Femoroacetabular impingement—outcomes and imaging

Femoroacetabular impingement (FAI) is characterised by abnormal morphology of the femur and/or acetabulum causing abutment up against each other during hip movements causing injury. FAI is suspected of affecting 10-15% of the population and is thought to be the most common cause of hip pain in young adults and predisposes to osteoarthritis of the hip. Surgery involves trimming the bone that prevents normal movement. Although the aim of the surgery is to change the mechanics of the joint we still know very little about what it actually achieves, and if we can better predict who is going to have a positive result. Correct patient selection is critical for good outcomes. While we know younger patients, no sign of arthritic changes, shorter duration of symptoms, and lower preoperative pain and functional scores are associated with better outcomes, there is still a group of patients who do not have a good outcome. We are using preoperative imaging in an attempt to predict 1 year iHOT-33 outcomes. Results of this could help improve our ability to select patients who will have a good surgical outcome.

A novel image registration technique is being used to investigate 3D hip kinematics which involves fitting a 3D CT scan to 2D dynamic fluoroscopic images. This study will implement this novel method for investigating hip kinematics in FAI. In conjunction with this project, we are looking at the effect of a 3D planning software on outcomes and complications of FAI. Initial results indicate that the planning software can help reduce complications related to under resection.