Impact of CT-Based Posterior Malleolar Fracture Classifications on Clinical Outcomes in Bimalleolar Ankle Fractures Involving the Posterior and Lateral Malleoli.

Background

The prognostic value of computed tomography (CT)-based posterior malleolar fracture classifications in uniformly treated fractures remains uncertain.

Purpose

To examine associations of the Haraguchi, Bartoníček/Rammelt, and Mason-Molloy classifications with 1-year functional and early radiographic outcomes. STUDY

Design

Retrospective cohort study.

Methods

Fifty-eight patients with posterior malleolar and Weber B lateral malleolar fractures underwent fixation of both malleoli through a posterolateral approach. Outcomes were the 1-year American Orthopaedic Foot & Ankle Society (AOFAS) score and Kellgren-Lawrence grade. Classification subgroups were compared using Kruskal-Wallis tests; fragment dimensions were assessed using Spearman correlations.

Results

Mean AOFAS score was 92.97 ± 5.28 (95% confidence interval [CI], 91.58-94.35); 10 patients (17%) scored 100 and 24 (41%) scored ≥ 95. Subgroup mean scores were 91.0-93.3 for Haraguchi (p = 0.994), 84.0-96.5 for Bartoníček/Rammelt (p = 0.130), and 87.0-93.3 for Mason-Molloy (p = 0.836). Kellgren-Lawrence grades did not differ across Haraguchi, Bartoníček/Rammelt, or Mason-Molloy subgroups (p = 0.449, p = 0.277, and p = 0.608, respectively). AOFAS correlations with axial and sagittal fragment lengths were ρ = 0.001 (95% CI, -0.273 to 0.285; p = 0.992) and ρ = 0.049 (95% CI, -0.242 to 0.342; p = 0.717), respectively.

Conclusions

No significant associations with 1-year outcomes were detected. Small, uneven subgroups and upper-end AOFAS clustering limited precision; potentially meaningful prognostic associations cannot be excluded.