A novel alphanumeric classification system for ankle fractures: clinical applications and evaluation

Area of Science:

• Orthopaedic surgery
• Radiology
• Trauma classification

Background:

• Traditional ankle fracture classification systems (AO/OTA, Weber, Lauge-Hansen) have limitations in reliability and prognostic value.
• A novel alphanumeric system, the Descriptive Ankle Fracture Classification (DAFC), has been developed to address these limitations.

Purpose of the Study:

• Introduce and evaluate the Descriptive Ankle Fracture Classification (DAFC) system.
• Assess the reliability and prognostic value of the DAFC system.
• Compare the DAFC system against established AO/OTA, Weber, and Lauge-Hansen classifications.

Main Methods:

• Retrospective review of 90 surgically treated ankle fractures.
• Four observers with varying experience classified fractures using DAFC, AO/OTA, Weber, and Lauge-Hansen systems.
• Interobserver and intraobserver reliability assessed using Fleiss' Kappa coefficient; functional outcomes evaluated with AOFAS and OMAS scores.

Main Results:

• DAFC demonstrated superior interobserver reliability for medial malleolus fractures and syndesmotic injuries compared to other systems.
• DAFC exhibited consistently high intraobserver reliability (Kappa 0.967–1.000).
• DAFC classification showed significant associations with functional outcomes: dislocation (D2) and posterior malleolus fractures (P2) correlated with lower AOFAS/OMAS scores. No significant outcome differences were found with AO/OTA, Weber, or Lauge-Hansen classifications.

Conclusions:

• The DAFC system provides a reliable and comprehensive method for ankle fracture classification.
• DAFC offers valuable prognostic insights into dislocation and posterior malleolus involvement.
• High reliability across experience levels suggests DAFC is clinically valuable; further validation in larger cohorts is recommended.