Femoro acetabular Impingement (FAI)
This is a condition that has been recognised and understood only relatively recently. This has arisen from the observation that some patients, usually males, develop early arthritis in their hips because in their hips the femoral head has a non-spherical shape. Commonly, people who have hips with this abnormal shape, start to get symptoms quite early on in their late 20’s and early 30’s. Now a characteristic pattern of symptoms and x-ray signs are recognised.
The importance in the recognition of FAI lies in appropriate intervention before there is damage to the articular cartilage which may well stop this from developing into arthritis later in life, or at least delay the onset. The majority of cases are of a combined cam and pincer lesion with damage to the acetabular labrum.
Symptoms of FAI
The condition usually becomes apparent in young athletic individuals who start to get pain in the groin and hip area. This is usually activity related and may become severe enough to cause them to give up specific sporting activities. Frequently the condition is considered a “groin strain”, pubalgia or a sportsman hernia. Often patients undergo courses of physiotherapy to try to address the problem. Usually it is resistant to treatment with physiotherapy and pain frequently recurs with return to full activity.
Patients may find that certain movements of the hip have become uncomfortable. This is usually flexion of the hip up towards the chest, as in putting on shoes, and frequently there is a restriction in the amount of internal rotation of the hip. There may be clicking of the hip joint.
The condition is usually recognisable on plain x-rays of the hip. The hip generally shows an elliptical rather than a spherical femoral head (cam impingement).
There may also be abnormalities on the socket (acetabular) side of the hip with too much coverage of the femoral head leading to a different type of impingement (pincer impingement). The signs may be quite subtle and many radiologists who report the x-ray appearance of the hip won’t necessarily recognise the condition. This means that many patients get false reassurance from the report of a normal x-ray when in fact there may be an abnormality present.
Once the condition is recognised on x-ray more investigations may be necessary, such as CT scans or an MRI with an arthrogram (dye) to give more information about the shape of the joint and the damage that may have occurred to the lining of the joint and to the labrum as a result of the abnormal shape.
Labral tear shown on MRI Arthrogram
If the symptoms cannot be managed by modification of activities, or people find that they can no longer do the activities that they wish, then surgical intervention is appropriate. This involves a procedure to alter the shape of the femoral head and to address the damage that may have occurred to the articular cartilage of the hip joint socket (acetabulum) and to the labrum. The aim of the surgery is to improve pain and range of movement in the hip joint and to try to prevent or slow down, and possibly halt, the progression of arthritis in the joint by reducing the damage to the articular cartilage. This will depend on the amount of damage that may have already occurred and this is variable from one person to another. It is possible to address the abnormality with keyhole surgery of the hip joint (hip arthroscopy). In some circumstances it is necessary to do an open operation on the hip to treat the abnormalities. Mr Aslam Mohammed has been performing Hip Arthroscopy since 1995.
Arthroscopic cam removal
Open surgery for FAI
The results of these procedures are usually very satisfactory, but it usually takes between 4 and 6 months to return to sporting activities.