Ligamentous Injuries and the Risk of Associated Tissue Damage in Acute Ankle Sprains in Athletes: A Cross-sectional MRI Study.

Background: Ankle joint injuries are extremely common sports injuries, with the anterior talofibular ligament involved in the majority
of ankle sprains. There have been only a few large magnetic resonance imaging (MRI) studies on associated structural injuries
after ankle sprains.
Purpose: To describe the injury pattern in athletes who were referred to MRI for the assessment of an acute ankle sprain and to
assess the risk of associated traumatic tissue damage including lateral and syndesmotic ligament involvement.
Study Design: Cross-sectional study; Level of evidence, 3.
Methods: A total of 261 ankle MRI scans of athletes with acute ankle sprains were evaluated for: lateral and syndesmotic ligament
injury; concomitant injuries to the deltoid and spring ligaments and sinus tarsi; peroneal, flexor, and extensor retinacula and
tendons; traumatic and nontraumatic osteochondral and osseous changes; and joint effusion. Patients were on average 22.5
years old, and the average time from injury to MRI was 5.7 days. Six exclusive injury patterns were defined based on lateral
and syndesmotic ligament involvement. The risk for associated injuries was assessed by logistic regression using ankles with
no or only low-grade lateral ligament injuries and no syndesmotic ligament damage as the reference.
Results: With regard to the injury pattern, there were 103 ankles (39.5%) with complete anterior talofibular ligament disruption
and no syndesmotic injury, and 53 ankles (20.3%) had a syndesmotic injury with or without lateral ligament damage. Acute osteochondral
lesions of the lateral talar dome were seen in 20 ankles (7.7%). The percentage of chronic lateral osteochondral lesions
was 1.1%. The risk for talar bone contusions increased more than 3-fold for ankles with complete lateral ligament ruptures
(adjusted odds ratio [aOR], 3.43; 95% CI, 1.72-6.85) but not for ankles with syndesmotic involvement. The risk for associated
deltoid ligament injuries increased for ankles with complete lateral ligament injuries (aOR, 4.04; 95% CI, 1.99-8.22) compared
with patients with no or only low-grade lateral ligament injuries.
Conclusion: About 20% of athletes referred for MRI after suffering an acute ankle sprain had evidence of a syndesmotic injury
regardless of lateral ligament involvement, while more than half had evidence of any lateral ligament injury without syndesmotic
involvement. Concomitant talar osseous and deltoid ligament injuries are common.
Keywords: magnetic resonance imaging; ankle sprain; risk factors; syndesmosis; athletes; osteochondral lesions