Learning objectives
To describe the radiographic features of Cam and Pincer femoroacetabular impingement (FAI) and to review the precipitating factors andthe currentcriteria to performcomplementarycross-sectional exams.
Background
FAI is a spectrum of morphological/anatomicalcongenital bone deformities and/or angular misalignments that are a major risk factor to premature hip osteoarthritis.
It has an estimated prevalence of 10-15% and affects mainly young individuals,
usually in their 20s-40s.
1, 2
Conventional x-ray imaging is the gold standard for the early assessment of FAI.
Two major types can be distinguished by x-ray films: Cam and Pincer.
(fig.
1)
In the Cam type there is a proximal femoral head distortion and the clinical FAI syndrome can be due...
Findings and procedure details
Femoroacetabular impingement
Clinical findings
Pain,
although unspecific,
has a major role in the diagnosis of FAI.
Without hip pain the diagnosis should not be made,
since radiographic signs of pincer or cam deformities are very prevalent in asymptomatic patients (67% and 37%,
respectively) and so they are clinically irrelevant.
3.
In patients who complaint of hip pain it is typically described as a deep,
diffused groin pain,
which exacerbates during flexion,
adduction or internal rotation.
This clinical syndrome is a common indication for further imaging...
Conclusion
Due toa premature reactive ossification and osteoarthritis,
prompt recognition and early surgical intervencioniscrucial topreventend stage femoroacetabular impingement pathology.
Xrayremains the first-lineimaging exam forquick recognition and initial differential diagnosis of femoroacetabular impingement.
References
1. Laborie LB,
Lehmann TG,
Engesaeter IO,
Eastwood DM,
Engesaeter LB,
Rosendahl K.
Prevalence of radiographic findings thought to be associated with femoroacetabular impingement in a population-based cohort of 2081 healthy young adults.
Radiology.
2011;260(2):494-502.
2. Moritz Tannast KAS,
and Suzanne E.
Anderson.
Femoroacetabular Impingement: Radiographic Diagnosis—What the Radiologist Should Know.
American Journal of Roentgenology.
2007; 188:6:1540-52
3. Frank JM,
Harris JD,
Erickson BJ,
Slikker W,
3rd,
Bush-Joseph CA,
Salata MJ,
et al.
Prevalence of Femoroacetabular Impingement Imaging Findings in Asymptomatic Volunteers: A Systematic Review....