Imaging Features of Avulsion Injuries

Abstract

Avulsion injuries are common among participants in organized sports, especially among adolescent participants. Imaging features of both acute and chronic avulsion injuries of the pelvis, knee, ankle and foot, shoulder, and elbow were evaluated to help distinguish these injuries from more serious disease processes such as neoplasm and infection. At radiography, acute injuries (ie, those resulting from extreme, unbalanced, often eccentric muscular contractions) may be associated with avulsed bone fragments, whereas subacute injuries have an aggressive appearance that may include areas of mixed lysis and sclerosis. Chronic injuries (ie, those resulting from repetitive microtrauma or overuse) or old inactive injuries may be associated with a protuberant mass of bone and may bear a striking resemblance to a neoplastic or infectious process. Although not usually required, computed tomography is helpful in the diagnosis if radiographic findings are equivocal or if the injury is not in the acute phase. MR imaging is best suited for the evaluation of injuries to muscles, tendons, and ligaments. Recognition of characteristic imaging features and familiarity with musculotendinous anatomy will aid in accurate diagnosis of avulsion injuries.

Segond Fracture Revealed by Ultrasonography

“…6 Moreover, unrecognized and untreated anterolateral instability may lead to osteoarthritis or the failure of surgical reconstruction of the ACL. 9 In the acute stage of the avulsion fracture, clinical evaluation of the knee may be difficult because of pain, muscle spasm, hemarthrosis, and soft tissue edema.…”

“…The Segond fracture was previously thought to result from an avulsion fracture at the insertion of the middle portion of the lateral joint capsule, also called the LCL, of the knee. [1][2][3][4][5][6] In this regard, Weber and colleagues collateral ligament in an oblique fashion to insert at the midportion of the lateral tibia, posterior to the LCL; and fourth, an attachment of these structures connected to each other at the typical site of the Segond fracture (ie, the lateral tibial rim). These authors suggested that, in addition to the LCL, fibers of the iliotibial tract and the AOB are important factors in the pathogenesis of the Segond fracture.…”

Paediatric musculoskeletal US beyond the hip joint

“…The injury leads to partial or complete detachment of the apophysis onto which the tendon is attached. Acute apophyseal injuries can be subdivided into major and minor based on the degree of dislocation of the apophyseal fragment [6]. Major apophyseal lesions cause dislocation of the avulsed fragment at an extent that precludes resorption.…”

Ultrasound of the elbow: Examination techniques and US appearance of the normal and pathologic joint

“…Medial epicondylar avulsion is also frequently seen with posterolateral dislocation of the elbow. In valgus stress, the medial joint space is temporarily opened, and at times the avulsed fragment is trapped within the joint [13]. In acute avulsions, US reveals local soft-tissue swelling and separation of the medial epicondyle.…”