Hip Joint Injections

I. Introduction The Hip Joint injection procedure targets the hip joint thought to be responsible for a patient’s pain. The joint is injected and anesthetized with the intent of relieving this pain. The hip injection procedure delivers a low volume of concentrated medication directly into the affected hip joint. Hip pain usually arises from a degenerated or osteoarthritic hip. However, occasionally it can be “referred” pain, meaning that the patient feels the pain in the hip, but it is actually coming from the lumbar spine, and less commonly from the knee on the same side. The hip joint injection is useful in both the diagnosis and the treatment of hip pain; therefore, it is both a diagnostic as well as a therapeutic procedure. In other words, if we inject a medication within the suspected hip joint space and the pain improves, we are fairly confident that the hip joint is responsible for the pain; conversely, if we inject a medication and the pain is no better, this implies that the pain is likely referred, most often from the lower back or the knee.

II. The Hip Joints

• The Hip Joints (see illustration) contain joint fluid and are lined by cartilage.
• Like any other joint in the body, hip joints can become diseased, and thereby become painful.
• By far the most common disease affecting the hip joints is arthritis. This is a degenerative, inflammatory condition that over time results in loss of joint cartilage, bone overgrowth (‘osteophytes’ or ‘spurs’), erosions of the joint, and ultimately instability of the joint itself.
• The hip joints and their surrounding tissues are lined with nerves. As this degenerative, inflammatory condition progresses, the nerve endings become irritated and inflamed; this produces the sensation of pain. Any and all of this degenerative process may be painful.
• The primary role for imaging studies prior to the procedure is to evaluate for other arthritis, or other less likely causes of back pain.

III. Patient Selection

• Unfortunately, while imaging studies (X-rays, MRI and CT scans) are helpful in screening the hips for a potential cause of pain, they are often unreliable in determining whether or not a given hip joint may be the source of pain.
• They help in identifying and characterizing the extent of hip degeneration, but like any other joint in the body, the extent of degeneration doesn’t necessarily correlate with the amount of pain. In other words, some patients may show severely degenerated hip joints on imaging studies, but be relatively asymptomatic. Conversely, some patients experiencing severe pain from the hip joints may show relatively mild degenerative findings on imaging studies. For this reason, the patient’s history and physical exam are very important in helping to clarify the source responsible for pain.

IV. Procedure: Hip Join Injection

• The procedure is explained to the patient, questions are answered and informed consent is obtained.
• The patient is placed supine (stomach up) on the fluoroscopic table, and the symptomatic hip is sterilely cleansed with povidone-iodine (Betadine) and alcohol.
• The exact level is located with the fluoroscope, and the skin overlying this area is anesthetized (numbed) with lidocaine.
• A needle is sterilely advanced into the hip joint.
• Typically, as small amount of water-soluble contrast (dye) is injected to confirm proper needle tip position.
• Once this is confirmed, a mixture of anesthetic (lidocaine or bupivacaine) and anti-inflammatory medication (steroid) is injected.
• The needle is slowly withdrawn
• This procedure is performed with Fluoroscopic (X-RAY) guidance.
• Shortly after the procedure, the radiologist will examine the patient to determine if there has been improvement.