What is Femoroacetabular Impingement (FAI)?

Hip impingement, also known as femoroacetabular impingement (FAI), is a condition where there is abnormal contact between the femur bone (femoral head) and the socket of the hip joint (acetabulum) during certain movements of the hip.

The resulting impact can lead to damage of the cartilage inside the hip joint. This may in turn lead to premature arthritis.

FAI is traditionally described as due to either an abnormality of the shape of the ball of the femur (CAM deformity) or of the acetabular socket (PINCER deformity). Movement of the hip joint is complex, and more recent research has demonstrated that the overall 3-dimensional shape and orientation of the hip should be considered to properly evaluate and treat clinical impingement.

Symptoms:

Patients with FAI often experience pain in the groin with deep flexion (bending) or rotation of the hip during certain activities. There may also be inflammation of the tissues surrounding the hip such as on the outer side of the hip (trochanteric bursitis), the groin muscles (adductor tendonitis) or inflammation of tendons in front of the hip, especially if the condition has been around for some time. Eventually, as the damage continues, the patient may begin to develop more arthritic symptoms such as a stiffness and a dull ache in the groin. Hip-related pain is not always felt directly over the groin. It may also be felt on the outer aspect of the thigh, the buttock or traveling down the leg.

Investigations:

Patients who have symptoms suggestive of hip impingement are usually investigated with x-rays of the hip first. Further investigations could include a CT scan and special MRI scan. The CT scan is performed to study the bony detail of the hip and the MRI is used to assess the cartilage, labrum and other soft tissue structures in and around the hip.

Treatment:

Non-surgical Treatment for FAI:

Treatment of femoroacetabular impingement symptoms often begins with conservative, non-surgical methods. Physiotherapy treatment may involve soft tissue work to relieve tight muscles around the hip, however the majority of treatment is rehabilitative based, to try strengthen the deep hip stabilizing muscles. The aim is to improve the stability and function of the hip. At Port Melbourne Physiotherapy & Pilates we commonly treat patients with hip/groin pain with a structured Pilates program aimed at strengthening the hip and pelvic muscles.
Rest, activity modifications and selective use of non-steroidal anti-inflammatory medication are often helpful in alleviating early symptoms. An injection of the hip joint with anaesthetic can provide some relief as well as diagnostic information in patients with symptoms which are unresponsive to treatment.

Surgical Treatment for FAI:

For patients not responding to conservative management, Femoroacetabular Impingement (FAI) can be addressed with surgery to improve the shape of the hip.
The aim is to correct the bony deformity before there is irreversible joint damage. In many cases this can be done by hip arthroscopy (keyhole surgery).

If you’d like further information on FAI or if you feel your symptoms match the description above, speak to your physio about what treatment options are available for you and whether further investigations are required.

This post was written by Sheree Freedman – Physiotherapist/ Director at Port Melbourne Physiotherapy & Pilates