An Optical Tracking-Based Robot-Assisted System for Spinal Fixation Rod Bending.

BACKGROUND

In spinal pedicle screw-rod fixation, rod contouring quality influences insertion ease, construct stability, and corrective effect. Conventional bending relies on surgeon experience and is limited by insufficient support, repeated adjustment, and inefficient workflow.

METHODS

This study developed a tracking-based robot-assisted system for rod bending comprising an acquisition unit, software, and actuator. The system acquires screw-head coordinates, generates target rod shape, and discretises the curve into bending positions, axial rotations, and angles.

RESULTS

In five in vitro experiments, five assisted-versus-manual comparisons, and twenty paired cases, planned rods showed high consistency with target curves, with mean angle, rotation, and length errors within acceptable ranges. Assisted bending improved efficiency and reduced placement errors versus manual bending; clinically, the assisted side had a shorter operation time.

CONCLUSIONS

The system achieves a workflow from acquisition to rod formation, improving quantifiability, consistency, efficiency, and conformity, thus providing a pathway towards automated spinal rod shaping.