Zygomatic arch reconstruction with a patient-specific polycaprolactone/beta-tricalcium phosphate scaffold after parosteal osteosarcoma resection in a dog.

Objective: To describe the surgical application of a 3D-printing-based, patient-specific, biocompatible polycaprolactone/beta-tricalcium phosphate (PCL/β-TCP) scaffold to reconstruct the zygomatic arch after tumor resection in a dog.

Animal: A 13 year old female spayed Maltese.

Study design: Case report METHODS: The dog's presenting complaint was swelling ventral to her right eye. A round mass arising from the caudal aspect of the right zygomatic arch was identified by computed tomography (CT). The histopathologic diagnosis was a low-grade spindle-cell tumor. Surgical resection was planned to achieve 5 mm margins. A patient-specific osteotomy guide and polycaprolactone/beta-tricalcium phosphate (PCL/β-TCP) scaffold were produced. Osteotomy, including 30% of total zygomatic arch length, was performed using an oscillating saw aligned with the guide. The scaffold was placed in the defect. Parosteal osteosarcoma was diagnosed based on histopathological examination. Excision was complete, with the closest margin measuring 0.3 mm.

Results: Mild epiphora, due to surgical site swelling, subsided after 20 days. Tissue formation within and around the porous scaffold was noted on CT 10 months postoperatively, with no evidence of metastasis or local recurrence. Facial conformation appeared symmetrical, and no complications were noted 16 months postoperatively.

Conclusion: The use of a 3D-printing-based, patient-specific, biocompatible PCL/β-TCP scaffold successfully restored the structure and function of the zygomatic arch without complications, even following wide zygomectomy for complete tumor removal.