Back

What is a hip impingement? That's what I've been told is causing my hip pain.

The full medical term for this problem is femoroacetabular impingement. Impingement just means pinching. Femoroacetabular refers to the place in the hip where the round head of the femur (thigh bone) comes in contact with the acetabulum or hip socket. Two types of impingement are known to cause pinching of the soft tissues in this area. The first is called cam-type impingement. This occurs when the round head of the femur isn't as round as it should be. It's more of a pistol grip shape. It's even referred to as a pistol grip deformity. The femoral head isn't round enough on one side and it's too round on the other side to move properly inside the socket. The result is a shearing force on the labrum and articular cartilage, which is located next to the labrum. The labrum is a dense ring of fibrocartilage firmly attached around the acetabulum (socket). It provides depth and stability to the socket. The articular cartilage is the protective covering over the hip joint surface. Sometimes cam-type impingement occurs as a result of some other hip problem (e.g., Legg-Calvé-Perthes disease, slipped capital femoral epiphysis or SCFE). But most of the time, it occurs by itself and is the main problem. Men are affected by cam-type impingement more often than women. The second type of impingement is called pincer-type (more common in women). In this type, the socket covers too much of the femoral head. As the hip moves, the labrum comes in contact with the femoral neck just below the femoral head. Repeated microtrauma at this site can cause the bone to overgrow, a condition called heterotopic bone growth. Pincer-type impingement is usually caused by some other problem. It could be as a result of 1) hip dysplasia, 2) a complication after osteotomy surgery to correct hip dysplasia, or 3) an abnormal position of the acetabulum called retroversion. Hip dysplasia is a deformity of the hip (either of the femoral head or the acetabulum, or both) that can lead to hip dislocation. The condition is brought to the orthopedic surgeon's attention when the patient reports groin pain that occurs when the hip is bent or flexed. Although the condition is often present on both sides, the symptoms are usually only felt on one side. In some cases, the groin pain doesn't start until the person has been sitting and starts to stand up. There is often a slight limp because of pain and limited motion. The diagnosis is usually confirmed through clinical tests and X-rays. Sometimes advanced imaging such as MRIs or CT scans are also ordered. Once all the test results are available, a course of action is determined. This may be conservative (nonoperative) care with antiinflammatories and physical therapy. In some cases, surgery is required.

« Back