Bone Bruises of the Ankle and Mid-foot Often Associate with Ankle Sprain

Background: Ankle sprains are one of the most common musculoskeletal injuries. However, they may be more serious than commonly believed since many patients reportedly experience chronic problems afterwards. It is necessary to improve the treatment, such as the method and duration of fixation, of sprained ankles.Methods: Magnetic resonance imaging of 70 patients with acute moderate or advanced ankle sprains presenting consecutively between November 2014 and December 2019 were reviewed for analysis of bone bruising associated with ankle sprains. The patients were treated conservatively with a solid splint or cast until walking pain could be resolved without external fixation. In cases with pain at the time of weight bearing after solid fixation, crutches were prescribed for pain relief. The fixation period ranged from 8 days to 72 days (mean: 29.5 days). Afterwards, 54.0% of patients had walking pain and required the use of crutches. The ankle joint pain disappeared after conservative treatment in all patients.Results: The incidence of bone bruises detected by magnetic resonance imaging in the ankle and midfoot associated with ankle sprain was 81.4%. Bone bruises of the midfoot, including the tarsal bone and Chopart joint, were found in 34.3% of ankle sprains. Bone bruises of the talus were the most common, being present in 60% of ankle sprains. Bone bruises were also evident in the tibia (44.3%), the calcaneus (21.4%), and the tarsal bone (25.7%). There was a significant association between bone bruises of the talocrural joint surface and use of the crutches after fixation (P=0.041). Multiple regression analysis adjusted for age and gender revealed that bone bruises of the talocrural joint surface of the talus was a significant independent predictor of crutch use (P=0.045), with an odds ratio (95% confidence interval) of 3.03 (1.03-8.94).Conclusion: Bone bruises of the ankle and midfoot are often present in ankle sprains. In moderate or advanced cases of ankle sprain, external solid fixation of both the ankle and midfoot should be performed. In cases with pain at weight bearing following solid fixation, crutches are advised for pain relief and proper ligament and bone healing.