title: Sonographic Findings of Chondral Avulsion Fractures of the Lateral Ankle Ligaments in Children.
abstract: In this series, we aimed to describe the sonographic findings of chondral avulsion fractures that develop concomitant with lateral ankle ligament injury in children. We performed stress sonography during a manual anterior drawer stress procedure of the ankle in 9 skeletally immature patients who had recently had a lateral ankle sprain. Echo videos were obtained through the course of treatment, and all videos were reviewed. We elucidated the common features of chondral avulsion fractures of the lateral ankle ligaments in the children. The features of avulsion fractures on conventional sonography included absence of a fracture with hyperechoic spots (sonographic occult fracture type), cortical discontinuity with hyperechoic spots (cortical disruption fracture type), fracture line in the cortical bone (double-line fracture type), and a step-off deformity of the cortical bone with cartilage (displaced fracture type). In contrast, the features of chondral fractures on stress sonography included abnormal motion of the chondral lesions and mobility/fluidity of hyperechoic spots along the chondral fracture site. The presence of hyperechoic spots around the chondral lesion is an important sonographic sign for diagnosing chondral fractures concomitant with ankle lateral ligament injury. Hence, we believe that stress sonography should be considered for the detection of chondral fractures concomitant with radiographically negative ankle lateral ligament injuries in skeletally immature patients with lateral ankle pain and ankle sprains, if hyperechoic spots are present in the cartilage of the distal fibula.
authors.affiliation: Maeda Orthopedic Clinic, Nara, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Maeda
authors.affiliation: Maeda Orthopedic Clinic, Nara, Japan.
authors.forename: Nana
authors.initials: N
authors.lastname: Maeda
authors.affiliation: Takaoka Orthopedic Clinic, Nara, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Takaoka
authors.affiliation: Department of Orthopedic Surgery, Nara Medical University, Nara, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D016512:Ankle Injuries / Q000000981:diagnostic imaging*; D000843:Ankle Joint / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D005260:Female; D000071562:Fractures, Avulsion / Q000000981:diagnostic imaging*; D006801:Humans; D017844:Lateral Ligament, Ankle / Q000000981:diagnostic imaging* / Q000293:injuries*; D008297:Male; D014463:Ultrasonography / Q000379:methods*
keywords: anterior talofibular ligament; children; chondral fractures; musculoskeletal ultrasound; os subfibulare; stress sonography