Deformable 3D-2D Registration for Guiding K-Wire Placement in Pelvic Trauma Surgery

Area of Science:

• Medical Imaging
• Surgical Navigation
• Orthopedic Surgery

Background:

• Pelvic Kirschner wire (K-wire) insertion is complex due to 3D anatomy interpretation from 2D fluoroscopy.
• K-wire deformation during long trajectories (>10-25 cm) compromises conventional rigid navigation accuracy.
• Proximity to nerves and vessels necessitates precise K-wire placement within narrow bone corridors.

Purpose of the Study:

• To present a novel system for accurate 3D localization and guidance of rigid or deformable surgical devices, specifically K-wires.
• To overcome the limitations of K-wire deformation in achieving accurate tip location and orientation.
• To enable enhanced surgical precision and safety in trauma surgery using existing imaging modalities.

Main Methods:

• Patient registration to preoperative CT via digitally reconstructed radiographs (DRRs) matched to intraoperative X-ray projections.
• K-wire localization using deformable known-component registration (dKC-Reg) by matching DRRs of a deformable K-wire model.
• Cadaver study involving pelvic K-wire trajectory delivery and system performance evaluation.

Main Results:

• Achieved a target registration error (TRE) of 2.1 ± 0.3 mm for K-wire tip location (median ± IQR).
• Demonstrated an orientation TRE of 0.8 ± 1.4° at the K-wire tip (median ± IQR).
• Provided accurate 3D guidance without reliance on external surgical trackers, using standard intraoperative imaging.

Conclusions:

• The presented system offers accurate 3D guidance for deformable K-wires in pelvic surgery.
• It leverages standard surgical imaging (e.g., inlet/outlet views) for quantitative navigation.
• This approach has the potential to improve precision and safety in trauma surgery by extending navigation benefits.