3D Printed PLA+ Bone Support Devices: Raster Angle Optimization for Enhanced Mechanical Performance in Orthopedic Applications

This study investigates the mechanical performance optimization of PLA+ (Polylactic Acid Plus) specimens fabricated via fused deposition modeling (FDM) with four distinct raster angle configurations (0°/90°, ± 45°, 20°/70°, 0°/45°/-45°/90°) for advanced bone support and orthopedic cast applications. Through comprehensive experimental characterization encompassing tensile testing following ASTM D638-14 standards, single edge notched bend (SENB) fracture toughness evaluation per ASTM D5045-14, and validated finite element analysis (FEA), we demonstrate the critical role of strategic raster pattern optimization in achieving medical-grade mechanical performance. The ± 45° raster configuration exhibited superior mechanical properties with ultimate tensile strength of 31.7 ± 2.1 MPa, elastic modulus of 3.8 ± 0.3 GPa, and exceptional fracture toughness of 364.2 ± 18.5 MPa√m, representing a 30% improvement over conventional 0°/90° configurations (280.0 ± 15.2 MPa√m). Finite element validation confirmed stress distribution patterns with maximum concentrations of 45.3 MPa under physiological loading conditions (1500 N), well within material safety margins. These findings establish definitive design guidelines for patient-specific 3D printed bone support devices that offer enhanced mechanical performance, biodegradability, customization capabilities, and reduced weight compared to traditional plaster casting systems, supporting clinical translation toward personalized orthopedic care.