Imaging findings of femoroacetabular impingement syndrome

Skeletal Radiol. 2005 Nov;34(11):691-701. doi: 10.1007/s00256-005-0932-9. Epub 2005 Sep 20.


Femoroacetabular impingement syndrome (FAI) is a pathologic entity which can lead to chronic symptoms of pain, reduced range of motion in flexion and internal rotation, and has been shown to correlate with degenerative arthritis of the hip. History, physical examination, and supportive radiographic findings such as evidence of articular cartilage damage, acetabular labral tearing, and early-onset degenerative changes can help physicians diagnose this entity. Several pathologic changes of the femur and acetabulum are known to predispose patients to develop FAI and recognition of these findings can ultimately lead to therapeutic interventions. The two basic mechanisms of impingement-cam impingement and pincer impingement-are based on the type of anatomic anomaly contributing to the impingement process. These changes can be found on conventional radiography, MR imaging, and CT examinations. However, the radiographic findings of this entity are not widely discussed and recognized by physicians. In this paper, we will introduce these risk factors, the proposed supportive imaging criteria, and the ultimate interventions that can help alleviate patients' symptoms.

Publication types

  • Review

MeSH terms

  • Acetabulum / diagnostic imaging*
  • Acetabulum / pathology
  • Cumulative Trauma Disorders / diagnostic imaging
  • Cumulative Trauma Disorders / pathology
  • Femur Head / abnormalities
  • Femur Head / diagnostic imaging*
  • Femur Head / pathology
  • Femur Neck / abnormalities
  • Femur Neck / diagnostic imaging*
  • Femur Neck / pathology
  • Hip Joint / diagnostic imaging*
  • Hip Joint / pathology
  • Humans
  • Joint Diseases / diagnostic imaging*
  • Joint Diseases / pathology
  • Osteoarthritis, Hip / etiology
  • Radiography