Greater Trochanteric Pain Syndrome (GTPS)

The greater trochanter is an important bony prominence that can be felt on the outside of the femur (thigh bone). The greater trochanter is the attachment point for the important abductor muscles of the hip that not only function to bring the leg out from the midline of the body but also to help stabilize the pelvis during movement. These large abductor muscles of the hip are called the gluteus muscles and the gluteus medius and minimus tendons attach directly onto the greater trochanter.

As a principle, whenever a tendon attaches onto bone, there will be a bursal sac. A bursa is a small fluid-filled sac that helps to reduce friction between the tendon and the bone. For the greater trochanter, between the trochanter and the gluteus tendons are the trochanteric bursae and subgluteal bursae that function to reduce friction.

The other important structure we should mention on the outside of the hip is the Iliotibial (IT) band. The IT band is a large band of tissue that runs from the iliac crest on the outside of the hip all the way down the outside of the thigh and inserts down at Gerdy’s tubercle on the front/outside part of the tibia (shin bone). The IT band has several important functions. It provides dynamic lateral stability to the hip and knee joint, it acts as a tension cable between the hip and knee to transmit force like a grounding pad (especially during running), and it provides another layer against friction between the bone and overlying soft tissue. Tightness in the IT band as it runs either over the greater trochanter or at its insertion near the knee can cause pain.

It’s most useful to visualize these structures from deep to superficial. The deepest structure is the greater trochanter followed by the gluteus tendons, the bursa over the tendons, and IT band over the bursa.

GTPS is primarily due to progressive inflammation and damage to the three main structures on the outside of the hip which include the gluteus medius/minimus tendons, trochanteric bursa, and IT band

1. Gluteus minimus/medius tendons: Inflammation within the tendons (tendiniopathy) can progress over time to become partial thickness or full thickness tears through the tendon.
2. Bursa: There can be inflammation or thickening of that overlying trochanteric bursa which is also known as bursitis
3. IT band: If there is tightness within the IT band, this can cause excessive friction and pinching of the underlying bursa.

There are certain risk factors for developing GTPS:

1. Female patients especially those aged 40 to 70 years old are at the highest risk for developing GTPS. This occurs because the female pelvis is anatomically much wider than the male pelvis which causes the IT band to naturally become tighter over time. Combining this stretch on the IT band and abductor tendons with the age-related changes within the abductor tendons causes this particular population to have the highest risk for developing GTPS.
2. Tightness of the IT band or weakness in the hip abductors can predispose patients to GTPS.
3. Lumbar spine disease or leg length discrepancy can cause the abductor tendons to tighten during gait. In a similar vein, gait changes that can occur after hip, knee, or lumbar surgery can cause overload on the lateral hip structures.
4. Overuse which includes activities such as running or repetitive climbing without adequate rest and stretching of the IT band can lead to inflammation of the lateral hip

GTPS is characterized by lateral-sided hip pain directly at the greater trochanter. This is exacerbated by activities such as:

1. Laying on one’s side especially on an unsupportive mattress or a hard surface over a prolonged period of time which can irritate the trochanteric bursa
2. Going from a position of hip flexion to hip extension such as climbing stairs or getting out of a car
3. Crossing the affected leg to the other side of the body which puts the lateral hip structures on stretch
4. Prolonged walking or standing

GTPS is diagnosed with a combination of the history and patient symptoms, physical exam, and imaging findings

Physical exam

1. Clarifying the location of pain is essential when diagnosing GTPS. When there is a tight and painful IT band, patients often have pain on the outside of the hip that does radiate down the thigh. Importantly, this pain does not go past the knee. This helps differentiate GTPS from a commonly associated condition of lumbar radiculopathy the latter of which is actually coming from the low back due to a pinched nerve root.
2. Patients will have reproducible focal tenderness over the lateral hip right around the greater trochanter.
3. This lateral hip pain is reproduced with resisted hip abduction either with the patient side lying or lying on their back while attempting to perform a bridge maneuver.
4. Tightness of the IT band can be confirmed with the Ober’s test which is a maneuver where a contracted IT band will not allow the leg to drop down past the midline of the body.
5. A more worrisome exam feature is if a patient demonstrates a positive Trendelenburg gait. This means that as a patient walks, they shift their trunk over to the affected hip indicating there is weakness of the abductor muscles and possible tearing of the tendon insertion on the greater trochanter.

Imaging

1. Although the diagnosis of GTPS is a clinical diagnosis, imaging helps confirm the cause of the hip pain and exclude intra-articular disease.
2.  X-rays
   • Joint hip x-rays help to rule out hip joint arthritis as a cause of lateral hip pain. Although joint pain is usually more of a front pocket type of pain, true joint pain can occasionally cause more of a buttock or lateral sided pain. Thus, X-rays can help make sure that the pain is actually not referred from the hip joint.
   • X-rays of the hip are also useful to see if there are any calcific changes of the gluteus tendons as they insert onto the greater trochanter which can indicate a more chronic picture of disease where the tendons have been inflamed for a long time.
3. If there are coexisting features between pain on the outside of the hip and pain that goes down past the knee, x-rays should also be obtained of the lumbar spine to look at the low back.

MRI

1. MRI is particularly useful when lateral hip pain persists despite extended non-operative treatment.
2. The true value of the MRI in the outside of the hip is not just to visualize bursitis but also to detect the presence of any partial or complete tears through the gluteus medius or minimus tendon insertion. If tears are present, this may significantly change the management.