R. A. Gsell, D. H. Brinkerhuff, D. M. Hawkins, Zimmer, Inc., Warsaw, IN
Historically, assessment of the cleanliness of orthopedic implants was largely based on visual, microbial and clinical evaluations. There were no specific industry or international standards defining cleanliness or a consensus on the best methods to evaluate an orthopedic implant’s cleanliness. In more recent years a few specific types of implants (spinal devices, heart valves, etc.) have seen requirements for endotoxin residuals but nothing on foreign material residues.
Recognition of the importance of minimizing and controlling the cleanliness of an implant is not new concept, but standardization mostly grew out of the pharmaceutical and electronic industries. These industries have mature requirements for product cleanliness; both for foreign matter and microbial residuals as well as methodologies for assessing and controlling them. Good Manufacturing Procedures (GMP), Association for Advancement of Medical Instrumentation (AAMI) guidelines and more recently the ISO 13485 guidelines have greatly improved the control of orthopedic implant cleanliness. However, these systems do not include any specific limits, methodologies or definitions of cleanliness.
In 2000 a major international orthopedic device manufacturer faced a recall believed to be a result of residual processing materials on the implants. This event spurred the industry to improve the control of implant device cleanliness, both for processing material and microbial residues. In 2001 the American Society for Testing Materials International (ASTM) organized a cleanliness testing task group under its main committee on Medical and Surgical Materials and Devices (F04) to begin developing standard methodologies and limits for orthopedic implant device cleanliness. In 2005 this group produced its first international standard (F-2459) describing how to quantify the amount of residual processing materials present on a device (chemical cleanliness). This paper will discuss the current state of standardization of orthopedic implant device cleanliness, its future needs and some difficulties that must be overcome for successful global standardization.
Summary: Historically, assessment of the cleanliness of orthopedic implants was largely based on visual, microbial and clinical evaluations. There were no specific industry or international standards defining cleanliness or a consensus on the best methods to evaluate an orthopedic implant's cleanliness. Recognition of the importance of minimizing and controlling the cleanliness of an implant is not a new concept, but standardization is still mostly nonexistent. This presentation reviews the recent advances in this area and discusses its future needs.
