# Robot-Assisted Placement of Thoracic Carbon-Fiber-Reinforced Polyetheretherketone (CFR-Peek) Pedicle Screws in the Cervical Spine for Giant Cell Tumor: Technical Note

## TL;DR

This paper describes a case where robot-assisted surgery was used to place thoracic CFR-PEEK screws in the cervical spine to treat a tumor, highlighting the potential and challenges of this approach.

## Contribution

The paper introduces a novel technique using robotic navigation to adapt thoracic CFR-PEEK screws for cervical spine surgery in oncology.

## Key findings

- Robotic guidance enabled safe placement of thoracic CFR-PEEK screws in narrow cervical pedicles.
- The procedure achieved rigid stabilization without immediate neurological complications.
- The technique shows potential but requires further study on reproducibility and long-term outcomes.

## Abstract

Carbon-Fiber-Reinforced Polyetheretherketone (CFR-PEEK) instrumentation is increasingly preferred in spinal oncology for its physical properties, minimizing imaging artifacts and facilitating precise postoperative radiotherapy planning and tumor surveillance. However, a significant technical limitation exists: the current unavailability of dedicated CFR-PEEK pedicle screws for the cervical spine. The smallest available implants are designed for thoracic use (minimum diameter 4.5 mm, minimum length 25 mm), posing substantial risks of neurovascular injury when applied to smaller cervical pedicles. We present a technical note/feasibility report illustrated by a single case of robot-assisted placement of thoracic CFR-PEEK screws in the cervical spine for the treatment of a C7 Giant Cell Tumor. Following neoadjuvant therapy with Denosumab, a single-stage, two-step circumferential resection and reconstruction was performed. The anterior step was complicated by an iatrogenic injury to the highly adherent left vertebral artery (VA), which was successfully repaired. Consequently, the posterior step required maximal precision to preserve the sole remaining intact VA on the right side. Given the anatomical mismatch between the 4.5 mm thoracic screws and the narrow cervical pedicles (measuring as narrow as 3.2 mm on the critical right side), robotic navigation (ExcelsiusGPS®) was utilized to plan and execute safe trajectories. Specifically, on the side of the intact VA, a small, controlled medial cortical violation was planned to avoid lateral vascular compromise. The procedure resulted in rigid, artifact-free stabilization with no immediate neurological sequelae. This single-case experience suggests that robotic guidance may facilitate adaptation of thoracic CFR-PEEK instrumentation to the cervical spine in selected oncologic scenarios; reproducibility, costs, and long-term outcomes remain uncertain.