Pincer type femoroacetabular impingement


This is a classic case of pincer type FAI. The demographics is also typical with 40 being the average age of presentation.

Pincer type FAI is characterized by one or more of the following abnormality including acetabular retroversion, coxa profunda and protrusio acetabuli. These changes leads to overcoverage of the femoral head by the overhanging acetabulum and resulting in impingement at the extreme of joint motion.

Typically pincer type FAI has a smaller anterosuperior coup lesion and a more pronounced contre-coup lesion posteriorly as demonstrated in this case. Pincer type FAI can co-exist with Cam type FAI thus assessment of the femoral head-neck junction is paramount to exclude co-existing pathology.