Evaluation of a Bioabsorbable Scaffold and Interlocked Nail System for Segmental Bone Defect

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Regenerative Medicine

Background:

• Long-bone segmental defects pose significant challenges in orthopedic reconstruction.
• Current treatments often involve autografts or allografts with limitations.
• Biocompatible and biodegradable scaffolds offer a promising alternative for bone defect repair.

Purpose of the Study:

• To design and manufacture a novel scaffold and fixation system for rabbit tibia segmental defects.
• To evaluate the degradation, mechanical properties, and cell viability of the developed scaffold.
• To assess the accuracy and efficacy of the fixation system using a 3D-printed surgical jig in a rabbit model.

Main Methods:

• Utilized polycaprolactone (PCL) and PCL-alginate (PCL-Alg) for scaffold fabrication via phase separation casing.
• Conducted degradation and mechanical testing on scaffolds.
• Assessed cell viability on scaffolds.
• Designed and 3D-printed a stereolithography (SLA) surgical jig for accurate component placement.
• Performed cadaver tests on New Zealand White rabbits to validate jig accuracy and system mechanical integrity.

Main Results:

• PCL and PCL-Alg scaffolds exhibited suitable degradation rates and early weight-bearing capacity.
• Scaffold porosity allowed for alginate hydrogel infiltration.
• Cell viability increased by Day 7 and showed a marginal decrease by Day 14.
• 3D-printed surgical jigs enabled accurate placement of scaffolds, nails, and screws in rabbit cadavers.
• Designed fixation components demonstrated sufficient strength for surgical insertion.

Conclusions:

• The developed PCL-based scaffold and fixation system are suitable for rabbit tibia segmental defect reconstruction.
• The novel 3D-printed surgical jig ensures accurate placement of the reconstructive components.
• The system exhibits promising potential for clinical translation in orthopedic regenerative medicine.