Cleaning of Orthopaedic Implants before Sterilization
- Thread starter mpfizer
- Start date
P
phloQS
Hi mpfizer,
There are no such standards for implants you can refer to. In our company we ve made a comparison between exposion of humans to pesticides trough drinking water. The amount of these pesticides is about 5µg per liter (Germany)->Three liters a day-> 1.5µg a day. The cleanliness of the implants in regard to all residues should be smaller. All residues on the surface of Implants should not be that toxic as pesticides.
Our NB follows this argumentation
Regards
phloQS
There are no such standards for implants you can refer to. In our company we ve made a comparison between exposion of humans to pesticides trough drinking water. The amount of these pesticides is about 5µg per liter (Germany)->Three liters a day-> 1.5µg a day. The cleanliness of the implants in regard to all residues should be smaller. All residues on the surface of Implants should not be that toxic as pesticides.
Our NB follows this argumentation
Regards
phloQS
I
iamtroll
I don't have direct experience with gamma sterilization, but I worked in EO sterilization for several years. The cleanliness required was a combination of the bioburden (tested for prior to sterilization validation) and the ability of the EO to kill the bacteria Bacillus subtilis. Normally a sterilization validation is carried out to determine the level of EO that would achieve the result of The Sterility Assurance Level, after a certain specified exposure to ethylene oxide is 10−6, meaning that the chance of finding a single bacterium is below 1 per million. I would expect that the specifications for gamma Sterilization Assurance Level would be similar if not identical in requirements and that a search of this site or the internet would produce references that you could utilize to determine what the bioburden might be.
The sterilization process on the other hand would be dependant on the configuration of you product and how it was package when it was subject to the gamma sterilization and so could only be deternined through direct validation or by similarity to another existing product and packaging.
Hope that this helps.
JeantheBigone
Quite Involved in Discussions
Usually cleaning is done by a contract supplier. There is a list of accepted cleaning agents and also forbdden chemicals. I am not sure if these are the same in all countries.
It also depends on what has been done, has the implants been grit blasted, acid etched etc. The purpose of the cleaning is to ensure that no residue remains from prior processes, particularly aluminum oxide particles, which can wreak havoc. Or even cutting oil!
This is mentioned in an FDA Guidance Document for dental implants.
http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm072424.htm
In the section on blasted surfaces they mention chemical analysis and SEM to verify the cleaning procedure. We've used XPS (x-ray photoelectron spectroscopy, aka ESCA, Electron Spectroscopy for Chemical Analysis) as the chemical analysis procedure in FDA submissions.
Take a look at this protocol for cleaning and sterilizing implants which are supplied non-sterile, it might be useful.
http://www.synthes.com/sites/NA/Documents/implants.pdf
It also depends on what has been done, has the implants been grit blasted, acid etched etc. The purpose of the cleaning is to ensure that no residue remains from prior processes, particularly aluminum oxide particles, which can wreak havoc. Or even cutting oil!
This is mentioned in an FDA Guidance Document for dental implants.
http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm072424.htm
In the section on blasted surfaces they mention chemical analysis and SEM to verify the cleaning procedure. We've used XPS (x-ray photoelectron spectroscopy, aka ESCA, Electron Spectroscopy for Chemical Analysis) as the chemical analysis procedure in FDA submissions.
Take a look at this protocol for cleaning and sterilizing implants which are supplied non-sterile, it might be useful.
http://www.synthes.com/sites/NA/Documents/implants.pdf
M
MIREGMGR
Focusing only on sterilization and bioburden, and not associated issues such as pyrogenicity or gamma dosage materials effects:
Conceptually, there is no requirement for a particular level of pre-sterilization cleanliness. The requirement instead is that you validate your sterilization process for a particular "normal worst case" amount and type of contamination, then never exceed that amount and type of contamination during production operations.
Thus, the point for you is to figure out what range of cleanliness-level you can achieve on an absolutely consistent basis, then conduct your sterilization validation with samples that are at the worst case edge of that range of contamination levels.
As it has been stated already, there are no specific requirements of cleanliness prior to gamma irradiation, the requirements just state that it should be controlled.
You do have to validate your sterilisation process and depending on the route this can set a "cleanliness"
ISO 11137 is on defines the validation requirements for sterilisation by radiation. The most common (and easiest method) to validate is the VDmax method. This requires a bioburden of less than 1000cfu to be valid.
Other things you need to consider for cleanliness and aren't measured by bioburden testing are:
pyrogenicity
non-biological contamination (i.e. manufacturing lubricants/oils)
You do have to validate your sterilisation process and depending on the route this can set a "cleanliness"
ISO 11137 is on defines the validation requirements for sterilisation by radiation. The most common (and easiest method) to validate is the VDmax method. This requires a bioburden of less than 1000cfu to be valid.
Other things you need to consider for cleanliness and aren't measured by bioburden testing are:
pyrogenicity
non-biological contamination (i.e. manufacturing lubricants/oils)
M
MIREGMGR
"Active" and "orthopedic" are usually mutually exclusive, though, with the exception of experimental thought-controlled powered appendages and the like.
There are a few devices that overlap. For instance, there is a company that makes replacement leg bones (for treatment of osteosarcoma) that incorporate a motor driven screw to allow the length of the implant to be increased so that a growing paediatric patient can have the adjustment without further surgery.
But I was just suggesting 45502 as the source of a possible test even if not totally the right standard. The test involves washing in saline and gives limits for allowable particle size and quantity per volume and is itself based on a pharmaceuticals test.
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