Computed Tomography Improves Interobserver Agreement and Influences Surgical Planning in Lauge-Hansen Classification of Ankle Fractures.

Background: The Lauge-Hansen classification is commonly used for ankle fractures but demonstrates poor interobserver reliability when based on radiographs alone. This study was conducted to determine whether the addition of computed tomography (CT) improves observer agreement and influences surgical planning.

Methods: A retrospective analysis was conducted on patients with operatively treated ankle fractures. Five masked observers (2 orthopaedic surgeons and 3 orthopaedic surgery residents) classified fractures using the Lauge-Hansen system in 2 sessions: first with radiographs alone and then with radiographs in combination with CT. Interobserver agreement was assessed using Cohen kappa and Fleiss kappa, whereas consistency of each observer's classifications between radiograph-only and CT-assisted sessions was also evaluated. Changes in fracture classification and treatment plans following CT evaluation were also recorded.

Results: A total of 145 patients were included. Interobserver agreement improved significantly with the addition of CT, increasing from κ = 0.464 (95% CI: 0.41-0.52) with radiographs alone to κ = 0.804 (95% CI: 0.76-0.85) with radiographs plus CT (P < .001). The use of CT led to a change in fracture classification in 73 to 80 cases across observers (50.3% to 55.2%), and treatment plans were revised in 69 to 75 cases (47.6% to 52.0%).Among these changes, decisions to fix the posterior malleolus increased from 41 to 64 cases after CT evaluation (Δ = 15.9%, 95% CI: 10.8%-22.7%, P = .008), and syndesmotic stabilization was newly planned in 36 to 59 cases (Δ = 15.9%, 95% CI: 10.8%-22.7%, P = .014), depending on the observer. These findings indicate that CT provided critical diagnostic details that influenced both classification and surgical decision making.

Conclusion: CT significantly improves the consistency of the Lauge-Hansen classification and can have a substantial impact on surgical decision making. CT imaging may be considered, especially when posterior malleolar or syndesmotic involvement is suspected; however, its impact on clinical outcomes remains uncertain.