TRAUMATIC ANTERIOR DISLOCATION OF THE HIP - SPECTRUM OF PLAIN FILM AND CT FINDINGS

Traumatic anterior dislocation of the hip represents 11% of ail hip di slocations and is classified into superior and inferior types [1]. Whe reas inferior anterior hip dislocation is easily recognized on an ante roposterior radiograph of the pelvis, the radiographic appearance of s uperior anterior hip dislocation is less straightforward, often leadin g to an initial misdiagnosis of posterior hip dislocation. Misdiagnosi s of the direction (anterior versus posterior) of a hip dislocation ca n result in failed closed reduction or an improper surgical approach t o open reduction. In addition, recognition of associated impaction fra ctures is important, as patients with this finding have a greater tend ency to develop traumatic arthritis [2, 3]. This pictorial essay, whic h is based on our experience with 20 cases of anterior hip dislocation , including five of the rare superior type, illustrates the spectrum o f radiographic findings and distinguishing features associated with an terior hip dislocation.