Letter to the Editor

Abstract

To the editor, We read the study, “Femoroacetabular Impingement Predisposes to Traumatic Posterior Hip Dislocation” by Steppacher et al. [3] with great interest. As the authors mentioned, the proposal that femoroacetabular impingement could play a role in low-energy hip dislocations was suggested by Philippon et al. [2], based on the arthroscopic findings in professional athletes during active competition. There are scarce references reporting anatomic factors that predispose to posterior hip dislocation [4]. Steppacher and colleagues’ article proposed a mechanism of fulcrum by the interaction between the nonspherical femoral head and the acetabular rim in patients with femoroacetabular impingement-type CAM [3]. We were satisfied to read that the authors agreed with the mechanism that we recently described and represented graphically [1] in a case report of a young soccer player with femoroacetabular impingement that suffered from a low-energy posterior fracture-dislocation. In our publication, we also suggested other factors that could enhance posterior hip dislocation in patients with femoroacetabular impingement: retroversion of the femoral neck, retroversion of the acetabulum, and decreased acetabular depth. The study by Steppacher et al. [3] shows a higher prevalence of femoroacetabular features in patients with posterior hip dislocation compared with the normative data of the proposed mechanism. We believe posterior low-energy hip dislocation should not only be attributed to femoroacetabular impingement as an isolated mechanism. Further investigations should be performed to rule out the contributing factors in this entity.