ABM/P-15 Bone Graft vs Traditional Bone Graft in Adult Spinal Deformity Surgery - a Randomized Controlled Clinical Trial

2. Description and classification of medical device

i-Factor Peptide Enhanced Bone graftTM: "i-FACTOR Bone Graft is a pure, natural form of hydroxyapatite (anorganic bone mineral or ABM) containing P-15™, a synthetic peptide. It is provided in putty form, comprised of ABM/P-15 particles that are suspended in an inert biocompatible hydrogel. Hydroxyapatite is the major mineral component of bone. P-15 is a fifteen amino acid sequence polypeptide, a portion of Type-I collagen that serves as a biomimetic attachment site for bone cells. The hydrogel carrier (glycerin and carboxymethylcellulose, or CMC) forms the matrix that improves overall the handling characteristics and helps contain the i-FACTOR Bone Graft at the surgical site. The bovine-derived ABM particles within the matrix are radiopaque and sized between 250 and 425 microns. i-FACTOR Bone Graft provides a bone graft substitute that is remodeled into new bone during the natural healing process." The i-Factor Peptide Enhanced Bone graftTM is classified as a CE-marked class III medical device.

i-Factor flex FRTM: "i-FACTOR Bone Graft is a pure, natural form of hydroxyapatite (anorganic bone mineral or ABM) containing P-15, a synthetic peptide. i-FACTOR Flex FR is comprised of ABM/P-15 particles that are suspended in an inert biocompatible carrier, and has been lyophylized (freeze-dried) to form flexible strips. Hydroxyapatite is the major mineral component of bone. P-15 is a fifteen amino acid sequence polypeptide, a portion of Type-I collagen that serves as a biomimetic attachment site for bone cells. The carrier (carboxymethylcellulose, glycerin, and purified silk) forms the matrix that helps contain i-FACTOR Flex FR at the surgical site. The bovine-derived ABM particles within the matrix are radiopaque and sized between 250 and 425 microns. i-FACTOR Flex FR provides a bone graft substitute that is remodeled into new bone during the natural healing process." The i-Factor flex FRTM is classified as a CE-marked class III medical device.

Rationale for the project ASD is associated with excessive pain, severe disability and significantly reduces health-related quality of life. Surgical treatment is often considered the only viable option in patients with severe ASD, although surgery is associated with certain risks. In ASD surgery, the risk of revision surgery due to either postoperative mechanical failure of the implants or pseudarthrosis is common. Although several changes to treatment have been implemented in the last decade, revision surgery is still common and necessary in up to 30% of patients following the index procedure. Therefore, increased attention has been directed towards reducing the risk of pseudarthrosis, and ABM/P-15 bone graft may play a considerable role in preventing that. The effects have previously been described in patients undergoing cervical spinal discectomy with promising results. Promising results has also been found in the treatment of periodontal infrabony defects through enhanced regenerative bone capacity. Furthermore, ABM/P-15 bone graft in combination with locally harvested autograft has shown superiority compared to allogenic bone graft in non-instrumented posterolateral fusion. The use of ABM/P-15 bone graft has, however, not been assessed in patients undergoing long instrumented spinal fusion surgery which is the case in ASD surgery. The ABM/P-15 bone graft will be used as its CE-mark intends.

Literature Since the introduction of iliac crest bone graft (ICBG) in 1958 leading to enhanced spinal fusion rates and lowering the rate of pseudarthrosis, bone grafts have been widely accepted as a supplement to instrumented fusion. Autologous bone graft taken from the iliac crest is often considered "gold standard" in spinal surgery due to its biomechanical properties of osteoconductivity, osteoinductivity, and osteogenesis. Osteoconduction is the combination of the three-dimensional structure of the bone graft and the capability of new bone formation on this particular scaffold. Moreover, availability of growth factors stimulating undifferentiated pluripotent cells into bone-forming cells is known as osteoinduction. Lastly, osteogenetic properties in bone synthesis rely on the continuous contribution of vital and established osteoprogenitor cells. Autologous bone graft consist of all three biomechanical properties however; the supply of is limited. Additionally, the use of autologous bone graft has been associated to potential donor-site complications, forcing surgeons to look for other viable options such as allogenic bone grafts or other alternatives such as demineralized bone matrix ceramics, bone morphogenetic protein, autologous growth factors, stem cell products (allogenic bone graft cellular matrix), synthetic peptides and bioactive peptides. Allogenic bone graft is described as the transfer between two genetically dissimilar individuals of the same species and is the second most transplanted tissue only surpassed by blood transfusions. Allogenic bone graft bears the properties of full osteoconduction, variably osteoinduction but completely lacks osteogenic properties due to loss of cellular elements. However, industrialized allogenic bone grafts, as well as other non-autologous bone grafts, does have some important advantages compared to autologous bone graft including decreased operative time, decreased blood loss, no donor-site morbidity and finally, almost unlimited quantities. The allogenic bone grafts (morselized femoral heads) from local bone banks are naturally with some restrictions to quantities, however; allogenic bone grafts compared to autologous bone grafts are more accessible.