Surgeons have many ways to monitor what’s going on during surgery. Special imaging such as fluoroscopy gives a view inside the spine. This helps with the insertion and placement of hardware such as plates and screws.
With some types of screws, the surgeon can also use a special probe to assure correct placement. This handheld device gives an electrical stimulation to the screw once it has been put in place. If the screw is where it should be, it takes a certain amount of current to cause a muscle contraction and wave on the monitor.
If it is in the wrong place, less current is needed to cause a muscle contraction. This is called an evoked EMG. The surgeon uses this information to change the
placement of the screw. This type of monitoring helps prevent damage to the nerve root or spinal cord.
Other monitoring units are used to alert the surgeon during the procedure to possible nerve damage. An immediate change is made in the operative technique to avoid damage to the nerve tissue. This type of intraoperative monitoring (IOM) isn’t always used. You may want to ask your surgeon what plans are being made to monitor you and prevent complications of this type.