Spine Wear Simulation Laboratory

Exponent’s biomedical engineering laboratory facilities have the capabilities to perform wear and fatigue simulations for total disc replacements, nucleus replacements, and posterior dynamic stabilization spine implants. Exponent is an ISO 17025 accredited laboratory ISO 17025 (A2LA Certificate: 2561.01) for setting up the wear simulations which comply with ISO 18192 or ASTM F2423 standards for regulatory submission. In addition, we have extensive expertise in evaluating wear mechanisms in retrieved spine implants, including total disc replacements, posterior dynamic stabilization, and fusion instrumentation. This includes evaluating Mode I, Mode III and Mode IV performance of devices.

Our spine-wear simulation and evaluation capabilities include:

Spine-Wear Simulator Equipment

  • Six-station MTS wear simulator with load-soak control station
  • Six-degrees-of-freedom load/motion application:
    • Flexion/Extension ±10º
    • Lateral Bending ±10º
    • Rotation ±7.5º 
    • Axial Load 4kN 
    • AP Translation ±4.5 mm
    • ML Translation ±4.5 mm
  • Customized fixtures for mounting implants
  • Temperature-controlled and monitored stations that can be maintained at 37 ±2°C
  • Distinct testing profiles for lumbar and cervical implants
  • Programmable input loading and motion profiles
  • Fully validated by comparison with retrieved total disc replacements

Imaging Capabilities 

  • Digital Keyence Microscope
    • Low-High magnifications (1-1000x)
  • Scanning electron microscopes
    • High-magnification surface imaging (e.g., 5,000×)
  • White-light interferometry
    • Average surface roughness evaluation (manufactured vs. worn)

Additional Services

  • Gravimetric analysis (0.0001g)
  • Serum analysis for particles
  • Implant surface characterization before and after wear simulation
  • Comparison to retrieval collections