Engineering patient-specific drill templates and bioabsorbable posterior cervical plates: a feasibility study

Area of Science:

• Orthopedic Surgery
• Biomaterials Engineering
• Medical Imaging

Background:

• Cervical spine surgery often uses pedicle screws for posterior instrumentation, but anatomical challenges like vertebral arteries and nerve roots complicate safe screw placement.
• Computer-generated templates offer a promising solution to assist with accurate screw placement in the cervical spine.

Purpose of the Study:

• To describe a novel method for generating customized cervical implants using computer models.
• To introduce techniques for creating patient-specific, bioabsorbable posterior cervical implants and drill templates.

Main Methods:

• Volumetric CT scans of cadaver cervical spines (C2-T1) were acquired.
• Commercial software was used to generate volumetric models for cervical drill templates and multi-vertebral plate molds.
• Rapid prototyping created physical models, and polylactic acid resin was used to form approximately 5-mm-thick bioabsorbable plates cast on cervical molds.

Main Results:

• The resulting bioabsorbable plates exhibited a secure, lock-and-key fit on the cadaver spines.
• The described techniques were found to be robust and reproducible, providing a foundation for further development.

Conclusions:

• Patient-specific bioabsorbable posterior cervical plates and multilevel drill templates show significant promise for cervical spine surgery.
• Further feasibility and in vitro studies are necessary to confirm the safety and efficacy of these patient-specific templates and implants.