Post-traumatic osteoarthritis after ankle fracture fixation: A minimum three-year follow-up.

Purpose: Post-traumatic osteoarthritis (PTOA) is a prevalent and serious complication after ankle fracture surgery, and due to its delayed nature and nonspecific symptoms, identifying the risk factors is highly cost-effective. The aim of this study is to investigate the incidence and risk factors associated with PTOA following ankle fracture surgery.

Methods: This study retrospectively analyzed patients who presented with ankle fractures and underwent open reduction and internal fixation (ORIF) at a university-affiliated tertiary care facility, between January 2018 and October 2021. Patients included must have complete data and a minimum 3-year follow-up assessments. Radiographic PTOA was diagnosed and classified in accordance with a validated and widely used criteria. Twenty-two potential risk factors selected based on literature, univariate statistical analysis and biologic plausibility were included for analysis. Univariate analysis and multivariable regression model were used to identify the independent risk factors.

Results: A total of 477 eligible patients were included, comprising 279 males and 198 females, with a mean age of 49.0 ± 9.5 years, and the mean follow-up was 4.3 years. Radiographic PTOA was present in 163 patients (34.2 %), classified as grade Ⅰ in 96 (20.1), grade Ⅱ in 47 (9.9 %), and grade Ⅲ in 20 patients (4.2 %), respectively. Five risk factors were identified, including age (≥ 60 years) (OR, 1.416; 95 %CI, 1.122-2.161), physical labor intensity (> II) (OR, 2.997; 95 % CI, 1.791-5.015), BMI ≥ 28 kg/m (OR, 2.186; 95 % CI, 1.067-4.112), posterior malleolus and involvement of the articular surface (≤ 25 %: OR, 2.024; 95 % CI, 1.167-3.511; > 25 %: OR, 3.533; 95 % CI, 1.630-67.658), and postoperative articular incongruency (OR, 2.011; 95 % CI, 1.138-4.058).

Conclusions: These findings enhance the understanding of its risk profile, and may inform clinical decision-making and guide targeted interventions to mitigate the risk in vulnerable populations.