Femoral acetabular impingement – “Yikes,  that’s quite a mouthful, what is that?” You may be asking yourself. Femoroacetabular Impingement also known as FAI in simple terms, a condition where the bones of your hip joint are pressing on each other.

The hip joint, like the shoulder joint, is a ball and socket joint, where the femur (or thigh bone) forms the ball of the joint while the acetabulum (rounded socket of the pelvis) forms the socket in which the head of the femur fits. When we move, the femur head moves within the socket of the acetabulum, the degree of movement is dictated by how well the ball fits in the socket.

There are two main types of FAI – CAM and Pincer Impingement. CAM Impingement occurs when the shape of the femoral head is not well rounded, thus affecting its fit in the socket. In Pincer Impingement the edges of the socket of the acetabulum protrude more than normal, making the socket edges look like pincers and hence the name, and thus making the socket deeper. A third type would be combined FAI, where both Cam and Pincer presentations occur. In all these types of impingement, the femur and acetabulum press against each other prematurely in a movement, causing pain and disfunction.

Causes

Some people are born with FAI and others develop it throughout their lifespan. Genetics, age, sex are believed to be contributing factors to developing FAI. Activity level is another contributing factor to developing this condition. It is believed that early exposure to sports or exposure to high volumes of training in repetitive sports cause changes in the join which leads to impingement. Some people may also develop FAI after undergoing some hip corrective surgeries.

Symptoms

• Limited range of motion of the hip, especially hip flexion above 90 degrees.
• Hip or groin pain caused by extended periods of sitting or activities that require repetitive hip flexion. Pain may also affect back, thigh and/or buttock.
• Stiffness around the hip and buttock area.
• Hip clicking, crackling or locking in certain positions or movements.

Diagnosis

For someone to be diagnosed with FAI, there needs to be a combination of 3 things. Symptoms, clinical signs and diagnostic imaging. The symptoms are as those mentioned above. Clinical signs consist of specific functional and mechanical tests carried out by a professional to identify the source of the issue. And lastly, diagnostic imaging can be done through X-ray, preferably an anterior-posterior view of the pelvis and a lateral view of the femur. CT and MRI may be also be used in some cases where other pathologies may be suspected.

Treatment

First thing to do is activity modification, where the aggravating activities or positions are avoided as far as possible, then we proceed to physiotherapy interventions to decrease pain and improve function. These may be a combination of different techniques such as stretching, tissue release, strength and mobility training amongst other modalities. Physiotherapy interventions may be coupled with some pain medication and/or anti-inflammatories depending on the severity. In cases where the conservative treatment as described above does not work, surgery may be considered.

It is important to note that FAI has been shown to improve with treatment but that if it is not addressed it may worsen over time.

This condition is especially important within the athletic population as it can cause quite a bit of pain and hinder performance. It is important to make the correct assessment in order to get the correct diagnosis which will consequently lead to the correct and most effective treatment and management.

Please contact us if you have any questions with regards to FAI.