Background. Revision hip arthroplasty for excessive bone loss because of osteolysis or infection is difficult theme. Bone grafting is essential technique for bone loss and need of allograft is increasing. Recently, many hospital
A radiation sterilisation dose (RSD) of 25 kGy is commonly recommended for sterilisation of allograft bone. However, the mechanical and biological performance of allograft bone is gamma dose-dependent. Therefore, this study aimed to apply Method 1 – ISO 11137–2: 2006 to establish a low RSD for frozen bone allografts. Two groups of allograft bones were used: 110 femoral heads (FH) and 130 structural and morselized bones (SMB). The method included the following stages: bioburden determination using 10 FHs and 30 SMBs; verification dose selection using table six in the ISO standard and bioburden; the verification dose was used to irradiate 100 samples from each group; then irradiated bone segments were tested for sterility. The criterion for accepting the RSD as valid is that there must be no more than two non-sterile samples out of 100. The radiation sterilisation dose is then established based on table five, ISO 11137– 2: 2006. The bioburden of both types of frozen allograft was zero. The verification dose chosen was 1.3 kGy. Two hundred bone segments were irradiated at 1.3 kGy. The average delivery gamma dose was 1.23 kGy (with minimum dose of 1.05 kGy maximum dose of 1.41kGy), which is acceptable according to the ISO standard. Sterility tests achieved 100% sterility. Accordingly, 11 kGy was established as a valid RSD for those frozen bone allografts. A reduction in the RSD from 25 kGy to 11 kGy will significantly improve bone allograft mechanical and biological performance because our data show that this dose level improves the mechanical toughness and osteoclast activity of the allograft by more than 10 and 100 percent, respectively, compared with bone allografts irradiated at 25 kGy. A low RSD of 11 kGy was established for allograft bones manufactured at Queensland
Fresh-frozen allograft bone is frequently used
in orthopaedic surgery. We investigated the incidence of allograft-related
infection and analysed the outcomes of recipients of bacterial culture-positive
allografts from our single-institute
Femoral revision after cemented total hip arthroplasty (THA) might include technical difficulties, following essential cement removal, which might lead to further loss of bone and consequently inadequate fixation of the subsequent revision stem. Bone loss may occur because of implant loosening or polyethylene wear, and should be addressed at time of revision surgery. Stem revision can be performed with modular cementless reconstruction stems involving the diaphysis for fixation, or alternatively with restoration of the bone stock of the proximal femur with the use of allografts. Impaction bone grafting (IBG) has been widely used in revision surgery for the acetabulum, and subsequently for the femur in Paprosky defects Type 1 or 2. In combination with a regular length cemented stem, impaction grafting allows for restoration of femoral bone stock through incorporation and remodeling of the proximal femur. Cavitary bone defects affecting the metaphysis and partly the diaphysis leading to a wide femoral canal are ideal indications for this technique. In case of combined segmental-cavitary defects a metal mesh is used to contain the defect which is then filled and impacted with bone grafts. Cancellous allograft bone chips of 2 to 4 mm size are used, and tapered into the canal with rods of increasing diameters. To impact the bone chips into the femoral canal a dummy of the dimensions of the definitive cemented stem is inserted and tapped into the femur to ensure that the chips are firmly impacted. Finally, a standard stem is implanted into the newly created medullary canal using bone cement. To date several studies from Europe have shown favorable results with this technique, with some excellent long-term results reported. Advantages of IBG include the restoration of the bone stock in the proximal femur, the use of standard length cemented stems and preserving the diaphysis for re-revision. As disadvantages of the technique: longer surgical time, increased blood loss and the necessity of a
Fresh-frozen allograft bone is frequently used in orthopaedic surgery. We investigated the incidence of allograft-related infection and analysed the outcomes of recipients of bacterial culture-positive allografts from our single-institute
The purpose of this study was to understand the effects of terminal sterilisation and residual calcium on human demineralised bone matrix (DBM) in ectopic bone formation in nude rat. The intramuscular implantation of human DBM prepared by the Queensland
Adamantinoma are rare, low grade malignant, bone tumors, making up only 0.1–0.48 percent of primary malignant bone tumors. They occur predominantly in the long bones, especially the tibia. Histogenetically it is thought that it originates from embryological displacement of basal epithelium of the skin, although other hypotheses have been proposed. Clinically most patients present with swelling and possible bending of the tibia, painful or painless. It's often noticed in an earlier stadium, but symptoms are non-specific and have a slow progressive character. Median patient age is 25 to 35 years, with a range from two to 86 years. It is slightly more common in men than woman, with a ratio of 5:4. Occurrence in children is even rarer. A study by Van Rijn et al. finds only 119 references, and presents six more cases. Treatment is the same. An MRI-scan should be performed to check for metastasis, loco regional staging and for operative planning. Operative excision and reconstruction is necessary to prevent metastasis and maintain load bearing capacity. Generally these resections and reconstructions are done without objective measurements. The surgeon uses a rule of thumb, like a sculptor, or ruler approach to recreate the excised bone, either with allo- or autograft materials. An optimal fit, i.e. a minimal space between tibia and graft, is not always achieved, possibly resulting in pathological fractures. This risk of pathological fractures lengthens recovery time. The fractures elongate hospitalization time and recovery time and are a heavy burden to patients. Computer assisted surgery (CAS) systems, used for example in prosthesis placement, offer objective measurements in 3d space of hard structures with high accuracy. These can be used to produce an accurate copy of the resected bone. If the reconstruction accurately fits the bone defect that's left after the resection, it's likely that the occurrence of pathological fractures decreases. An adamantinoma in the tibia of a 12 year old boy was treated. Surgery consisted of hemicortical resection and inlay allograft reconstruction. The software used was the Orthomap navigation software (Stryker). A donor bone was supplied with help from the