Orthopedic physicians and surgeons at DePaul use a variety of diagnostic tests to help correctly diagnose your injury or illness. Results of these tests are also used to plan an appropriate course of treatment. Here are some of the most frequently used diagnostic tests.

Arthrography
Arthrography is often used to help diagnose the cause of unexplained joint pain. A contrast iodine solution is injected into the joint area to help highlight the joint structures, such as the ligaments, cartilage, tendons and joint capsule. Several X-rays of the joint are taken, using a fluoroscope, a special piece of X-ray equipment that immediately shows the image. You may be asked to fast prior to the exam. During the examination, you may be asked to move the joint into various positions as the images are taken. It is normal to experience some discomfort or tingling during the procedure. If you are or may be pregnant, or are allergic to iodine or shellfish, notify your physician; you may be at a higher risk of complications.

Blood Tests
Your orthopedist may order a variety of blood tests. Some conditions, such as rheumatoid arthritis, may be identified by the presence of a specific substance in your blood. You may be asked to fast prior to the exam.

Bone Scans
A bone scan is used to identify areas where there is unusually active bone formation. It is frequently used to pinpoint stress fracture sites or the presence of arthritis, infection, or cancer. About three hours before the scan, you will be given a dose of a mildly radioactive substance called "technetium" through an intravenous line (IV). This substance occurs naturally in your body and is used in the bone formation process. The bone scan itself is performed about three hours later, which gives the bone time to absorb the technetium. As you lie on a table, a special nuclear camera takes a picture of your entire body. This process takes 45 to 60 minutes. Areas of abnormal bone formation activity will appear brighter than the rest of the skeleton.

CT scans
A CT scan (computed tomography) is a modern imaging tool that combines X-rays with computer technology to produce a more detailed, cross-sectional image of your body. A CT scan lets your doctor see the size, shape and position of structures that are deep inside your body, such as organs, tissues or tumors. You may need a CT scan if you have a problem with a small, bony structure or if you have severe trauma to the brain, spinal cord, chest, abdomen or pelvis. As with a regular X-ray, sometimes you may need to drink or be injected with barium sulfate or a dye to make certain parts of your body show up better.

Discography
Discography is a test used to determine whether the discs, the cushioning pads that separate the bones of the spine, are the source of back pain. It may be performed before surgery to positively identify the painful disc(s). Before the procedure begins, you will be given antibiotics and relaxation medications through an IV line. Medication is used to numb the skin over the test site. During the procedure, the doctor inserts a needle into one or more discs and injects a contrast dye. You'll feel pain when the dye is introduced into the problem disc. Afterward, a CT scan will show any changes in the disc size or shape.

Doppler Ultrasound
An orthopaedist who suspects that you have a blockage in the blood vessels of your legs or arms may prescribe an ultrasound test. An ultrasound uses high-frequency sound waves that echo off the body. This creates a picture of the blood vessels. The Doppler audio system transmits the "swishing" sound of the blood flow. This is a noninvasive test that has no side effects.

DEXA or Bone Density Test
Dual-energy X-ray absorptiometry (DEXA) is the most widely used test for measuring bone density. It can accurately and precisely monitor changes in bone density in patients with osteoporosis who are undergoing treatments. This machine takes a picture of the bones in the spine, hip, total body and wrist and calculates their density. It is painless and noninvasive, requiring no special preparations.

Electrodiagnostic testing
Your nerves and muscles create electrical signals that deliver messages to and from your brain that activate your muscles. Injuries or diseases that affect nerves and muscles can slow or halt the movement of these electrical signals. If you have pain, weakness or numbness in your back, neck or hands, measuring the speed and degree of electrical activity in your muscles and nerves can help your doctor make a proper diagnosis. This process is called electrodiagnostic testing. Two tests commonly used are electromyography (EMG) and nerve conduction studies (NCS).

Electromyography (EMG)
During an EMG, small, thin needles are placed in the muscle to record the electrical activity. Your doctor will ask you to relax the muscle and to tense it slightly. The doctor will listen and watch a TV-like screen that broadcasts the electrical signals. You will also be able to hear the signal sounds as you move the muscle. If you are taking blood-thinning medications, have lung disease or are at risk for infection, tell the physician who is conducting the test. On the day of the test, do not put any lotions or creams on the area to be tested and do not wear any jewelry. Usually, you can get the results immediately after the test.

Flexibility Tests
Flexibility tests are used to measure the range of motion in a joint and are often part of the physical examination. They may be used to help determine whether you have a muscle imbalance or arthritis in a joint. They may also be used to help determine the progression of a condition such as shoulder impingement or a sprain. There are several different kinds of flexibility tests, geared to specific joints and muscles.

Magnetic Resonance Imaging (MRI)
MRI uses a large magnet, radio waves and a computer to create images of your bones and soft tissue without the use of surgery or radiation. An MRI may help your doctor to diagnose your torn knee ligaments and cartilage, torn rotator cuffs, herniated disks, hip and pelvic problems and other problems. Tell your doctor if you have implants, metal clips or other metal objects in your body before you undergo an MRI scan.

Nerve conduction studies (NCS)
NCS are often done along with the EMG to determine if a nerve is functioning normally. Your doctor will tape wires (electrodes) to the skin in various places along the nerve pathway. Then the doctor stimulates the nerve with an electric current. In healthy nerves, electrical signals can travel at up to 120 miles per hour. If the nerve is damaged, however, the signal will be slower and weaker. By stimulating the nerve at various places, the doctor can determine the specific site of the injury. Nerve conduction studies also may be used during treatment to test the progress being made.

Stress Tests
Because your bones, muscles and connective tissues (ligaments and tendons) are constantly responding to stress (pressure or force), your orthopedist may use applied stress to measure their response. For example, your doctor may hold your lower leg still with one hand and move your heel up and around with the other. This motion applies stress to the ligaments connecting the heel and your lower leg. Excessive or asymmetrical motion indicates that your ligaments are overstretched or loose.

Venography
Venography is used to determine whether you have a blood clot in your leg, a condition called deep vein thrombosis. This is a serious condition because if the clot breaks free, it could travel to your lungs, creating a potentially fatal condition called pulmonary embolism. In this test, a contrast solution (or dye) is slowly injected into your leg as you lie on a tilting X-ray table. The dye causes a warm, flushed feeling in the leg and might also make you feel nauseous. X-rays are taken to identify the location of the clot. After the test, a clear fluid is injected in the same spot to clear the dye from your veins. The test takes less than an hour and can be done on an outpatient basis.

X-rays
X-rays (radiographs) are the most common diagnostic imaging technique. The part of your body being pictured is positioned between the X-ray machine and photographic film. The machine briefly sends electromagnetic waves (radiation) through your body, exposing the film to reflect your internal structure. The level of radiation exposure from X-rays is not harmful, but your doctor will take special precautions if you are pregnant. Sometimes, to make certain organs stand out in the picture, you are asked to drink or be injected with barium sulfate or a dye.