What is the non-surgical treatment for a bony mallet finger?

Non-Surgical Treatment of Bony Mallet Finger

Conservative treatment with continuous splinting of the DIP joint in extension for 6-8 weeks is the recommended first-line treatment for bony mallet finger, regardless of fragment size, unless volar subluxation is present. 1, 2

Treatment Protocol

Splinting Technique and Duration

• Immobilize the DIP joint in slight hyperextension (for tendinous injuries) or neutral/straight position (for bony avulsions) using a dorsal splint for 6-8 continuous weeks 1, 3
• Continue nighttime splinting for an additional 2 weeks after the initial 6-8 week period 4
• The splint must maintain uninterrupted immobilization throughout the entire treatment period—any interruption requires restarting the full 6-8 week course 3

Specific Indications for Conservative Management

Conservative treatment is appropriate for:

• Bony mallet fingers involving up to two-thirds of the articular surface 2
• Fractures with up to 3mm fragment displacement and 1mm fragment rotation 2
• All mallet finger injuries EXCEPT those with irreducible volar subluxation (Tubiana stage IV) 1, 2

This represents a significant departure from older teaching that recommended surgery for fragments involving more than one-third of the joint surface. Recent evidence demonstrates excellent remodeling and joint congruency even with larger fragments when treated conservatively 2.

Critical Management Points

When Conservative Treatment Fails

• If the initial 6-8 week splinting course fails, offer a second trial of conservative splinting before considering surgery 3
• Recurrence of deformity within the first week after splint removal should be managed with an additional 8 weeks of continuous splinting 4

Monitoring Requirements

• Obtain radiographs at presentation to confirm diagnosis and assess for volar subluxation 1
• The presence of reducible subluxation (stage III) can still be managed conservatively with appropriate splinting 1
• Only irreducible volar subluxation (stage IV) is an absolute contraindication to conservative treatment 1, 2

Expected Outcomes

Functional Results

Conservative management produces excellent outcomes with:

• Extension lag of ≤5 degrees in the majority of cases 2
• Flexion reduction of ≤10 degrees in a minority of patients 2
• Pain-free outcomes in all successfully treated patients 2

Radiographic Remodeling

• Excellent remodeling of the DIP joint surface occurs even with initially displaced fragments, achieving anatomic joint congruency 2
• No secondary volar subluxation develops when appropriate splinting is maintained 2

Chronic Cases

• Even chronic mallet fingers (4-18 weeks old) respond well to conservative splinting, with the same 8-week continuous protocol plus 2 weeks of night splinting 4
• The time limit for effective conservative treatment continues to be extended beyond what was previously thought possible 3

Critical Pitfalls to Avoid

Avoid Premature Surgery

• Do not convert closed injuries to open surgical cases—this significantly increases complication rates without improving outcomes 3
• Surgical stabilization often produces unsatisfying results regarding anatomic reconstruction and DIP joint mobility 2

Avoid Treatment Interruption

• Any break in splint immobilization requires restarting the full 6-8 week treatment course 3
• Patient compliance is the primary determinant of success—emphasize this clearly 1

Avoid Overlooking Subluxation

• Always assess for volar subluxation on lateral radiographs—this is the only absolute indication for surgical intervention 1, 2
• Distinguish between reducible subluxation (treatable conservatively) and irreducible subluxation (requires surgery) 1

Surgical Consideration

Surgery should only be considered for Tubiana stage IV mallet finger with irreducible volar subluxation 1, 2. If surgery becomes necessary after failed conservative treatment, transarticular Kirschner wire fixation is the preferred simple option 3.