When you walk, get up from a chair, or swing your leg around, you may feel or hear a "snapping" sensation in your hip. Snapping hip, also known as hip arthroscopy, is usually painless and harmless, although the sensation can be annoying. Young athletes and dancers frequently experience snapping hip.
Causes of Snapping Hip
The snapping sensation results from the movement of a muscle or tendon (the tough, fibrous tissue that connects muscle to bone) over a bony structure. In the hip, the most common site is at the outer side where a band of connective tissue (the iliotibial band) passes over the broad, flat portion of the thighbone known as the greater trochanter.
When the hip is straight, the band is behind the trochanter. When the hip bends, the band moves over the trochanter so that it is in front of it. The band is always tight, like a stretched rubber band. Because the trochanter juts out slightly, the movement of the band across it creates the snap you hear. Eventually, this could lead to hip bursitis. Bursitis is thickening and inflammation of the bursa, a fluid-filled sac that allows the muscle to move smoothly over bone.
Another tendon that could cause a snapping hip runs from the inside of the thighbone up through the pelvis (rectus femoris tendon). As you bend the hip, the tendon shifts across the head of the thighbone; when you straighten the hip, the tendon moves back to the side of the thighbone. This back-and-forth motion across the head of the thighbone causes the snapping.
A tear in the cartilage or debris in the hip joint can also cause a snapping or clicking sensation. This type of hip arthroscopy usually causes pain and may be disabling. A loose piece of cartilage can cause the hip to catch or "lock up."
Diagnosis of Hip Arthroscopy
Most people do not bother seeing a doctor for hip arthroscopy unless they experience some pain. Your doctor will first determine the exact cause of the snapping. You may be asked where it hurts, what kinds of activities bring on the snapping, whether you can demonstrate the snapping, or whether you have experienced any trauma to the hip area.
You may also be asked to stand and move your hip in various directions to reproduce the snapping. The doctor may even be able to feel the tendon moving as you bend or extend your hip.
X-rays of people with snapping hip are typically normal, but they may be requested along with other tests so that the doctor can rule out any problems with the bones or joint.