Bone Grafts And Orthobiologics

Question 1

What are some benefits of bone grafts

Answer 1

• important in treatment of nonunion
• Fill large defects
• Structural integrity
• Increase vascularity

Question 2

What is the gold standard for bone grafts

Answer 2

Authogenous grafts

Question 3

Describe the properties of Autogenous grafts

Answer 3

• osteogenic
• osteoconductive
• osteoinductive

Question 4

What are some common sites for harvesting Autogenous bone grafts

Answer 4

Calcaneus
Tibia
Fibula
Iliac crest

Question 5

What is the importance of the cortical portion of the corticocancellous bone grafts

Answer 5

Structure and length

Question 6

What is the importance of the cancellous portion of corticocancellous bone in a bone graft

Answer 6

BMP mediates osteoprogenitor/MSCs, necessary for incorporation

Question 7

What is the trephine technique

Answer 7

• percutaneous
• largely cancellous,
• good for small defects
• can be mixed with other products

Question 8

What is the maximum free graft that can be interposed/implanted

Answer 8

2.5cm

Question 9

If greater than 2.5cm of bone graft is needed, what can be done

Answer 9

• onlay/inlay graft
• bone transport
• vascularized graft

Question 10

What are the properties of allogenic grafts

Answer 10

• osteoinductive
• osteoconductive

Question 11

What is the advantages of allogenic grafts

Answer 11

• no donor sire morbidity
• decreased OR time

Question 12

The success of orthobiologics depends on what

Answer 12

• vascularity
• surgical intervention with adequate preparation
• proper alignment
• application of stable fixation

Question 13

What is he make of of osteoinductive orthobiologics

Answer 13

• PRP
• BMP
• Growth factors

Question 14

Wha is the make up os osteoconductive orthobiologics

Answer 14

• DBM
• Bioceramics
• Bioglass

Question 15

What is the make up osteogenic orthobiologics

Answer 15

• Mesenchymal stem cells

Question 16

Describe the osteoinductive PRPs

Answer 16

Platelet Rich Plasma
- used for bone, ligament and tendon healing
- centrifuging the patient’s blood to separate out and obtain a gel-like concentration of growth facts
- PRP injected in and around the surgical site

Question 17

How many BMPs are recognized and how play a role in bone healing

Answer 17

• 20 recognized
• 7 play a role in bone healing

Question 18

The BMPs that play a role in bone healing belong with which family

Answer 18

TGF-beta superfamily

Question 19

Describe osteoinductive growth factors

Answer 19

• naturally occurring and are prominent at various phases of the healing process

Question 20

What happens when PDGF is combined with tricalcium phosphate

Answer 20

An osteoinductive and conductive substrate is produced

Question 21

What is osteoconductive DBM

Answer 21

Processed allograft - lacks mineralization but retains growth factors and collagen

Question 22

Describe how DBM is prepared

Answer 22

• combinations of acids or detergents/solvents
• antibiotics and freeze dryin

Question 23

Is DBM osteoconductive or osteoinductive

Answer 23

Can be both osteoconductive and osteoinductive

Question 24

What is the disadvantage of sterilizing DBM with gamma irradiation, formaldehyde and/or ethylene oxide prep?

Answer 24

It will strip the osteoinductive properties of DBM

Question 25

What is one benefit of DBM

Answer 25

It comes in many forms: gel, putty, sheets and chips, different strengths and pliability

Question 26

What are the most common materials for osteoconductive Calcium based bioceramics

Answer 26

- hydroxyapatite ** - tricalcium phosphate ** - ceramics - fibrillation collagen - and/or coralline hydroxyapatite

Question 27

What are the two important considerations for osteoconductive calcium based bioceramics

Answer 27

- calcium-phosphate ratio - Pore size of the graft

Question 28

Why is the calcium-phosphate ratio of calcium based bioceramics important

Answer 28

- it dictates the rate of absorption - when filling a bone void, the rate of resorption cannot exceed the rate of bone deposition because that will destroy our scaffolding

Question 29

What is the ideal and most widely accepted resorption to bone deposition ratio

Answer 29

1.5 - 1.67

Question 30

Why is pore size of the calcium based bioceramics graft important

Answer 30

- pore size is critical to allow influx of appropriate cells and growth factors and subsequent osteogenesis

Question 31

What is the idea pore size of calcium based bioceramics graft that have yielded better angiogenesis and healing

Answer 31

300 micrometers or greater

Question 32

What is one benefit of using calcium sulfate and calcium phosphate in combination as a bone graft

Answer 32

Greater compressive strength

Question 33

Which bone graft may be combined with antibiotics to treat infections while serving as a filler? What does that mean for Autogenous graft?

Answer 33

Bioceramics Decreases the need for Autogenous graft

Question 34

What is the advantage of using bioceramics combined with antibiotics over polymethylmethacrylate beads

Answer 34

Bioceremics are absorbable and does not need removal

Question 35

What is osteoconductive bioglass made of

Answer 35

Calcium Phosphorous Silicon dioxide

Question 36

Which graft has osteoconductive and osteointegrative properties

Answer 36

Bioglass

Question 37

What is the importance of the osteoconductive and osteointegrative properties of the bioglass

Answer 37

Binding with hydroxyapatite forming a scaffold for healing, which is subsequently resorbed

Question 38

What is the importance of the calcium phosphate deposition from bioglass

Answer 38

Attracts osteoblasts which results in electrical bone growth stimulation

Question 39

Which bone graft has intrinsic antomicrobial activity due to the additional bactericidal activity from its components

Answer 39

Bioglass - possible enhance bone tissue regeneration

Question 40

What is a key feature of Osteogenic MSCs

Answer 40

Can differentiate into osteoblasts and chondroblasts

Question 41

What is a common source of osteogenic MSCs

Answer 41

bone marrow aspirate (BMA) - tibia using jamshidi or syringe

Question 42

What is BMA containing MSCs typically combined with

Answer 42

DBM or calcium-based bioceramics - to get all three components we’re looking for

Question 43

What is the risk associated with allogenic MSCs

Answer 43

Cross-reactivity

Question 44

Is the chance of cross-reactivity in allogenic MSCs high

Answer 44

Studies show low potential for rejection as well as high content of viable cells at time of implantation with resultant osteogenesis