Case Report
An adolescent female dancer with excessive femoral anteversion presented with posterior and anterior hip pain aggravated by poses that required extension and external rotation. Imaging revealed an atypical cam deformity of the posterior head-neck junction. During surgery, the posterior head-neck junction was observed to impinge on the posterior acetabulum with anterior subluxation of the hip. After a derotational femoral osteotomy, the patient experienced resolution of her symptoms./r/nExcessive femoral anteversion can lead to reactive cam deformity, posterior intra-articular impingement, and anterior hip instability in patients who require repetitive hip extension and external rotation, such as ballet dancers.