Weber Ankle Fracture Classification System Yields Greatest Interobserver and Intraobserver Reliability Over AO/OTA...

No previous studies have evaluated the intra- and interobserver reliability between the Weber, Lauge-Hansen and AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification systems under time constraints. This study compares the interobserver and intraobserver reliability of the aforementioned classification systems under simulated time constraints. Anteroposterior and lateral radiographs of ankle malleolar fractures from 80 consecutive patients from 2015 to 2016 were classified by 2 independent observers according to Weber, Lauge-Hansen and AO/OTA. Classifications were conducted over 4 successive weeks under timed (25-seconds) and untimed conditions, with 1-week gaps between each classification. Cohen's kappa and percentage agreement were calculated. Cohen's kappa for interobserver agreement ranged 0.67 to 0.67 and 0.59 to 0.73 for untimed and timed classifications for Weber; 0.38 to 0.47 and 0.44 to 0.50 for Lauge-Hansen; 0.28 to 0.49 and 0.13 to 0.37 for AO/OTA. Intraobserver agreement ranged from 0.83 to 0.85 and 0.78 to 0.79 for untimed and timed classifications for Weber; 0.46 to 0.65 and 0.59 to 0.73 for Lauge-Hansen; 0.42 to 0.63 and 0.40 to 0.51 for AO/OTA. Based on the Landis and Koch's benchmark scale, there was substantial agreement in the inter- and intraobserver variables for Weber; moderate agreement in inter- and intraobserver variables for Lauge-Hansen; fair and moderate agreement in inter- and intraobserver variables respectively for AO/OTA. Interobserver and intraobserver reliability was the most substantial for Weber, followed by Lauge-Hansen and AO/OTA. Time constraint did not have a statistically significant effect on the reliability of classifications. We recommend concurrent usage of the Weber and Lauge-Hansen system, since they demonstrate the greatest reliability and reproducibility, and confer better understanding of the fracture type, respectively.