The relationship between changes in distal tibiofibular joint congruence and clinical and functional results in the short-term follow-up of patients operated on for ankle fracture.

Background: The effects of changes in distal tibiofibular joint (DTFJ) congruence on clinical and functional outcomes are unclear in patients operated on for ankle fractures. The present study aims to evaluate the relationship between changes in DTFJ congruence and clinical and functional outcomes in the short-term follow-up of the patients operated on for ankle fractures.

Methods: In this study, hospital records of patients who were operated on for ankle fractures were retrospectively analyzed. The data of patients who underwent bilateral ankle computed tomography scans at least 18 months after surgery were used. DTFJ congruence was evaluated using four methods. Method 1: the distance between the most prominent anterior points of the tibia and fibula (anterior incisura [AI]) and that between the most prominent posterior points of the tibia and fibula (posterior incisura [PI]) were measured. Method 2: the direct anterior (DA) and direct posterior (DP) distances were measured based on perpendicular lines drawn from the most prominent anterior and posterior points of the longitudinal axis of the fibula to the tibia, respectively, and a direct translation (DT) distance was measured based on a perpendicular line drawn to the DA from the most prominent anterior point of the tibia. Method 3: the angle between a line connecting the most anterior and posterior points of the tibia and a line connecting the most anterior and posterior points of the fibula (rotational angle [RA]) was measured. The differences in distances and angles (dAI, dPI, dDA, dDP, dDT, and dRA) between the injured and non-injured sides were calculated in the first three methods. Method 4: any rotational/translational incongruency on the injured side was subjectively reported. The American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, Olerud-Molander Ankle Score (OMAS), and Visual Analog Scale (VAS) were used for clinical and functional evaluations.

Results: Thirty patients (18 males and 12 females; mean age, 43.3 [range, 20-78 years] years) were included in this study. The average follow-up was 37.6 (range, 18-54 months) months. Negative correlations were detected between dDA and the AOFAS-pain subscale (r=-0.37; p=0.04), between dDP and the OMAS (r=-0.57; p=0.01), and between dDT and the AOFAS-pain, AOFAS-function, and OMAS (r=-0.55 p=0.01; r=-0.40; p=0.03; r=-0.39; p=0.04, respectively).

Conclusion: Changes in dDA, dDP, and dDT values affect the clinical and functional outcomes. These parameters should be provided in accordance with the anatomy of the patient during the reduction of the DTFJ to achieve better outcomes.