Taskforce Report on Implant Retrieval Wolfgang Klauser MD, Patrick Sussmann MD, and Timothy Wright, PhD III International Society of Orthopaedic Centers Meeting Bologna, Italy May 1, 2010

Goal Foster research collaboration through the utilization of orthopaedic implant retrieval analysis as a means to answer research questions common to participating ISOC members

Specific Aims 1. Identify timely, high impact research questions centered around device technology for which retrieval analysis can lead to clinically useful answers

Specific Aims 2. Survey ISOC members who are retrieving implants to determine available numbers of implants and availability of demographic, clinical, and radiographic data

Specific Aims 3.Establish necessary policies for conducting collaborative research a. Oversight and selection of projects b. Material transfer agreements c. Authorship policy d. Data ownership e. Data/implant transfer and coordination

Specific Aims 4.Survey ISOC members for available resources a. Information technology b. Methodologies for retrieval analysis c. Experimental design/statistical analyses d. Funding

Specific Aims 5.Conduct pilot project(s) as demonstration of the effectiveness of the collaborative process

Suggestions for Pilot Projects Metal-on-metal bearings for THA and hip resurfacing Much is known of wear and surface damage mechanisms for metal-on-polyethylene bearings, but the resurgence of metal- on-metal bearings has received little clinical evaluation on the basis of retrieval analysis Surgical and patient factors hypothesized to contribute to rapid wear and pseudotumors, but variation in performance (as observed on retrieved implants) in response to variations in these factors has not been established What are the modes of wear and surface damage in metal- on-metal bearings? How are the presence and severity of these modes affected by patient, surgical, and design factors?

Suggestions for Pilot Projects Rotating platform versus fixed bearing TKA Rotating platform TKAs were intended in part to reduce wear by allowing two conforming bearings A recent study by one ISOC member (HSS) showed considerable wear at both bearing surfaces, suggesting that reduced wear is not being achieved What is the relation between rotating platform surface damage and actual wear (i.e., do damaged surfaces necessarily mean considerable material has been worn away)? How do rotating platform designs compare to similar fixed bearing designs in terms of surface damage and wear to the femorotibial articulating surfaces and in terms of total damage and wear?

Suggestions for Pilot Projects Rotating platform versus fixed bearing TKA Rotating platform TKAs were intended in part to reduce wear by allowing two conforming bearings A recent study by one ISOC member (HSS) showed considerable wear at both bearing surfaces, suggesting that reduced wear is not being achieved What is the relation between rotating platform surface damage and actual wear (i.e., do damaged surfaces necessarily mean considerable material has been worn away)? How do rotating platform designs compare to similar fixed bearing designs in terms of surface damage and wear to the femorotibial articulating surfaces and in terms of total damage and wear?

Suggestions for Pilot Projects Rotating platform versus fixed bearing TKA Rotating platform TKAs were intended in part to reduce wear by allowing two conforming bearings A recent study by one ISOC member (HSS) showed considerable wear at both bearing surfaces, suggesting that reduced wear is not being achieved What is the relation between rotating platform surface damage and actual wear (i.e., do damaged surfaces necessarily mean considerable material has been worn away)? How do rotating platform designs compare to similar fixed bearing designs in terms of surface damage and wear to the femorotibial articulating surfaces and in terms of total damage and wear?

Survey of Retrieval Resources Registry information technology Software/web-based solutions Links to patient registries Methodologies for retrieval analysis Surface and geometric analysis - Damage grading/damage mapping - Light and scanning electron microscopy - Profilometry - Laser scanning - Micro-computed tomography Histological grading Radiographic review Chemical and physical characterization - Density - Infrared spectroscopy - Differential scanning calorimetry

Funding Institutional commitments (CEOs) Federal/Int’l grant proposals and contracts Commercial contracts Philanthropy/Foundations