Before agreeing to spinal fusion surgery for our eight-year-old son, I want full disclosure of all possible problems during and after the procedure. I have a list of things that can happen (provided by the surgeon’s office). Some of them are pretty scary like stroke and death. They said they would use the kind of screws (pedicle) that have lower risks and “superior” results. This does not make me feel any better. How often do these kinds of things really happen?

It might help you to know a little bit about the history of pedicle screws, how they are used, when they are used, and the results of some recent research related to the complication rates of these devices.

Back in the 1960s, surgeons started to use this type of fixation device to help hold the spine together during a fusion procedure. The pedicle is a column of the vertebra between the main body and the back half of the spinal bones. Placement of a screw through this portion of the vertebra has some risks but many advantages over other types of fixation (e.g., wires, hooks). For example, there is less movement in screws compared with wires or hooks. This increased stability of the fixation device reduces the risk that the hardware will poke into the spinal canal damaging the spinal cord. Likewise, there is less risk of injury to blood vessels in the area.

Pedicle screws are also able to give better correction of the spinal deformity by providing multiplanar correction. Vertebral bones are able to rotate, flex, and extend as well as slide and glide slightly forward, back, and sideways. Multiplanar stabilization stops motion in all directions. Superior correction of spinal deformity with fewer problems make pedicle screws (as a fixation device) the preferred choice of many surgeons.

At first, this screw through the bone was only used in the lumbar spine (low back). But over time, the use of pedicle screws expanded — first to the thoracic spine in adults and then to the spine of adolescents and now younger children.

Studies show that pedicle screws used in the lumbar and thoracic spines of adolescents and adults are less likely to pull out or fail compared with hooks and wires. Complication rate and types of complications have recently been reported for children up to age 12 (compared with children between the ages of 13 and 18) having spinal fusion for scoliosis or other spinal deformities. Rates of infection, hardware failure, and neurovascular (nerve tissue or blood vessel) problems were reported after at least one full year of follow-up.

Overall complication rates were 13.6 per cent for the younger group and 16.9 per cent in the adolescent group. Broken down by category, there was a 0.5 per cent rate for neurovascular complications in the younger group compared with 1.92 per cent among the adolescents. Hardware-related problems were 13.4 per cent (younger group) versus 15.4 per cent (older group). And the infection rate was 9.2 per cent (younger group) compared with 11 per cent among the older patients.

Other areas examined in this study were 1) number of screws used and risk of complication (no link between these two factors), 2) timing of neurovascular complications (all occurred within the first 24 hours), and most common late complications (screw prominence sometimes requiring screw removal).

Very rarely, complications such as stroke during the surgery, aspiration pneumonia, failure of wound healing, and ileus (bowel blockage) are reported. Such complications are not directly caused by the use of pedicle screws but are usually associated with having major (spinal) surgery. Only one child in this study had a stroke (due to other serious health problems) and there was complete recovery for that individual. There were no deaths among the 726 children in the study.