Self-test - Orthopaedic Biomaterials in Research and Practice - page 421

19. Wear debris (select the phrase that best completes the sentence)

A. Are unimportant in vivo ___

B. May contribute to device “loosening” ___

C. May produce “third-body” wear ___

D. Are trapped in situ ___

E. None of the above ___

(5)

20. Consider the following wear-debris-response relations ( true or
false ):

A. In a metal-on-polymer articulation, the polymer component
will more likely wear.

____

B. In a ceramic on metal articulation, the ceramic component will
more likely wear.

____

C. Metallic wear particles are generally smaller than polyethylene
wear particles.

____

D. A particle size greater than 100 μm is required to induce
osteolysis.

____

E. Like pairs of materials tend to show higher wear rates than
unlike pairs.

____

(5)

21. Poly(methylmethacrylate) bone cement (PMMA) ( true or false )

Has a higher tensile modulus than cortical bone

___

When newly mixed, sticks to old PMMA in situ, in vivo

___

___

Is notch sensitive

___

Can be used to bear load in bone defects

Is naturally radiopaque

___
(5)

22. Composite materials (select the phrase that best completes the
sentence)

A. Combine the properties of their phases ___

B. Have the wear properties of their major phase ___

C. Have isotropic mechanical properties ___

D. Can mimic mechanical properties of hard and soft tissues ___

E. None of the above ___

(5)