The Direct Anterior Approach to Hip Reconstruction

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SECTION III Intermediate Direct Anterior Approach Topics

turns into an iliac oblique image after traction is placed on the leg either manually or via a specialized table. It is imperative to acknowledge this and adjust the rotation of the C-arm until the coccyx is aligned with the pubic sym physis. Underrecognition of this can lead to a malposi tioned acetabular component as a well-positioned cup on an iliac oblique view. However, this will become overly anteverted on the true AP radiograph once the rotation is corrected back to neutral and risks postoperative anterior instability ( Figure 14.7 ). It is essential that, for each step in which fluoroscopy is being used, whether determining

acetabular component position or final limb length and offset, the exact AP pelvis image should be replicated. This will minimalize variables and lead to increased pre cision of the fluoroscopic measurements. 11 Using a Digital Line to Recreate the Bi-ischial Reference in Lieu of a Radiopaque Bar As described previously, fluoroscopic images can be sub ject to parallax and distortion, leading to an altered AP pelvis image. Using the radiopaque rod helps the surgeon

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C FIGURE 14.7 A, A well-positioned acetabular cup; however, the image is a slight iliac oblique view. B, When the image is adjusted to neutral pelvic rotation, the acetabular component becomes overly anteverted. C, This malposition was recognized, and the acetabular version was adjusted. Copyright © Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited. 2024