Femoroacetabular Impingement (FAI)

What is Femoroacetabular Impingement?

Femoroacetabular impingement or FAI is a condition of too much friction in the hip joint.  Basically, the ball (femoral head) and socket (acetabulum) rub abnormally creating damage to the hip joint.  The damage can occur to the articular cartilage (smooth surface of the ball or socket) or the labral cartilage (soft tissue bumper of the socket). FAI is a leading cause for the development of osteoarthritis, particularly in men.

 

What causes Femoroacetabular Impingement?

Figure: FAI. Abnormal ridge of bone at upper end of thigh bone marked

An abnormality in the shape of the hip joint bones may be present at birth or may develop in early childhood after some childhood hip conditions.   In most cases the condition has been asymptomatic for many years.

 

Why does it become painful?

The hip becomes painful when there has been enough damage in the joint. The first symptom is usually mild groin discomfort. Once the joint becomes painful, there is usually a gradual deterioration. Reducing activity levels may reduce the symptoms.

 

What is the natural course of Femoroacetabular Impingement?

FAI causes hip discomfort and pain. Symptoms fluctuate according to activity levels and are often made worse by sport and activities which require deep bending of the hip (for example getting out of a car). Some patients report recurrent ‘groin sprains’ which typically are slow to settle or recur easily. Over time, FAI causes progressive damage to the cartilage on the rim of the hip socket, leading to osteoarthritis. While osteoarthritis develops over a long time, surgical treatment of the abnormality causing FAI may slow or prevent the progression of joint damage and improve symptoms.

 

What Treatment is available?

Many patients with FAI can improve their symptoms non surgically.  Reducing or modifying activity levels, in combination with pain killers and anti-inflammatory medication may provide relief.  . Surgical treatment depends on the type of FAI and its cause. In the absence of significant arthritis, many patients will benefit from hip arthroscopy (minimally invasive key-hole surgery). Other surgical treatments for FAI include open debridement, femoral osteotomy and triple pelvic osteotomy. Knowing which procedure is most appropriate for an individual patient requires clinical assessment.

 

What is hip arthroscopy?

Arthroscopy is key-hole surgery using a pencil sized fibre-optic camera. It allows the surgeon to safely and accurately assess damage to the joint and to perform corrective procedures. Hip arthroscopy is a minimally invasive procedure, useful in the treatment of FAI.    The most common types of FAI can often be treated with an arthroscopic bone reshaping procedure called an osteoplasty.  Arthroscopy lends itself to a relatively rapid post-operative recovery

 

What is open hip debridement?

Open debridement may be  used in situations where the shape of the ball or socket is too distorted to allow treatment by arthroscopy, or where the portion of bone that needs to be reshaped is better accessed by an open procedure. Open debridement involves an incision to the skin  allowing the bone of the hip joint to be easily accessed for reshaping.

 

What is femoral osteotomy?

Femoral osteotomy is a procedure used to realign an abnormally twisted thigh bone. Femoral osteotomy can be used to treat FAI.  In addition, it can also provide improved range of motion to the hip joint and help correct leg length inequality. A femoral osteotomy involves cutting the thigh bone and placing a metal plate and screws to hold the bone in the corrected position until the bone unites. Sometimes femoral osteotomy is recommended at the same time as open hip debridement.