A higher association of medial collateral ligament injury of the knee in pronation injuries of the ankle

To evaluate the prevalence of medial collateral ligament (MCL) injury of the knee among ankle-fracture patients and to determine the risk factors associated with MCL injury in this patient group. 303 patients (303 affected ankles) who underwent surgical treatment for an ankle fracture were assessed. Supination versus pronation injury, Danis-Weber classification, age, sex, body mass index (BMI), limb dominance, and mechanism of injury were reviewed to identify factors related to MCL injury. Prevalence of MCL injury of the knee among the total number of patients with an ankle fracture was 3.96% (12 out of 303 injuries). Multivariable logistic and linear regression analysis with adjustment of possible confounding factors confirmed that female sex and pronation injury were associated significantly (p < 0.05) with MCL injury. The prevalence of MCL injury among females and the pronation type of ankle injury was 8.19% (10 out of 122 females) and 10.75% (10 out of 93 pronation injuries), respectively. More careful physical examination of the knee joint is strongly recommended in patients with ankle fractures, especially if the patient is female or the ankle-fracture pattern corresponds to the pronation type of injury.