Does a mallet finger patient need to continue splinting after achieving a 15-degree lag following four months of extension splinting?

Management of Mallet Finger with 15-Degree Lag After Four Months of Splinting

Splinting can be discontinued after achieving a 15-degree extension lag following four months of treatment, as continued splinting is unlikely to provide additional functional improvement.

Understanding Mallet Finger Outcomes

Mallet finger injuries typically show good long-term results with appropriate splinting treatment. Research indicates that:

• Extension lag tends to stabilize or slightly improve over time, with studies showing an average extension lag of 7 degrees at 6 months improving to 5 degrees at 61 months post-injury 1
• The final functional outcome is generally good regardless of when treatment is initiated, with successful restoration of active extension (defined as no more than 10-degree extension lag) achievable in most patients 2

Splinting Duration Considerations

The decision to discontinue splinting should be based on several factors:

• After 4 months of continuous splinting, the healing process has likely reached a plateau, with minimal additional improvement expected 1
• Prolonged splinting beyond the necessary healing period may lead to:
  • Potential stiffness and decreased range of motion 3
  • Muscle deconditioning from immobilization 3
  • Possible development of learned non-use patterns 3

Functional Implications of a 15-Degree Lag

A 15-degree extension lag represents a reasonable functional outcome:

• While not perfect extension, this degree of lag typically allows for adequate hand function in daily activities 1
• Studies evaluating mallet finger outcomes consider extension lag of 10 degrees or less as a successful result, with your patient approaching this benchmark 2

Rehabilitation After Splint Discontinuation

After discontinuing the splint, focus should be on:

• Gradually increasing active range of motion exercises to improve both extension and flexion 3
• Implementing strategies that promote normal movement patterns rather than compensatory movements 3
• Monitoring for any increase in extension lag, which might indicate inadequate healing 3

Common Pitfalls to Avoid

When managing mallet finger patients after splinting:

• Avoid activities that place excessive stress on the distal interphalangeal (DIP) joint during the initial weeks after splint removal 3
• Be aware that some patients may develop secondary subluxation after splint removal, requiring radiographic follow-up 4
• Recognize that overnight splinting for an additional 4-6 weeks after discontinuing full-time splinting may help maintain correction in some cases 5

Special Considerations

It's important to differentiate between tendinous and bony mallet injuries, as they may have different healing characteristics:

• Tendinous mallet injuries (typically in older patients following low-energy trauma) may have larger initial extension lags (mean 31°) 6
• Bony mallet injuries (typically in younger patients following high-energy trauma) often present with smaller extension lags (mean 13°) 6

In summary, after four months of appropriate splinting with achievement of a 15-degree extension lag, continued splinting is unlikely to provide significant additional benefit and may potentially lead to stiffness and decreased function. The focus should shift to rehabilitation and gradual return to normal hand function.