Your hip joint is where your thigh bone meets your pelvis. It is called a ball-and-socket joint because the ball-like top of your thigh bone fits into a cup-like area within your pelvis, much like a ball fits into a glove.
Normally this ball glides smoothly within the socket, but a problem with the ball or socket rim can interfere with smooth motion. Trauma from repetitive hip flexion damages the cartilage of the socket, leading to hip impingement or femoro acetabular impingement (FAI). It is believed to be a major cause of osteoarthritis of the hip, particularly in those under age 40.
You can have hip impingement for years and not know it because it is often not painful in its early stages. When it causes symptoms, it is called hip impingement syndrome. The main symptoms are “pain” in the groin, especially when walking or flexing the hip and decreased range of motion in the hip.
At first, you may only feel pain when you move the hip near its limits. As the condition progresses, however, you may feel pain with more subtle activities, such as sitting for a long time or walking up a hill. Pain that occurs at night or when walking on flat ground suggests that the cartilage cushioning the ball and socket has begun to break down and wear away, a condition known as osteoarthritis.
The two main causes of hip impingement are:
• A deformity of the ball at the top of the femur (cam impingement). If the head is not shaped normally, the abnormal part of the head can jam in the socket when the hip is bent. This may occur with activities such as riding a bike or tying your shoes.
• A deformity of the socket (pincer impingement). If the front rim of the socket (acetabulum) stick out too far, the area of the thigh bone (femur) just below the ball, called the neck of the femur, may bump into the rim of the socket during normal hip flexion movement.
In some cases there is a problem with both the ball and the socket. Some of these include:
• Legg-Calve-Perthes disease in which the ball part of the hip joint doesn’t get enough blood which causes the bone to die.
• Slipped capital femoral epiphysis, a separation of the ball from the thigh bone at the upper growing end (growth plate) of the bone in adolescents. It is more common in children who are obese.
• Coxo vara, an unusual condition in which the thigh bone and ball do not grow at the same pace as children. This discrepancy leads to deformity of the hip joint.
If you have symptoms of hip impingement or hip pain in general, our doctors can diagnose the problem based on your symptoms, physical exam, and the findings of one of these imaging tests, x-rays, MRI, or CT scan. There are varying types of treatment for hip impingement depending on the severity of your symptoms. If you are having any hip pain or pain in the groin, please call and make an appointment for an evaluation with us. There may be some simple options to try to gain relief before your symptoms become too severe! No referral necessary. 515-955-6767
