Biomaterials L28

Question 1

Define a biomaterial.

Answer 1

A material which does not provoke a negative response within the body.

Question 2

Today’s orthopaedic biomaterials

• ____1____: Cobalt Chromium Molybdenum (CoCrMo); Stainless Steel; Titanium (Ti)
• ____2____: Alumina; Zirconia; blends of Alumina and Zirconia
• ____3____: UHMWPE (ultra high molecular weight polyethylene); XLPE (cross-linked polyethylene); PEEK (poly ether ether ketone) and PEEK blends
• Others: silicone; pyrocarbon; ‘low-wear’ coatings; hydroxyapatite

Answer 2

1. Metals
2. Ceramics
3. Polymers

Question 3

Knee replacements are the most common joint replacement procedure in the UK and the world.

The number of operations increases every year and cannot solely be explained by an increasing and ____1____ population.

A proportion do fail, many of these are linked to wear particle induced ____2____.

Answer 3

1. Ageing
2. Osteolysis

Question 4

‘The joint replacement of choice for several decades’ (Linscheid, 2000)

Name the finger-joint replacement.

Answer 4

Swanson.

Question 5

Why do flexible designs dominate the MCP joint replacement market? (1+5bp)

Answer 5

Positive long-term clinical results have been achieved, particularly by the Swanson design

• Pain relief
• Improved cosmetic appearance
• More functional arc of motion
• Patient satisfaction is high
• Implantation is relatively straightforward, as is removal should it be necessary

Question 6

List the problems with silicone MCP prostheses. (5)

Answer 6

• Fracture rates of up to 82%
• No increase in grip strength
• Minimal increase in range of motion (ROM)
• Silicone synovitis due to wear debris
• Lack of belief in finger arthroplasty by some hand surgeons and rheumatologists

Question 7

Define synovitis.

Answer 7

Inflammation of a synovial membrane.