Should Spinal Fusion Be Done in One or Two Stages?

Complex and involved operations to fuse the spine place the patient under anesthesia for a long time. In this study, surgeons explore the option of doing a staged (two-part) operation.

The goal is to reduce the risk of complications from too much anesthesia. The biggest risk of this procedure is blindness. Staying in a prone (face down) position required for spinal fusion for more than six hours has been linked with this and other complications.

In the first stage, headless pedicle screws or K-wire placeholders were inserted. The placeholders keep the pathway open for screw insertion, which is done in stage two. Stage one was done using interventional radiology (IR). This means imaging is used to guide the surgeon as the hardware is inserted under the skin without an open incision.

The second stage was done at least a week later. This stage was open surgery with an incision through the skin and soft tissues over the spine. K-wires were removed and the hole for the screw was made larger. Pedicle screws and rods were placed to complete the fusion.

Steps involved in both stages were described in detail. Some parts of the procedure changed over the course of the study. This was because the techniques evolved and improved. The authors identified the slight changes in methods as Sequence one and Sequence two.

The results of this study showed that this new approach is possible without risking patient safety. Accuracy of wire and screw placement was between 96 and 100 per cent. There was one case of infection and no other serious complications.

It’s not clear yet what all the advantages may be of a staged procedure for spinal fusion. The length of time under anesthesia for two operations may be more than if the entire procedure was done at one time. But the time for each individual operation will be less than six hours.

There may be other advantages of performing spinal fusion in two separate sections. Less exposure to radiation is a benefit for both the patient and the hospital staff. The surgeon may have greater accuracy in placing the screws with a staged procedure. There may be some cost savings with decreased operating room time.

The authors will continue studying this method to better understand all the risks and advantages. Further reports are forthcoming. For now, they strongly advise the use of imaging radiology when placing screws or K-wire fragments. Close communication is needed between the surgeon and the radiologist for accurate placement of these devices.