In Brief:
This in vitro study investigated the influence of bone mineral density, load-bearing cross-sectional area, and implant angulation on anchorage stability of angular stable anterior spinal implants. Subsidence and angular displacement of two prototypes (MP1, MP2, both Synthes) and a commonly used implant (MACS TL, Aesculap) were measured, increasing the craniocaudal load stepwise (100 N, 200 N, 400 N) for 1,000 cycles each. Subsidence within each implant group was influenced by bone mineral density and load-bearing cross-sectional area. Although both prototypes had smaller load-bearing cross-sectional areas, they survived significantly longer than the MACS TL system. Screw angulation was not revealed as a significant factor for implant stability.