What is FAI / hip impingement?
The long bone of the leg (femur) usually fits neatly into the hip socket (acetabulum). The surfaces of the two bones are cushioned by smooth cartilage that allows the bones to move freely against each other. In FAI (also referred to as hip impingement), extra bony growths develop in the hip socket, or on the ball of the hip joint and this alters the shape of the bone. These growths cause the bones to abnormally rub against each other leading to friction and damage to the joint. This eventually results in pain and stiffness, known as impingement.
What causes FAI / hip impingement?
FAI occurs because the bones of the hip form abnormally during childhood development. As such, it cannot be prevented. Mildly misshapen bones may never cause symptoms, but larger bony growths will often cause damage to the cartilage in the hip joint and this is when pain develops. If you have an athletic lifestyle, this can cause extra wear and tear on the imperfect hip joints and lead to symptoms developing sooner, but it does not directly cause FAI.
How is FAI / hip impingement diagnosed?
FAI often causes pain in the groin or on the outside of the hip, made worse by twisting or turning. Your specialist will ask you some questions about your hip symptoms and perform a careful assessment of your hip. They will likely also perform an impingement test; this involves gently moving your hip in a particular way to test for pain, which is characteristic of FAI. Imaging such as x-rays, CT or MRI scans of the hip may also be used to help with diagnosis.
Treatment and recovery
Non-surgical treatments, such as avoiding activities that cause pain, taking anti-inflammatory medicines, and physiotherapy can all help to relieve your symptoms.
If there is damage to the cartilage in your hip joint and non-surgical treatments have not been effective, then surgery will be needed. Keyhole surgery, known as arthroscopy, uses a small camera to look at the joint. During the procedure, the surgeon can remove any damaged cartilage and trim off the abnormal bony growths. Arthroscopy is a very effective treatment as it involves only small cuts and does not cause damage to the muscles and tendons around the joint. You will be able to leave hospital on the same day, or the day after surgery. Full recovery takes up to 6-12 weeks and we can use physiotherapy and gentle exercises to speed up the healing process.