Additively Manufactured Patient-Specific Trabecular Bone Imitations in Anatomical Bone Models for Preoperative Planning and Surgical Training: A Manufacturing Framework

PURPOSE: Additively manufactured (3D-printed) anatomical bone models are used for medical education and surgical training. Manufacturing of patient-specific anatomies and rare pathologies has improved rapidly in the recent past, enabling training opportunities that were previously restricted to limitedly available anatomic specimens. However, the imitation of patient-specific trabecular bone in additively manufactured bone models remains complex and thus inadequately addressed. METHODS: Test specimens in the form of Gyroid and Voronoi lattice cubes were manufactured via fused filament fabrication (FFF)-printing at varying densities with polylactide, polylactide /carbon fiber composite and polyamide /glass fiber composite filaments, and submerged in gelatin. Additionally, trabecular bone test cubes were removed from bovine femoral specimens, and the bone mineral density (BMD) was assessed utilizing quantitative computed-tomography (QCT). Subsequently, haptic drill resistance of all test cubes was evaluated by four orthopedic and trauma surgeons, and the mechanical drill resistance was assessed using a load frame. RESULTS: ≤ 0.89) enabled the extraction of practical manufacturing parameters linking them with patient-specific BMD. CONCLUSION: The imitation of trabecular bone models via FFF-printing is feasible and could substantially enhance the haptic feedback in additively manufactured anatomical bone models. Applying the presented manufacturing framework enables the cost- and time-efficient production of patient-specific anatomical models to enhance preoperative planning and surgical training.