What is the best next step for a patient with a jammed finger, flexed distal phalanx that cannot be extended actively but can be passively extended, swollen and tender distal interphalangeal (DIP) joint, and no fracture on x-rays?

Mallet Finger: Immediate Splinting in Extension

The best next step is to immediately splint the DIP joint in extension for continuous immobilization, as this patient has a classic mallet finger (extensor tendon rupture at the DIP joint). 1

Clinical Diagnosis

This presentation is pathognomonic for mallet finger:

• Inability to actively extend the DIP joint with preserved passive extension indicates extensor tendon disruption (either tendinous rupture or bony avulsion) 2
• X-rays showing no fracture confirm this is a tendinous mallet injury rather than a bony avulsion 1
• The mechanism (jamming injury) and physical findings (flexed DIP, swelling, tenderness) are classic 2

Immediate Management Steps

1. Apply Ice and Splint in Position Found

• Apply ice-water mixture for 10-20 minutes with a thin towel barrier to reduce swelling 1, 3
• Never attempt to manually straighten the finger before splinting 1
• Splint the DIP joint in the position found until definitive splinting can be applied 1

2. Definitive Splinting Protocol

• Immobilize the DIP joint in full extension (or slight hyperextension) continuously for 6-8 weeks 2, 4, 5
• Use a custom-made thermoplastic splint or stack splint 5
• Uninterrupted immobilization is critical—even brief splint removal restarts the healing timeline 1
• After 6-8 weeks of continuous wear, continue night splinting for an additional 2 weeks 4

Critical Management Pitfalls

Patient compliance is the primary determinant of outcome:

• Non-compliance with splinting leads to poor results 5
• Educate the patient that removing the splint even briefly (for showering, hygiene) will restart the 6-8 week clock 1
• Consider percutaneous K-wire fixation if compliance is questionable, though this carries rare but serious complications including finger amputation 5, 6

Expected Outcomes

With proper continuous splinting:

• Mean extension lag of 5-13 degrees is typical 5
• Conservative splinting yields excellent to good results in most compliant patients 4
• Recurrence can occur if splinting is discontinued prematurely, but responds to repeat 8-week splinting 4

When to Consider Surgery

Surgery is NOT indicated for this patient, but would be considered if:

• Bony avulsion involving ≥1/3 of the articular surface 1, 3
• Interfragmentary gap >3mm or palmar subluxation of the distal phalanx 1, 3
• Open injuries 1

Follow-Up Instructions

• Begin active finger motion exercises of the PIP and MCP joints immediately while keeping the DIP splinted to prevent stiffness 7, 3
• Re-evaluate immediately if unremitting pain develops during the immobilization period 7, 3
• Remove splint only after 6-8 weeks of continuous wear, then begin DIP active range of motion 2