What is femoroacetabular impingement?
Femoroacetabular impingement (FAI) is a condition in which extra bone grows along one or both of the bones that form the hip joint, which leaves the bones in an irregular shape. As the bones are irregularly shaped and do not fit together, they rub against each other during movement. This can cause damage to the joint, creates pain and can limit activity.
What are the different types of femoroacetabular impingement?
There are three different types of FAI, which are known as:
• Pincer – this occurs because extra bone extends over the normal rim of the acetabulum. This crushes the labrum under the prominent rim of the acetabulum.
• Cam – In cam impingement the femoral head is not round and therefore cannot rotate smoothly inside the acetabulum. The edge of the femoral head grinds the cartilage inside the acetabulum.
• Combined – this mean that both the pincer and cam types are present.
What causes femoroacetabular impingement?
It occurs because the hip bones do not form correctly during the childhood growing years. When the hip bones are shaped abnormally, there is little that can be done to prevent femoroacetabular impingement.
What are the symptoms of femoroacetabular impingement?
The symptoms of FAI include:
How is femoroacetabular impingement diagnosed?
During an examination with a specialist, the doctor will perform an impingement test. Your knee will be brought up towards the chest and rotate it inward towards the opposite shoulder. If this causes hip pain then it tests positive for impingement. Imaging tests such as an X-ray, CT and MRI scan will also help determine whether you have femoroacetabular impingement.
What is the treatment for femoroacetabular impingement?
Nonsurgical treatment may involve taking anti-inflammatory medications, changes to any activities that may cause symptoms and physical therapy.
If symptoms are not relieved through nonsurgical treatment, surgery may be recommended using the arthroscopy procedure. Surgery can successfully reduce symptoms and correcting the impingement can prevent further damage to the hip joint. Not all of the damage can be completely fixed by surgery, especially if treatment has been delayed.