Review Question - QID 212914

This patient has femoral acetabular impingement with Cam morphology, which involves a non-spherical femoral head and leads to chondral-labral separation.

Femoroacetabular impingement is caused by an anatomical mismatch between the femur and acetabulum. Cam morphology creates a non-spherical femoral head with a radius of curvature greater than that of the hemispherical acetabulum. This leads to contact at the labral-chondral junction, separating the two and damaging the articular cartilage.

Ganz et al. first proposed the concept of femoroacetabular impingement as it related to cartilage damage. They detailed the pathomechanics of the cam lesion entering into the acetabulum and damaging the articular cartilage, thus creating early arthritic change in the hip.

Frank et al. reviewed common hip injuries among adolescents. A wide variety of different pathology leads to similar symptoms, requiring both a detailed history including onset and aggravating factors and a meticulous physical exam to determine the correct diagnosis.

Figure A is an AP radiograph of the pelvis showing bilateral Cam morphology. Illustrations A and B by Ganz depicts Cam and Pincer impingement, respectively.

Incorrect Answers:
Answer 1: This describes acetabular retroversion with findings of pincer impingement.
Answer 2: This describes acetabular dysplasia.
Answer 4: This describes internal impingement of the hip.
Answer 5: This is seen in the setting of femoral head AVN.