Pedicle screw instrumentation and spinal deformities: have we gone too far?

Placement of pedicle screws within the thoracic and lumbar spine has become the "state of the art" for the treatment of spinal deformities. Newly trained surgeons are often trained only with the placement of pedicle screws within the thoracic and lumbar spine and not with hooks or other means of fixation. However, if the benefits of pedicle screw instrumentation in terms of correction ability cannot be questioned on some issues pertaining to their safety, their rationale for all situations as well as their long-term adverse consequence and or early or late complications start to arise.

We therefore present four case examples that illustrate the advantages, questions and complications inherent to pedicle screw instrumentation in spinal deformities. These four cases serve as discussion supported by a review of the literature. The literature search was performed to include pedicle screws associated risks, costs and complications. Articles focusing on instrumentation of the thoracic and lumbar spine for the treatment of adult and pediatric scoliosis were reviewed.

Pedicle screw instrumentation in the treatment of spinal deformity is here to stay, however a fair number of issues have come up since their widespread use that started 10 years ago: these include their misplacement with the inherent risks to the vascular or neurologic structures, the rate of misplaced pedicle screw not per number of screws inserted, but per patient operated, the number of screws really necessary to achieve a satisfactory outcome while maintaining costs, their contraindications in some very challenging deformities where the risks clearly outweigh their advantage compared to hooks. At last, the use of pedicle screw instrumentation has driven many centers in increasing the safety of such procedures using intraoperative spinal cord monitoring as well as improved imaging technologies.

To answer our provocative title "Pedicle screw instrumentation have we gone too far?" Definitively we can answer that for some spinal deformities instrumented with all-pedicle-screw instrumentation, we have observed cases where the surgeons have gone way too far; in other cases, where such instrumentation was used in a comprehensive and rational manner, the answer to "Have we gone too far" is no, and such use of pedicle screw has improved outcome with minimum complications.