Most hip diseases are diagnosed with a thorough history, a straightforward physical examination, and routine x-rays (radiographs). Blood tests and additional imaging tests, such as MRI, are not typically required for most diagnoses.

An orthopaedic surgeon will typically ask questions about the involved joint, activity levels, and symptoms. In most offices, an initial intake questionnaire usually covers most of the basic questions and medical history. The surgeon usually looks this over first, and x-rays may be ordered before or after examining the patient. Nearly all patients having hip or knee surgery will have an x-ray beforehand.

The history is often the most informative part of the interview. Surgeons usually ask about the location, severity, and frequency of the pain, along with what sorts of things bring it on and what makes it better. Specific questions with hip problems may deal with previous history, particularly if there has been any prior surgery or accidents, or with risk factors associated with certain disease processes (such as alcohol consumption when considering avascular necrosis). The physical examination usually focuses on the affected joints themselves and adjacent joints, checking range of motion and function. Neurologic and vascular function are usually noted. There are many provocative tests and maneuvers used during a physical examination to further narrow down the particular source of the problem, such as a straight leg raise test for checking sciatic nerve problems.

Do not be surprised if your surgeon watches how you walk in and out of the office. Gait abnormalities are often very suggestive of the problem.

Radiographs (X-rays)

An x-ray showing severe degenerative changes
in the patient's left hip (on your right, looking at
the page). The opposite hip, in contrast, appears
relatively normal with a rounded femoral head
and a visible joint space made up of articular cartilage.

Plain x-rays of the hips are usually taken to evaluate for arthritis, fractures, congenital anomalies (such as hip dysplasia, or shallow sockets), tumors or metastatic disease, and other conditions. There are many things that the surgeon will be evaluating, often focusing on the appearance of the joint itself.

The cartilage that coats the surfaces of the joints is transparent on the x-ray, but if the gap is not apparent, "bone-on-bone" arthritis can be seen. Other features of arthritic joints include subchondral sclerosis (hardening of the underlying bone), osteophytes (spurs), loose bodies, and cysts in the bone. Fractures, tumors, and disease processes such as avascular necrosis are usually also readily visible on routine radiographs. These are also used to evaluate previous joint replacements.

Magnetic Resonance Imaging (MRI)

An MRI of the hips. The patient's left hip (circled, on your right)
has extensive disease [avascular necrosis] when compared
to the opposite hip. This would not be as easily detectable yet
on routine x-rays.

MRI may sometimes be ordered to evaluate for soft tissue problems (such as muscle injury, evaluation of a soft tissue mass, etc.) or for bone marrow problems. It often will "light up" for increased water content, signaling edema and injury. Bone bruises and stress fractures show up in this manner. Avascular necrosis (osteonecrosis) is often diagnosed on MRI much earlier than when it appears evident on regular x-rays.

A torn rim of cartilage around the hip socket (a labral tear) is often visible on MRI, although sometimes an MRI arthrogram is required to see it well. This involves injecting the hip joint with a contrast dye in order to see tears more clearly. Intravenous contrast can be used also and is helpful for diagnosing tumors and infections with MRI.

Computed Tomography (CT)

A Technicium bone scan. Areas of increased uptake (tumor)
appear more dense in these images. This patient has
metastatic breast cancer, involving the spine, left upper
humerus, and right hip. The hip was about to fracture,
and she underwent a hip replacement. Currently,
she is alive and well, walking about on the hip replacement,
with stable control of her cancer for years now with current
oncology options.

A computed tomography (CT) scan uses many xray "slices" to examine cross sections of a body or limb. The patient lays on a table while moving through a ring that contains a spinning x-ray camera. While it does have applications in spine surgery and trauma (especially when examining complex pelvic fractures), CT scans are not typically used to evaluate for arthritis.

Nuclear Bone (Technecium) Scans

Bone scans involve administering a very small amount of radioactive material via an IV, then using a camera to view how it is taken up and moved by the tissues. Areas with high uptake, such as a tumor, infection, or fracture, will often "light up." This test is also useful for determining if an old hip or knee replacement is loosened from the bone, although it will provide a false positive if a bone scan is obtained within about 1 year or less of the surgery (because of normal bone remodeling).

White Blood Cell (WBC) Scans

A tagged white blood cell scan is a similar test to a bone scan, except white blood cells are taken from the body and "tagged" with a tiny amount of radioactive material. It is then re-injected, and the scanner shows where all of those tagged white blood cells congregate in order to localize an infection. This is used when trying to find an infection in the bone or around an artificial joint. It is usually used in conjunction after a routine technicium bone scan if infection is suspected. A related scan is a marrow (sulfur colloid) scan, which is also used to help diagnose and localize infections.

Ultrasound

An ultrasound examination uses sonic waves to make a picture of soft tissues. While it may be used to examine cysts or other soft tissue abnormalities (such as checking to see if an Achilles tendon is ruptured), its most common application in orthopaedics is to detect the presence of blood clots in deep veins

Hip Aspiration (Arthrocentesis)

Sometimes it is useful to draw joint fluid out of the joint with a needle for laboratory analysis. This is most common in situations where there has been or there is suspicion for an infection in the joint itself. Usually the skin is anesthetized with a local anesthetic and the needle is placed into the joint under live x-ray. This is typically a quick procedure that is not much more uncomfortable than starting an I.V. The aspirated fluid is then sent to the laboratory for analysis to see if there is any evidence of bacteria or infection.

Hip Injection

Sometimes it is useful to diagnostically inject the hip joint with anesthetic and/or steroid in the same manner as for an aspiration (in fact, aspiration and injection are often performed together), but for very different reasons. This is most commonly done if there are multiple potential sources for the hip pain and/or it is difficult to sort out how much of the problem is originating from the hip itself.

A common scenario is the patient who has both an arthritic hip and sciatic pain originating from the spine. If the patient's pain improves significantly for a while, then this gives some idea of where the pain is coming from (e.g., it confirms that the pain is coming from within the hip joint). If not, then it is helpful to know and efforts can be focused elsewhere and on other causes of referred pain.

Hip injections are also performed for temporary pain relief, such as for a patient who needs a hip replacement but cannot (for medical or social reasons) proceed with the surgery for some time. The steroid injection often provides at least some pain relief that lasts from weeks to months.

Please remember the information on this site is for educational purposes only and should not be used to make a decision on a condition or a procedure. All decisions should be made in conjunction with your surgeon and your primary care provider.