Intramedullary vs Plate Fixation of Distal Fibular Fractures: Use Rates, Fracture Patterns, Patient Characteristics, and Complication Rates

Abstract

Category: Trauma; Ankle Introduction/Purpose: The traditional surgical treatment for distal fibula fractures is open reduction and plate fixation (PF). However, intramedullary fixation (IMF) has been shown to provide advantages over plate fixation, particularly in patients and injuries with higher risks of soft tissue complications. Current evidence comparing the two fixation types remains scarce and is limited by modest sample sizes. Using a large national database, this retrospective cohort study aims to examine differences in use rates, associated fracture patterns, patient characteristics (e.g. age, gender, comorbidities, Elixhauser Comorbidity Index (ECI)), and complication rates between fibular IMF and PF within the United States. Methods: Patients (age≥18) with lower leg or ankle fractures treated with fibular IMF or PF between October 2015 and October 2021 were identified using a United States insurance claims database. The monthly ratio of IMF-treated patients to PF-treated patients was tracked over time to compare use rates. Fracture patterns were determined using fracture diagnoses within one month preceding surgery. Further analyses of patient characteristics and complication rates only included fibula fracture patients with 12 months of post-operative follow-up, and patients with concomitant upper tibia or tibia shaft fractures were excluded. To compare complication rates, a 1:4 (IMF:PF) matched comparison was performed, controlling for age, gender, high-energy (i.e. pilon, lower tibia, and trimalleolar) fractures, diabetes, tobacco use, obesity, and chronic kidney disease (CKD). Comparisons were conducted using chi-squared tests for categorical variables and t-tests for means. Ordinary least squares regression was used to visualize the trend in monthly relative use rates. Results: In total, 39329 patients (2294 IMF, 37035 PF) were identified. IMF use trended upwards relative to PF use over time (Figure 1). Tibia and fibula shaft fractures were the most common fractures in IMF patients versus trimalleolar and bimalleolar fractures in PF patients. A higher proportion of IMF patients had open fractures (p < 0.01). 627 IMF and 29703 PF patients were included for further analysis of patient characteristics and complications. The IMF cohort was younger, with higher mean ECI, fewer females, and higher rates of CKD (ps < 0.01). No significant differences in diabetes, tobacco use, or obesity rates were identified. Among 316 IMF and 1254 PF matched patients, no significant differences in infection, nonunion, malunion, revision, hardware removal, pulmonary embolism, and deep vein thrombosis rates were found. Conclusion: The upward trend in the ratio of IMF-treated to PF-treated patients suggests that the popularity of IMF is steadily rising. The higher rate of concomitant tibia shaft fractures and open fractures seen among IMF-treated patients in this study is consistent with the use of fibular IMF in cases involving higher-energy trauma and soft-tissue disruption. Higher ECI scores and rates of CKD in IMF patients also suggest that IMF is used more frequently in medically complex patients with impaired wound healing. Lastly, fibular IMF appears to be a viable alternative to PF when used in similar populations.