Bone infections due to fractures or implants are a big medical problem. In experimental medicine, many experimental models have been created on different animal species to simulate the disease condition and to do experience treatments. The aim of this paper was to present an antibacterial efficacy of using a bone allograft developed according to the Marburg system of bone bank on a model of chronic osteomyelitis induced in rabbits. In research was used 54 rabbits. Osteomyelitis was induced in rabbits by a human strain of St. aureus ATCC 43300, in the rabbit femur. There have been created 3 groups of animals. In 1. st. group used antibiotic impregnated biodegradable material “PerOssal”. In 2. nd. group used antibiotic impregnated whole bone allograft. In 3. rd. group used antibiotic impregnated perforated bone allograft. Evaluation of installation and evolution of the disease was done by microbiological. A separate study of microbiological data is presented here. This study showed, in the 1. st. and 3. rd. groups there is a persistent decrease in CFU by 14 knocks to 120.4 in the 1. st. group and to 3.5 in the 3. rd. group, and in the 2. nd. group, on the contrary, there is an increase in CFU to 237.33. This shows the lack of effectiveness of using a whole bone allograft. The results showed, after 7 days there was no statistically significant difference between the groups. After 14 days the perforated bone allograft impregnated with antibiotic was better than the biodegradable material “PerOssal”

Introduction. Cancellous and cortical bone used as a delivery vehicle for antibiotics. Recent studies with cancellous bone as an antibiotic carrier in vitro and in vivo showed high initial peak concentrations of antibiotics in the surrounding medium. However, high concentrations of antibiotics can substantially reduce osteoblast replication and even cause cell death. Objectives. To determine whether impregnation with gentamycine impair the incorporation of bone allografts, as compared to allografts without antibiotic. Materials and method. Seventy two healthy rabbits (24 rabbits in each group) were used for this study. Bone defects (3-mm diameter, 10-mm depth) were created in the femur. Human femoral head prepared according to the Marburg bone bank system was used as bone allograft. In the experimental groups, in 1 group - the defects were filled with bone allografts, in 2 group – Perforated Gentamycin-impregnated bone allografts. The control group did not receive any filling. The animals were killed after 14, 30 and 60 days. Evaluations consisted of X-ray plain radiography, histology at 14-, 30- and 60-days post-surgery. Results. Active osteoblast activity and active formation of new bones were detected around the defect area in all groups, but the amount of new bone formation was greater in the experimental groups than the control group. We found no statistically significant differences in the rate of bone formation between 1 and 2 groups at 14, 30 and 60 days in any of the parameters studied. X-ray results showed no significant difference in bony callus formation around allografts in 1 and 2 groups. In contrast, no significant callus formation was observed in the control group. Conclusion. The use of gentamycin-impregnated bone allografts may be of value in procedures performed at the site of osteomyelitis which require a second stage reconstruction with impacted bone grafting techniques

Bone allograft use in trauma and orthopaedic surgery is limited by the potential for cross infection due to inadequate acceptable decontamination methods. Current methods for allograft decontamination either put the recipient at risk of potentially pathogenic organisms or markedly reduce the mechanical strength and biological properties of bone. This study developed a technique of sterilization of donor bone which also maintains its mechanical properties. Whole mature rat femurs were studied, as analogous to strut allograft. Bones were inoculated by vortexing in a solution of pathogens likely to cause cross infection in the human bone graft situation. Inoculated bones were subjected to supercritical carbon dioxide at 250 bar pressure at 35 degrees celsius for different experimental time periods until a set of conditions for sterilization was achieved. Decontamination was assessed by vortexing the treated bone in culture broth and plating this on suitable culture medium for 24 hours. The broth was also subcultured. Controls were untreated-, gamma irradiated- and dehydrated bone. Mechanical testing of the bones by precision three-point bending to failure was performed and the dimensions and cross-section digitally assessed so values could be expressed in terms of stress. Mechanical testing revealed bone treated with supercritical carbon dioxide was consistently significantly stronger than that subjected to gamma irradiation and bones having no treatment (due to the minor dehydrating effect of the carbon dioxide). Terminal sterilization of bone is achieved using supercritical carbon dioxide and this method maintains the mechanical properties. The new technique greatly enhances potential for bone allograft in orthopaedic surgery

The purpose of this study is to enhance massive bone allografts osseointegration used to reconstruct large bone defects. These allografts show >50% complication rate requiring surgical revision in 20% cases. A new protocol for total bone decellularisation exploiting the vasculature can offer a reduction of postoperative complication by annihilating immune response and improving cellular colonization/ osseointegration. The nutrient artery of 18 porcine bones - humerus/femur/radius/ulna - was cannulated. The decellularization process involved immersion and sequential perfusion with specific solvents over a course of one week. Perfusion was realized by a peristaltic pump (mean flow rate: 6ml/min). The benefit of arterial perfusion was compared to a control group kept in immersion baths without perfusion. Bone samples were processed for histology (HE, Masson's trichrome and DAPI for cell detection), immunohistochemistry (IHC : Collagen IV/elastin for intraosseous vascular system evaluation, Swine Leukocyte Antigen – SLA for immunogenicity in addition to cellular clearance) and DNA quantification. Sterility and solvent residues in the graft were also evaluated with thioglycolate test and pH test respectively. Compared to native bones, no cells could be detected and residual DNA was <50ng/mg dry weight. Intramedullary spaces were completely cleaned. IHC showed the preservation of intracortical vasculature with channels bounded by Collagen IV and elastin within Haversian systems. IHC also showed a significant decrease in SLA signaling. All grafts were sterile at the last decellularization step and showed no solvent residue. The control group kept in immersion baths, paired with 6 perfused radii/ulnae, showed that the perfusion is mandatory to ensure complete decellularisation. Our results prove the effectiveness of a new concept of total bone decellularisation by perfusion. These promising results could lead to a new technique of Vascularized Composite Allograft transposable to pre-clinical and clinical models

Bone allograft is the most widely accepted approach in treating patients suffering from large segmental bone defect regardless of the advancement of synthetic bone substitutes. However, the long-term complications of allograft application in term of delayed union and nonunion were reported due to the stringent sterilization process. Our previous studies demonstrated that the incorporation of magnesium ions (Mg2+) into biomaterials could significantly promote the gene up-regulation of osteoblasts and new bone formation in animal model. Hence, our group has proposed to establish an Mg2+ enriched tissue microenvironment onto bone allograft so as to enhance the bone healing. The decellularization and gamma irradiation process were performed on bovine bone allograft and followed by magnesium plasma treatment. To evaluate the biocompatibility and bioactivity, materials characterizations, in vitro and in vivo studies were conducted, respectively. Mg composite layer on bone surface ranged from 500nm to ∼800nm thick. The cell viability on magnesium enriched allograft was significantly higher than that of the control. The ALP gene expression of hTMSCs in the group of PIII&D treated samples was highly up-regulated. The bone regeneration ability of Mg modified bone allograft implanted in animal model was significantly superior than the control after 2-month post-operation

Successful reconstructive surgery with allografts is severely limited by a failure rate of 30 – 40%. Allograft failure is due to nonunion of the graft-host junction. The molecular mechanism by which this occurs is not yet fully elucidated. Using a sheep femoral allograft model, we have investigated the cellular and molecular mechanisms associated with nonunion of bone allografts. Five, from a total of twelve operations, resulted in the development of graft-host nonunion, reflecting a failure rate of 42%. Histological assessment revealed that allograft failure was due to the excessive accumulation of and resorption by, osteoclasts (Ocs) on the surface of the bone allograft. Three distinct layers, lying adjacent to the allograft bone surface, in the nonunion groups, were identified. The outer fibroblastic layer contained abundant fibroblasts and connective tissue. Underlying this layer were synovial-like cells and some multinuclear giant cells. The third layer, opposing the bone surface, consisted of Ocs and round mononuclear cells. Histomorphometric analysis showed that allograft unions, featured a large amount of newly formed bone on the surface, (OS/BS = 47.81%) with a small proportion of eroded surface (ES/BS = 20.59%). The number of osteoclasts associated with the allograft bone surface were few (Oc/B.Pm = 1.7190/mm) and activity (ES/BS = 46.68%) of Ocs with a reduced amount of new bone formation (OS = 6.35%). Both calcitonin receptor and H+ATPase mRNA, characteristically expressed by Ocs, were localised to the multinuclear giant cells, indicating that they were Ocs. Synovial-like cells in the histological layer above the Ocs, expressed gene transcript for the Osteoprotegrin Ligand (OPGL), a membrane bound factor that is critical for the induction of Oc activity and osteoclastogenesis. In conclusion, these findings suggest that failure of bone allografts is partially due to excessive resorption by host Ocs, accompanied by reduced bone formation. The production of OPGL by synovial-like cells, may be responsible for the recruitment and generation of Ocs

The Use of bone allograft in orthopaedic Surgery has been predicted to increase particularly in joint revision surgery. This has led to a potential problem with supply. Questionnaires were distributed to all 146 Consultant orthopaedic Surgeons working in Scotland in 2000. They were asked to indicate their current usage of bone and tissue allograft, any problems encountered with supply and if alternatives to allograft such as processed bone, might be used. The questions asked were very similar to those asked in a survey by the author (GG) in 1995 to enable comparisons to be made. 74% of all bone issued by the SNBTS in 2000 –2001 was used in revision hip arthroplasy. This compares with only 66% of bone issued in 1998–1999. Replies were received from 125 consultants (87%) of whom 93 reported using bone allograft. 41 consultants (46%) predicted an increase in their requirement for bone allograft, and 23 (26%) felt they could currently use more bone if this became available. Sixty percent of Surgeons would consider using processed bone as an alternative. In comparison with figures from a previous study in 1995, an increasing number of surgeons are prepared to use processed bone as an alternative to fresh frozen allograft. As the number of revision THR’ s continues to increase the amount of bone required is likely to continue to increase. The need to increase efficiency in harvest and supply of bone is therefore great. The use of more SNBTS nurses in selection of patients and collection of bone may increase efficiency. More surgeons may have to use processed bone, which would allow more bone to be released. Also processing may help reduce transmission of infective particles such as HIV and new variant CJD. With rising public and medical concerns over these issues this seems most desirable

Major drawbacks associated with autologous bone grafting are the risk of donor site morbidity and its limited availability. Sterilized bone allograft, however, lacking osteoinductive properties, carries the risk of graft failure resulting from insufficient osseointegration of the graft. The aim of this study was to vitalize bone allograft with human osteoprogenitor cells under GMP-conform conditions. For this purpose we investigated proliferation, osteogenic differentiation and large-scale gene expression of human MSCs cultured three-dimensionally on peracetic acid (PAA)-treated spongious bone chips. MSCs were isolated from healthy donors (N=5) and seeded onto PAA-treated spongious bone samples (~5×5×5 mm, DIZG, Germany) under GMP-conform conditions. Proliferation (total protein assay), osteogenic differentiation (cell-specific ALP activity assay, quantitative gene expression analysis of selected osteogenic marker genes), and morphology were assessed. RNA was isolated and microarray analysis was performed using the PIQORTM Stem Cell Microarray system (Miltenyi Biotec) including 942 target sequences. Increasing cellularity was observed during the 42 d observation period while cell-specific ALP activity peaked at day 21. Effective proliferation and adhesion of human MSCs on PAA-treated spongious bone was confirmed by histology, scanning electron and confocal laser scanning microscopy. Gene expression of early (Runx-2), intermediate (ALP), and late (osteocalcin) osteogenic marker genes was present during 42 days of cultivation. Microarray analysis of MSCs cultivated on bone allograft versus 2-D tissue culture demonstrated temporal upregulation of genes involved in extracellular matrix synthesis (e.g., matrix metalloproteases, collagens), osteogenesis (e.g., BMPR1b, Runx-2) and angiogenesis (angiopoietin, VEGF). PAA-treated spongious bone allograft is a biocompatible carrier matrix for long-term ex vivo cultivation of MSCs as observed by favorable proliferation, cell distribution, gene expression profile, and persisting osteogenic differentiation. GMP-grade vitalisation of bone allograft by cultivation with autologous MSCs represents a promising clinical application for the treatment of osseous defects

Background: Early failure of morselized impaction bone allograft is usually due to shear forces. Soil mechanics tells us that in aggregates such as bone allograft, the resistance to these shear forces can be increased by altering the fluid concentration, varying the particle size, and improving the morphology of the graft particle. Finding an idealized concentration of fat and water in bone graft could improve the resistance to interparticle shear and therefore decrease the failure rate of impaction bone graft. Ensuring the quality of the bone source is adequate can also improve the initial strength the bone graft. Furthermore optimizing the graft can be achieved by screening methods and simple intra-operative techniques. Methods: Human femoral heads were retrieved from both total hip arthroplasty and hemiarthroplasty procedures. Bone mineral density was determined by DEXA scanning. The fat and water content of the graft was varied by combinations of squeezing and drying the graft and also by washing the graft using pulse lavaged water and 1:1 mixture of chloroform: methanol. The amount and characteristics of the fat and water in human morselized cancellous bone was quantified by the Karl Fischer extraction techniques, and gas chromatography. The overall shear strength of each graft preparation was determined by the direct shear test, adapted from an accepted protocol in soil mechanics and the optimum mixture which would resist shear forces was determined. Results: An optimum level of fat and water was determined which was 50% stronger than unaltered bone graft. This is most closely approximated in an operating theatre situation by washing the graft with pulse lavaged normal saline and subsequently squeezing the bone graft in a vice with a force of 335kPa for 5 minutes. Whereas osteoarthritic and osteoporotic bone were similar in their fat and water content and initial resistance to shear forces, after processing, the resistance to shear forces of osteoarthritic bone improved by 147% and that of osteoporotic bone only improved by 12% (p< 0.001) Conclusions: Optimizing the fat and water content of bone graft and closely choosing the source of graft produces a stronger graft which is more resistance to shear stresses, protecting the surgical construct until bone growth can occur

Management of bone defects is a common surgical challenge encountered following any high energy trauma. Femur fractures with bone loss account for 22% of all the fractures with bone loss/defect, and 5% to 10% of distal femur fractures are open injuries. It was estimated in 2008, that, more than 4.5 million open fractures occur annually in India. In this retrospective study, patients who received bone allograft from our tissue bank between May 2012 and September 2015 were analysed. Of the 553 allografts issued, at that point in time, 26 were used in patients who underwent reconstruction for distal Femur fractures primarily. Fractures with defect or bone loss from 12 cc (1cm) to 144 cc (12cm) were treated with either Internal or External fixation and bone allograft. Morcellised cancellous, or a cortical strut, were used to fill or reconstruct the defect or void. The radiological outcome in terms of fracture union was assessed and Knee society score was used to assess the functional outcome. Complications such as non- union, infection, stiffness and need of revision or additional procedures were also assessed. Osseous consolidation was achieved in all the 26 patients with a Median time of 24 weeks (16 to 60). The Median Functional Knee Society Score was 80, indicating satisfactory functional outcome. Infection was noted in one patient, but it was not attributed to the allograft. Additional minor procedures like bone marrow infiltration, corticotomy for bone lengthening were required in 10 patients. Our studycomprises the largest group of patients treated primarily with Allograft to reconstruct or fill the void of bone loss encountered with distal Femur fracture. Reconstruction of massive bone defects, in patients of distal Femur fractures, with bone allograft, shows encouraging results. The surgeon can achieve the goal of restoring form and function of these difficult injuries in a single stage and the technique will provide the freedom to reconstruct the bony defect up to 150 cc (12 cm length) and recreate the anatomy to near normal. This allows for early mobilisation of patients and restoration of their daily routine at the earliest

Structural bone allografts are a viable option in reconstructing massive bone defects in patients following musculoskeletal (MSK) tumour resection and revision hip/knee replacements. To decrease infection risk, bone allografts are often sterilised with gamma-irradiation, which consequently degrades the bone collagen connectivity and makes the bone brittle. Clinically, irradiated bone allografts fracture at rates twice that of fresh non-irradiated allografts. Our lab has developed a method that protects the bone collagen connectivity through ribose pre-treatment while still undergoing gamma-irradiation. Biomechanical testing of bone pretreated with our method provided 60–70% protection of toughness and 100% protection of strength otherwise lost with conventional irradiation. This study aimed to determine if the ribose-treated bone allografts are biocompatible with host bone. The New Zealand White rabbit (NZWr) radius segmental defect model was used, in which 15-mm critically-sized defects were created. Bone allografts were first harvested from the radial diaphysis of donor female NZWr, and treated to create 3 graft types: C=untreated controls, I=conventionally-irradiated (33 kGy), R=our ribose pretreated + irradiation method. Recipient female NZWr (n=24) were then evenly randomised into the 3 graft groups. Allografts were surgically fixed with a 0.8-mm Kirschner wire. Post-operative X-rays were taken at 2, 6, and 12 weeks, with bony healing assessed by a blinded MSK radiologist using an established radiographic scoring system. The reconstructed radii were retrieved at 12 weeks and analysed using bone histomorphometry and microCT. Kruskal-Wallis and Mann-Whitney tests were utilised to compare groups, with statistical significance when p<0.05. Radiographic analysis revealed no differences in periosteal reaction and degree of osteotomy site union between the groups at any time point. Less cortical remodeling was observed in R and I grafts compared to untreated controls at 6 weeks (p=0.004), but was no longer evident by 12 weeks. Radiographic union was achieved in all groups by 12 weeks. Histologic and microCT analysis further confirmed union at the graft-host bone interface, with the presence of mineralising callus and osteoid. Histomorphometry also showed the bridging external callus originated from host bone periosteum and a distinct cement line between allograft and host bone was present at the union site. Previous studies have shown that the presence of non-enzymatic glycation end products in bone can impair fracture healing. However, these studies investigated bony healing in the setting of diabetic states. Our findings showed that under normal conditions, ribose pretreated grafts healed at rates similar to controls via mechanisms also seen in retrieved human allografts clinically in use. These findings that grafts pretreated with our method are biocompatible with host bone in the rabbit help to further advance this technology for clinical trials

We analysed the histological findings in 1146 osteoarthritic femoral heads which would have been considered suitable for bone-bank donation to determine whether pathological lesions, other than osteoarthritis, were present. We found that 91 femoral heads (8%) showed evidence of disease. The most common conditions noted were chondrocalcinosis (63 cases), avascular necrosis (13), osteomas (6) and malignant tumours (one case of low-grade chondrosarcoma and two of well-differentiated lymphocytic lymphoma). There were two with metabolic bone disease (Paget’s disease and hyperparathyroid bone disease) and four with inflammatory (rheumatoid-like) arthritis. Our findings indicate that occult pathological conditions are common and it is recommended that histological examination of this regularly used source of bone allograft should be included as part of the screening protocol for bone-bank collection

Introduction: Bone grafts are frequently used in orthopaedic operations to augment bone healing. Autologous bone graft is the gold standard for osteogenesis, but the amount available from the patient’s iliac crest is often insufficient to fill the defect and donor site morbidity is a significant complication. Alternatively, allograft can be implanted into patients, however, processing is necessary to reduce the immunicity of the graft and the risk of transmission of infection, but this destroys osteoprogenitor cells and hence reduces the osteogenic properties of the graft. Mesenchymal stem cells (MSCs) are present in bone marrow and have the ability to differentiate into osteoblasts. Therefore our study examined the use of MCSs, from bone marrow, to enhance the osteogenic properties of allograft. Hypothesis: MSCs cultured on freeze-dried ethylene oxide treated bone allograft differentiate into osteoblasts, thereby increasing the osteogenic nature of the graft material. Method: After informed consent, bone marrow aspirates were taken from 10 patients during elective orthopaedic operations. MSCs were characterized using Stro-1 antibody and grown on freeze-dried ethylene oxide treated bone allograft in vitro. The hypothesis was tested on three groups of graft, with eight samples in each group. Firstly, freeze-dried ethylene oxide treated bone graft was tested (group 2). For a negative control, allograft was heated to 70°C to denature the osteogenic proteins (group 1). The final group tested the effect of additional osteogenic supplements (100nM dexamethasone, 0.05mM ascorbic acid and 10mM (-glycerol phosphate) on MSCs on allograft (group 3). Osteoblastic differentiation of MSCs was observed under scanning (SEM) and transmission (TEM) electron microscopy, and by measuring protein levels: alkaline phosphatase (ALP), osteopontin and type I pro-collagen over 14 days. Results: SEM confirmed that MSCs could be successfully cultured on bone allograft. Cells grown in groups 2 and 3 were characteristic of metabolically active osteoblasts and collagen extracellular matrix was observed under TEM. The amount of ALP protein produced by MSCs cultured in groups 2 and 3 increased significantly over 14 days (P< 0.05), but there was no increase in group 1. ALP, osteopontin and type I pro-collagen production was significantly greater for group 2 than for group 1 and for group 3 than for group 2 (P< 0.05). Discussion and Conclusions: ALP, type I pro-collagen and osteopontin proteins are known to be produced by osteoblasts during increasing cell maturation and the levels of each of these proteins increased significantly when MSCs were cultured on allograft for 14 days compared with the negative control. The addition of osteogenic supplements significantly increased production of these proteins. Furthermore, MSCs cultured in groups 2 and 3 produced extracellular collagen matrix. These results are consistent with allograft causing MSCs to differentiate into osteoblasts and that this differentiation increases with additional osteogenic supplements. This study confirms that MSCs, derived from autologous bone marrow, could be used to increase the osteogenic potential of allograft, thereby increasing bony healing in patients

Revision hip surgery is becoming increasingly common, 300 procedures being performed in 2001 at our institution. In order to achieve a good outcome bone stock needs to be of good quantity frequently necessitating the use of impaction bone grafting using allograft bone. Donor bone may frequently take three months before it becomes available for use due to the stringent screening procedure. Donor patients must have a clean bill of health, swabs taken at the time of surgery must obviously demonstrate no growth and blood samples taken at donation and an interval of three months, free from viral infectious diseases. It is thus easy to see the lag from the time of donation to availability and why, with increasing demand, need for allograft bone is rapidly exceeding supply. We need to look for an alternative supply of human bone allograft. We have compared the harvest of bone at the time of primary total knee replacement with that of the femoral head by both mass and volume. Sixty consecutive patients undergoing primary hip or knee arthroplasty were included in the study, and the masses and volume of the femoral heads compared with that of the total bone cuts in knee arthroplasty. The type of knee replacement used was documented as was whether the femoral head had had a bone block removed. It was found that the mass of femoral heads was 81g, that of knee cuts 95g this is a statistically significant difference; the volume of femoral heads 66ml and that of knee cuts 75ml. The volumes of bone available from knee arthroplasty cuts are at least comparable femoral heads obtained using hip replacement and could, perhaps, provide a realistic source of bone allograft

Introduction: We conducted a retrospective study at our institution to see what effect, if any, the use of impacted morsellised bone allograft technique had on the incidence of early and late infection in revision hip arthroplasty where contemporary measures were taken. Patients and Methods: This study included 120 patients. Patients were 36 male and 84 females with the mean age at the time of revision surgery was 71.4 years (range 42 – 89 SD 9.7). In all the patients their indication for revision surgery was aseptic loosening. All the patients had impacted morsellised bone allograft as part of the reconstruction used with cemented prostheses. Clinical and radiological assessments of all patients were conducted for average of four years follow up. Results: At mean follow up period of 4 years the early infection rate was 0.8% and late infection rate was 0%. Conclusion: In our study the use of morsellised bone allograft does not appear to have added risk effect on the incidence of early or late hip joint infection provided contemporary measures are taken

Purpose of the study: The mechanical and radiological course of bone allografts is often favorable but osteointegration properties could be improved. We associated a safe allograft with mesenchymatous bone marrow stem cells (MSC) with known osteogenic potential. The purpose of this preliminary study was to study the biocompatibility of the treated allograft, assess the osteoblastic differentiation properties of the MSC, and determine the optimal period for colonizing the bone matrix. Material and methods: The support was a safe bone allograft preserved in a collagenic grid (Osteopure™). MSC harvested by adherence were seeded in a medium favoring osteoblastic differentiation by comparison with standard culture medium. Culture conditions varied to study the influence of the presence or not of support, the culture time, or the presence of human serum in the culture medium. For each culture medium, we noted: the number of cells, osteoblastic differentiation using markers: alkaline phosphate and osteocalcin. A histological study was also performed. Results: Peak cell amplification was achieved at three weeks culture. Presence of osteoblastic differentiation markers was clearly identified in cultures grown in the presence of support material. Microscopy demonstrated that cells stimulated by the differentiation medium adhered strongly to the bone network. Histology revealed the presence of osteoblastic activity in differentiation medium with cells taking on the classical cytological aspect of osteoblasts. Cell proliferation was at least equivalent in medium with human serum as with fetal calf serum. Discussion: This study demonstrated that the allogenic matrix does not modify the capacity of human MSC for colonization and differentiation. The cell organization is optimal compared with the absence of supporting material. Use of the patient’s own serum in the culture medium was validated enabling an autologous procedure. Use of a complex cell graft appears to be optimal after three weeks of culture. This first step proves the feasibility of the concept designed to optimize the support with the patient’s own MSC. The next step is to develop an in vivo model

INTRODUCTION. Allograft reconstruction after resection of primary bone sarcomas has a non-union rate of approximately 20%. Achieving a wide surface area of contact between host and allograft bone is one of the most important factors to help reduce the non-union rate. We developed a novel technique of haptic robot-assisted surgery to reconstruct bone defects left after primary bone sarcoma resection with structural allograft. METHODS. Using a sawbone distal femur joint-sparing hemimetaphyseal resection/reconstruction model, an identical bone defect was created in six sawbone distal femur specimens. A tumor-fellowship trained orthopedic surgeon reconstructed the defect using a simulated sawbone allograft femur. First, a standard, ‘all-manual’ technique was used to cut and prepare the allograft to best fit the defect. Then, using an identical sawbone copy of the allograft, the novel haptic-robot technique was used to prepare the allograft to best fit the defect. All specimens were scanned via CT. Using a separately validated technique, the surface area of contact between host and allograft was measured for both (1) the all-manual reconstruction and (2) the robot-assisted reconstruction. All contact surface areas were normalized by dividing absolute contact area by the available surface area on the exposed cut surface of host bone. RESULTS. The mean area of contact between host and allograft bone was 24% (of the available host surface area) for the all-manual group and 76% for the haptic robot-assisted group (p=0.004). CONCLUSIONS. This is the first report to our knowledge of using haptic robot technology to assist in structural bone allograft reconstruction of defects left after primary bone tumor resection. The findings strongly indicate that this technology has the potential to be of substantial clinical benefit. Further studies are warranted

Aim: Failed primary hip arthroplasty often results in significant loss of host bone. Revision surgery may require bone grafting to restore bone stock prior to insertion of a new cup. A two to five year follow up of one method of acetabular revision for severe bone stock loss is presented

Materials and Methods: Seventeen patients had acetabular revision with the use of impacted morcellised bone and a cage reconstruction with a cemented cup. The average age at the time of revision was 62. All patients were followed prospectively with regular X-rays. A variety of cages were employed and bone graft was hand morcellised from femoral heads or cadaver distal femurs.

Aim: The biological activity of demineralised bone matrix (DBM) led to the discovery of bone morphogenetic proteins (BMP). OP-1 (BMP 7) is an osteoinductive protein and has been demonstrated to be capable of inducing new bone formation in rat subcutaneous tissue and in both orthotopic and heterotopic sites in primates. In this study we have investigated whether demineralisation and addition of osteogenic. protein 1 (OP-1) improves osteoinductive properties of allograft. Methods: A randomised controlled blind trial was performed in 16 rats. One group received two pellets of fresh frozen allograft; the other received two pellets of demineralised bone (DBM) intramuscularly. In each rat one pellet was treated with OP-1 (2mg/25mg of graft). The rats were sacriþced at 28 days and tissue þxed and processed for sectioning with haematoxylin and eosin for morphology and Alcian blue and Sirrus red for collagen types I, II. Qualitative observations were made and each specimen graded 0–5 on the degree of new bone formation and integration by two blind observers. Results & Conclusions: DBM with OP-1 yielded optimal results, being signiþcantly superior to allograft alone and allograft with OP-1. DBM alone was shown to be more effective compared to the allograft preparations. Hence we have shown that demineralization and OP-1 signiþcantly improve the osteoinductive properties of allograft

This study assessed factors responsible for exclusion of patients from bone donation at primary hip arthroplasty in order to improve bone banking.

Fifty-five patients underwent screening in preoperative clinics assessing their suitability for femoral head donation. Records at the bone bank were then reviewed post operatively to check whether bone had been harvested from these individuals during surgery.

Overall, 95% of the patients screened did not proceed to bone banking. After the initial screening stage 60% of patients were excluded. The majority of exclusions (70%) were unacceptable as donors because of their potential risk of transmission of disease to recipients. Although 40% were consented for donation, femoral heads from only 5% were harvested and sent for storage in the bone bank during hip arthroplasty.

Orthopaedic surgeons must take an active part in bone banking and alternative sources of bone grafts require exploration in the future to meet the increasing demand.