Reliability of classification for post-traumatic ankle osteoarthritis

Area of Science:

• Orthopaedic surgery
• Radiology
• Osteoarthritis research

Background:

• Post-traumatic osteoarthritis is a common complication following ankle fractures.
• Accurate classification systems are crucial for clinical outcome studies and decision-making.
• Existing systems like van Dijk, Kellgren, and Takakura require rigorous evaluation for reliability.

Purpose of the Study:

• To determine the most reliable classification system for categorizing post-traumatic osteoarthritis in clinical outcome studies.
• To compare the interobserver reliability of the van Dijk, Kellgren, and Takakura osteoarthritis classification systems.
• To assess the suitability of these systems for clinical decision-making.

Main Methods:

• 118 orthopaedic surgeons evaluated 128 ankle radiographs using the van Dijk, Kellgren, and Takakura classification systems.
• Radiographs were of patients with bi- or trimalleolar ankle fractures.
• Interobserver reliability was assessed using Siegel and Castellan's multirater kappa measure.

Main Results:

• The van Dijk osteoarthritis scale achieved fair interobserver agreement (kappa = 0.24).
• The Takakura (kappa = 0.19) and Kellgren (kappa = 0.18) systems showed poor interobserver agreement.
• These differences in reliability were statistically significant (p < 0.001).

Conclusions:

• The van Dijk osteoarthritis scale demonstrated fair interobserver agreement.
• The Takakura and Kellgren osteoarthritis classification systems exhibited poor interobserver agreement.
• Due to low interobserver agreement, none of these systems are currently suitable for clinical decision-making in post-traumatic osteoarthritis.