[Longitudinal splitting syndrome of the short fibular tendon. . Imaging and classification by MRI]

We present a series of 38 cases of longitudinal splitting of the peroneus brevis tendon revealed by MR imaging (12 lesions were confirmed at surgery). MRI enabled classification in four surgical grades. The frequency of such lesions in chronic ankle instability as observed in our series is often reported in the literature. Bilateral cases are common. Asymptomatic cases do occur, especially in grades I and II. MRI has been shown to be a very effective investigation for demonstrating this tendinous lesion; the proton density weighted sequence in the axial plane is the most adequate sequence.