Cam Impingement

A femoracetabular impingement (FAI) is a condition where the bones of the hip are abnormally shaped and there is an abnormality in the way the ball of the femur (thighbone) and the acetabulum (hip socket) fit together. A cam impingement is a type of FAI where the ball of the femur is misshapen and does not move smoothly within the hip socket. The friction creates a protrusion on the ball of the femur that places pressure on the cartilage in the joint and damages it. As a result, bone spurs may develop,causing joint damage and pain. This condition is caused by hip bones that do not form normally during the years of growing and development in childhood.

Symptoms of Cam Impingement

Patients with a cam impingement typically experience pain around the hip area that may be dull and persistent. In some cases, sharp, stabbing pain sometimes occurs with sudden movement such as twisting or turning. Pain may occur in the groin area or toward the outside part of the hip.

Diagnosis of Cam Impingement

A cam impingement is diagnosed through a review of the patient's medical history as well as a a physical examination of the hip and surrounding joints. Additional tests may include:

  • X-ray
  • CT scan
  • MRI scan

The doctor may also perform an impingement test by moving and rotating the knee towards the chest and opposite shoulder, to see if these movements recreate any pain. If symptomatic pain is recreated with these movements, the patient will test positive for an impingement.

Treatment of Cam Impingement

Cam impingement may respond to conservative treatments such as limiting certain physical activities and taking non-steroidal anti-inflammatory medication. Physical therapy may be helpful in restoring range of motion and strength to the muscles around the hip joint. In severe cases, if the symptoms do not improve, arthroscopic surgery may be recommended to remove any damaged cartilage and trim the bony protrusion of the hip socket and femur. The goal of the procedure is to trim the bones enough to prevent the impingement from occurring.

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