Implant Retrieval Analysis

Evaluation of wear and other factors that affect the long-term performance of orthopaedic implants during clinical use, including determining the nature of the local and systemic reactions to implants, wear particles and metal ions.

Scope
The investigators of the Implant Retrieval Laboratory apply a variety of analytical techniques to determine the factors that affect the clinical performance of prosthetic joints. These studies include characterizing the local and systemic reactions to the implant (bulk materials, wear particles and metallic ions), and determining the causes of clinical failure. The goal is to provide clear guidelines to assist manufacturers in the design of more durable implants and to educate surgeons in factors that enhance the useful lifespan of prosthetic joints.

Research
Currently, the research focus is on the failure analysis of metal-on-metal hip resurfacing components, including analysis of retrieved implants, bone and soft tissue, and joint fluids. The femoral implants are sectioned to allow analysis of the depth of cement penetration and its distribution, and the nature of the bone-cement interface, as well as the viability of the bone and its remodeling responses. Soft tissues are examined for the cellular response to the metal wear products, including metal allergy or sensitivity, and the joint fluids can be analyzed for metal particles and ion levels.

Apparatus
EXAKT implant cutting saw, Buehler cabinet grinders, Zeiss Scanning Electron Microscope, Leica Polycut II microtome, Leica Polycut Ultramiller, Mahr Feinpruf laser profilometer, Olympus BHS Microscope, Wild Makroscope, Faxitron x-ray machine, Metamorph image analysis system.

Staff
The Implant Retrieval Laboratory is under the direction of Pat Campbell, Ph.D., assisted by Christina Esposito, B.Sc.

Publications
In 2006, the research on hip resurfacing performed at the Implant Retrieval Laboratory was recognized by the Hip Society John Charnley Award.

  1. Campbell P, Shen FW, McKellop HA: Alternative bearing surfaces for young adult patients: Biological and tribological considerations. Clin Orthop Rel Res 418:98-111, 2004
  2. Amstutz HC, Campbell PA: LeDuff M: Fracture of the neck of the femur after surface arthroplasty of the hip. J Bone and Joint Surg 86A: 1874-1877, 2004.
  3. Davies AP, Willert HG, Campbell PA, Learmonth ID, Case CP: An unusual lymphocytic perivascular infiltration in tissues around contemporary metal-on-metal joint replacements. J Bone and Joint Surg 87B:18-27. 2005
  4. Beaulé PE, Campbell PA, Shim P: Femoral head blood flow during hip resurfacing. Clin Orthop Rel Res, epub Oct 2006
  5. Campbell P, Beaulé PE, Ebramzadeh E, LeDuff M, De Smet K, Lu Z, Amstutz HC: A study of implant failure in metal-on-metal surface arthroplasties. Hip Society Award. Clin Orthop Rel Res, 453:35-46, 2006

Contact
Pat Campbell, Ph.D., PCampbell@mednet.ucla.edu, tel:             (213) 742-1134