Rebecca Hope Jessel BA, Presenter: Nothing to Disclose

Christoph Zilkens MD, Abstract Co-Author: Nothing to Disclose

Carl Tiderius MD,PHD, Abstract Co-Author: Nothing to Disclose

Young-Jo Kim MD,PHD, Abstract Co-Author: Nothing to Disclose

The purpose this study was to determine the feasibility of assessing early osteoarthritis (OA) in hips with femoroacetabular impingement (FAI) using delayed Gadolinium enhanced MRI of Cartilage (dGEMRIC).

A review of patients who presented with FAI was performed. 38 hips in 31 patients who had a dGEMRIC scan and radiographic evidence of FAI were identified. Clinical symptoms were assessed using WOMAC questionnaire. The following radiographic measurements were performed to determine acetabular and femoral morphology: lateral center edge angle (LCE), acetabular index of Tönnis (TILT), and femoral head ratio of Murray (FHR). Acetabular version was assessed by the presence of the cross-over and posterior wall signs. The severity of OA was determined using Tönnis grade and minimum joint space width (JSW). On MRI, the alpha angle was measured on the sagittal oblique cuts. Along with patient age, correlations between dGEMRIC index, patient symptoms, morphologic measurements, and OA were determined.

Mean age of the cohort was 25 years [13-48]. The mean LCE was 31 deg [18-45]. Significant correlations were observed between dGEMRIC index, pain (p<0.05), and LCE (p<0.05). There was no correlation between pain and JSW or Tonnis grade. There were no significant correlations between dGEMRIC index and any other morphologic measurements of the hip.

For dysplastic hips we have shown that dGEMRIC is a better measure of OA than traditional radiographic measurements. This data supports the hypothesis that dGEMRIC index is a better measure of OA in hips with FAI, as well. The negative correlation of dGEMRIC and LCE implies that hips with a deep acetabulum, such as in acetabular protrusio and profunda, show signs of early OA. However, assessment of FAI using dGEMRIC is not as consistent as with DDH because of the dynamic and complex spatial nature of FAI deformity and damage. The results of osteoplasty for FAI depend on the amount of pre-existing OA in the joint. Our goal is to develop imaging techniques that may help identify hips that are inappropriate candidates for joint preserving surgeries.

dGEMRIC is a useful tool to identify and evaluate early OA in hips with FAI.

Jessel, R, Zilkens, C, Tiderius, C, Kim, Y, Assessment of Early Osteoarthritis in Hips with Femoroacetabular Impingement using Delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC).  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4436067.html