Orthopedic and surgical implant device manufacturers could be spending more time and money on testing than necessary by not considering family grouping when validating the cleaning and sterilization processes that occur at healthcare facilities. Cleaning and sterilization validations help ensure patient safety and minimize healthcare-acquired infections, corrective actions, and recalls.

Device manufacturers can use worst case or family grouping for the validations of cleaning and sterilization processes that occur at a healthcare facility unless the device is very unique and specialized. These devices must be individually validated.

Cleaning Validation Family Grouping
Performing a cleaning validation aids manufacturers in complying with international and U.S. standards and guidance documents, current good manufacturing practices, and quality systems regulation. To evaluate the effectiveness of the cleaning process, residual testing is performed to identify the presence of markers after cleaning is complete. Protein, hemoglobin, total organic carbon, bacterial endotoxin, bioload reduction, and detergent residuals are some of the tests available to measure the efficacy of the cleaning process. Recommended acceptable levels of each marker are provided in AAMI TIR30:2011, and the results of residual testing will help determine whether a device is appropriately clean. The most recent U.S. Food and Drug Administration (FDA) guidance recommends testing at least two fully quantitative markers for validating manufacturers seeking marketing clearance for their devices. The cleaning markers chosen to be tested should reflect what the device would come in contact with during clinical use.

To save time and money, manufacturers can choose to family group the devices for validation and comply with FDA guidance. There are three main approaches to evaluating whether family grouping for cleaning is appropriate for the medical devices a manufacturer is validating—device use, material type, and size and challenge features.

Device Use: If the devices have similar use during surgical procedures, they may qualify for family grouping. An example of this is drill bits. Devices can be grouped by their function, use, and degree of patient contact based on intended use. Similarly configured devices or parts used for generally the same purpose and that contact comparable amounts of human tissue, blood, mucus, etc. may be grouped together for validation.

Material Type: If a group of devices are made out of the same metals and soft materials, they could qualify for family grouping. One example of this is the parallel graft knife handle. Devices are made from materials ranging from metal to ceramic to polymers, and sometimes, a mix of several materials. Each of these materials holds onto residue differently and, therefore, should be grouped accordingly. For instance, an all-titanium device requires different cleaning considerations than a polymer device with silicone parts and other soft plastics. In addition, devices that are 3D printed present unique considerations for cleaning in that they are typically very textured and porous, and thus, more likely to hold onto residue.

Size and Challenge Features: Medical devices of similar size and challenge features may be grouped together as a family. An example of this is catheters, which require cleaning procedures to ensure the narrowest lumen is thoroughly cleaned. The considerations that are employed in this type of grouping include components and product design and size.

An important aspect of the validation of the cleaning process after the manufacturing process includes using worst-case cleaning parameters and worst-case contamination similar to the manufacturing process.

Another option for determining production variability uses a validation process in which a range of parameters is examined. For example, if a device is cleaned using between 1/8 and 1.0 oz./gallon of detergent, then the validation might include a bracketing validation using the least concentration and the highest concentration to show that any concentration in between would appropriately clean the devices.

Sterilization Validation Family Grouping
A somewhat different approach needs to be taken for determining a worst-case tray for a steam sterilization cycle. Steam sterilization is the most common type of sterilization at a healthcare facility, so that is the focus of this approach. Manufacturers will determine a worst-case tray by the aspects of weight, mass, complexity of devices, volume to vent ratio, and the ability of the tray and all of the devices to allow air removal and steam penetration.

Many locations of the tray can be tested during a steam sterilization overkill approach to validation. Locations within the tray are chosen based on areas that would limit steam penetration; these locations would include locations that would heat up slower (bulky areas of the trays), complexity of devices, lumens, mated surfaces, etc. A biological indicator is placed in each of these locations and tested separately after the half cycle. This worst-case tray may even be considered a master product, which does not just contain devices for one surgical procedure but many complex devices from many types of surgical procedures. Using this information, all of the other sets of trays may be able to be justified from the validation of the master product tray.

Conclusion
Family grouping of medical devices for the cleaning validation or tray types for sterilization validations is very important, as validating every device or tray is not an option due to the cost and time of the validations. It also is unnecessary. The justifications for choosing family grouping or worst-case devices and why other devices and trays would fall under these categories must be submitted to the FDA or another regulatory agency, or filed in case this information is requested at a later date. 

---

Nick Workman, CQPA (ASQ), is currently a study director III, and specializes in and consults with clients about cleaning, disinfection, and sterilization of reusable medical devices. His current role includes operating in-house validations and R&D testing, assisting with section training modules, and mentoring and presenting the cleaning and disinfection portion the Sterilization Specialist class.

Emily Mitzel, M.S., B.S., is a consulting manager at Nelson Laboratories. Her expertise includes reusable device reprocessing validations, pharmaceutical testing, and microbiology testing. Emily presents at Nelson Laboratories’ seminars and client facilities across the U.S. and Europe. She is an active committee member of many working groups with the Association for the Advancement of Medical Instrumentation (AAMI) and American Society for Testing and Materials (ASTM).