Predisposing Factors for Posttraumatic Osteoarthritis After Malleolus Fracture Fixation in Patients Younger Than 50 Years

Abstract

Background: The purpose of this study was to identify the risk factors for posttraumatic osteoarthritis (OA) after surgery for ankle fractures in patients aged ≤50 years. Methods: We performed a retrospective review of consecutive patients who underwent surgery for ankle fractures and were followed up for a minimum period of 5 years. The patients were assigned to 2 groups according to the presence of advanced OA at the last follow-up. Binary logistic regression was used to model the correlation between risk factors and OA. Functional outcomes were assessed using the Foot and Ankle Outcome Score. Results: The data of 332 patients who met the inclusion criteria were included in the analysis. The overall rate of posttraumatic arthritis was 27.7% (nonarthritis group: 240 patients, arthritis group: 92 patients). The arthritic change was significantly affected by BMI (95% confidence interval [CI] 1.29-19.76; adjusted odds ratio [OR] ≥ 30, 6.56), fracture-dislocation injury (CI 1.66-11.57; adjusted OR, 4.06), posterior malleolus (PM) fracture (CI 1.92-12.73, adjusted OR > 25% of the articular surface, 5.72), and postoperative articular incongruence (CI 1.52-18.10; adjusted OR, 7.21). The mean scores of the arthritis group were lower than those in the nonarthritis group ( P < .05). Conclusion: Obesity, fracture-dislocation injury, concomitant large PM fracture, and articular incongruence were risk factors of posttraumatic OA after surgery for ankle fractures. Surgeons should be aware that accurate reduction is critical in patients with ankle fractures with associated large PM fractures, especially those with obesity or severe initial injuries such as fracture-dislocation. Level of Evidence: Level III, case control study.