What is Hip Impingement (FAI)?

Femoroacetabular impingement (FAI), commonly known as hip impingement, is an important cause of hip or groin pain. It is a newly identified cause of pain, being more common in the younger age group. It is increasingly seen as a cause of premature osteoarthritis of the hip. The primary problem in FAI is an abnormality of the shape of the hip. This can be thought of as too much bone in the wrong place, either around the ball of the joint (a CAM lesion), or around the socket (a PINCER lesion). Occasionally a mixture of both is seen. This causes either a restriction of range of movement, or a loss of the sphericity of the joint. Both of these scenarios can cause damage to the edge of the joint (labral tear or chondral delamination), which can then worsen and lead to arthritis of the joint.

What is the treatment?

A mixture of plain radiographs (x-Rays), computed tomography (CT),and magnetic resonance imaging (MRI), are used to diagnose FAI. In addition, a diagnostic injection of the hip joint can be performed if there is doubt regarding the origin of the pain.

A good physiotherapy programme to strengthen core muscle and hip muscles can be very effective in reducing symptoms. In addition activity modification may be all that is required. If this is not effective, surgery to alter the shape of the hip joint and treat damaged tissue can be effective in improving symptoms. Surgery may prevent the onset of premature osteoarthritis. Keyhole methods of surgery are most commonly used, however occasionally open surgery is performed.

Surgery usually takes between 1-2 hours, and patients usually stay in hospital overnight.

Post-operatively, a period of rehabilitation will commence. This consists of a supervised programme of exercises. The first 4 weeks can involve the use of crutches and partial weight bearing. After this, gentle exercise is introduced. A return to competitive sport doesn’t usually occur before 4 months post-op.