Implant Pathology and Biocompatibility Laboratory

The Implant Pathology and Biocompatibility Laboratory in the Department of Orthopedic Surgery focuses on the analysis of retrieved tissues and implant devices from patients with joint replacements. Such devices can either be surgically retrieved components from revision surgery (failure cases) or postmortem retrievals (well-functioning devices).

Our work

The main emphasis of our lab has been retrieved joint replacements for the hip, knee, and shoulder, but we also study retrieved ankle replacements and spine implants. The postmortem retrievals are collected by our team according to a previously published protocol. The analysis of retrieved tissue concentrates especially on tissue reactions to foreign bodies such as wear debris and corrosion products that are generated from joint replacements. In order to determine the type of tissue reaction that has occurred, we employ specific histology and immunohistochemical methods. Furthermore, we are able to analyze the chemical and structural composition of foreign bodies using custom developed methods. Our device retrieval analysis includes the analysis of specific damage features and the determination of the occurring damage mode, implant alloy metallurgy, determination of material loss using metrology methods, wear particle analysis and the analysis of the interaction of implant surfaces with the body (e.g., osseointegration). For the latter, we are also able to conduct in vivo studies using established animal models.

Specific areas of research include the following:

  • To determine failure modes of failed joint replacements
  • Analysis of tissue reactions to wear debris and corrosion products generated from implants
  • Systemic reactions to wear debris and corrosion products
  • Animal models to test osseointegration properties of implant surfaces and bone graft substitutes
  • Determination of material loss from implant surfaces (metrology)
  • Implant alloy characterization (metallography)
  • Particle analysis


Our laboratory houses all equipment needed to perform plastic embedded histology, numerous light microscopes with digital cameras and image processing systems, a wet lab and a full metallography lab (sample preparation of metallic samples). A precision cut-off machine, an automated polishing machine and a hot-mounting are utilized for metallography. The lab also houses a scanning electron microscope (SEM) (JSM-6490LV, JEOL) for the analysis of particles, corrosion products and damage features on implant surfaces at high magnification. The SEM is also equipped with energy dispersive x-ray spectrometer (EDS) (INCA, Oxford) for the determination of the chemical composition of materials.


  • NIH/NIAMS: grant R01 AR070181
  • Rush Translational Science Consortium: pilot grant


Links to PubMed bibliography of laboratory publications:

Our team

Our team consists of experts in orthopedic science, biology, histology, materials science and engineering, in order to have a coordinated effort in studying the entire patient/implant construct correlating the cellular responses of interface, local and systemic tissues of the body to the wear, corrosion, and metallurgy of the joint components.


  • Robert M. Urban, associate professor and lab director
  • Deborah J. Hall, assistant professor and lab manager
  • Thomas Turner, DVM, associate professor
  • Robin Pourzal, PhD, assistant professor


  • Stephanie McCarthy, BS, research assistant
  • Jennifer Wright, MS, research assistant

Contact us