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