Bone Grafts
Focus on autograft
Composition
Donor bone from patients own iliac crest (gold standard)
Pros
- Cheap (but prolonged surgery time)
- Osteogenic, osteoconductive and osteoinductive
- Extensive clinical experience
Cons
- Warrants 2nd operation
- Pain from harvest 6-8
- Donor site morbidity 6-8
- Limited availability
- Quality donor dependent
Focus on allograft
Composition
Donor bone from another patient (femoral heads)
Pros
- Osteoconductive
- No pain complications
- Good availability
- Extensive clinical experience
Cons
- Risk of disease/virus transfer
- Risk of graft rejection
- Variable quality (donor specific)
- Expensive (>600 Euro/femoral head)
Focus on BMP’s
Composition
Re-combinant produced materials in Chinese hamster ovaries
Pros
- Osteoinductive and somewhat osteoconductive
- Effective (Fusion levels PLIF 60-100%) 15
- Extensive clinical experience
Cons
- Expensive
- Dose not optimal (super physiological)
- Can have both a anabolic or catabolic effect on bone regeneration
- High complications rate reported in spinal surgery
- In general BMP-2 direct bone formation and BMP-7 endochondral bone formation
Focus on DBM
Composition
DBM ➔ exposing allograft bone to demineralizing agents
(hydrochloric acid) affecting handling,osteoconductive / osteoinductive potential
Pros
- Good handling properties (easy to mold/shape)
- Various growth factors in material
- Extensive clinical experience
Cons
- Risk of disease / virus transmission
- Variable quality (donor specific)
- Inconsistent osteoinductive (BMP % variable and low)
- Minimal osteoconductive
- No FDA device approval (DBM minimally manipulated tissue for transplantation)
Focus on Ca-P ceramics
Composition:
- Hydroxylapatite (HA)
- Tricalcium phosphate (TCP)
- Biphasic
- One of the above with added material Si, Mg
Pros
- Osteoconductive
- No risk of disease/virus transfer
- Availability every shape, porosity, composition
- Unlimited supply / long shelf life
Cons
- Handling differs among products
- Never osteoinductive by themselves
- Large variance material properties, level of evidence
Focus on bioactive peptides
Composition:
- I-FACTOR P-15 peptide
- Type 1 collagen derivative + ABM
Pros
- Osteoconductive with osteoinductive properties (increase expression of BMP2)
- Effective (fusion levels: ACDF (+88%), PLIF (+97%), ALIF (+94%), TLIF (+83%))
- Safe (peptide with high degree of biological specificity)
- Proven (extensive clinical experience, Level I data (cervical and lumbar))
Cons
- More expensive than standard osteoconductive scaffolds
- Limited product forms
Potential BMP drawbacks (dosage, complications and costs) may be waylaid using bioactive peptides
I-Factor P-15 mechanism of action
Recruitment osteogenic precursor cells by making P-15 binding sites available for cellular adhesion.
The high affinity between cells and the P-15 peptide supports the natural physiological mechanism by which cells attachment and interact with Type I collagen.
The P-15 peptide enhances bone formation by activation natural mechanical and chemical signalling pathways within the cell stimulating the release of specific growth factors and creating a microenvironment conducive to new bone formation.
Bone Fusion Materials
BMPs
- Bone formation activity very fast and high amount new bone
- Bone remodeling quick <3M
- Bone resorption activity high (anabolic and catabolic effect) <3M
AUTOGRAFT
- Bone formation intermediate , medium amount new bone
- Bone remodeling timely 3-6M
- Bone resorption activity physiological 6M
Bioactive peptides
- Bone formation quick (less high as BMPs, higher as autograft)
- Bone remodeling quick <3M
- Bone resorption activity physiological 3-6M
Ca-P ceramics
- Bone formation slower as BMP, bioactive peptides, autograft
- Bone remodeling slow (material dependent) -> creeping substitution
- Bone resorption slow (material dependent) TCP 12-18M / HA 5-10YRS
DBM
- Bone formation activity lower as BMP, bioactive peptides, autograft
- Bone remodeling intermediate (material dependent) -> creeping substitution
- Bone resorption activity slow (material dependent) 6-12M