ePoster #807 - ISHA Annual Scientific Meeting 2016

The Relationship Between Arthroscopically Defined Acetabular Cartilage Defects and Preoperative dGemric Indices in Non-Arthritic Hips: Refining the Use of dGemric

Itay Perets, MD, Westmont, IL UNITED STATES
Edwin Chaharbakhshi, BS, Hinsdale, IL UNITED STATES
David E. Hartigan, MD, Westmont, IL UNITED STATES
John P. Walsh, MA, Westmont, IL UNITED STATES
Mary R. Close, BS, Westmont, IL UNITED STATES
Benjamin G. Domb, MD, Chicago, IL UNITED STATES

American Hip Institute, Westmont, IL, UNITED STATES

FDA Status Not Applicable

Summary: The three established dGEMRIC index measurements (sagittal superior, coronal superior, and sagittal anterosuperior) did not accurately predict intraoperative acetabular localized chondral damage in non-arthritic hips; however, the coronal anterolateral (CAL) index was able to differentiate between non/mild and moderate/severe localized damage, and so could provide a more refined preoperative asses

Abstract:
Background: dGEMRIC is an advanced imaging technique that may detect early chondral damage. Although dGEMRIC may have high utility in diagnosing early arthritis, there is a paucity of literature correlating local chondral damage with dGEMRIC indices. Purpose: To report associations between dGEMRIC indices and intraoperatively defined acetabular cartilage damage in non-arthritic hips with femoro-acetabular impingement and/or labral tears, and to evaluate a new technique of measuring dGEMRIC indices that may improve utility in predicting the aforementioned chondral defects. Methods: Between April 2010 and August 2015, 195 hips (183 patients) underwent hip arthroscopy after undergoing dGEMRIC. Exclusion criteria were as follows: previous hip conditions, arthritis of >1 Tönnis grade, previous hip surgeries, delay greater than 180 days between MRI and surgery, and missing sagittal superior dGEMRIC index. dGEMRIC indices measured using four methods, one of which was newly formulated to potentially detect coronal anterolateral (CAL) acetabular damage, were compared to arthroscopically-defined cartilage damage (ALAD and Outerbridge classifications). dGEMRIC indices were compared between non-arthritic hips with no/mild (grades 0 and 1) and those with moderate/severe localized chondral damage (grades 2, 3, and 4). Results: The three established dGEMRIC index measurements (sagittal superior, coronal superior, and sagittal anterosuperior) were not found to be significantly different when comparing no/mild to moderate/severe localized chondral damage. These indices demonstrated weak correlations to acetabular cartilage damage. The CAL indices demonstrated a significant difference between no/mild and moderate/severe localized chondral damage, according to both ALAD (p < 0.0001) and Outerbridge (p < 0.0001) groups. In addition, the CAL index was moderately correlated to ALAD (rho = -0.403; p < 0.0001) and outerbridge (rho = -0.454; p < 0.0001) grades. Conclusions: The three established dGEMRIC indices did not accurately predict the intraoperative acetabular localized chondral damage in non-arthritic hips. The CAL index was the only method that was able to differentiate between local non/mildly and moderately/severely chondral damage in non-arthritic hips, and was also moderately correlated with these findings. We believe that the new dGEMRIC index should be added to the current measurements prior to hip preservation surgery, in order to provide a more refined preoperative assessment of cartilage.