Retrieved Device & Tissue Analysis

Exponent staff has extensive expertise in creating and managing international multicenter programs to collect and analyze components from explanted orthopedic, spine, and cardiovascular implants including total joint replacements, artificial discs, pacemakers, implantable cardioverter-defibrillators (ICDs) and stents.

Retrieval of tissues and related medical devices can be done at various stages of the product life cycle. The analysis of retrieved implants, tools, and tissues is essential for a complete understanding of how a device functions, as it provides unique information related to in vivo device mechanics, kinematics, and material performance. For this reason, recent 522 Orders and deficiency letters by the FDA have required retrieval analysis protocols as an integral component of clinical studies and post-market surveillance.

Exponent is accredited to ISO 17025 (A2LA Certificate 2561.01) for it retrieval protocols based on ASTM F561, "Standard Practice for Retrieval and Analysis of Medical Devices and Associated Tissues and Fluids" and ISO 12891, "Retrieval and analysis of surgical implants." 

We use the standards to create custom protocols to ensure appropriate collection, shipping, and analysis of retrieved devices, tools, and tissues. Validated analysis techniques are used to assess wear and damage modes, evaluate fracture surfaces, evaluate material degradation, and quantify wear, deformation and penetration of biomaterials. The results are summarized into reports suitable for direct submission to regulatory agencies. In addition, Exponent’s biomedical engineering consultants can assist with regulatory submissions, deficiency responses, and can be present at meetings with regulatory bodies in order to present the results of the analyses conducted.


Our services include:

  • Creation of customized retrieval protocols using ASTM F561 and ISO 12891 to meet total product life cycle needs
  • Design of a retrieval kit (including instructions and clinical data forms) compliant with international shipping regulations 
  • Selection of appropriate analysis techniques based on device material, anatomical location, and function
  • Evaluation of retrievals comprised of traditional (UHMWPE on CoCr) bearing materials, alternate (metal and ceramic) bearing materials and novel new bearings (hard coatings, hydrogels, alternate polymers)
  • Evaluation of wear patterns, failure mechanisms, fracture, corrosion, degradation, and deformation 
  • Qualitative and quantitative mapping of wear, deformation, and penetration
  • Evaluation of fluid and tissue surrounding the implant, including histology, trace metal, and particle analysis
  • Chemical and electrical evaluation of batteries in pacemakers and implantable cardioverter-defibrillators and associated leads 
  • Correlation of retrieved damage modes and mechanisms to in vitro tested devices 
  • Report preparation suitable for direct submission to the FDA containing methodology and results of all findings
  • Response to FDA deficiency letters and other regulatory inquiries

Figure 1. Components that may be included in a device-specific retrieval kit.

Figure 2. SEM image of retrieved elbow joint replacement.

Figure 3. Mapping of wear, deformation, and penetration.

Figure 4. Retrieved pacemaker.

Figure 5. Images of a retrieved metal-on-metal (MOM) cervical total disc replacement (left, 2.3 y) and an in vitro tested MOM cervical disc replacement (right, 0.1 MC).



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