Practical Aspects of Biomaterials

Question 1

Steam sterilisation?

Answer 1

AD: fast, effective, simple, nontoxic
DIS: all surfaces must contact steam, not for biodeg pols

Question 2

EO sterilisation?

Answer 2

AD: no heat, moisture, low temp, v. penetrative
DIS: highly toxic, flammable, special equip, slow, MW changes in polymers

Question 3

Gamma irradiation?

Answer 3

AD: v. penetrative, effective, quick, nontoxic, no heat, moisture, allows prepackaging and sealing
DIS: expensive, extensive shielding, not for some biomaterials, continuous isotope decay

Question 4

Electron beam sterilisation?

Answer 4

AD: range of materials, similar to gamma
DIS: penetration distance (thin products after packaging only)

Question 5

Implant and device complications

Answer 5

thrombosis
infection
inappropriate healing
structural failure
adverse local tissue reaction
migration
system effects

Question 6

Potential causes of implant failure

Answer 6

Development and individual implant

Question 7

Measurement techniques to predict biomaterial permformance

Answer 7

1 - measure specific surface physiochemical properties and correlate with a biointeraction response such as protein adsorption or blood cell interaction
2 - measure protein adsorption or cell adhesion and predict in vivo performance
3 - measure an animal response to materials and predict clinical perfomance

Question 8

Implant retrieval goals

Answer 8

determine rates, modes and mechanisms of failure
identify effects of patient and prosthesis factors
establish factors that promote implant success
determine dynamics, temporal variations and mechanisms of interactions
develop design criteria of future implants
determine adequacy of animal models
(normalise for patient conditions)

Question 9

Techniques for implant evaluation

Answer 9

Implant
spectrophotometry, fatigue/fracture analysis, GPC
Tissue
spectrophotometry, cell culture, gel electrophoresis, histology, immunochemistry

Question 10

Implant evaluation strategy

Answer 10

Stage I - routine device identification and description
Stage II - photography and non-destructive analysis
Stage III - destructive analytical technique, material specific

Question 11

Orthopaedic plates, screws, rods lessons learned

Answer 11

don’t mix alloys
match the hardness and stiffness
metallic implant wear and corrosion, may be allegeric

Question 12

Femoral stem lessons learned

Answer 12

cobalt allows require high quality casting
welded regions may fail
don’t etch part numbers

Question 13

Cardiovascular lessons learned

Answer 13

caged ball valves absorbed blood lipids and became swollen and brittle
bioprosthetic heart valves - tissue calcification, pronounced in flexion areas and young people