Clinical presentation of femoroacetabular impingement in adolescents.

Femoroacetabular impingement (FAI) is a recently recognized hip disorder resulting from an abnormal morphology of the proximal femur and acetabulum. This morphology results in increased hip contact forces with hip motion, specifically flexion. This may lead to labral-cartilage injury and pain. The purpose of this study is to describe the clinical presentation and diagnosis of FAI as a cause of hip pain in adolescents.Thirty-five patients with FAI as the etiology of chronic hip pain from one institution were reviewed. The common symptoms, physical examination, and radiographic findings were analyzed.The age range was 13 to 18 years. There were 30 girls and 5 boys. All patients complained of anterior groin pain. All patients performed a sport/activity that contributed to the symptoms such as dancing. Patients had decreased flexion and limited internal rotation on physical examination. All patients had a positive impingement test. Fifteen patients (43%) had primarily pincer impingement with a crossover sign or acetabular retroversion. Cam impingement was the primary type in 2 patients (6%). There were findings of cam and pincer in 18 patients (51%). Sixteen of 28 patients had a positive labral tear on magnetic resonance imaging (57%). Femoroacetabular impingement is a cause of hip pain in the adolescent population. The diagnosis can be derived from reproducible history, physical examination, and radiographic findings. It is more common in female adolescents, and pincer type is more prevalent.