MR imaging characteristics of ankle joint chronic injuries in asymptomatic professional soccer players: a preliminary study

Objective: Analysis the MR imaging characteristics of ankle joint chronic injuries in asymptomatic professional soccer players. Methods: The eighteen professional soccer players from Tianjin local region soccer club were selected as research subjects from March to May 2017. All subjects can normally participate in training and competition, and no ankle joint symptoms within six months. 3.0 T MRI was used to obtain MR images. The athletes' foot bones, ligaments, and tendons were evaluated. The incidence of structural damages between striking foot and support foot were compared using Fisher's exact test. Results: Bone injuries were mainly bone marrow edema, cystic change, loose bodies, and irregular osteoid bumps. Bone marrow edema was identified in 12 persons in 17 ankle joints (striking foot 10, support foot 7); loose bodies in 3 persons in 3 ankle joints (striking foot 1, support foot 2); posterior ostrigonum of talus in 7 persons in 7 ankle joints (striking foot 5, support foot 2); irregular osteoid bumps in 2 person in 2 ankle joints (striking foot 1, support foot 1). There was no significant difference in incidence of bony injury between striking foot and support foot (all P > 0.05). The medial deltoid ligament injure was identified in 5 persons in 5 ankle joints (striking foot 2, support foot 3); anterior talofibular ligament injure in 17 persons in 25 ankle joints (striking foot 8, support foot 17); calcaneofibular ligament injure in 9 persons in 12 ankle joints (striking foot 5, support foot 7); anterior tibiofibular ligament injure in 1 person in 1 ankle joint (striking foot); no posterior talofibular ligament and posterior tibiofibular ligament injure was found. Incidence rate of anterior talofibular ligament injure was higher in support foot than striking foot (P = 0.003). There was no significant difference in injury of the other ligaments between striking foot and support foot (all P > 0.05). Tendon sheath effusion was the main manifestation of tendon injuries. The flexor hallucis longus tendon sheath effusion was found in 17 persons in 26 ankle joints (striking foot 12, support foot 14); flexor digitorum longus tendon sheath effusion in 8 persons in 10 ankle joints (striking foot 5, support foot 5); tibialis posterior tendon sheath effusion in 9 persons in 12 ankle joints (striking foot 5, support foot 7); peroneus longus and peroneus brevis tendon sheath effusion in 4 persons in 4 ankle joints (striking foot 2, support foot 2); extensor digitorum longus tendon sheath effusion in 2 person in 2 ankle joint (striking foot 1, support foot 1); no anterior tibialis tendon sheath effusion, extensor hallucis longus tendon sheath effusion, and Achilles tendon effusion were found. There was no significant difference in incidence of effusion between striking foot and support foot (all P > 0.05). Conclusion: Hard training and competitions is easily lead to repeated ankle injuries in the professional soccer players, the primary features were bone marrow edema, cystic change, ligament injury, and tendon sheath effusion. Injury characteristics between striking foot and support foot may be different, because the different function of different foot. (authors)