Hip impingement (femoral acetabular impingement) is a disorder of the hip that is becoming more recognized as a cause of hip pain in the active adult. It is also thought to be a previously unrecognized cause of arthritis in the young adult.

Causes of Hip Impingement

Hip impingement is caused by lack of room or clearance between the neck of the femur at the top of the thigh bone, and the rim of the socket (acetabulum). This lack of room may originate on the femoral neck, acetabulum, or both. The head of the femur may not be sufficiently offset from the neck of the femur to allow room when the hip is flexed.

This can be caused by childhood disorders or from wear over time stimulating new bone to be laid down on the front of the femoral neck. The acetabulum may be the cause of the impingement by covering too much of the femoral head in the front of the hip joint. There may also be multiple causes in the same hip.

This lack of clearance causes the neck and rim of the socket to jam together as the hip is flexed (as in sitting or running). This contact between the femoral neck and socket leads to damage of the contacting structures. This damage may be a tear of the cartilage around the socket (acetabular labrum) to more advanced cartilage damage and degenerative arthritis of the hip.

Symptoms of Hip Impingement

Typically the person with hip impingement complains of pain in the groin region during hip flexion activities such as running or jumping. There may also be symptoms after prolonged sitting. During most of these activities, the hip is placed in a flexed position, although pain may also occur with standing and walking when irritation of the hip is more generalized.

The acetabular labrum is a structure attached to the outside rim of the hip socket. This labrum is made of fibrous cartilage, a flexible material present in multiple joints of the body. In the hip, the labrum is thought to act as a gasket, keeping fluid in the joint during the normal loading of the joint that occurs with movement. It also acts as a stabilizer of the joint keeping the head seated in the socket.

Causes of Labral Tears

Various conditions can lead to damage of this labrum. These include traumatic events, degenerative conditions over time, as well as situations where the shape of the hip bones is incorrect. Traumatic events leading to labral tears can occur with multiple activities including motor vehicle accidents as well as common trips and falls. Degenerative labral tears are a component of generalized hip degeneration where the cartilage throughout the hip joint becomes rough and torn.

Conditions where the shape of the hip bones is incorrect are currently falling under the term hip impingement. These conditions involve improper shape of the hip socket, junction of the thigh bone head and neck, and more commonly a combination of both. This improper shape causes the labrum to be pinched or rubbed during normal movement leading to tearing and degeneration.

Treatment of Labral Tears

Treatment of labral tears involves repairing tissue if possible and removing the tissue that is too severely torn. Attention is then directed at correcting any bony abnormalities that have caused the labral tear in the first place. This is usually possible with hip arthroscopy, but may require more invasive procedures to correctly address the underlying bony problem.

More Information

Read our answers to Frequently Asked Questions about hip impingement and labral tears.

Finding a lump on your hand or wrist can be a frightening experience. But most of the time, these are harmless ganglion cysts, or wrist cyst, that will often disappear in time.

Commonly, ganglion cysts grow on the top of the wrist (dorsal ganglions). But they can also be found on the underside of the wrist (between the thumb and your pulse point), at the end joint of a finger or at the base of a finger.

A ganglion grows out of a joint, like a balloon on a stalk that rises out of the connective tissues between bones and muscles. Inside the balloon is a thick, slippery fluid similar to the fluid in your joints. Usually, the more active you are, the larger the lump becomes; when you rest, the lump decreases in size.

What causes Ganglion Cysts?

No one knows what triggers the formation of a ganglion. Women are more likely to be affected than men, and ganglions are common among gymnasts, who repeatedly apply stress to the wrist. Because the fluid-filled sac puts pressure on the nerves that pass through the joint, some ganglion cysts may be painful.

Large ganglions, even if they are not painful, are unattractive. Smaller ganglions that remain hidden under the skin (occult ganglions) may be quite painful.

Examination and Diagnosis

Your doctor may ask you how long you’ve had the ganglion, whether it changes in size and if it is painful. He or she may apply pressure to see if there is any tenderness, or hold a penlight up to the cyst to see if the light shines through.

You will probably need to get an X-ray, so that the doctor can rule out conditions such as arthritis or a bone tumor. Sometimes, an MRI or ultrasound is needed to find a ganglion cyst hidden under the skin.

Wrist Cyst Treatment Options

The first course of treatment is nonsurgical and conservative.

• Observation. Because the ganglion is not cancerous and may disappear in time, the physician may recommend just waiting and watching to make sure that no radical changes occur.
• Immobilization. Activity often causes the ganglion to increase in size, thus increasing the pressure on nerves and causing pain. Your physician may recommend that you wear a wrist brace or splint to relieve symptoms and allow the ganglion to decrease in size. As pain decreases, your doctor may prescribe exercises to strengthen the wrist and improve range of motion.
• Aspiration. If the ganglion causes significant pain or severely limits your activities, you may choose to have the doctor drain the fluids with a procedure called “aspiration.” The doctor will numb the wrist and puncture the cyst with a needle to remove the fluid.

These treatments leave the outer shell and the stalk of the ganglion intact, so it may reform and reappear. Outpatient surgery can remove the ganglion, but is no guarantee that the cyst will not recur. Part of the involved joint capsule or tendon sheath may also be removed.

This is of little concern, but afterwards you may feel some tenderness, discomfort and swelling. You should be able to resume normal activities in two to six weeks.