Before Orthopedic Surgery: Tests For Disk Injuries

Doctors are keenly aware that surgery is the last resort in treating any spinal condition, and to ensure that an operation upon a spinal disk or nerve injury is necessary, there is a range of tests that look for the precise cause of a patient’s pain or limitations. Muscle spasm, tingling, weakness, or lack of range of motion in the arms or legs-all of which might be caused by a disk injury-are not enough, and there should be proof that these arise from an identifiable, specific lesion that matches the complaints.

For instance, for pain radiating from the neck to the little finger, a doctor might suspect an injury at the level of the eighth cervical nerve (C8)-the lowest in the neck-but would want to be able to see that injury on a scan and verify it with an EMG/NCS (Electromyogram/Nerve Conduction Study), since it might call for nonsurgical treatment or be caused by a condition not related to the disks, such as thoracic outlet syndrome. Plain X-rays are one step in diagnosing an injury but are not as informative as CT scans (Computed Tomography), or an MRI (Magnetic Resonance Imaging), which provide extremely detailed information about the examined area. These may be accompanied by the EMG/NCS, which sends electrical impulses through the patient’s affected nerves and muscles. Ideally, the data from the tests should conform with what a doctor observes on physical examination, the outcome of conservative treatment, and the patient’s reported history in order for there to be a need for orthopedic surgery.

In a CT scan, one lies down on a table, which is then slid into a doughnut-shaped scanner, which then rotates around and takes a series of x-rays, creating a stack of images to show the three-dimensional structure of the part being scanned. This takes only a brief time – most of the appointment is spent in preparation time rather than inside the machine. Sometimes, it may be necessary for dye to be injected in the affected level(s) of the spine for the resulting image to provide better contrast.

An MRI is a similar experience in that a person, again, lies inside a machine that surrounds him or her, although an open machine may be available for those who are uncomfortable in small spaces. Since it uses strong magnetic fields, this scan shows different information from x-rays and adds to the total knowledge available about an injury.

If your doctor has ordered an EMG/NCS, he or she will wish you to prepare by ceasing to take medications that might interfere with the results: blood thinners, for instance. To prevent any possibility of infection, your physician or a technologist will clean the skin over areas being tested, then insert a sterile needle electrode into your muscle. Recording machines typically include a video monitor that shows the results as wavy or spiky lines and audio devices that make popping, firecracker-like noises to help your doctor reach a diagnosis.

To see if orthopedic surgery is necessary, the electromyogram determines whether a patient’s nerves are functioning abnormally. So, first, resting muscular electrical activity is recorded, before one contracts and relaxes that part of the body. The electrode may be relocated several times to gather information from different regions. This typically continues for 30 to 60 minutes. As with any needle, you may experience a minor, sharp pain when the electrode is applied. Afterwards, you should expect some swelling and tingling for a couple of days.

For a nerve conduction study, several metal discs will be attached over the affected nerves’ pathways using paste or tape and a short series of quick (nearly instantaneous) electric shocks of a very low voltage will be sent through them. This enables the instruments to measure how quickly a muscle contracts- its conduction velocity. Often, the other side of the body will be tested for comparison. A difference between the two sides’ results is one of the indicators for orthopedic surgery. The NCS typically goes on for between 15 minutes and an hour, depending on how many different nerves and muscles are studied. It does tend to make some people anxious, but the strength of electricity involved is too low to cause injury.

The combination of all information from a person’s experience with conservative treatment (exercise and therapy), reports of symptoms, those physically observable such as muscle spasm, and the result of radiographic, magnetic, and electrical tests combine to inform a doctor about the nature of one’s injury, whether it lies within the spinal disks, and whether orthopedic surgery should be both necessary and helpful.