Trochanteric Bursa Injection

Indications and Clinical Considerations

Bursae are formed from synovial sacs that allow easy sliding of muscles and tendons across one another at areas of repeated movement. These synovial sacs are lined with a synovial membrane invested with a network of blood vessels that secrete synovial fluid. Inflammation of the bursa results in an increase in the production of synovial fluid with swelling of the bursal sac. With overuse or misuse, these bursae may become inflamed, enlarged, and on rare occasions infected. Although there is significant intrapatient variability as to the number, size, and location of bursae, anatomists have identified a number of clinically relevant bursae, including the trochanteric bursa, which lies among the greater trochanter and the tendon of the gluteus medius and the iliotibial tract ( Fig. 129.1 ). This bursa may exist as a single bursal sac or in some patients as a multisegmented series of sacs that may be loculated.

The trochanteric bursa is vulnerable to injury from both acute trauma and repeated microtrauma. Acute injuries frequently take the form of direct trauma to the bursa via falls directly onto the greater trochanter or previous hip surgery, as well as overuse injuries, including running on soft or uneven surfaces. If the inflammation of the trochanteric bursa becomes chronic, calcification of the bursa may occur.

The patient with trochanteric bursitis frequently reports pain in the lateral hip that can radiate down the leg, mimicking sciatica. The pain is localized to the area over the trochanter. Often the patient is unable to sleep on the affected hip and may note a sharp, “catching” sensation with range of motion of the hip, especially on first rising. The patient may note that walking upstairs is increasingly more difficult. Trochanteric bursitis often coexists with arthritis of the hip joint, back and sacroiliac joint disease, and gait disturbance.

Physical examination may reveal point tenderness in the lateral thigh just over the greater trochanter. Passive adduction and abduction, as well as active resisted abduction of the affected lower extremity, reproduce the pain. Sudden release of resistance during this maneuver markedly increases the pain ( Fig. 129.2 ). There should be no sensory deficit in the distribution of the lateral femoral cutaneous nerve, as is seen with meralgia paresthetica, which often is confused with trochanteric bursitis.

Plain radiographs, ultrasound imaging, and magnetic resonance imaging (MRI) of the hip may reveal calcification of the bursa and associated structures consistent with chronic inflammation ( Figs. 129.3 and 129.4 ). MRI is indicated if occult mass or tumor of the hip or groin is suspected. Electromyography helps distinguish trochanteric bursitis from meralgia paresthetica and sciatica. The injection technique described later serves as both a diagnostic and a therapeutic maneuver.

Clinically Relevant Anatomy

The trochanteric bursa lies between the greater trochanter and the tendon of the gluteus medius and the iliotibial tract. The gluteus medius muscle has its origin from the outer surface of the ilium, and its fibers pass downward and laterally to attach on the lateral surface of the greater trochanter. The gluteus medius locks the pelvis in place when walking and running. This action can irritate the trochanteric bursa, as can repeated trauma from repetitive activity, including jogging on soft or uneven surfaces or overuse of exercise equipment for lower extremity strengthening (see Fig. 129.1 ). The gluteus medius muscle is innervated by the superior gluteal nerve.