What is the treatment for mallet finger (mallet finger tx)?

Treatment of Mallet Finger

For mallet finger injuries, conservative treatment with continuous splinting of the distal interphalangeal joint (DIPJ) in extension for 6-8 weeks is the primary treatment approach for both tendinous and most bony injuries, with surgical intervention reserved only for specific fracture patterns involving >1/3 articular surface with palmar subluxation that cannot be reduced with splinting. 1, 2

Initial Diagnostic Approach

• Obtain radiographs immediately to differentiate between tendinous rupture and bony avulsion, as this determines specific splinting position and identifies surgical indications 1
• Look specifically for: fragment size (>1/3 articular surface), palmar displacement of the distal phalanx, and interfragmentary gap >3mm 1
• Standard 3-view radiographic examination of the hand is sufficient for diagnosis 1

Conservative Treatment Algorithm (First-Line for Most Cases)

Tendinous Mallet Finger

• Splint the DIPJ in slight hyperextension (not excessive) for 6-8 weeks continuously, followed by 2-4 weeks of night splinting 2, 3, 4
• Stack or Winterstein splints are established options 4
• One high-quality study supports extended immobilization up to 12 weeks full-time plus 4 weeks night splinting, achieving 56% excellent and 25% good results 5

Bony Mallet Finger (Avulsion Fractures)

• Splint the DIPJ in neutral/straight position (not hyperextension) for 6-8 weeks to avoid displacing the bony fragment 2
• Conservative treatment is effective even for fractures involving 1/3 to 2/3 of the joint surface, regardless of initial fragment displacement 6
• Radiological remodeling occurs with anatomic joint congruency restoration, even with initial 3mm displacement 6

Chronic Mallet Finger (>4 weeks old)

• Conservative splinting remains highly effective and should be attempted before surgery, regardless of initial extension deficit 3, 4
• Use the same 8-week continuous splinting protocol as acute injuries 3
• Results are actually superior to acute injuries, with 87.9% achieving extension deficit <10 degrees and higher patient satisfaction 4

Surgical Indications (Rare)

Surgery is indicated only for:

• Bony avulsion involving >1/3 of the articular surface with palmar subluxation that cannot be reduced with splinting (Stage IV) 1, 2
• Palmar displacement of the distal phalanx that remains unreduced 1
• Interfragmentary gap >3mm 1

Important caveat: Even fractures with >1/3 articular involvement can be treated conservatively if the joint reduces with splinting (Stage III), as surgical results are often unsatisfying regarding joint mobility and anatomic reconstruction 2, 6

Critical Pitfalls to Avoid

• Never hyperextend the DIPJ when splinting bony avulsions - use neutral position to prevent fragment displacement 2
• Patient compliance is the primary determinant of success - emphasize continuous wear without interruption for the full treatment period 2, 5
• Do not operate based solely on fragment size - assess for reducibility with splinting first, as conservative treatment succeeds even with large fragments 6
• If recurrence occurs after initial treatment (seen in 2/10 patients in one study), repeat the full 8-week splinting protocol rather than proceeding to surgery 3
• Untreated mallet finger leads to swan-neck deformity and DIPJ osteoarthritis - early intervention is essential 2

Expected Outcomes

• With proper conservative treatment, 70-88% of patients achieve extension deficit <10 degrees 4
• Mean final extension lag of 2.6 degrees with flexion preserved at 68 degrees 5
• Chronic cases (4-18 weeks old) respond as well or better than acute injuries 3, 4