In the process of screening evaluation lab methodology for the purpose of understanding what happened to the hip implant, the following points have been raised about the exam protocol which was attached as exhibit A in the explant preservation and examination order issued by the MDL:
(1) There is no requirement to obtain exact wear measurements on the implant which will tell the patient at the end, how much metal went into their body.
(2) co-ordinate measuring machines specified in the MDL order give wear volumes and out-of-roundness machines give wear depths, however the procedure appears to ignore the use of such machines for wear measurements.
(3) Instead, the procedure suggests studying articulating surfaces of failed hips by eye, and evaluating them qualitatively to determine the damage to them.
- In reviewing the summary of the requested inspection and capabilities, this is what they are requesting in the order:
- photography of components as received
- photography of the decontaminated components
- Macro and sterocommicroscopic exam of each component
- general shape, staining etc
- using a coordinated measurement machine (CMM) to do surface profiling for measurement to engineering drawings
- Surface finish measurement.
- I can see in this order that there are suggested machines to use during this evaluation by the MDL/Depuy agreement but I do not see any where in the exhibit a srequest to report how much metal went into the patient's body as a result of this hip wear. Here is the equipment recommended for use though:
- digital camera with certain specs
- Optical steromicroscope
- Coordinate measurement machine
They are often used for:
- Dimensional measurement
- Profile measurement
- Angularity or orientation measurement
- Depth mapping
- Digitizing or imaging
- Shaft measurement
- contact profilometer
As you all know, I have no science training whatsoever. I am merely sharing information and observations that I find in my investigation for my own case. I agree with the observation that what I want to know from the "wear analysis" is how much metal has gone into my body. If the current protocol recommended by the MDL doesn't provide that answer, that is a problem.
Apparently, there are a few labs in the world that have the equipment capable of rendering the measurement which results in the answer to the question: how much metal has gone into the person's body. The equipment required to do that is a high precision coordinate measuring machine coupled with customized software written to determine the ware volumes (exact measurements).
As I uncover additional information on this subject, I will let you know. I have a few weeks off over the holiday and was planning on focusing on the DNA testing but I need to finish this exploration first.