Bone grafts

Tabata, M., Shimoda, T., Sugihara, K., Ogomi, D., Serizawa, T. and Akashi, M. (2003) Osteoconductive and hemostatic properties of apatite formed on/in agarose gel as a bone-grafting material. Journal of Biomedical Materials Research Part B Applied Biomaterials, 67B, 680-688. 

Bone is one of the few tissues capable of self-regeneration during skeletal deficiency, but this regeneration is limited by the nature and size of the defect. In general, skeletal deficiency occurs as a result of trauma, tumor, bone disease, or abnormality. In the case of severe fracture, bone will not heal by itself. For this reason, artificial bone substitutes may be required to restore routine function without damaging living tissue, and the selection of the bone graft substitute is the most important factor for better performance in vivo. 

Natural bone grafts would appear to provide the ideal material. However, autografts are necessarily limited in volume and xenografts or allografts should be considered with caution due to the potential risk for transmission of viruses or other non-conventional agents [6]. For these reasons, there has been a growing... 

Hydroxyapatite constitutes -65% of human bone by weight. There is another 18% collagen fiber which makes the bone flexible and more durable. Then, there is -10% genetic tissue (mostly living bone cells). This tissue carries the genetic code of the person or animal and unless it is in a denatured form, which also kills the bone, it is likely to be rejected in the body as a bone graft. Therefore, it is impossible to successfully implant living bone even from closely related donors. The remainder of bone is composed of capillaries, nerves, and so on. 

Bone Graft Data from the Laboratory of Dr. Ralph Holmes of the University of California, San Diego, on the Spinal Fusion Study by Dr. Glenn O Sullivan, Orthopedic Surgery Staff of Stanford University School of Medicine (10)... 

Oxygen is used for the correction of hypoxia and as a diluent or carrier gas for vapors and gases, primarily anesthetic agents. The use of oxygen at increased pressure is termed hyperbaric oxygen therapy. This therapy is used in diverse conditions such as multiple sclerosis, traumatic spinal cord injury, cerebrovascular accidents, bone graft, fractures, and leprosy. However, there are no available authentic data, as there are no well-controlled clinical trials. 

Orthophosphates of most metals are known, but by far the most important are those of calcium, particularly those of the apatite type,44 for which the general formula is Ca5(P04)3X. Fluoroapatite, where X = F, is the major constituent of phosphate rock which occurs in vast deposits in many places in the world and is the chief ore of phosphorus. Other important apatites are those in which X = Cl or OH. Biologically, apatites are indispensable since they are key components of both teeth and bone. Synthetic apatites that permit bone grafts are now available.45... 

Research is ongoing into the possibilities of using some types of corals for bone grafts, and as artificial eyeballs, as the human body is less likely to reject coral than man-made substances. 

Mehlisch, D.R., Leider, A.S., and Roberts, W.E., Histologic evaluation of the bone/graft interface after mandibular augmentation with hydroxylapatite/pnrified fibrillar collagen composite implants. Oral Surg. Oral Med. Oral Pathol., 70, 685, 1990. 

Bone graft/Cage (rBMP with metal cage) Infuse Bone Graft/LT-Cage (Medtronic/Wyeth) Low back pain from spinal disc degen tibia shaft fracture... 

Catastrophic failure of two cemented cobalt-containing femoral stems that had been used in conjunction with the impacting bone-grafting technique has been reported in two cases (5). 

A 51-year old woman sustained a fracture of the left femoral neck, later treated by total hip arthroplasty, which was revised several times with the impaction bone grafting technique and insertion of a prosthesis with cement. She developed a persistent weakness of the hip in flexion and abduction. Later the left hip buckled and she fell while walking. X-rays showed a periprosthetic fracture with bending of the femoral component. 

Jazrawi LM, Della Valle CJ, Kummer FJ, Adler EM, Di Cesare PE. Catastrophic failure of a cemented, collarless, polished, tapered cobalt-chromium femoral stem used with impaction bone-grafting. A report of two cases. J Bone Joint Surg Am 1999 81(6) 844-7. 

Ekaputra AK et al (2009) Composite electrospun scaffolds for engineering tubular bone grafts. Tissue Eng A 15(12) 3779—3788... 

S J. Kalita, et al., Porous calcium aluminate ceramics for bone-graft applications. J. Mater Res. 17(12), 3042-3049 (2002). 

Ideally, bone substitute materials should be replaced by mature bone without transient loss of mechanical support. Unfortunately, at present there is no material available fulfilling these requirements. Consequently, mechanically unstable bone defects ought to be stabilised with a non-resorbable metallic fixation made from stainless steel or titanium and the bone defect filled with a bone graft substitute. While the mechanical properties of the bone graft substitute are of minor importance, much more important it is to optimise the resorption rate of the bone graft substitute to minimise the time required for bone healing (Bohner, 2010). To control the resorption rate several strategies such as modification of the... 

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