Factors associated with subluxation in mallet fracture

Area of Science:

• Orthopedic Surgery
• Traumatology
• Radiology

Background:

• Mallet fractures are common injuries affecting the distal interphalangeal joint.
• Subluxation is a potential complication that can impact treatment outcomes.
• Understanding risk factors for subluxation is crucial for effective management.

Purpose of the Study:

• To identify factors associated with initial and late subluxation in mallet fractures.
• To quantify the risk of subluxation based on fragment size and displacement.

Main Methods:

• Retrospective review of adult patients with mallet fractures (2004-2014).
• Identification of fractures using ICD-9 codes and radiographic report searches.
• Manual verification of 392 true mallet fractures, noting subluxation incidence.

Main Results:

• Fragment size, displacement, and time to treatment correlated with subluxation.
• No subluxation observed when fracture size was <39% of the articular surface.
• A 4% increased risk of subluxation for each 1% increase in articular surface involvement (>39%) and for each 1% displacement.

Conclusions:

• Fragment size and displacement are significant predictors of mallet fracture subluxation.
• Fractures involving less than 39% of the articular surface may have a lower risk of subluxation.
• These findings aid in risk stratification and treatment planning for mallet fractures.