Ultrasound for the evaluation of femoroacetabular impingement of the cam type. Diagnostic performance of qualitative criteria and alpha angle measurements
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Florian M. Buck Juerg Hodler Marco Zanetti Claudio Dora Christian W. A. Pfirrm
- چاپ و سال / کشور: 2010
Description
Objective To develop and assess a technique to evaluate cam type femoroacetabular impingement (FAI) using ultrasound (US). Methods Fifty patients (24 women, 26 men) were included (mean age: 39.1years; age range: 16–59). US images of the anterior and anterosuperior contour of the femoral neck were obtained and analysed in 50 patients. Non-spherical shape of the head-neck junction (cam deformity), bony protuberances at the femoral neck, shape of the femoral neck (waist deficiency) and alpha angle were assessed. Magnetic resonance (MR) arthrography served as the standard of reference. Diagnostic performance and receiver operating characteristics (ROC) curves were calculated. Results Based on MR arthrography 28 patients had camtype FAI. On US, an anterosuperior cam deformity was seen in 40/44 patients (Reader 1/Reader 2; sensitivity 93%/89%, specificity 36%/14%). A bony protuberance anterosuperiorly in 23/13 patients (sensitivity 71%/ 32%, specificity 86%/82%) and an anterosuperior waist deficiency in 19/ 35 patients (sensitivity 25%/54%, specificity 100%/54%). Sensitivity and specificity of the other criteria were lower than 70% (average of Reader 1 & 2). Conclusion A technique to evaluate cam type FAI using US is presented. The detection of an anterosuperior cam deformity is sensitive, and presence of an anterosuperior bony protuberance is specific for cam FAI. Alpha angle measurements are not helpful in establishing the diagnosis.
Eur Radiol (2011) 21: 167–175 DOI 10.1007/s00330-010-1900-x Received: 22 March 2010/ Revised: 8 June 2010/ Accepted: 20 June 2010/ Published online: 26 July 2010
