Femoroacetabular impingement

One of the major pathogenic factors in primary osteoarthritis of hip
Occurs due to morphologic changes in proximal femur and/or acetabulum with repetitive contusions during flexion, internal rotation and adduction.
Leads to acetabular labral and cartilage damage

Clinical feaures:
Slow onset of groin pain in young active adults; painful internal rotation; impingement test - 90° flexion, adduction and internal rotation of hip causes groin pain

1. Cam (femoral) femoroacerabular impingement

2. Pincer (acetabular) femoroacetabular impingement

3. Mixed Cam and Pincer impingement:Most common type?

Cartilage changes: cam type - anterior superior, pincer type - posteroinferior

References:
1. Kassarjian A et al. Triad of MR Arthrographic Findings in Patients with Cam-Type Femoroacetabular Impingement. Radiology 2005;236:588-592
2. Schmid MR et al.Cartilage lesions in the hip: diagnostic effectiveness of MR arthrography. Radiology 2003; 226:382–386
3. Leunig M et al. Fibrocystic Changes at Anterosuperior Femoral Neck: Prevalence in Hips with Femoroacetabular Impingement. Radiology 2005;236:237-246

Review articles:
1. Laude F et al. Anterior femoroacetabular impingement. Joint bone spine. Vol 74: 127-132
2. Tannast M et al. Femoroacetabular Impingement: Radiographic Diagnosis—What the Radiologist Should Know. AJR 2007; 188:1540-1552

3. Kassarjian A et al. Femoroacetabular impingement. European Journal of Radiology. Volume 63, Issue 1, July 2007, Pages 29-35