A new category of bone graft
Understand three key factors that will help you choose a bone graft substitute wisely.
The bone formation process is a complex series of biological and chemical events that is described by a collection of complicated and, at times, confusing words and phrases. Buried within those acronyms and scientific terms are the basic components required for new bone to form – scaffold (the workplace), cells (the workers), and signals (the work instructions). Autograft provides all three components and is, therefore, considered the gold standard all bone graft materials are developed to meet.
When choosing a bone graft, the characteristics of the bone graft should be matched with the specific needs of the patient, the surgical procedure, and the desired outcome. Understanding how it works, what makes it work, and having proof that it works are all key to making an educated decision.
How It Works
Within tissues are cells that are controlled by and interact with Type I collagen. Many of these connective tissue cells are “attachment activated“. This means that the cells seek out attachment points on the Type I collagen, become attached, and activate the cascade of events leading to bone formation. How the bone graft material responds to these cells is referred to as the mechanism of action. The core elements of this response are:
- Providing a scaffold for local cells (osteoconduction)
- Providing instructions to local cells (osteoinduction)
- Introducing donor cells (osteogenesis)
i-FACTOR Bone Graft is based on the biological activity of the synthetically derived 15-amino acid peptide found naturally in Type I human collagen. This 15-amino acid peptide (P-15) is responsible for the attachment and proliferation of osteogenic cells. These cells have an affinity for and attach to the P-15 found in i-FACTOR Bone Graft in a similar way they would naturally with Type I collagen in bone.
i-FACTOR Bone Graft facilitates and expedites the ingrowth of bone by promoting the migration of mesenchymal stem cells and other progenitor cells from surrounding tissue.
The high affinity between cells and P-15 supports the physiological mechanism of action in which cells bind to the P-15 and “turn on” to perform their genetically programmed job of making bone.
The novel i-FACTOR Bone Graft “Attract, Attach, Activate” mechanism of action enhances the body’s natural bone healing process.
What Makes It Work
The way a bone grafting technology works depends on many factors including the properties of the graft itself. Whether natural (allograft, simple demineralized bone matrix) or synthetic (hydroxyapatite, calcium phosphate), structure is key to an osteoconductive scaffold providing a suitable workplace for bone forming cells. Resorption time, porosity, and mechanical strength can vary widely in this class of products. An osteoinductive bone graft (rhBMP, formulated DBM) is defined as a material that can induce the differentiation of mesenchymal cells into osteoblasts. Only a bone graft that is preserved with an osteoinductive factor (e.g., members of the transforming growth factor family) can be considered osteoinductive. Where rhBMPs have been engineered to maintain the growth factors, the processing of DBMs causes significant variability in the amount of osteoinductive factors that remain in the final product. A bone graft is considered osteogenic if it contains living osteogenic cells that are able to survive in the host environment. Some would suggest that this only occurs when autogenous bone has been implanted immediately or when a bone graft substitute has been enriched with autogenous cells. Unfortunately, the viability of cells in non-vascularized, processed allogeneic bone grafts (cellular bone matrix) is unknown.
i-FACTOR Bone Graft is a peptide bone matrix (PBM) – a composite bone substitute consisting of a synthetic collagen fragment (P-15) bound to calcium phosphate particles. As an engineered product, P-15 quantity and viability remain consistent from lot to lot.
Proof It Works
Evidence comes in many forms – with personal experience being the most credible. But before personal experience can be gathered, most bone graft materials must be evaluated under the regulation of the FDA. Tissue products (cellular bone matrices and simple allografts) are not required to provide any clinical proof of safety or performance to the FDA. Evidence supporting device products (formulated DBMs and synthetics) must compare favorably in animal studies to a similar bone graft material already on the market. A drug/device combination (peptide bone matrix and rhBMP) is proven in a human clinical trial.
The U.S. FDA IDE pivotal clinical study was a prospective, randomized, multicenter study comparing i-FACTOR Putty to autologous bone (control) in patients with degenerative cervical disc disease who underwent a single-level instrumented anterior discectomy and fusion procedure. Patient enrollment was completed in May 2013 with a total of 319 patients participating in the study. The key study results – Fusion Rates, Neck Disability Index (NDI), Neurological Outcome, and Complication Rates – were assessed at 12 months after surgery. Most of the patients in the study have been followed for up to six years. The one-year results of this study have been published in the peer-reviewed journal Spine.