Structural Optimization of Magnesium Alloy Rib Claw and Evaluation of Its Mechanical Reliability In Vitro and In Vivo

The structural optimization and mechanical reliability of novel biodegradable JDBM magnesium alloy rib claws were investigated in this study. Simulation analysis, in vitro bending tests, and a 24-week animal implantation experiment demonstrated the promising application potential of the optimized Gen3 magnesium alloy rib claw. Compared with the pre-optimized Gen1 design, finite element analysis (FEA) confirmed that the Gen3 claw—achieved by increasing the width from 6.0 mm to 8.52 mm and adding 1.65 mm transitional fillets at stress concentration zones—resulted in a 54.15% reduction in the maximum von Mises stress (from 116.91 MPa to 53.59 MPa) and a 54.4% decrease in the equivalent strain. In vitro four-point bending tests (ASTM F382-compliant, 11.7 mm span) showed that the Gen3 magnesium claws exhibited a significantly higher yield load (358 ± 21 N) compared with titanium claws (219 ± 16 N; p < 0.05, independent t-test). A 24-week in vivo evaluation in Bama pigs further confirmed the excellent mechanical reliability of the optimized Gen3 magnesium alloy rib claw, and no fractures were observed throughout the implantation period.