ePoster #800 - ISHA Annual Scientific Meeting 2016

Comparison of Radiographs and Computed Tomography for the Diagnosis of Anterior Inferior Iliac Spine Impingement

Broc R Schindler, BS, Vail, CO UNITED STATES
Melanie B Venderley, BS, Vail, CO UNITED STATES
Jacob D. Mikula, BS, Vail, CO UNITED STATES
Jorge Chahla, MD, Vail, CO UNITED STATES
Grant Dornan, MSc, Vail, CO UNITED STATES
Travis Turnbull, Vail, CO UNITED STATES
Robert F. LaPrade, MD, PhD, Vail, CO UNITED STATES
Marc J. Philippon, MD, Vail, CO UNITED STATES

Steadman Philippon Research Institute, Vail, CO, UNITED STATES

FDA Status Not Applicable

Summary: In the future, radiographic methods developed in this study may provide physicians with an alternative to 3D CT for the diagnosis and treatment of AIIS extra-articular hip pathologies.

Abstract:
Purpose: Validate radiographic and 3D CT imaging modalities to diagnose anterior inferior iliac spine (AIIS) impingement by establishing imaging measurements for the AIIS. These measurements will detect lateral and anterior/inferior morphology changes on AP and false-profile radiographs, respectively. Methods: Anteroposterior and false-profile radiographs and 3D CT scans were obtained on ten human cadaveric pelvises. On the anteroposterior view for each methodology, two measurements were calculated: distance to the most lateral AIIS from the 12-o’clock position on the acetabular rim, and the angle between the most lateral AIIS and the sagittal plane. On the false-profile view for each methodology, two measurements were calculated: distance to the anterior AIIS from the 12-o’clock position on the acetabular rim, and the angle between the anterior AIIS and the sagittal plane. For both methods, interrater and intrarater reliability analyses were performed and an intermethod analysis. Results: Generally, the radiographic false-profile view was the most repeatable orientation for all distance and angle measurements, demonstrating excellent reproducibility in both interrater and intrarater analyses. The median distance from the 12 o’clock position of the acetabular rim to the most anterior aspect of the AIIS was 41.4 mm and 16.4 mm on the radiographic false-profile and AP views, respectively. Intermethod analysis demonstrated a systematic, quantitative bias between modalities, which will remain relatively consistent as evidenced by the strong individual reproducibility of each measurement. Conclusion: The morphology of the AIIS in relation to the acetabular rim 12-o’clock position and its angle relative to the sagittal plane can be quantitatively determined when using either radiographic or 3D CT imaging modalities. This information may aid the diagnosis of AIIS extra-articular hip pathologies. In the future, using our proposed method, exact angle and distance measurements could be developed for both imaging modalities that define the morphology of the AIIS in symptomatic and asymptomatic subspinal impingement patient populations. These discrete values could then be used in conjunction with the qualitative morphology classification developed by Hetsroni et al. to evaluate AIIS morphology during preoperative and postoperative treatment of patients with AIIS-involved subspinal impingement. Clinical Relevance: Utilizing radiographic evaluation in the diagnosis of AIIS impingement would greatly decrease patient radiation exposure. Citation: 1. Hetsroni I, et al. Clin Orthop Relat Res. 2013;471:2497-2503.