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Impact location linked with force delivered to component junctions in dual-taper modular hip implants
Results from this study of more than 100 tests indicated that in dual-taper modular hip implants, the location of impact had a significant influence on the force transmitted to both the head-neck junction and the neck-stem junction.
Researchers performed 144 impact tests with six different directions between the head-neck and neck-stem junctions of dual-taper modular hip implants. Investigators measured the heck-neck alone and then at three different neck angulations at 0°, 8° and 15°. The impactor was guided onto the custom head of the simulated assemblies using a drop tower.
Results showed the range from the impact force on the hammer on the head was between 3,800 N and 4,500 N. Investigators noted axial impact delivered the greatest force of impact on the head, but did not provide the greatest force transmission to the neck-stem. According to researchers, the force measured at the neck-stem for all directions of impact for the 8° neck had limited variability, while there was a greater force transmitted to the neck-stem junction when the off-axes were directed in the proximal direction and in the posterior direction. ‒ by Monica Jaramillo
Disclosures: Frisch reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.