Corrections in alpha angle following two different operative approaches for CAM-type femoral acetabular impingement – Ganz surgical hip dislocation vs anterior mini-open

Femoroacetabular impingement (FAI) is a predisposing factor for secondary osteoarthritis of the hip joint. The two extensively described impingement mechanisms of FAI are CAM and Pincer-type. Initially managed conservatively, operative intervention should be offered to the persistently symptomatic patient. The measurement of the alpha angle is considered a standard method of assessing the severity of pathology in Cam-type FAI on pre-operative plain radiographs. The radiological correction of the alpha angle has not been previously compared between different surgical approaches. We hypothesize that there is no difference in alpha angle correction between Ganz surgical hip dislocation and the anterior mini-open approach.