Biomechanical evaluation of a new femoral stem design for total hip replacement in a canine model

Acta Cir Bras. 2021 Jun 18;36(5):e360506. doi: 10.1590/ACB360506. eCollection 2021.

Abstract

Purpose: To evaluate the biomechanical properties of a novel total hip replacement femoral stem.

Methods: Eight pairs of femurs from dog cadavers were used. The femurs were separated into different groups. A novel femoral stem with a convex proximal portion (Stem B) was biomechanically evaluated and compared to awell-known veterinary collared stem (Stem A). Femoral stems were inserted into the contralateral femurs from the same dog, forming 16 constructs. A flexo-compression load was applied on the axial axis of each sample. Maximum strength, deflection, stiffness, and energy absorption were analysed.

Results: Group B constructs showed significantly higher values (p ? 0.05) for the variables, except stiffness. The mean maximum strength was 1,347 ± 357 N for Group A and 1,805 ± 123 N for Group B (p ? 0.0069). The mean deflection was5.54 ± 2.63 mm for Group A and 10.03 ± 3.99 mm for Group B (p ? 0.0056). For the energy variable, the force was 6,203 ± 3,488 N/mm for Group A and 12,885 ± 5,056 N/mm for Group B (p ? 0.0054). Stem B had greater maximum strength, deflection, and energy.

Conclusions: The new stem was effective in neutralizing the impact of axial flexion-compression stresses during biomechanical tests in cadaveric models.

MeSH terms

  • Animals
  • Arthroplasty, Replacement, Hip*
  • Biomechanical Phenomena
  • Cadaver
  • Dogs
  • Femur / surgery
  • Pressure