Interobserver variation in classification of malleolar fractures

Area of Science:

• Orthopedic surgery
• Radiology
• Traumatology

Background:

• Malleolar fracture classification is debated, with a need for systems that are easy to use and provide good agreement.
• Existing systems like Weber, AO, and Lauge-Hansen have limitations in clinical application.

Purpose of the Study:

• To evaluate the interobserver agreement of established malleolar fracture classification systems (Weber, AO, Lauge-Hansen).
• To assess the reliability of measuring posterior fragment size in trimalleolar fractures.
• To propose a more clinically useful classification approach.

Main Methods:

• An interobserver study involving four orthopedic surgeons classifying 100 ankle X-rays.
• Application of Weber, AO, and Lauge-Hansen classification systems.
• Measurement of posterior fragment size in trimalleolar fractures and calculation of agreement using Cohen's kappa and intraclass correlation coefficient (ICC).

Main Results:

• Moderate interobserver agreement was observed for all three classification systems (Weber: κ=0.49, AO: κ=0.45, Lauge-Hansen: κ=0.47).
• Substantial agreement was found for the presence of posterior malleolar fractures (κ=0.63), largely due to small fragments.
• Moderate agreement was noted for estimating posterior fragment size (ICC=0.57).

Conclusions:

• Classical malleolar fracture classification systems demonstrate moderate interobserver reliability.
• A comprehensive classification detailing fibular and medial malleolar fractures, deltoid ligament status, and posterior malleolar involvement is more practical.
• Computed tomography (CT) scans are valuable for detecting small posterior fragments and preoperative planning in trimalleolar fractures.