e1
QUESTIONS
1. The following statements characterize, in part, the
goals and specific aims of an implant retrieval and
evaluation program. Answer True or False.
a. Determine rates, modes, and mechanisms of
implant failure;
b. Identify effects of patient and prosthesis factors
2. Indicate five patient conditions that may influence
orthopedic device failure or success.
a. Polyarthritis syndromes;
b. Connective-tissue disorders;
c. Osteoarthritis;
d. Trauma;
e. Infection;
3. Indicate five patient conditions that may influence
cardiovascular device failure or success.
a. Atherosclerosis;
b. Diabetes;
c. Infection;
d. Hypertension;
4. What are the two common mechanisms of failure of
prosthetic heart valves, vascular grafts, and cardiac
assist devices?.
5. What is the most common mechanism of failure of
7. True or False?: Analysis of retrieved orthopedic and
cardiovascular implants has revealed that PTFE
(Teflon®) was a good choice for bearing surfaces and
components subject to wear.
8. The wear of polymeric materials often results in par-
ticles visible in microscopic evaluation of adjacent
tissues.
12. Retrieved devices should be thoroughly cleaned
before being examined.
13. Infection as a cause of implant failure is diagnosed
only by bacterial culture and histological examina-
tion of the tissues is not of value.
14. Acute inflammation at the site of an implant in place
tory of the patient nor why the device was removed.
b. The investigator removes the device from the
formalin, rinses it, and scrapes off the adherent
tissue.
c. All the scraped off adherent tissue is sent to the
laboratory for routine embedding in paraffin and
e. The investigator reports that the material is 316
LVM stainless steel with no evidence of corrosion
or failure.
16. Why is it important to consider implant analysis in
CHAPTER III.1.5
Implant Retrieval and Evaluation
2
18. True or False: Minor changes in implant design and
manufacture are inconsequential.
19. Describe three instances where implant retrieval
20. Why retrieve and evaluate implants performing well?
ANSWERS
1. a. T
b. T
c. T
f. T
2. Any five (a through k) are true
3. Any five (a through i) are true
5. Intimal hyperplasia.
6. Calcification (atherosclerosis).
16. Various diseases/conditions and other patient vari-
ables such as recipient activity level, as well as the
circumstances occurring during implantation sur-
fication, and mechanical failure modes.
18. False. There are many instances, some of which are
described in this chapter, where minor changes in
implant design intended to decrease the propensity
to a particular complication, have inadvertently had
serious unintended consequences (see case study –
Björk-Shiley heart valve prosthesis).
19. See Table III.1.5.8 of this chapter.
provided that a focused question is asked. For exam–
ple, after implant retrieval studies of a low-profile
disk valve composed of a disk and cage fabricated
parts fabricated from pyrolytic carbon was intro-
duced. Retrieval studies of carbon valves recovered