Snapping Hip Syndrome

Most things that pop and snap around the hip are not coming from the joint itself. Hip joint problems may cause sharp stabbing pain, catching, or a sense of locking, but the two most common things that snap or pop are the iliopsoas tendon and the iliotibial band. These are structures that reside outside the joint.

Iliopsoas Tendon

The iliopsoas tendon forms from the iliacus and psoas muscles fusing together to form the tendon as it crosses the front of the hip and then inserts below it on the lesser trochanter. The tendon flipping back and forth across the front of the hip can often produce an audible “clunk” that can be heard from across the room, although other times it is more subtle. Typically, the clunking sensation occurs as the hip goes from a flexed to extended position. This is present normally in 5 to 10% of the population, and is not an indication of progressive damage or future problems.

Occasionally, from injury or overuse activities, the clunk can occur and start to be painful. This can usually be managed with conservative treatment. The most important first step is to identify factors such as activities that tend to worsen the symptoms, and modify these for a temporary period of time until the discomfort resolves. Physical therapy and oral anti-inflammatory medications can often be beneficial.

For rare cases that do not respond to conservative treatment, the origin of the clunk can be investigated further. Ultrasound is a simple, noninvasive way of visualizing the tendon flipping back and forth in front of the hip.

This has traditionally been managed with an open operation. Various techniques have been described and the results have been generally favorable, but complications are not infrequent.

Snapping of the iliopsoas tendon can now be addressed with arthroscopic techniques. This has eliminated many of the complications associated with the open procedure. It is much less invasive and allows for an easier recovery. Another important finding is that many patients with a snapping iliopsoas tendon also have damage inside the joint. With the arthroscopic method, this joint damage can be addressed and the snapping tendon can be released in the same setting.

The arthroscopic technique consists of releasing the tendinous portion of the iliopsoas, preserving its muscular fibers at its attachment site to bone. This results in relaxation of the iliopsoas and eliminates its snapping. Because the iliopsoas is a powerful hip flexor, lengthening this can result in a period of hip flexor weakness. Our experience has been that the strength returns and the snapping is eliminated.

Iliotibial Band

The iliotibial band is a broad tendon that goes down the side of the hip and thigh to the level of the knee. It forms from the muscles of the tensor fascia lata and gluteus maximus above the hip, along the brim of the pelvis. The tendon normally glides back and forth over the prominence of the greater trochanter and can be felt along the outside edge of the hip. A condition can develop where the tendon snaps back and forth across this bony prominence. This can occur from trauma, but some people can demonstrate the anomaly even in absence of injury and it is not an indication of future problems. The snapping is visually quite evident. While snapping of the iliopsoas tendon can sometimes be heard from across the room, snapping of the iliotibial band can be seen from across the room. It may even give the appearance that the hip is popping out of the joint, but this is not the case. The visual effect is simply created by the bulk of the muscle and tendon as it flips across the greater trochanter.

If the condition becomes painful, most patients will respond to conservative treatment. Again, this starts with trying to modify activities that seem to provoke the symptoms. Supervised physical therapy and oral non-steroidal anti-inflammatory medications can also be helpful. Stubborn cases of snapping iliotibial band may benefit from judicious use of a cortisone injection into the bursa beneath the iliotibial band. The injection alone does not cure the snapping, but may reduce the associated discomfort and allow therapy a better chance to work.

Surgery is rarely necessary for this condition and should be considered only as a last resort. Under favorable circumstances, the surgery can be helpful. We originally described a simple open operation to correct this and have now refined this to a less invasive arthroscopic procedure. The technique consists of selective incisions that relax the tendon while preserving its structural integrity. This corrects the snapping while allowing a fairly liberal recuperation. Physical therapy and structured post-operative precautions are still important.