Mallet Finger

Types

• Tendinous: Extensor tendon disruption, no fracture on XR

• Bony: Avulsion fracture of the dorsal distal phalanx

Clinical Features

• Pain and swelling at the DIP joint

• Inability to actively extend the DIP joint while passive extension is preserved

• Often occurs after forced flexion of an extended finger (e.g., catching a ball)

Management

Conservative

• Splinting:

  • DIP in full extension, PIP free, 6–8 weeks continuous wear (including at night)

  • If DIP flexes at any point, restart the splinting period

  • After the initial phase, night-time splinting may be continued for an additional 2–4 weeks to prevent recurrence

• Indications for Splint Alone:

  • No volar subluxation

  • Bony involvement <30% of the articular surface

  • Preserved passive extension

  • No significant gap between bone fragments on imaging

Surgical Referral

• 30% articular surface involvement

• Inability to maintain passive extension

• Volar subluxation of the distal phalanx

• High functional demand (e.g., athletes, manual workers)

• Large displaced bony fragment or joint malalignment

Timing of Referral

• Refer within 7 days for assessment

• Low threshold for referral in cases of diagnostic uncertainty, joint instability, or failure of conservative management

Key Notes

• Continuous splinting is critical for success

• Hand therapy post-splinting for functional recovery, focusing on DIP joint mobility and strengthening

• Late presentation can still be treated conservatively, but prolonged splinting may be required

• Monitor for complications such as extensor lag or stiffness