)
   • Patient education on proper splint care is crucial
   • Regular follow-up to ensure proper positioning
   • If splint is removed for any reason, the finger must be kept in extension

Surgical Treatment (Limited indications)

Surgical intervention should be considered for:

• Type IV mallet finger with irreducible subluxation
• Open injuries with skin laceration
• Failed conservative treatment after appropriate trial
• Selected cases of large articular fragments (>1/3 of joint surface)

Surgical options include:

• Percutaneous DIP joint pinning with Kirschner wire
• Open reduction and internal fixation for large bony fragments
• Tenodermodesis or other reconstructive procedures for chronic cases

Complications to Monitor

• Skin maceration or pressure necrosis from splinting
• Permanent extension lag
• DIP joint stiffness
• Development of swan-neck deformity if untreated
• Rare but serious complications with surgical treatment, including finger amputation after K-wire pinning 4

Expected Outcomes

• Successful outcomes in approximately 77% of conservatively treated cases 2
• Patient satisfaction around 83% with conservative treatment 2
• Average extension lag of 2.6° after appropriate splinting protocol 3
• Full recovery of DIP joint flexion in most cases

Important Considerations

• Conservative treatment is safe, cost-effective, and well-accepted by patients
• Surgical treatment carries risks of stiffness, infection, and joint arthritis
• Patient compliance is critical for successful conservative management
• Left untreated, mallet finger can lead to swan-neck deformity and DIP joint osteoarthritis 1

The evidence strongly supports conservative management as the first-line treatment for most mallet finger injuries, with surgery reserved for specific indications where splinting is unlikely to be effective.