THE CLINICAL SYNDROME
The ischial bursa lies between the gluteus maximus muscle and the bone of the ischial tuberosity. It may exist as a single bursal sac or, in some patients, as a multisegmented series of sacs that may be loculated in nature. The ischial bursa is vulnerable to injury from both acute trauma and repeated microtrauma. Acute injuries frequently take the form of direct trauma to the bursa from falls onto the buttocks and from overuse such as prolonged riding of horses or bicycles. Running on uneven or soft surfaces such as sand may also cause ischial bursitis. If the inflammation of the ischial bursa becomes chronic, calcification of the bursa may occur.
Ischiogluteal bursitis is often perpetuated by running on soft, uneven surfaces and will present clinically as point tenderness over the initial tuberosity.
SIGNS AND SYMPTOMS
The patient suffering from ischial bursitis will frequently complain of pain at the base of the buttocks with resisted extension off the lower extremity. The pain is localized to the area over the ischial tuberosity with referred pain noted into the hamstring muscle, which may also develop coexistent tendonitis. Often, the patient will be unable to sleep on the affected hip and may complain of a sharp, catching sensation when extending and flexing the hip, especially on first awakening. Physical examination may reveal point tenderness over the ischial tuberosity. Passive straight leg raising and active resisted extensive of the affected lower extremity will reproduce the pain. Sudden release of resistance during this maneuver will markedly increase the pain.
Initial treatment of the pain and functional disability associated with ischiogluteal bursitis should include a combination of the nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors and physical therapy. The local application of heat and cold may also be beneficial. Any repetitive activity that may exacerbate the patient’s symptomatology should be avoided. For patients who do not respond to these treatment modalities, the following injection technique may be a reasonable next step.
To inject the ischiogluteal bursa, the patient is placed in the lateral position with affected side up and the affected leg flexed at the knee. Although the treatments are the same, ischial bursitis can be distinguished from hamstring tendonitis by the fact that Ischia bursitis will present with point tenderness over the ischial bursa and that the tenderness of hamstring tendonitis is more diffused over the upper muscle and tendons of the hamstring. This injection technique is extremely effective in the treatment of ischial bursitis and hamstring tendonitis.