How to manage mallet finger?

Management of Mallet Finger

Conservative treatment with continuous extension splinting of the distal interphalangeal joint (DIP) for 6-8 weeks is the recommended first-line treatment for most mallet finger injuries, regardless of whether they are tendinous or bony mallet injuries with fracture fragments involving up to two-thirds of the articular surface. 1, 2, 3

Diagnosis and Assessment

• Obtain standard 3-view radiographic examination (PA, lateral, and oblique views) to confirm diagnosis and determine if the injury is purely tendinous or involves a fracture 4
• Assess for:
  • Size of avulsion fracture (if present)
  • Articular surface involvement
  • Presence of palmar subluxation of the distal phalanx
  • DIP joint extension lag

Treatment Algorithm

Conservative Management (First-Line)

1. Splinting Technique:

   • Immobilize the DIP joint in full extension or slight hyperextension
   • Common splint options include:
     • Stack splint (prefabricated)
     • Custom thermoplastic splint
     • Aluminum foam-padded splint (dorsal or volar)

2. Duration of Splinting:

   • Full-time splinting for 6-8 weeks continuously 1, 5
   • Some protocols recommend longer immobilization (up to 12 weeks full-time followed by 4 weeks night splinting) for better outcomes 6
   • The splint must be worn continuously during the treatment period
   • If the DIP joint flexes even once during the treatment period, the clock resets

3. Follow-up:

   • Clinical reassessment at 2-3 weeks
   • Radiographic follow-up to confirm healing before discontinuing immobilization 7
   • Consider longer immobilization if:
     • Patient reports continued pain
     • Clinical examination reveals tenderness at fracture site
     • Follow-up radiographs show incomplete healing

4. Rehabilitation:

   • Begin active range of motion exercises for uninvolved joints immediately to prevent finger stiffness 7
   • After splint removal, begin gentle active motion exercises of the DIP joint
   • Night splinting may be continued for an additional 2-4 weeks after full-time splinting

Surgical Management (Reserved for Specific Cases)

Surgical intervention is indicated for:

• Open injuries
• Avulsion fractures involving >1/3 of the articular surface WITH palmar subluxation of the distal phalanx
• Failed conservative treatment after adequate trial
• Chronic mallet deformity with significant functional impairment

Surgical options include:

• Transarticular Kirschner wire fixation
• Open reduction and internal fixation
• Extension block pinning

Common Pitfalls and Caveats

1. Splint Compliance:

   • Even brief removal of the splint allowing DIP flexion can reset the healing process
   • Patient education about continuous splinting is critical for success

2. Skin Complications:

   • Monitor for skin maceration, pressure sores, or dermatitis
   • Periodically check skin condition under the splint
   • Consider changing splint type if skin irritation develops

3. Bony Mallet Misconceptions:

   • Many surgeons recommend surgery for bony mallet injuries with >1/3 articular involvement, but evidence shows conservative treatment can achieve good results even with larger fragments 3
   • Surgery should be reserved primarily for cases with palmar subluxation

4. Chronic Mallet:

   • Conservative treatment can still be effective for chronic mallet injuries (up to several months after injury)
   • Success rates decrease with longer delay in treatment

5. Finger Stiffness:

   • Stiffness is extremely difficult to treat after fracture healing
   • Early motion of uninvolved joints is crucial for optimal outcomes 7

Expected Outcomes

With proper conservative management:

• 56-78% of patients achieve excellent to good results 6
• Mean extension lag of approximately 2-5 degrees at final follow-up 6
• Most patients regain functional DIP joint motion and are pain-free

Remember that finger stiffness is one of the most functionally disabling complications, emphasizing the importance of early motion of uninvolved joints while maintaining strict immobilization of the DIP joint.