Femoroacetabular impingement syndrome (FAI)

Femoroacetabular impingement syndrome or FAI is a condition of abnormal movement within the hip joint causing symptoms. The ball (femoral head) and socket (acetabulum) rub abnormally, leading to symptoms, clinical signs and changes in morphology (the particular form, shape, or structure). To diagnose FAI, syndrome symptoms, clinical signs and imaging findings must all be present.

What causes FAI syndrome?

FAI syndrome occurs when an overgrowth of bone on the ball, socket, or both parts of the hip joint (known as cam or pincer morphology), prevents normal movement of the joint. It is likely that FAI syndrome is the result of a combination of an individual’s genetics and environment. Some experts believe that significant athletic activity before skeletal maturity increases the risk of FAI, but evidence is not definitive at this stage. Recent reviews have found FAI morphologic features are common in people who have no symptoms, particularly athletes.  


How do I know if I have FAI syndrome?

FAI often presents as hip and groin pain with restricted range of hip motion. Symptom onset can be acute, after an injury, or insidious (slow onset). Pain often comes on with prolonged sitting, walking, crossing the legs, or during and after sport or exercise. Pain is primarily felt deep in the groin at the front of the hip. More rarely, it can be on the side of the hip or the buttock. Symptoms, clinical findings and imaging findings must be present to diagnose FAI. Your GP or physiotherapist can diagnose FAI by asking about your symptoms, examining your hip movements and ordering imaging if appropriate. Antero-posterior X-rays can be undertaken to confirm the diagnosis. Where further assessment of hip structures is needed, cross-sectional imaging may be appropriate. 


How can physiotherapy help with FAI syndrome?

Physiotherapy for FAI aims to improve hip strength, neuromuscular control, range of motion, balance and patterns of movement. Your physiotherapist may use a variety of techniques to stretch any tight structures, including the joint capsule or muscles. Physiotherapy will improve soft tissue flexibility and length, strengthen the supporting hip muscles, progress hip muscle proprioception, joint position sense and functional control to dynamically control your hip. Treatment should also include education about the condition, activity and lifestyle modifications.

Surgery for FAI?

Open or arthroscopic (minimally invasive) surgery can be performed to improve the hip structure, and repair or remove damaged tissues. There is no current evidence to suggest that surgery will reduce the risk of later developing osteoarthritis, or ‘cure’ your hip problem. Physiotherapy post-surgery is important for assisting people in regaining range of movement, strength, mobility and returning to sport. The decision regarding surgery should be made after consultation with your physiotherapist and doctor.


How effective is physiotherapy for FAI syndrome?

There is currently no high-level evidence to support the choice of one treatment for helping the symptoms of FAI. However, people with FAI have been shown to have problems with hip function, including muscle weaknesses and loss of range of motion. Exercise prescribed by physiotherapists is effective at addressing these issues in many other conditions. A systematic review found very few studies examining physiotherapy for FAI. Studies are currently underway directly comparing physiotherapy to surgical intervention.


What can I do at home?

Taking note of, and limiting aggravating activities and positions is helpful for when you consult your physiotherapist. Avoid placing your hip into positions that cause pain—these are generally when the hip is bent up and twisted in or out, and can include sitting with legs crossed, pivoting and squatting in sports.

Use of painkillers and anti-inflammatories may temporarily help the pain and reduce the local anti-inflammatory reaction.


How long until I feel better?

Symptoms frequently improve for people with FAI when treated. Without any treatment, symptoms are likely to gradually worsen over time. The long-term outlook for people with FAI is currently not known, as well as whether treatment for FAI can prevent later development of hip osteoarthritis.


Source: Choose.physio