Allografts 101 Flashcards
What is bone grafting?
The healing of two bones to one another.
(Stops motion and thereby pain.)
Or to fill a void (restore bone strength)
What are the two primary types of grafts?
Structural-struts, shafts, etc…
And osteobiologics - more regenerative and not structural
What are the reasons for bone grafting? 5
Trauma Degeneration Osteolytic Neoplasm - destructive tumor Iatrogenic - caused by surgery Implant failure - joint reconstruction failure
Whats the bone graft market in 2017
2.3 Billion
80% spine
10-15% foot and ankle
Average age for fusion is 54.2
What 3 characteristics does autograft provide?
- Scaffold - provides structure to guide the formation of new bone
- Signal - Naturally occurring growth factors recruit host cells and guide the formation of new bone
- Cells - Host cell population to support bone growth
Why was allostem developed?
To approximate the desired qualities of autograft bone
What are the 3 characteristics of allostem?
- Cells - Replace natural cell population to support bone growth
- Scaffold - Allograft bone provides ideal structure to guide the formation of new bone.
- Signal - Naturally occurring growth factors present in allograft bone recruit host cells and encourage the formation of new bone
Types of autograft
Source: patient
Iliac crest
Spinous process
Types of Demineralized Bone Matrix Putty
Source: Allograft donor
AlloFuse
Grafton
DBX
Types of Demineralized Bone Fibers
Source: Allograft Donor
3Demin
Vesuvis
Types of Synthetics
Source: Various
ViToss
TCP
HA
Types of Bone Morphogenic Protein
Source: Grown in mammalian model
InFuse
Types of Cellular Allograft
Source: Allograft donor
AlloStem
OsteoCel
Trinity
Types of Bone Marrow Aspirate
Source: Patient
ProCuRE
Retrieve
Types of Platelet Rich Plasma
Source: Patient
Harvest
Angel
Amniotic Derived Cells
Source: Allograft donor
BioD
NuCel
What are Embryonic Stem Cell characteristics?
Harvested from human embryos
Pluripotent - can become any type of cell
Uncontrolled growth an issue
Can become liver, spleen, kidney, etc…
What are Adult Stem Cell characteristics?
Recovered from adult tissue
Multipotent
Limited growth
Can only differentiate into fat, cartilage or bone
What is a mesenchymal stem cell?
- Capable of repairing and/or differentiating into fat, cartilage/muscle, or bone
- Can be transplanted from donor to recipient without stimulating and immune response
- Must be able to attach to a viable substrate
How are cells and DBM substrate combined?
Single donor
Adipose recovery/washing
Enzymatic digestion
Centrifutgation
/
Cancellous bone recovery
Demineralization process
/
Combined cells onto bone grafts
Cell selection and bonding
Rinse
Cryopreservation
How many products have a super concentration of mesenchymal stem cells adhered to a demineralized bone scaffold?
Only 1 - Allostem
How do we know that it’s MSC that are adhering to the DBM?
Defined by the International Society of Cellular Therapy to have 3 characteristics
- must adhere to scaffold
- Must stain positive for certain surface markers
- Must be able to differentiate into bone, fat or cartilage cells
How many MSC’s per cc in Allostem?
66,255k
How many MSC’s do you need per cc of cellular allograft?
We don’t know
One study suggested 30k per cc
Allostem vs. Bone Marrow Aspirate concentration
Allostem 66k
Bone-Marrow Aspirate BMAC 2500/cc upon implantation
Allostem lacks immunogenic components
Our adipose cell concentration, or stromal vascular fraction, contains MSC’s, leukocytes, erythrocites, etc
Allostem combines the SVF onto the bone graft
MSC’s adhere to the substrate
Therefor most immunogenic components wash off in the rinse leaving behind a high concentraiton of MSC’s that adhere to the bone.
How do we know MSC’s adhered and the immunogenic components rinsed off?
We took a picture under a high powered microscope
What are leukocytes?
White Blood Cells
are the cells of the immune system that are involved in defending the body against both infectious disease and foreign invaders.
What are erythrocytes?
Red blood cells, also called erythrocytes, are the most common type of blood cell and the vertebrate organism’s principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system.
What do MSC’s on allostem Show?
Strong osteogenic proliferative ability
Adipose cells vs Bone Marrow Cells
Equally good at producing bone
They both contain MSCs
The difference is there are many more MSCs in Adipose tissue when compared to Bone Marrow Cells.
Typical bone marrow will have 250,000 MSCs and Adipose will have 18,000,000 MSCs from Adipose
Even in ideal conditions, what needs time to adhere to the scaffold?
MSCs
Important when considering irrigation
How long is typical graft prep?
10-15 minutes
Only 6.2% will stick to the desired scaffold
What type of scaffold does Allostem use?
Nature’s scaffold
Cells prefer the naturally occuring boney nanostructure to synthetics by nearly 2x the rate of leading synthetics
Does Allostem adapt to different cage designs?
Yes. Whether you perform cervical, deformity, MIS, lateral, stand-alone, etc, Allostem has a product to fit their needs
What does demineralization create?
A more biologically active graft with all-natural growth factors in quantities safe for bone growth
Where are BMPs found?
Naturally in demineralized bone
What are the BMPs key in growing new bone?
BMP 2 and BMP 7
How long has DBM been used?
40+ years
What type of BMP is InFuse?
rhBMP
What are the down sides of InFuse?
Can create too much bone growth
Linked to a number of cancer, ectopic bone growth and sterility
How much more BMP is there in rhBMP than in standard DBM?
1,000,000x more
What is the Allostem quality process?
Tissue donation Rigorous donor screening Rigid recovery procedures Extensive donor testing Aseptic processing Post-processing review Terminal sterilization - where appropriate Allograft distribution
