Bone substitute material

As a bone substitute material in medicine artificially generated or derived from animal or human bone is used when own bone for filling accident inflammatory, or tumor-related bone defects is not available or can not be taken in sufficient quantity.

Bone substitute material is mainly used in trauma surgery and orthopedics as well as in neurosurgery and in dentistry and oral and maxillofacial surgery . An ideal bone substitute material should have sufficient stability and meet the three basic conditions for new bone formation:

• Osteoconductivity: the surface of the material allows the immigration and attachment of connective tissue cells
• Osteoinduction: the bone substitute attracts the body's own connective tissue stem cells and causes them to settle on the material.
• Osteogenesis: The bone substitute actually creates permanent new bone, which slowly takes over the function of the substitute material.

If, on the other hand, your own bone is removed from another location in order to fill in a bone defect, it is an autogenous bone transplant , and if a donor bone is used, it is an allogeneic bone transplant . For the former, bone is often removed from the iliac crest in the form of bone marrow or as bone graft, but removals from the shin near the knee or the radius near the wrist are also not uncommon. As donor bones, femoral heads are often used, which are removed as part of an implantation of a hip endoprosthesis and are preserved in a bone bank, but tubular bones and the like are also used. a. available.

Dentistry

In dentistry, bone substitute material is sometimes used to fill larger cavities after extractions or resections . The aim is to prevent the cavity from growing through with soft tissue and to accelerate bone formation, since only bone forms a stable basis for teeth , implants and prostheses . The bone substitute material is usually in the form of small spheres (granules).

The use of bone substitute material of biological or synthetic origin in dentistry is quite expensive and also not undisputed, since the bone substitute material is often not built through with stable bone tissue as desired by the body.

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Orthopedics and trauma surgery

According to an English study, there were a total of 59 bone substitute materials on the British market in 2013, from 17 different companies. Because they are considered medical devices ; No proof of efficacy and no clinical study is required for approval . Thus, the authors found only 22 of these products (37%) at all scientific publications with clinical data and only for the four products Norian SRS (Synthes), Vitoss (Orthovita) Cortoss (Ortho Vita) and alpha-BSM 5etex were randomized controlled trials of Evidence class I.

In general, bone substitutes belong to one of the following six product groups, a few are also mixtures of two or more different individual substances:

• Demineralized bone matrix is usually offered as a malleable paste ("paste") or kneadable filler ("putty") and is produced by acid extraction of the calcium phosphate from donor bones. This preserves the proteins, especially the collagen and the glycoproteins, as well as the osteoinductive "bone morphogenetic proteins (BMPs)" . Due to the paste form, these products lack sufficient mechanical hardness and porosity, which is important for new bone formation. They are mainly used when mixed with the body's own bone marrow to fill bone defects in traumatology and spinal surgery.
• Calcium phosphate and calcium hydroxyapatite : Calcium phosphate is a white powder with a mixture of tri-calcium phosphate, mono-calcium phosphate and calcium carbonate, which hardens when water is added without generating heat ("isothermal") and has a compressive strength that above that of normal bone marrow. It is widely used to close drill holes in neurosurgery, but also in oral and maxillofacial surgery. With a very low rate of degradation, it is considered a permanent bone substitute material. Norian SRS belongs to this group and is the best-studied substitute material. There are also preformed porous granules and blocks that can be adapted to the defect, and pure calcium hydroxyapatite can also be obtained hydrothermally from the exoskeleton of corals and adapted to the bone defect - but there are few scientific studies on this.
• Calcium sulfate
• Bioactive glass
• Collagen and collagen-hydroxyapatite mixture
• Silicone and magnesium hydroxyapatite

Individual evidence

1. ^ Vallet-Regi M. Revisiting ceramics for medical applications. Dalton Trans. 2006 Nov 28; (44): 5211-20. Epub 2006 Oct 3rd Review.
2. ↑ Cutter CS, Mehrara BJ. Bone grafts and substitutes. J Long Term Eff Med Implants. 2006; 16 (3): 249-60.
3. ↑ Mueller, Klaus Clinical experience with beta-tricalcium phosphate in oral surgery , Quintessenz 1985 Apr; 36 (4): 661-9. PMID 3863158 , PMID 3863166 .
4. ↑ T. Kurien, RG Pearson, BE Scammell: Bone graft substitutes currently available in orthopedic practice: the evidence for their use. In: The bone & joint journal. Volume 95-B, Number 5, May 2013, pp. 583-597, doi : 10.1302 / 0301-620X.95B5.30286 , PMID 23632666 (review).

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !