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Sample records for morselized allograft bone

  1. Mechanical behaviour of Bioactive Glass granules and morselized cancellous bone allograft in load bearing defects.

    PubMed

    Hulsen, D J W; Geurts, J; van Gestel, N A P; van Rietbergen, B; Arts, J J

    2016-05-01

    Bioactive Glass (BAG) granules are osteoconductive and possess unique antibacterial properties for a synthetic biomaterial. To assess the applicability of BAG granules in load-bearing defects, the aim was to compare mechanical behaviour of graft layers consisting of BAG granules and morselized cancellous bone allograft in different volume mixtures under clinically relevant conditions. The graft layers were mechanically tested, using two mechanical testing modalities with simulated physiological loading conditions: highly controllable confined compression tests (CCT) and more clinically realistic in situ compression tests (ISCT) in cadaveric porcine bone defects. Graft layer impaction strain, residual strain, aggregate modulus, and creep strain were determined in CCT. Graft layer porosity was determined using micro computed tomography. The ISCT was used to determine graft layer subsidence in bone environment. ANOVA showed significant differences (p<0.001) between different graft layer compositions. True strains absolutely decreased for increasing BAG content: impaction strain -0.92 (allograft) to -0.39 (BAG), residual strain -0.12 to -0.01, and creep strain -0.09 to 0.00 respectively. Aggregate modulus increased with increasing BAG content from 116 to 653MPa. Porosity ranged from 66% (pure allograft) to 15% (pure BAG). Subsidence was highest for allograft, and remarkably low for a 1:1 BAG-allograft volume mixture. Both BAG granules and allograft morsels as stand-alone materials exhibit suboptimal mechanical behaviour for load-bearing purpose. BAG granules are difficult to handle and less porous, whereas allograft subsides and creeps. A 1:1 volume mixture of BAG and allograft is therefore proposed as the best graft material in load-bearing defects. PMID:26972764

  2. Morsellized bone grafting compensates for femoral bone loss in revision total knee arthroplasty. An experimental study.

    PubMed

    van Loon, C J; de Waal Malefijt, M C; Verdonschot, N; Buma, P; van der Aa, A J; Huiskes, R

    1999-01-01

    This study was undertaken to examine the contribution of uncontained morsellized bone graft to the structural properties of a femoral reconstruction in total knee arthroplasty and to serve as a basis for an in vivo animal study. Ten human distal femora with a standard unicondylar uncontained medial bone defect were prepared to fit a femoral component of a cruciate sacrificing TKA. A cyclic axial load of 750 N was applied to the medial part of the femoral component in the presence of impacted morsellized bone graft. After removal of the bone graft, the cyclic loading was repeated for the unsupported situation. None of the grafts collapsed and all cement mantles stayed intact during the experiments. Elastic deformation during cyclic loading was significantly less when graft was added while time-dependent deformation was not affected. We conclude that impacted morsellized bone graft, used for reconstruction of uncontained femoral bone loss in revision knee arthroplasty, may improve the structural resistance against loading. Further animal experimentation for in vivo application is warranted. PMID:9916775

  3. Biomechanical properties of bone allografts

    SciTech Connect

    Pelker, R.R.; Friedlaender, G.E.; Markham, T.C.

    1983-04-01

    The biomechanical properties of allograft bone can be altered by the methods chosen for its preservation and storage. These effects are minimal with deep-freezing or low-level radiation. Freeze-drying, however, markedly diminishes the torsional and bending strength of bone allografts but does not deleteriously affect the compressive or tensile strength. Irradiation of bone with more than 3.0 megarad or irradiation combined with freeze-drying appears to cause a significant reduction in breaking strength. These factors should be considered when choosing freeze-dried or irradiated allogeneic bone that will be subjected to significant loads following implantation.

  4. Bone allograft and implant fixation tested under influence of bio-burden reduction, periosteal augmentation and topical antibiotics. Animal experimental studies.

    PubMed

    Barckman, Jeppe

    2014-01-01

    Loosening of an artificial joint prosthesis is a painful and debilitating condition that can be treated only by re-operation. Re-operations accounted for approximately 15% of all hip replacement operations performed in Denmark between the year 1995 and 2010. The process of loosening is often accompanied by destructive inflammation and osteolysis, which leads to insufficient bone stock that often requires extensive bone grafting. Impacted morselized bone graft is a well-established method for improving the amount and quality of bone stock that ensures sufficient stability and anchorage of the revision implants. Among bone graft options, the autologous bone graft is considered the gold standard. It is naturally biocompatible, but its use in revision surgery is curtailed by its limited volume and by considerable donor site morbidity. Allograft bone is readily available and is the most commonly used graft material. However, it has been shown that the incorporation of allograft bone into the host bone is not always complete, and substantial fibrous tissue formation has been described. A reason for this may be that allograft bone is a foreign tissue, which, contrary to autogenic bone, may induce an immunogenic response that leads to increased fibrous tissue formation. Furthermore, the fresh-frozen allograft has minimal osteoinductive and no osteogenic capacity. The studies in this thesis have investigated ways of improving the incorporation of allograft bone by adding osteoinductive cells from the periosteum and reducing the immunogenic load of the allograft bone by rinsing. Furthermore, the impact of antibiotic protection of the bone graft has been evaluated. The same experimental implant model was used in all three studies. This model enables evaluation of early implant fixation and osseointegration of an uncemented implant surrounded by impacted morselized bone graft. Unloaded gap implants were inserted into the metaphysis of the proximal tibia (Study I) and distal

  5. Comparison of frozen and freeze-dried particulate bone allografts.

    PubMed

    Malinin, Theodore; Temple, H Thomas

    2007-10-01

    Freeze-dried and frozen particulate bone allografts are used interchangeably on the assumption that the biologic behavior of these grafts is similar. Dissimilarities in biologic behavior and differences in the rate and extent of bone incorporation of freeze-dried and frozen particulate grafts were demonstrated in a comparative study using a non-human primate model. Freeze-dried particulate allografts induced new bone formation and healing of the osseous defects much faster than the frozen allografts. PMID:17658506

  6. Effect of Storage Temperature on Allograft Bone

    PubMed Central

    Fölsch, Christian; Mittelmeier, Wolfram; Bilderbeek, Uwe; Timmesfeld, Nina; von Garrel, Thomas; Peter Matter, Hans

    2012-01-01

    Background The recommendations for storage temperature of allogeneic bone are varying between −20 °C and −70 °C and down to −80 °C. The necessary temperature of storage is not exactly defined by scientific data, and the effect of different storage temperatures onto the biomechanical and the biological behavior is discussed controversially. Methods The historical development of storage temperature of bone banks is described. A survey on literature concerning the biomechanical and biological properties of allograft bone depending on the procurement and storage temperature is given as well as on national and international regulations on storage conditions of bone banks (European Council, American Association of Tissue Banks (AATB), European Association of Tissue Banks (EATB)). Results Short-term storage up to 6 months is recommended with −20 °C and −40 °C for a longer period (AATB), and EATB recommends storage at −40 °C and even −80 °C while the regulations of the German German Medical Association (Bundesärztekammer) from 2001 recommend storage at −70 °C. Duration of storage at −20 °C can be maintained at least for 2 years. The potential risk of proteolysis with higher storage temperatures remains, but a definite impairment of bone ingrowth due to a storage at −20 °C was not shown in clinical use, and no adverse biomechanical effects of storage at −20 °C could be proven. Conclusion Biomechanical studies showed no clinically relevant impairment of biomechanical properties of cancellous bone due to different storage temperatures. Sterilization procedures bear the advantage of inactivating enzymatic activity though reducing the risk of proteolysis. In those cases a storage temperature of −20 °C can be recommended for at least a period of 2 years, and the risk of undesired effects seems to be low for native unprocessed bone. PMID:22896765

  7. Iontophoresis as a means of delivering antibiotics into allograft bone.

    PubMed

    Day, R E; Megson, S; Wood, D

    2005-11-01

    Allograft bone is widely used in orthopaedic surgery, but peri-operative infection of the graft remains a common and disastrous complication. The efficacy of systemic prophylactic antibiotics is unproven, and since the graft is avascular it is likely that levels of antibiotic in the graft are low. Using an electrical potential to accelerate diffusion of antibiotics into allograft bone, high levels were achieved in specimens of both sheep and human allograft. In human bone these ranged from 187.1 mg/kg in endosteal (sd 15.7) to 124.6 (sd 46.2) in periosteal bone for gentamicin and 31.9 (sd 8.9) in endosteal and 2.9 (sd 1.1) in periosteal bone for flucloxacillin. The antibiotics remained active against bacteria in vitro after iontophoresis and continued to elute from the allograft for up to two weeks. Structural allograft can be supplemented directly with antibiotics using iontophoresis. The technique is simple and inexpensive and offers a potential means of reducing the rate of peri-operative infection in allograft surgery. Iontophoresis into allograft bone may also be applicable to other therapeutic compounds. PMID:16260682

  8. Porous allograft bone scaffolds: doping with strontium.

    PubMed

    Zhao, Yantao; Guo, Dagang; Hou, Shuxun; Zhong, Hongbin; Yan, Jun; Zhang, Chunli; Zhou, Ying

    2013-01-01

    Strontium (Sr) can promote the process of bone formation. To improve bioactivity, porous allograft bone scaffolds (ABS) were doped with Sr and the mechanical strength and bioactivity of the scaffolds were evaluated. Sr-doped ABS were prepared using the ion exchange method. The density and distribution of Sr in bone scaffolds were investigated by inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS). Controlled release of strontium ions was measured and mechanical strength was evaluated by a compressive strength test. The bioactivity of Sr-doped ABS was investigated by a simulated body fluid (SBF) assay, cytotoxicity testing, and an in vivo implantation experiment. The Sr molar concentration [Sr/(Sr+Ca)] in ABS surpassed 5% and Sr was distributed nearly evenly. XPS analyses suggest that Sr combined with oxygen and carbonate radicals. Released Sr ions were detected in the immersion solution at higher concentration than calcium ions until day 30. The compressive strength of the Sr-doped ABS did not change significantly. The bioactivity of Sr-doped material, as measured by the in vitro SBF immersion method, was superior to that of the Sr-free freeze-dried bone and the Sr-doped material did not show cytotoxicity compared with Sr-free culture medium. The rate of bone mineral deposition for Sr-doped ABS was faster than that of the control at 4 weeks (3.28 ± 0.23 µm/day vs. 2.60 ± 0.20 µm/day; p<0.05). Sr can be evenly doped into porous ABS at relevant concentrations to create highly active bone substitutes. PMID:23922703

  9. Porous Allograft Bone Scaffolds: Doping with Strontium

    PubMed Central

    Zhao, Yantao; Guo, Dagang; Hou, Shuxun; Zhong, Hongbin; Yan, Jun; Zhang, Chunli; Zhou, Ying

    2013-01-01

    Strontium (Sr) can promote the process of bone formation. To improve bioactivity, porous allograft bone scaffolds (ABS) were doped with Sr and the mechanical strength and bioactivity of the scaffolds were evaluated. Sr-doped ABS were prepared using the ion exchange method. The density and distribution of Sr in bone scaffolds were investigated by inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS). Controlled release of strontium ions was measured and mechanical strength was evaluated by a compressive strength test. The bioactivity of Sr-doped ABS was investigated by a simulated body fluid (SBF) assay, cytotoxicity testing, and an in vivo implantation experiment. The Sr molar concentration [Sr/(Sr+Ca)] in ABS surpassed 5% and Sr was distributed nearly evenly. XPS analyses suggest that Sr combined with oxygen and carbonate radicals. Released Sr ions were detected in the immersion solution at higher concentration than calcium ions until day 30. The compressive strength of the Sr-doped ABS did not change significantly. The bioactivity of Sr-doped material, as measured by the in vitro SBF immersion method, was superior to that of the Sr-free freeze-dried bone and the Sr-doped material did not show cytotoxicity compared with Sr-free culture medium. The rate of bone mineral deposition for Sr-doped ABS was faster than that of the control at 4 weeks (3.28±0.23 µm/day vs. 2.60±0.20 µm/day; p<0.05). Sr can be evenly doped into porous ABS at relevant concentrations to create highly active bone substitutes. PMID:23922703

  10. Mathematical astronomy morsels III

    NASA Astrophysics Data System (ADS)

    Meeus, Jean

    2004-06-01

    In this third volume of his Morsels series, Belgian astronomer Jean Meeus deals masterfully with a host of new questions about eclipses and planetary conjunctions. The sky's rhythms are not strictly repetitive, as he proves time and again by finding entertaining quirks in the motions of the Moon and planets. Contents: The Moon. Eclipses. Planetary motions. Planetary phenomena. On the celestial sphere.

  11. Lateral Meniscal Allograft Transplantation: The Bone Trough Technique.

    PubMed

    Chahla, Jorge; Olivetto, Javier; Dean, Chase S; Serra Cruz, Raphael; LaPrade, Robert F

    2016-04-01

    The lateral meniscus plays a critical role in the stability and health of the knee. Treating patients who have undergone a total lateral meniscectomy or functional equivalent is challenging, especially young and active patients. Current literature regarding meniscal tears supports that repair should be the first surgical option. Moreover, it is recommended to preserve as much meniscal tissue as possible. In cases in which a total or functional meniscectomy is a pre-existing condition, a lateral meniscal allograft transplantation is a possible option. The purpose of this surgical technique description was to detail the method of lateral meniscal allograft transplantation using a bone trough. PMID:27462536

  12. Chest wall reconstruction using iliac bone allografts and muscle flaps.

    PubMed

    Garcia-Tutor, Emilio; Yeste, Luis; Murillo, Julio; Aubá, Cristina; Sanjulian, Mikel; Torre, Wenceslao

    2004-01-01

    Technically we can divide full-thickness thoracic reconstruction into 2 parts: providing a rigid support and ensuring well-vascularized coverage. Since 1986, the authors' center has had ample experience with bone banks and the use of cryopreserved bone grafts, which led them to consider the possibility of using these grafts for full-thickness chest wall reconstruction. They describe 3 patients in whom resection of the tumor and reconstruction of the thorax were carried out using iliac bone allografts covered with muscle flaps (1 pectoralis major and 2 rectus abdominis). None of the patients experienced breathing difficulties, pain, or instability after 14 months, 18 months, and 11 years of follow-up. The result of the reconstruction was excellent in all 3 patients in terms of function and aesthetics. The advantage of allografts compared with synthetic materials is their potential integration; they can become part of the host patient's living tissue. PMID:14676700

  13. New bone formation by murine osteoprogenitor cells cultured on corticocancellous allograft bone.

    PubMed

    Nelson, Ehren R; Huang, Zhinong; Ma, Ting; Lindsey, Derek; Jacobs, Christopher; Smith, Robert L; Goodman, Stuart B

    2008-12-01

    The gold standard for bone grafting in orthopedics is autograft, however autograft has a limited supply and is associated with significant morbidity at the harvest site. One alternative, allograft bone, provides an osteoconductive scaffold, is in less limited supply, and it does not require a harvest from the patient. However, allograft lacks both osteogenic cells and osteoinductive proteins that make autograft bone so advantageous. This study provides a model to investigate strategies for augmentation of corticocancellous allograft bone discs with bone marrow-derived osteoprogenitor cells (OPCs) plus exogenous growth factors in vitro. In this model, allograft bone discs were created by cutting 1-mm thick slices from the distal femur and proximal tibia of euthanized mice. The allografts were sterilized and scanned by micro-computed tomography (microCT) to provide the pre-culture graft volume and trabecular characteristics. The discs were then seeded with OPCs harvested from murine bone marrow. The seeded grafts were placed in organ culture until harvest, after which they were re-scanned by microCT and the data compared to the corresponding pre-culture data. In addition, bone morphogenetic protein-7 (BMP-7, also know as osteogenic protein-1 or OP-1), basic fibroblast growth factor (bFGF), and OP-1 combined with bFGF were added on a daily basis to the cultures. After final microCT scanning, all grafts were sectioned and evaluated histologically after hematoxylin and eosin (H&E) staining. microCT scans of cultured allografts with cells at 3, 5, and 9 weeks showed a time-dependent, statistically significant increase in bone volume. The trabecular thickness (Tb.Th.) of grafts, from both groups that were augmented with OP-1, showed a statistically significant increase in trabecular thickness of allografts with OPCs. These data suggest that bone marrow-derived OPCs adhere to, and produce, new bone on corticocancellous allograft in vitro. When exogenous OP-1 is added to

  14. Molecular profile of osteoprogenitor cells seeded on allograft bone.

    PubMed

    Smith, Kierann E; Huang, Zhinong; Ma, Ting; Irani, Afraaz; Lane Smith, R; Goodman, Stuart B

    2011-10-01

    In order to optimize and modulate bone formation it is essential to understand the expression patterns of key bone-specific growth factors, as osteoprogenitor cells undergo the processes of proliferation, differentiation and maturation. This study reports the sequential expression of bone-related growth and transcription factors when bone marrow-derived osteoprogenitor cells from C57BL mice were cultured on allograft bone discs. Mineralization and osteocalcin protein levels were used to track osteogenic differentiation and maturation. Bone-related growth factors, such as Bmp-2, Bmp-7, Ctnnb-1, Fgf-2, Igf-1, Vegf-a and Tgf-β1, and transcription factors, such as Runx-2 and osteocalcin, were examined by enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR). Total density of mineralized bone was significantly increased 7.6 ± 0.7% in allografts cultured with cells, compared with a 0.5 ± 2.0% increase in the controls without cells (p < 0.01). Osteocalcin protein levels peaked at day 4. Protein expression showed peaks of BMP-2 and TGF-β1 on day 2, with VEGF peaking on day 8, and IGF-1 decreasing on day 2. mRNA for Pdgf-a peaked on day 2; Bmp-2 on days 4 and 16; Ctnnb-1 on days 8 and 20; Vegf-a, Fgf-2, Runx-2 and Igf-1 on day 12; Tgf-β1 on day 16; and Pdgf-b on day 20. Osteogenic growth factors correlated with Runx-2 and Ctnnb-1, whereas a predominant vascular growth factor, Vegf-a, did not follow this pattern. Specific bone-related genes and proteins were expressed in a time-dependent manner when osteoprogenitor cells were cultured on cortico-cancellous bone discs in vitro. PMID:21953868

  15. Medial Meniscal Allograft Transplantation: The Bone Plug Technique.

    PubMed

    Dean, Chase S; Olivetto, Javier; Chahla, Jorge; Serra Cruz, Raphael; LaPrade, Robert F

    2016-04-01

    The medial meniscus is crucial for knee homeostasis. Treating patients who have undergone a subtotal or total meniscectomy, or equivalent irreparable tear pattern, can be extremely challenging, especially in young, active patients. The importance of meniscal preservation has been reported by several authors. Meniscal repair is now widely accepted as the first surgical option for treating medial meniscal tears. Moreover, current guidelines recommend preserving as much meniscal tissue as possible. Treating a symptomatic medial meniscectomized knee is challenging because of limited surgical options. In this context, medial meniscal allograft transplantation arises as the preferred procedure. The purpose of this article was to detail the arthroscopic medial meniscal allograft transplantation technique with the use of 2 bone plugs. PMID:27330948

  16. Polyglutamate directed coupling of bioactive peptides for the delivery of osteoinductive signals on allograft bone

    PubMed Central

    Culpepper, Bonnie K.; Bonvallet, Paul P.; Reddy, Michael S.; Ponnazhagan, Selvarangan; Bellis, Susan L.

    2012-01-01

    Allograft bone is commonly used as an alternative to autograft, however allograft lacks many osteoinductive factors present in autologous bone due to processing. In this study, we investigated a method to reconstitute allograft with osteoregenerative factors. Specifically, an osteoinductive peptide from collagen I, DGEA, was engineered to express a heptaglutamate (E7) domain, which binds the hydroxyapatite within bone mineral. Addition of E7 to DGEA resulted in 9× greater peptide loading on allograft, and significantly greater retention after a 5-day interval with extensive washing. When factoring together greater initial loading and retention, the E7 domain directed a 45-fold enhancement of peptide density on the allograft surface. Peptide-coated allograft was also implanted subcutaneously into rats and it was found that E7DGEA was retained in vivo for at least 3 months. Interestingly, E7DGEA peptides injected intravenously accumulated within bone tissue, implicating a potential role for E7 domains in drug delivery to bone. Finally, we determined that, as with DGEA, the E7 modification enhanced coupling of a bioactive BMP2-derived peptide on allograft. These results suggest that E7 domains are useful for coupling many types of bone-regenerative molecules to the surface of allograft to reintroduce osteoinductive signals and potentially advance allograft treatments. PMID:23182349

  17. Impacted morsellized bone grafting and cemented primary total hip arthroplasty for acetabular protrusion in patients with rheumatoid arthritis: an 8- to 18-year follow-up study of 36 hips.

    PubMed

    Rosenberg, W W; Schreurs, B W; de Waal Malefijt, M C; Veth, R P; Slooff, T J

    2000-04-01

    Between 1979 and 1989, we performed 36 primary total hip replacements in 31 rheumatoid arthritis patients with protrusio acetabuli. The deficient acetabulum was reconstructed with autologous morsellized bone grafts from the femoral head. 3 patients were lost to follow-up. 12 patients (13 hips) died within 8 years postoperatively, none had a revision. 16 patients (20 hips) were reviewed at an average follow-up of 12 (8-18) years. In 2 hips, a revision was performed for aseptic loosening of the acetabular component, 65 and 8 years after primary surgery, which means a 90% (95% CI: 77%-100%) survival rate at 12 years (Kaplan Meier analysis). This technique is a good option in cases with protrusio acetabuli due to rheumatoid arthritis. PMID:10852319

  18. Inaccuracy in selection of massive bone allograft using template comparison method.

    PubMed

    Paul, Laurent; Docquier, Pierre-Louis; Cartiaux, Olivier; Cornu, Olivier; Delloye, Christian; Banse, Xavier

    2008-06-01

    The use of massive bone allografts is increasing year by year and selection method remains unchanged. Superposition of patient's radiograph over allograft image and comparison of distances is the gold standard. Experiment was led to test selection procedure of a major european tissue bank. Four observers were asked to select an allograft for 10 fictive recipients. Nine allografts were provided. To simulate a perfect allograft, recipient himself was inserted in the pool of allografts (trap graft). The 10 potential bone transplants were classified in four categories (from adequate to unacceptable). In addition, observers were asked to choose the three best grafts for a given recipient. Quadratic kappa measuring agreement on classification between two observers ranged between 0.74 (substantial) and 0.47 (moderate). Trap graft was quoted by observers as adequate four times (10%) and was cited eight times (20%) among the three best matching allografts. None of the observers discovered that recipient was among allograft panel. This study demonstrates that current selection method is inaccurate for hemipelvic allograft selection. New methods should be developed and tested to assist tissue banks in bone allograft selection. PMID:18253861

  19. Selection of massive bone allografts using shape-matching 3-dimensional registration

    PubMed Central

    Docquier, Pierre-Louis; Cartiaux, Olivier; Cornu, Olivier; Delloye, Christian; Banse, Xavier

    2010-01-01

    Background and purpose Massive bone allografts are used when surgery causes large segmental defects. Shape-matching is the primary criterion for selection of an allograft. The current selection method, based on 2-dimensional template comparison, is inefficient for 3-dimensional complex bones. We have analyzed a 3-dimensional (3-D) registration method to match the anatomy of the allograft with that of the recipient. Methods 3-D CT-based registration was performed to match the shapes of both bones. We used the registration to align the allograft volume onto the recipient's bone. Hemipelvic allograft selection was tested in 10 virtual recipients with a panel of 10 potential allografts, including one from the recipient himself (trap graft). 4 observers were asked to visually inspect the superposition of allograft over the recipient, to classify the allografts into 4 categories according to the matching of anatomic zones, and to select the 3 best matching allografts. The results obtained using the registration method were compared with those from a previous study on the template method. Results Using the registration method, the observers systematically detected the trap graft. Selections of the 3 best matching allografts performed using registration and template methods were different. Selection of the 3 best matching allografts was improved by the registration method. Finally, reproducibility of the selection was improved when using the registration method. Interpretation 3-D CT registration provides more useful information than the template method but the final decision lies with the surgeon, who should select the optimal allograft according to his or her own preferences and the needs of the recipient. PMID:20175643

  20. Cross-correlative 3D micro-structural investigation of human bone processed into bone allografts.

    PubMed

    Singh, Atul Kumar; Gajiwala, Astrid Lobo; Rai, Ratan Kumar; Khan, Mohd Parvez; Singh, Chandan; Barbhuyan, Tarun; Vijayalakshmi, S; Chattopadhyay, Naibedya; Sinha, Neeraj; Kumar, Ashutosh; Bellare, Jayesh R

    2016-05-01

    Bone allografts (BA) are a cost-effective and sustainable alternative in orthopedic practice as they provide a permanent solution for preserving skeletal architecture and function. Such BA however, must be processed to be disease free and immunologically safe as well as biologically and clinically useful. Here, we have demonstrated a processing protocol for bone allografts and investigated the micro-structural properties of bone collected from osteoporotic and normal human donor samples. In order to characterize BA at different microscopic levels, a combination of techniques such as Solid State Nuclear Magnetic Resonance (ssNMR), Scanning Electron Microscope (SEM), micro-computed tomography (μCT) and Thermal Gravimetric Analysis (TGA) were used for delineating the ultra-structural property of bone. ssNMR revealed the extent of water, collagen fine structure and crystalline order in the bone. These were greatly perturbed in the bone taken from osteoporotic bone donor. Among the processing methods analyzed, pasteurization at 60 °C and radiation treatment appeared to substantially alter the bone integrity. SEM study showed a reduction in Ca/P ratio and non-uniform distribution of elements in osteoporotic bones. μ-CT and MIMICS (Materialize Interactive Medical Image Control System) demonstrated that pasteurization and radiation treatment affects the BA morphology and cause a shift in the HU unit. However, the combination of all these processes restored all-important parameters that are critical for BA integrity and sustainability. Cross-correlation between the various probes we used quantitatively demonstrated differences in morphological and micro-structural properties between BA taken from normal and osteoporotic human donor. Such details could also be instrumental in designing an appropriate bone scaffold. For the best restoration of bone microstructure and to be used as a biomaterial allograft, a step-wise processing method is recommended that preserves all

  1. Alveolar Ridge Preservation Using Xenogeneic Collagen Matrix and Bone Allograft

    PubMed Central

    Parashis, Andreas O.; Kalaitzakis, Charalampos J.; Tatakis, Dimitris N.; Tosios, Konstantinos

    2014-01-01

    Alveolar ridge preservation (ARP) has been shown to prevent postextraction bone loss. The aim of this report is to highlight the clinical, radiographic, and histological outcomes following use of a bilayer xenogeneic collagen matrix (XCM) in combination with freeze-dried bone allograft (FDBA) for ARP. Nine patients were treated after extraction of 18 teeth. Following minimal flap elevation and atraumatic extraction, sockets were filled with FDBA. The XCM was adapted to cover the defect and 2-3 mm of adjacent bone and flaps were repositioned. Healing was uneventful in all cases, the XCM remained in place, and any matrix exposure was devoid of further complications. Exposed matrix portions were slowly vascularized and replaced by mature keratinized tissue within 2-3 months. Radiographic and clinical assessment indicated adequate volume of bone for implant placement, with all planned implants placed in acceptable positions. When fixed partial dentures were placed, restorations fulfilled aesthetic demands without requiring further augmentation procedures. Histological and immunohistochemical analysis from 9 sites (4 patients) indicated normal mucosa with complete incorporation of the matrix and absence of inflammatory response. The XCM + FDBA combination resulted in minimal complications and desirable soft and hard tissue therapeutic outcomes, suggesting the feasibility of this approach for ARP. PMID:25328523

  2. Development of a Three-Dimensional (3D) Printed Biodegradable Cage to Convert Morselized Corticocancellous Bone Chips into a Structured Cortical Bone Graft

    PubMed Central

    Chou, Ying-Chao; Lee, Demei; Chang, Tzu-Min; Hsu, Yung-Heng; Yu, Yi-Hsun; Liu, Shih-Jung; Ueng, Steve Wen-Neng

    2016-01-01

    This study aimed to develop a new biodegradable polymeric cage to convert corticocancellous bone chips into a structured strut graft for treating segmental bone defects. A total of 24 adult New Zealand white rabbits underwent a left femoral segmental bone defect creation. Twelve rabbits in group A underwent three-dimensional (3D) printed cage insertion, corticocancellous chips implantation, and Kirschner-wire (K-wire) fixation, while the other 12 rabbits in group B received bone chips implantation and K-wire fixation only. All rabbits received a one-week activity assessment and the initial image study at postoperative 1 week. The final image study was repeated at postoperative 12 or 24 weeks before the rabbit scarification procedure on schedule. After the animals were sacrificed, both femurs of all the rabbits were prepared for leg length ratios and 3-point bending tests. The rabbits in group A showed an increase of activities during the first week postoperatively and decreased anterior cortical disruptions in the postoperative image assessments. Additionally, higher leg length ratios and 3-point bending strengths demonstrated improved final bony ingrowths within the bone defects for rabbits in group A. In conclusion, through this bone graft converting technique, orthopedic surgeons can treat segmental bone defects by using bone chips but with imitate characters of structured cortical bone graft. PMID:27104525

  3. Development of a Three-Dimensional (3D) Printed Biodegradable Cage to Convert Morselized Corticocancellous Bone Chips into a Structured Cortical Bone Graft.

    PubMed

    Chou, Ying-Chao; Lee, Demei; Chang, Tzu-Min; Hsu, Yung-Heng; Yu, Yi-Hsun; Liu, Shih-Jung; Ueng, Steve Wen-Neng

    2016-01-01

    This study aimed to develop a new biodegradable polymeric cage to convert corticocancellous bone chips into a structured strut graft for treating segmental bone defects. A total of 24 adult New Zealand white rabbits underwent a left femoral segmental bone defect creation. Twelve rabbits in group A underwent three-dimensional (3D) printed cage insertion, corticocancellous chips implantation, and Kirschner-wire (K-wire) fixation, while the other 12 rabbits in group B received bone chips implantation and K-wire fixation only. All rabbits received a one-week activity assessment and the initial image study at postoperative 1 week. The final image study was repeated at postoperative 12 or 24 weeks before the rabbit scarification procedure on schedule. After the animals were sacrificed, both femurs of all the rabbits were prepared for leg length ratios and 3-point bending tests. The rabbits in group A showed an increase of activities during the first week postoperatively and decreased anterior cortical disruptions in the postoperative image assessments. Additionally, higher leg length ratios and 3-point bending strengths demonstrated improved final bony ingrowths within the bone defects for rabbits in group A. In conclusion, through this bone graft converting technique, orthopedic surgeons can treat segmental bone defects by using bone chips but with imitate characters of structured cortical bone graft. PMID:27104525

  4. Osteoinductive effect of bone bank allografts on human osteoblasts in culture.

    PubMed

    de la Piedra, Concepción; Vicario, Carlos; de Acuña, Lucrecia Rodríguez; García-Moreno, Carmen; Traba, Maria Luisa; Arlandis, Santiago; Marco, Fernando; López-Durán, Luis

    2008-02-01

    Incorporation of a human bone allograft requires osteoclast activity and growth of recipient osteoblasts. The aim of this work was to study the effects produced by autoclavated and -80 degrees C frozen bone allografts on osteoblast proliferation and synthesis of interleukin 6 (IL6), activator of bone resorption, aminoterminal propeptide of procollagen I (PINP), marker of bone matrix formation, and osteoprotegerin (OPG), inhibitor of osteoclast activity and differentiation. Allografts were obtained from human femoral heads. Human osteoblasts were cultured in the presence (problem group) or in the absence (control group) of allografts during 15 days. Allografts produced a decrease in osteoblast proliferation in the first week of the experiment, and an increase in IL6 mRNA, both at 3 h and 2 days, and an increase in the IL6 released to the culture medium the second day of the experiment. We found a decrease in OPG released to the culture on the 2nd and fourth days. These results suggest an increase in bone resorption and a decrease in bone formation in the first week of the experiment. In the second week, allografts produced an increase in osteoblast proliferation and PINP release to the culture medium, indicating an increase in bone formation; an increase in OPG released to the culture medium, which would indicate a decrease in bone resorption; and a decrease in IL6, indicating a decrease in bone resorption stimulation. These results demonstrate that autoclavated and -80 degrees C frozen bone allografts produce in bone environment changes that regulate their own incorporation to the recipient bone. PMID:17853479

  5. Effect of two cleaning processes for bone allografts on gentamicin impregnation and in vitro antibiotic release.

    PubMed

    Coraça-Huber, D C; Hausdorfer, J; Fille, M; Steidl, M; Nogler, M

    2013-06-01

    Bone allografts are a useful and sometimes indispensable tool for the surgeon to repair bone defects. Microbial contamination is a major reason for discarding allografts from bone banks. To improve the number of safe allografts, we suggest chemical cleaning of the grafts followed by antibiotic impregnation. Comparison of two chemical cleaning processes for bone allografts aiming for antibiotic impregnation and consequently delivery rates in vitro. Bone chips of 5-10 mm were prepared from human femoral heads. Two cleaning methods (cleaning A and cleaning B) based on solutions containing hydrogen peroxide, paracetic acid, ethanol and biological detergent were carried out and compared. After the cleaning processes, the bone chips were impregnated with gentamicin. Bacillus subtilis bioassay was used to determine the gentamicin release after intervals of 1-7 days. Differences were compared with non-parametric Mann-Whitney U tests. The zones of inhibition obtained from the bone grafts cleaned with both cleaning processes were similar between the groups. The concentration of the released antibiotic was decreasing gradually over time, following a similar pattern for both groups. The cleaning procedure A as well as the cleaning procedure B for bone allografts allowed the impregnation with gentamicin powder in the same concentrations in both groups. The delivery of gentamicin was similar for both groups. Both cleaning procedures were easy to be carried out, making them suitable for routine use at the bone banks. PMID:22581168

  6. Cryopreserved cancellous bone allograft in periodontal intraosseous defects.

    PubMed

    Borghetti, A; Novakovitch, G; Louise, F; Simeone, D; Fourel, J

    1993-02-01

    The purpose of this study was to evaluate the potential of cryopreserved cancellous bone allograft (CCBA) in the treatment of intraosseous periodontal defects compared to surgical debridement alone (DEBR). Cancellous bone was procured from femur heads that had been extracted for hip prosthesis procedures and cryopreserved in liquid nitrogen (-196 degrees C) in a tissue bank. Ten patients without systemic disorders and advanced periodontal disease (at least 2 intraosseous defects) participated in this investigation. Measurements from the cemento-enamel junction were made after initial therapy for clinical attachment level; also gingival recession, probing pocket depth, plaque index, and gingival index and, at the time of surgery, alveolar crest height and osseous defect depth were measured. All measurements were repeated at 1 year-reentry. Sixteen defects were debrided and grafted (test sites) and 13 defects were debrided only (control sites). Soft tissue measurements showed no statistical differences between the 2 groups. Defect fill was significantly greater with CCBA (1.75 mm) than with DEBR (0.56 mm). Defect depth reduction was 2.06 mm for CCBA and 0.78 mm for DEBR. These values correspond to a percent-defect resolution of 60% for CCBA and 29% for DEBR. Hard tissue measurements showed significant differences between the 2 groups. CCBA seems to be effective in the short-term treatment of intraosseous periodontal defects. PMID:8433252

  7. Controlled Release of Growth Factors on Allograft Bone in vitro

    PubMed Central

    Ryu, WonHyoung; Ren, Peigen; Fasching, Rainer; Goodman, Stuart B.

    2008-01-01

    Allografts are important alternatives to autografts for treating defects after major bone loss. Bone growth factors have both local autocrine and paracrine effects and regulate the growth, proliferation, and differentiation of osteoprogenitor cells. To study the effects of prolonged, continuous, local delivery of growth factors on bone growth, we developed a new microelectromechanical system (MEMS) drug delivery device. Bone marrow cells from mice were seeded on mouse allograft discs and cultured in osteogenic media with osteogenic protein 1 (OP-1) and/or basic fibroblast growth factor (FGF-2) delivered from MEMS devices for 6 weeks. We monitored bone formation by changes of bone volume using micro-CT scanning and release of osteocalcin using ELISA. The data suggest the MEMS devices delivered constant concentrations of OP-1 and FGF-2 to the media. Bone marrow cells grew on the allografts and increased bone volume. Addition of OP-1 increased bone formation whereas FGF-2 decreased bone formation. Local delivery of growth factors over a prolonged period modulated the differentiation of osteoprogenitor cells on allograft bone. PMID:18509711

  8. Arthroscopic Meniscal Allograft Transplantation With Soft-Tissue Fixation Through Bone Tunnels

    PubMed Central

    Spalding, Tim; Parkinson, Ben; Smith, Nick A.; Verdonk, Peter

    2015-01-01

    Meniscal allograft transplantation improves clinical outcomes for patients with symptomatic meniscus-deficient knees. We describe an established arthroscopic technique for meniscal allograft transplantation without the need for bone fixation of the meniscal horns. After preparation of the meniscal bed, the meniscus is parachuted into the knee through a silicone cannula and the meniscal horns are fixed with sutures through bone tunnels. The body of the meniscus is then fixed with a combination of all-inside and inside-out sutures. This technique is reliable and reproducible and has clinical outcomes comparable with those of bone plug fixation techniques. PMID:26900554

  9. Arthroscopic Meniscal Allograft Transplantation With Soft-Tissue Fixation Through Bone Tunnels.

    PubMed

    Spalding, Tim; Parkinson, Ben; Smith, Nick A; Verdonk, Peter

    2015-10-01

    Meniscal allograft transplantation improves clinical outcomes for patients with symptomatic meniscus-deficient knees. We describe an established arthroscopic technique for meniscal allograft transplantation without the need for bone fixation of the meniscal horns. After preparation of the meniscal bed, the meniscus is parachuted into the knee through a silicone cannula and the meniscal horns are fixed with sutures through bone tunnels. The body of the meniscus is then fixed with a combination of all-inside and inside-out sutures. This technique is reliable and reproducible and has clinical outcomes comparable with those of bone plug fixation techniques. PMID:26900554

  10. Biomechanical Evaluation of Posterior Cruciate Ligament Reconstruction With Quadriceps Versus Achilles Tendon Bone Block Allograft

    PubMed Central

    Forsythe, Brian; Haro, Marc S.; Bogunovic, Ljiljana; Collins, Michael J.; Arns, Thomas A.; Trella, Katie J.; Shewman, Elizabeth F.; Verma, Nikhil N.; Bach, Bernard R.

    2016-01-01

    Background: Long-term studies of posterior cruciate ligament (PCL) reconstruction suggest that normal stability is not restored in the majority of patients. The Achilles tendon allograft is frequently utilized, although recently, the quadriceps tendon has been introduced as an alternative option due to its size and high patellar bone density. Purpose/Hypothesis: The purpose of this study was to compare the biomechanical strength of PCL reconstructions using a quadriceps versus an Achilles allograft. The hypothesis was that quadriceps bone block allograft has comparable mechanical properties to those of Achilles bone block allograft. Study Design: Controlled laboratory study. Methods: Twenty-nine fresh-frozen cadaveric knees were assigned to 1 of 3 groups: (1) intact PCL, (2) PCL reconstruction with Achilles tendon allograft, or (3) PCL reconstruction with quadriceps tendon allograft. After reconstruction, all supporting capsular and ligamentous tissues were removed. Posterior tibial translation was measured at neutral and 20° external rotation. Each specimen underwent a preload, 2 cyclic loading protocols of 500 cycles, then load to failure. Results: Construct creep deformation was significantly lower in the intact group compared with both Achilles and quadriceps allograft (P = .008). The intact specimens reached the greatest ultimate load compared with both reconstructions (1974 ± 752 N, P = .0001). The difference in ultimate load for quadriceps versus Achilles allograft was significant (P = .048), with the quadriceps group having greater maximum force during failure testing. No significant differences were noted between quadriceps versus Achilles allograft for differences in crosshead excursion during cyclic testing (peak-valley [P-V] extension stretch), creep deformation, or stiffness. Construct stiffness measured during the failure test was greatest in the intact group (117 ± 9 N/mm, P = .0001) compared with the Achilles (43 ± 11 N/mm) and quadriceps (43

  11. The effect of bone allografts combined with bone marrow stromal cells on the healing of segmental bone defects in a sheep model

    PubMed Central

    2014-01-01

    Background The repair of large bone defects is a major orthopedic challenge because autologous bone grafts are not available in large amounts and because harvesting is often associated with donor-site morbidity. Considering that bone marrow stromal cells (BMSC) are responsible for the maintenance of bone turnover throughout life, we investigated bone repair at a site of a critically sized segmental defect in sheep tibia treated with BMSCs loaded onto allografts. The defect was created in the mid-portion of the tibial diaphysis of eight adult sheep, and the sheep were treated with ex-vivo expanded autologous BMSCs isolated from marrow aspirates and loaded onto cortical allografts (n = 4). The treated sheep were compared with control sheep that had been treated with cell-free allografts (n = 4) obtained from donors of the same breed as the receptor sheep. Results The healing response was monitored by radiographs monthly and by computed tomography and histology at six, ten, fourteen, and eighteen weeks after surgery. For the cell-loaded allografts, union was established more rapidly at the interface between the host bone and the allograft, and the healing process was more conspicuous. Remodeling of the allograft was complete at 18 weeks in the cell-treated animals. Histologically, the marrow cavity was reestablished, with intertrabecular spaces being filled with adipose marrow and with evidence of focal hematopoiesis. Conclusions Allografts cellularized with AOCs (allografts of osteoprogenitor cells) can generate great clinical outcomes to noncellularized allografts to consolidate, reshape, structurally and morphologically reconstruct bone and bone marrow in a relatively short period of time. These features make this strategy very attractive for clinical use in orthopedic bioengineering. PMID:24495743

  12. Cyclosporine-impregnated allograft bone sterilized with low-temperature plasma.

    PubMed

    Lu, Haibo; Pei, Guoxian; Zhao, Peiran; Liang, Shuangwu; Jin, Dan; Jiang, Shan

    2010-12-01

    Deep-freezing, freeze-drying and gamma (γ)-irradiation have deleterious effects on bone healing and mechanical properties of allograft bones. We tried preparing bone allografts using cyclosporine plus low-temperature-plasma sterilization. To explore the feasibility of this method of preparation, segmental defects in the right radii of rabbits were repaired with cyclosporine-impregnated allograft bones (CABs) sterilized with low-temperature-plasma (in the study group) and deep-frozen/freeze-dried irradiated allograft bones (D/FIABs) (in the control group). X-ray and quantitative histological analysis, peripheral blood T lymphocyte subset analysis and CD₂₅ molecule immunohistochemistry stain, the four-point bending test and safety evaluations were respectively conducted to compare bone-healing, immunosuppression, mechanical properties and safety between the two groups. X-ray scores were higher in the study group than those in the control (p = 0.032). There were significant differences in new bone areas at most repairs in both groups (p < 0.05). There were no significant differences in the percentages of CD₄(+) T, CD₈(+) T, ratios of CD₄(+) T:CD₈(+) T or serum concentrations of GPT/Cr in both groups (p > 0.05). At 16 weeks postoperatively, the density of CD₂₅ molecules in the control group was higher than that in the study group. The ultimate loading in the study group was significantly higher than that in the control (p = 0.048). Bone marrow stromal cells (BMSCs) grew thickly around and on the surface of a cyclosporine-impregnated allograft. Livers and kidneys in the study and control groups remained histologically normal at 7 days postoperatively. These results indicate that the CAB might be a better material than the D/FIAB in terms of bone healing, preservation of mechanical properties and immunosuppression without severe side-effects. PMID:20665654

  13. Anterior Cruciate Ligament Reconstruction with Bone-Patellar Tendon-Bone Autograft Versus Allograft in Young Patients

    PubMed Central

    Atanda, Alfred; O’Brien, Daniel Francis; Kraeutler, Matthew John; Flato, Russell R.; Salminen, Matthew Robert; Henrichsen, Kevin; Kane, Patrick; Dodson, Christopher C.; Cohen, Steven B.; Ciccotti, Michael G.

    2015-01-01

    Objectives: Traditionally, bone-patella tendon-bone (BTB) autograft has been the gold standard graft choice for younger, athletic patients requiring ACL reconstruction. However, donor site morbidity, post-operative patella fracture, and increased operative time have led many surgeons to choose BTB allograft for their reconstructions. Opponents of allografts feel that slower healing time, higher rate of graft failure, and potential for disease transmission makes them undesirable graft choices in athletic patients. The purpose of this study is to evaluate the clinical outcomes, both subjective and objective, of young patients that who have undergone either BTB autograft or allograft reconstructions with a minimum of 2-year follow-up. Methods: One hundred and twenty patients (60 autograft, 60 allograft), age 25 and below at time of surgery, were contacted after being retrospectively identified as patients having an ACL reconstruction with either a BTB allograft or autograft by one senior surgeon. Patients were administered the Lysholm Knee Scoring Scale and IKDC Subjective Knee Evaluation questionnaires. Fifty (25 BTB autograft and 25 BTB allograft) of the 120 returned for physical examination as well as completion of a single leg hop test and laxity evaluation using a KT-1000 arthrometer evaluation. Of the 120 patients contacted, there were a total of 7 failures (5.8%) requiring revision, 6 in the allograft group (86%) and 1 in the autograft group (14%). Results: The average Lysholm scores were 89.0 and 89.56 and the average IKDC scores were 90.8 and 92.1 in the autograft and allograft groups respectively. The differences in the Lysholm scores and the IKDC scores were not significant. The single leg hop and KT-1000 scores were also not significantly different. One autograft patient had a minor motion deficit. Three allograft patients had a grade 1 Lachman and pivot glide. One autograft patient and two allograft patients had mild patellafemoral crepitus. There was no

  14. Decalcified allograft in repair of lytic lesions of bone: A study to evolve bone bank in developing countries

    PubMed Central

    Gupta, Anil Kumar; Keshav, Kumar; Kumar, Praganesh

    2016-01-01

    Background: The quest for ideal bone graft substitutes still haunts orthopedic researchers. The impetus for this search of newer bone substitutes is provided by mismatch between the demand and supply of autogenous bone grafts. Bone banking facilities such as deep frozen and freeze-dried allografts are not so widely available in most of the developing countries. To overcome the problem, we have used partially decalcified, ethanol preserved, and domestic refrigerator stored allografts which are economical and needs simple technology for procurement, preparation, and preservation. The aim of the study was to assess the radiological and functional outcome of the partially decalcified allograft (by weak hydrochloric acid) in patients of benign lytic lesions of bone. Through this study, we have also tried to evolve, establish, and disseminate the concept of the bone bank. Materials and Methods: 42 cases of lytic lesions of bone who were treated by decalcified (by weak hydrochloric acid), ethanol preserved, allografts were included in this prospective study. The allograft was obtained from freshly amputated limbs or excised femoral heads during hip arthroplasties under strict aseptic conditions. The causes of lytic lesions were unicameral bone cyst (n = 3), aneurysmal bone cyst (n = 3), giant cell tumor (n = 9), fibrous dysplasia (n = 12), chondromyxoid fibroma, chondroma, nonossifying fibroma (n = 1 each), tubercular osteomyelitis (n = 7), and chronic pyogenic osteomyelitis (n = 5). The cavity of the lesion was thoroughly curetted and compactly filled with matchstick sized allografts. Results: Quantitative assessment based on the criteria of Sethi et al. (1993) was done. There was complete assimilation in 27 cases, partial healing in 12 cases, and failure in 3 cases. Functional assessment was also done according to which there were 29 excellent results, 6 good, and 7 cases of failure (infection, recurrence, and nonunion of pathological fracture). We observed that after

  15. Investigation of bone allografts representing different steps of the bone bank procedure using the CAM-model.

    PubMed

    Holzmann, Philipp; Niculescu-Morzsa, Eugenia; Zwickl, Hannes; Halbwirth, Florian; Pichler, Monika; Matzner, Michael; Gottsauner-Wolf, Florian; Nehrer, Stefan

    2010-01-01

    Bone grafting is commonly used to treat large bone defects. Since autografts are limited and frequently associated with postoperative donor morbidity, allografts from bone banks are often used. However, vascularisation of the allograft is often impaired, resulting in inadequate bone healing and functional graft failure. In bone bank processing, tissue is stored at -80 degree Celsius and subsequently subjected to a harsh multi-step cleaning and sterilisation procedure to prevent immune rejection or transmission of diseases. To determine which step of this procedure diminishes the ability of allografts to induce or promote vascularisation, we used the chick chorioallantoic membrane (CAM) model to monitor the vascular reaction to sample bone chips representing the respective procedural steps. The CAM model monitors the angiogenic potency of xenogeneic and, hence, potentially immunogeneic materials (e.g. cells, tissues, tissue-engineered matrices). Due to the chicken embryo's lack of a fully functional immune system, it provides test conditions that are analogous to immunologically incompetent mice and is a well-suited alternative to their use. Bone chips were placed onto the CAM, and vascular reactions were quantified by image analysis after 48 h incubation. The vascular reaction was most pronounced to fresh, untreated bone chips that had been kept at +2 degree Celsius prior to the experiment. Surprisingly, storage of bone samples at -80 degree Celsius was sufficient to drastically reduce the vascular reaction. Consistent with this, samples representing different stages of the subsequent procedure showed similarly low vascular indices. PMID:20686742

  16. Preclinical Evaluation of Zoledronate to Maintain Bone Allograft and Improve Implant Fixation in Revision Joint Replacement

    PubMed Central

    Sørensen, Mette; Barckman, Jeppe; Bechtold, Joan E.; Søballe, Kjeld; Baas, Jørgen

    2013-01-01

    Background: Revision arthroplasty surgery is often complicated by loss of bone stock that can be managed by the use of bone allograft. The allograft provides immediate stability for the revision implant but may be resorbed, impairing subsequent implant stability. Bisphosphonates can delay allograft resorption. We hypothesized that zoledronate-impregnated allograft impacted around revision implants would improve implant fixation as characterized by mechanical push-out testing and histomorphometry. Methods: Twenty-four axially pistoning micromotion devices were inserted bilaterally into the knees of twelve dogs according to our revision protocol. This produced a standardized revision cavity with a loose implant, fibrous tissue, and a sclerotic bone rim. Revision surgery was performed eight weeks later; after stable titanium revision components were implanted, saline solution-soaked allograft was impacted around the component on the control side and allograft soaked in 0.005 mg/mL zoledronate was impacted on the intervention side. The results were evaluated after four weeks. Results: The zoledronate treatment resulted in a 30% increase in ultimate shear strength (p = 0.023), a 54% increase in apparent shear stiffness (p = 0.002), and a 12% increase in total energy absorption (p = 0.444). The quantity of allograft in the gap was three times greater in the zoledronate group compared with the control group (p < 0.001). The volume fraction of new bone in the zoledronate group (25%; 95% confidence interval [CI], 22% to 28%) was similar to that in the control group (23%; 95% CI, 19% to 26%) (p = 0.311). Conclusions: The data obtained in this canine model suggest that pretreating allograft with zoledronate may be beneficial for early stability of grafted revision arthroplasty implants, without any adverse effect on bone formation. Clinical studies are warranted. Clinical Relevance: The zoledronate treatment is simple to apply in the clinical setting. The treatment could

  17. Lower Limb Reconstruction with Tibia Allograft after Resection of Giant Aneurysmal Bone Cyst

    PubMed Central

    2016-01-01

    Aneurysmal bone cysts (ABCs) are benign, expansible, nonneoplastic lesions of the bone, characterized by channels of blood and spaces separated by fibrous septa, which occur in young patients and, occasionally, with aggressive behavior. Giant ABC is an uncommon pathological lesion and can be challenging because of the destructive effect of the cyst on the bones and the pressure on the nearby structures, especially on weight-bearing bones. In this scenario, en bloc resection is the mainstay treatment and often demands complex reconstructions. This paper reports a difficult case of an unusual giant aneurysmal bone cyst, which required extensive resection and a knee fusion like reconstruction with tibia allograft. PMID:27413565

  18. Bone transplantation and tissue engineering, part III: allografts, bone grafting and bone banking in the twentieth century.

    PubMed

    Hernigou, Philippe

    2015-03-01

    During the 20th century, allograft implantation waned in popularity as a clinical activity. Reports appeared in the literature describing several small series of patients in whom bone was obtained from amputation specimens or recently deceased individuals. The concept of bone banking became a reality during and after World War II when the National Naval Tissue Bank was established in Bethesda and a number of small banks sprang up in hospitals throughout the world. Small fragments, either of cortical or medullary bone, from these banks were used heterotopically to augment spinal fusions, to implant into cyst cavities, or to serve as a scaffolding for repair of non- or delayed union of fractures of the long bones. PMID:25720358

  19. Induction of tolerance to cardiac allografts in lethally irradiated rats reconstituted with syngeneic bone marrow

    SciTech Connect

    Hartnett, L.C.

    1983-01-01

    Generally, organ grafts from one individual animal to another are rejected in one-two weeks. However, if the recipients are given Total Body Irradiation (TBI) just prior to grafting, followed by reconstitution of hemopoietic function with syngeneic (recipient-type) bone marrow cells, then vascularized organ grafts are permanently accepted. Initially after irradiation, it is possible to induce tolerance to many strain combinations in rats. This thesis examines the system of TBI as applied to the induction of tolerance in LEW recipients of WF cardiac allografts. These two rat strains are mismatched across the entire major histocompatibility complex. When the LEW recipient are given 860 rads, a WF cardiac allograft and LEW bone marrow on the same day, 60% of the grafts are accepted. Methods employed to improve the rate of graft acceptance include: treating either donor or recipient with small amounts of methotrexate, or waiting until two days after irradiation to repopulate with bone marrow. It seems from these investigations of some of the early events in the induction of tolerance to allografts following TBI and syngeneic marrow reconstitution that an immature cell population in the bone marrow interacts with a radioresistant cell population in the spleen to produce tolerance to completely MHC-mismatched allografts.

  20. Cyclosporin A and tissue antigen matching in bone transplantation. Fibular allografts studied in the dog.

    PubMed

    Welter, J F; Shaffer, J W; Stevenson, S; Davy, D T; Field, G A; Klein, L; Li, X Q; Zika, J M; Goldberg, V M

    1990-12-01

    We studied the mechanical, metabolic, and histologic properties of short-term nonvascularized cortical bone grafts in a canine fibular graft model. Sham operated nonvascularized autotransplanted and allotransplanted bones were compared. The allografts were performed between dog leukocyte antigen (DLA) class I and II matched; DLA class I and II mismatched; and cyclosporin A (CsA) treated, DLA class I and II mismatched animals. Cyclosporin was given for 1 month, and all the animals were followed for 3 months after surgery. Mechanical properties were investigated using standard torsional tests, metabolic kinetics were assessed using isotopic prelabeling techniques, and histomorphometric analysis of cross-sectional area properties and sequential fluorochrome labels were performed. Autografts were mechanically stronger and stiffer than all the types of allograft. CsA-treated, DLA-mismatched allografts performed better than matched allografts. These in turn were stronger than non-CsA-treated, mismatched allografts, which underwent nearly complete resorption. These relationships were preserved in the metabolic and histologic analyses. In this short-term animal study, although DLA matching resulted in a slight improvement in graft outcome, mismatched grafts in dogs receiving a short course of cyclosporin A fared even better. PMID:2281759

  1. A comparative evaluation of freeze dried bone allograft and decalcified freeze dried bone allograft in the treatment of intrabony defects: A clinical and radiographic study

    PubMed Central

    Gothi, Rajat; Bansal, Mansi; Kaushik, Mayur; Khattak, Braham Prakash; Sood, Nikhil; Taneja, Vishal

    2015-01-01

    Background: Ideal graft material for regenerative procedures is autogenous bone graft but the major disadvantage with this graft is the need for a secondary surgical site to procure donor material and the frequent lack of intraoral donor site to obtain sufficient quantities of autogenous bone for multiple or deep osseous defects. Hence, to overcome these disadvantages, bone allografts were developed as an alternative source of graft material. Materials and Methods: In 10 patients with chronic periodontitis, 20 bilateral infrabony defects were treated with freeze dried bone allograft (FDBA-Group A) and decalcified freeze dried bone allograft (DFDBA-Group B). Clinical and radiographic parameters were assessed preoperatively and at 3 months and 6 months postoperatively. Data thus obtained was subjected to statistical analysis. Results: Significant improvement in the reduction in probing depth and relative attachment level (RAL) from the baseline to 3 months to baseline to 6 months in group A and group B, which was statistically significant but no statistically significant reduction was seen between 3 months and 6 months. On inter-group comparison, no significant differences were observed at all-time points. In adjunct to the probing depth and RAL, the radiographic area of the defect showed a similar trend in intra-group comparison and no significant difference was seen on inter-group comparison at all-time points. Conclusions: Within the limitations of the current study, it can be concluded that DFDBA did not show any improvement in the clinical and radiographic parameters in the treatment of the intrabony defects as compared to FDBA. PMID:26392690

  2. Use of Supercritical Sterilized Bone Allograft in Two Stage Revision ACL Reconstruction

    PubMed Central

    Roe, Justin; Rutten, Sjoerd; Bonnar, Fiona; Salmon, Lucy; Pinczewski, Leo

    2016-01-01

    Objectives: Revision ACL-reconstruction can be compromised by bone loss as result of tunnel widening or poorly placed tunnels. Two-stage revision ACL consist of initial removal of the old fixation hardware and remaining ACL-graft tissue, followed by bone grafting of the tunnels. After a period of graft incorporation and bone remodeling, an ACL-reconstruction is performed. Our primary aim is to examine the use of supercritical carbon dioxide sterilized bone allograft for tunnel grafting in order to determine the bone quality, graft incorporation and remodeling, by using histology and histomorphometric analysis. Secondarily, we aimed to determine whether the histological findings correlate with the timing of the second stage revision procedure. Methods: Case Series. 12 subjects underwent 2-stage revision ACL reconstruction. Femoral and tibial tunnels were bone grafted with supercritical carbon dioxide sterilized bone allograft (Australian Biotechnologies). Mean time from bone grafting to 2nd stage was 8.8 months (range, 5.6 to 21.3 months). Bone biopsies were taken at the time of the 2nd surgery and decalcified and embedded in paraffin. Sections were hematoxylin and eosin stained for microscopic analysis. Results: The graft material was easily identified by its necrotic appearance with empty osteocytes lacunes within the lamellar trabecular bone. In all tissue samples predominately lamellar host bone apposition was seen on the surface of graft fragments known as creeping substitution. Separate bone graft fragments were bridged by newly formed woven bone. In the histological sections of 2 subjects some small islands of chondral cell differentiation were seen, which may relate to endochondral ossification. Active bone remodeling and resorption through combined osteoclastic and osteoblastic activity was present in 2 subjects (7.0 and 6.3 months post grafting), suggesting more advanced phases of graft incorporation. Mean bone volume was 68% over tissue volume (range 33

  3. Maxillary sinus grafting with fresh frozen allograft versus bovine bone mineral: A tomographic and histological study.

    PubMed

    Xavier, Samuel Porfirio; Santos, Thiago de Santana; Sehn, Felipe Perraro; Silva, Erick Ricardo; Garcez-Filho, João de Andrade; Martins-Filho, Paulo Ricardo Saquete

    2016-06-01

    We evaluated histologically and tomographically the effects of fresh frozen bone allograft (FFB) or bovine bone mineral (BBM) in maxillary sinus floor augmentations. In total, 30 maxillary sinuses from 30 patients (mean age = 51.17 ± 10.86 years) underwent sinus augmentation. Patients were divided in two test groups (15 sinuses each). The first group was grafted with allograft bone, and the second group received bovine bone mineral. After 6 months, bone samples from each group were collected for histological examination. Implant survival rates were 97.78% (FFB group) and 100% (BBM group) 6 months after functional loading. Median volumetric reductions of 31.2% (11.33-40.56) and 12.22% (9.91-20.59) were observed in the FFB and BBM groups, respectively. Comparisons between the groups for differences in initial and final volumes of bone (p = 0.015) and the rate of resorption (p = 0.009) showed statistically significant differences. The FFB group showed osteoblastic cells in close contact with osteoid matrix, connected through bridges between allograft bone particles and new bone formation. The BBM group showed BBM particles in close contact with new bone, with visible osteoid matrix bridges and osteoblastic cells surrounding it. None showed signs of acute or chronic inflammatory infiltrate. Despite better results with BBM, both FFB and BBM in maxillary sinus augmentation resulted in high percentages of new bone formation, and allowed implant placement with a low rate of failure of osseointegration at a 6-month follow-up. PMID:27107475

  4. The long-term fate of fresh and frozen orthotopic bone allografts in genetically defined rats.

    PubMed

    Bos, G D; Goldberg, V M; Gordon, N H; Dollinger, B M; Zika, J M; Powell, A E; Heiple, K G

    1985-01-01

    Fresh and frozen orthotopic iliac crest bone grafts in rats were studied histologically for determination of the long-term effects of histocompatibility matching and the freezing process on orthotopic bone graft incorporation. Grafts exchanged between groups of inbred rats, syngeneic or differing with respect to major or minor histocompatibility loci, were studied histologically at 20, 30, 40, 50, and 150 days after bone transplantation. A numerical histologic scoring system was developed and used by three observers for evaluation of coded hematoxylin and eosin sections. All frozen graft groups had the same fate regardless of histocompatibility relations between donors and recipients, and all grafts were inferior to fresh syngeneic grafts. Both fresh allograft groups received similar scores and initially at 20 and 30 days had scores similar to those of the fresh syngeneic groups. In the later intervals, however, the fresh allografts were inferior to the fresh syngeneic grafts and similar to the frozen groups. This is consistent with an older model describing two distinct phases of osteogenesis. In the long term, frozen syngeneic and fresh and frozen allografts across major and minor histocompatibility barriers were comparable, but all were significantly inferior to fresh syngeneic bone grafts. PMID:3893828

  5. Sterilization of allograft bone: is 25 kGy the gold standard for gamma irradiation?

    PubMed

    Nguyen, Huynh; Morgan, David A F; Forwood, Mark R

    2007-01-01

    For several decades, a dose of 25 kGy of gamma irradiation has been recommended for terminal sterilization of medical products, including bone allografts. Practically, the application of a given gamma dose varies from tissue bank to tissue bank. While many banks use 25 kGy, some have adopted a higher dose, while some choose lower doses, and others do not use irradiation for terminal sterilization. A revolution in quality control in the tissue banking industry has occurred in line with development of quality assurance standards. These have resulted in significant reductions in the risk of contamination by microorganisms of final graft products. In light of these developments, there is sufficient rationale to re-establish a new standard dose, sufficient enough to sterilize allograft bone, while minimizing the adverse effects of gamma radiation on tissue properties. Using valid modifications, several authors have applied ISO standards to establish a radiation dose for bone allografts that is specific to systems employed in bone banking. These standards, and their verification, suggest that the actual dose could be significantly reduced from 25 kGy, while maintaining a valid sterility assurance level (SAL) of 10(-6). The current paper reviews the methods that have been used to develop radiation doses for terminal sterilization of medical products, and the current trend for selection of a specific dose for tissue banks. PMID:16821106

  6. Comparative efficacy of 2 different demineralized bone matrix allografts in treating long-bone nonunions in heavy tobacco smokers.

    PubMed

    Ziran, Bruce; Cheung, Sunny; Smith, Wade; Westerheide, Ken

    2005-07-01

    Smoking impairs bone healing and increases the risk for complications associated with nonunions. The efficacies of 2 different allografts, Grafton (demineralized bone matrix [DBM] in a gel-like glycerol carrier) and Orthoblast (DBM with a reverse thermal poloxamer carrier) were examined with respect to nonunions in patients who reported heavy tobacco use. The Grafton allograft was used in 25 patients, and the Orthoblast allograft was used in 13 patients. All patients smoked more than half a pack of cigarettes a day and did not use electric stimulators. A successful graft was defined as healing on the first graft attempt without complications or later regraft. The Grafton and Orthoblast success rates were 52% and 85%, respectively (P = .077). The unique thermal properties of the Orthoblast reverse poloxamer, which may enhance DBM osteoinduction, may account for the difference in success rates. Although results failed to reach statistical significance, the large difference and high likelihood ratio (4.2) between the 2 groups suggest that perhaps not all commercially available allografts may necessarily perform with the same efficacy with respect to heavy smokers. PMID:16130350

  7. Effects of Trypsinization and Mineralization on Intrasynovial Tendon Allograft Healing to Bone

    PubMed Central

    Qu, Jin; van Alphen, Nick A.; Thoreson, Andrew R.; Chen, Qingshan; An, Kai-Nan; Amadio, Peter C.; Schmid, Thomas M.; Zhao, Chunfeng

    2014-01-01

    The purpose of the current study was to develop a novel technology to enhance tendon-to-bone interface healing by trypsinizing and mineralizing (TM) an intrasynovial tendon allograft in a rabbit bone tunnel model. Eight rabbit flexor digitorum profundus (FDP) tendons were used to optimize the trypsinization process. An additional 24 FDP tendons were stratified into control and TM groups; in each group, 4 tendons were used for in vitro evaluation of TM and 8 were transplanted into proximal tibial bone tunnels in rabbits. The samples were evaluated histologically and with mechanical testing at postoperative week 8. Maximum failure strength and linear stiffness were not significantly different between the control and TM tendons. A thin fibrous band of scar tissue formed at the graft-to-bone interface in the control group. However, only the TM group showed obvious new bone formation inside the tendon graft and a visible fibrocartilage layer at the bone tunnel entrance. This study is the first to explore effects of TM on the intrasynovial allograft healing to a bone tunnel. TM showed beneficial effects on chondrogenesis, osteogenesis, and integration of the intrasynovial tendon graft, but mechanical strength was the same as the control tendons in this short-term in vivo study. PMID:25611186

  8. Evaluation of Clinical Results and Complications of Structural Allograft Reconstruction after Bone Tumor Surgery

    PubMed Central

    Gharedaghi, Mohammad; Peivandi, Mohammad Taghi; Mazloomi, Mehdi; Shoorin, Hasan Rahimi; Hasani, Mohammad; Seyf, Parham; Khazaee, Fatemeh

    2016-01-01

    Background: Massive bone allograft is an option in cases of limb preservation and reconstruction after massive benign and malignant bone tumor resection. The purpose of this study was to analyze the outcome of these procedures at Imam Reza Hospital, Mashhad University of Medical Sciences. Methods: In this study, 113 cases have been presented. Eleven cases were excluded (patients has a traumatic defect or they passed away before the completion of the study’s two-year follow up period). Each patient completed a questionnaire, went through a physical examination and, if indicated, X-ray information was collected. The patients were divided into three groups: chemotherapy, chemotherapy plus radiation therapy, and no-adjuvant-therapy. Results: Fifty-four cases were male and the mean age was 24.5±5.39. The number of cases and indications for surgery were: 33 cases of aggressive benign tumors or low grade malignant bone tumors (large bone defects) including 16 germ cell tumors, eight aneurysmal bone cysts, five low grade osteosarcomas, and four chondrosarcomas. Another 69 cases were high-grade malignant bone tumors including 42 osteosarcomas, 21 Ewing’s sarcoma, and six other high grade osteosarcomas. Patients were divided into three groups: the first group received no adjuvant therapy, the second group received chemotherapy, and the third group received chemotherapy plus radiotherapy. The location of tumors were as follows: eight cases in the pelvic bone, 12 in the proximal femur, 18 in the femoral shaft, 36 in the distal femur, 12 in the proximal tibia, and 16 in the humeral bone. The 12 cases of proximal femoral defects were reconstructed by allograft composite prosthesis, 18 diaphyseal defects with intercalary allograft, and 36 distal femoral defects were reconstructed using osteoarticular allograft. The rate of deep infection was 7:8% (eight patients) and in this regard, we found a significant difference among the three groups, such that most cases of infection

  9. Tunable Delivery of Bioactive Peptides from HA Biomaterials and Allograft Bone Using Variable Length Polyglutamate Domains

    PubMed Central

    Culpepper, Bonnie K.; Webb, William M.; Bonvallet, Paul P.; Bellis, Susan L.

    2013-01-01

    Hydroxyapatite (HA) biomaterials and allograft bone are common alternatives to autogenous grafts, however these materials lack the strong osteoinductive potential of autologous bone. Previous studies have established that polyglutamate domains, which bind selectively to HA, can be engineered onto bioactive peptides as a mechanism for coupling osteoinductive signals onto HA and allograft. In the current investigation, we adapted the polyglutamate approach to tailor delivery of a model collagen-derived peptide, DGEA, by manipulating the number of glutamates in the HA binding domain. Specifically, DGEA was modified with diglutamate (E2-DGEA), tetraglutamate (E4-DGEA) or heptaglutamate (E7-DGEA), and it was found that initial peptide binding to HA and allograft was significantly enhanced as the number of glutamates increased. We also determined that the rate of release of polyglutamate-DGEA from substrates over a 5-day interval increased proportionally as the number of glutamate residues was decreased. Additionally, we tuned the peptide release rate by creating mixtures of E2-DGEA, E4-DGEA and E7-DGEA, and observed that release kinetics of the mixtures were distinct from pure solutions of each respective peptide. These collective results suggest that variable length polyglutamate domains provide an effective mechanism for controlled delivery of osteoregenerative peptides on HA-containing bone graft materials. PMID:23625466

  10. Effects of particle size and porosity on in vivo remodeling of settable allograft bone/polymer composites.

    PubMed

    Prieto, Edna M; Talley, Anne D; Gould, Nicholas R; Zienkiewicz, Katarzyna J; Drapeau, Susan J; Kalpakci, Kerem N; Guelcher, Scott A

    2015-11-01

    Established clinical approaches to treat bone voids include the implantation of autograft or allograft bone, ceramics, and other bone void fillers (BVFs). Composites prepared from lysine-derived polyurethanes and allograft bone can be injected as a reactive liquid and set to yield BVFs with mechanical strength comparable to trabecular bone. In this study, we investigated the effects of porosity, allograft particle size, and matrix mineralization on remodeling of injectable and settable allograft/polymer composites in a rabbit femoral condyle plug defect model. Both low viscosity and high viscosity grafts incorporating small (<105 μm) particles only partially healed at 12 weeks, and the addition of 10% demineralized bone matrix did not enhance healing. In contrast, composite grafts with large (105-500 μm) allograft particles healed at 12 weeks postimplantation, as evidenced by radial μCT and histomorphometric analysis. This study highlights particle size and surface connectivity as influential parameters regulating the remodeling of composite bone scaffolds. PMID:25581686

  11. Long-term outcome of free fibula osteocutaneous flap and massive allograft in the reconstruction of long bone defect.

    PubMed

    Halim, Ahmad Sukari; Chai, Siew Cheng; Wan Ismail, Wan Faisham; Wan Azman, Wan Sulaiman; Mat Saad, Arman Zaharil; Wan, Zulmi

    2015-12-01

    Reconstruction of massive bone defects in bone tumors with allografts has been shown to have significant complications including infection, delayed or nonunion of allograft, and allograft fracture. Resection compounded with soft tissue defects requires skin coverage. A composite osteocutaneous free fibula offers an optimal solution where the allografts can be augmented mechanically and achieve biological incorporation. Following resection, the cutaneous component of the free osteocutaneous fibula flaps covers the massive soft tissue defect. In this retrospective study, the long-term outcome of 12 patients, who underwent single-stage limb reconstruction with massive allograft and free fibula osteocutaneous flaps instead of free fibula osteal flaps only, was evaluated. This study included 12 consecutive patients who had primary bone tumors and had follow-up for a minimum of 24 months. The mean age at the time of surgery was 19.8 years. A total of eight patients had primary malignant bone tumors (five osteosarcomas, two chondrosarcomas and one synovial sarcoma), and four patients had benign bone tumors (two giant-cell tumors, one aneurysmal bone cyst, and one neurofibromatosis). The mean follow-up for the 12 patients was 63 months (range 24-124 months). Out of the 10 patients, nine underwent lower-limb reconstruction and ambulated with partial weight bearing and full weight bearing at an average of 4.2 months and 8.2 months, respectively. In conclusion, augmentation of a massive allograft with free fibula osteocutaneous flap is an excellent alternative for reducing the long-term complication of massive allograft and concurrently addresses the soft tissue coverage. PMID:26420474

  12. Bioactive lipid coating of bone allografts directs engraftment and fate determination of bone marrow-derived cells in rat GFP chimeras.

    PubMed

    Das, Anusuya; Segar, Claire E; Chu, Yihsuan; Wang, Tiffany W; Lin, Yong; Yang, Chunxi; Du, Xeujun; Ogle, Roy C; Cui, Quanjun; Botchwey, Edward A

    2015-09-01

    Bone grafting procedures are performed to treat wounds incurred during wartime trauma, accidents, and tumor resections. Endogenous mechanisms of repair are often insufficient to ensure integration between host and donor bone and subsequent restoration of function. We investigated the role that bone marrow-derived cells play in bone regeneration and sought to increase their contributions by functionalizing bone allografts with bioactive lipid coatings. Polymer-coated allografts were used to locally deliver the immunomodulatory small molecule FTY720 in tibial defects created in rat bone marrow chimeras containing genetically-labeled bone marrow for monitoring cell origin and fate. Donor bone marrow contributed significantly to both myeloid and osteogenic cells in remodeling tissue surrounding allografts. FTY720 coatings altered the phenotype of immune cells two weeks post-injury, which was associated with increased vascularization and bone formation surrounding allografts. Consequently, degradable polymer coating strategies that deliver small molecule growth factors such as FTY720 represent a novel therapeutic strategy for harnessing endogenous bone marrow-derived progenitors and enhancing healing in load-bearing bone defects. PMID:26125501

  13. Incorporation of raloxifene-impregnated allograft around orthopedic titanium implants impairs early fixation but improves new bone formation

    PubMed Central

    Hermansen, Lars L; Sørensen, Mette; Barckman, Jeppe; Bechtold, Joan E; Søballe, Kjeld; Baas, Jørgen

    2015-01-01

    Background The anti-osteoporotic drug raloxifene reduces the risk of vertebral fractures by increasing bone mass density. We investigated whether raloxifene offers any benefits in augmenting early fixation of orthopedic implants in the setting of impaction bone grafting. Methods 24 non-weight-bearing grafted gap implants were inserted bilaterally into the tibia of 12 dogs. The 2.5-mm peri-implant gap was filled with either raloxifene-impregnated or untreated bone allograft. Implants were harvested after 28 days. Implant fixation was assessed by mechanical testing and histomorphometric evaluation. Results Raloxifene-treated allograft reduced early implant fixation compared to untreated allograft, as measured by inferior maximum shear strength (p < 0.001) and apparent shear stiffness (p = 0.001). We found that the raloxifene group had more newly formed bone in the gap around the implant (p = 0.02), but also less allograft (p = 0.03). Interpretation The accelerated allograft resorption in the raloxifene group explained the impaired early fixation, despite its stimulation of new bone formation. Our results with local and possible high-dose treatment are not consistent with current theory regarding the mechanism of how systemic raloxifene administration counteracts the decrease in BMD in postmenopausal women. Instead of being solely anti-resorptive as generally held, our results indicate a possible anabolic side of raloxifene. PMID:25175661

  14. A preclinical study of stem subsidence and graft incorporation after femoral impaction grafting using porous hydroxyapatite as a bone graft extender.

    PubMed

    Howie, Donald W; McGee, Margaret A; Callary, Stuart A; Carbone, Angelo; Stamenkov, Roumen B; Bruce, Warrick J; Findlay, David M

    2011-10-01

    This preclinical in vivo screening study compared bone graft incorporation and stem subsidence in cemented hemiarthroplasty after femoral impaction bone grafting with either morselized allograft bone (n = 5, control group) or a 1:1 mix of allograft and porous hydroxyapatite ceramics (HA) granules (n = 5, HA group). At 14 weeks, there was excellent bone graft incorporation by bone, and the stems were well fixed in both groups. The median subsidence at the cement-bone interface, measured using radiostereometric analysis, was 0.14 and 0.93 mm in the control and HA groups, respectively. The comparable histologic results between groups and good stem fixation in this study support the conduct of a larger scale investigation of the use of porous HA in femoral impaction bone grafting at revision hip arthroplasty. PMID:21802252

  15. In vitro effect of mineralized and demineralized bone allografts on proliferation and differentiation of MG-63 osteoblast-like cells.

    PubMed

    Lafzi, Ardeshir; Vahabi, Surena; Ghods, Shadab; Torshabi, Maryam

    2016-03-01

    Due to the extensive use of bone allografts in bone reconstruction and periodontal therapy as suitable alternatives to autografts, they are now marketed under different commercial brands. Considering the controversial reports regarding the osteoinductive properties of bone allografts, this study sought to assess the effect of type (mineralized/demineralized), amount and particle size of several allografts on the proliferation and differentiation of MG-63 osteoblast-like cells. MG-63 cells (24-h culture) were exposed to 20 and 40 mg amounts of nine different commercially available freeze-dried bone allografts. After 24 and 72 h of incubation, the effect of water-soluble allograft released materials on cell viability and proliferation was assessed using methyl thiazol tetrazolium (MTT) assay after 24 and 72 h of exposure. Cell differentiation and mineralization was assessed by real-time quantitative reverse transcription PCR and alizarin red staining after 72 h of exposure. The amount and particle size of understudy allografts had significant effects on cell viability after 24 h of exposure (in contrast to 72 h). Higher rate of proliferation was seen in non-differentiated or slow-differentiated groups. The amount and particle size factors had no significant effect on the amount of calcified nodules or the expression of osteogenic marker genes in most groups. Faster and more distinct differentiation and mineralization was noted in mineralized compared to demineralized groups during the 3-day study period. Based on the results, the understudy mineralized (non-demineralized) bone allografts had greater effect on osteogenic differentiation of the MG-63 cells and showed more in vitro osteoinductive activity compared to partially demineralized and fully demineralized types. PMID:26084504

  16. A retrospective study on annual evaluation of radiation processing for frozen bone allografts complying to quality system requirements.

    PubMed

    Ramalingam, Saravana; Mohd, Suhaili; Samsuddin, Sharifah Mazni; Min, N G Wuey; Yusof, Norimah; Mansor, Azura

    2015-12-01

    Bone allografts have been used widely to fill up essential void in orthopaedic surgeries. The benefit of using allografts to replace and reconstruct musculoskeletal injuries, fractures or disease has obtained overwhelming acceptance from orthopaedic surgeons worldwide. However, bacterial infection and disease transmission through bone allograft transplantation have always been a significant issue. Sterilization by radiation is an effective method to eliminate unwanted microorganisms thus assist in preventing life threatening allograft associated infections. Femoral heads procured from living donors and long bones (femur and tibia) procured from cadaveric donors were sterilized at 25 kGy in compliance with international standard ISO 11137. According to quality requirements, all records of bone banking were evaluated annually. This retrospective study was carried out on annual evaluation of radiation records from 1998 until 2012. The minimum doses absorbed by the bones were ranging from 25.3 to 38.2 kGy while the absorbed maximum doses were from 25.4 to 42.3 kGy. All the bones supplied by our UMMC Bone Bank were sterile at the required minimum dose of 25 kGy. Our analysis on dose variation showed that the dose uniformity ratios in 37 irradiated boxes of 31 radiation batches were in the range of 1.003-1.251, which indicated the doses were well distributed. PMID:25687771

  17. Inability of donor total body irradiation to prolong survival of vascularized bone allografts: Experimental study in the rat

    SciTech Connect

    Gonzalez del Pino, J.; Benito, M.; Randolph, M.A.; Weiland, A.J. )

    1990-07-01

    At the present time, the toxic side effects of recipient immunosuppression cannot be justified for human non-vital organ transplantation. Total body irradiation has proven effective in ablating various bone-marrow-derived and endothelial immunocompetent cellular populations, which are responsible for immune rejection against donor tissues. Irradiation at a dose of 10 Gy was given to donor rats six days prior to heterotopic transplantation of vascularized bone allografts to host animals. Another group of recipient rats also received a short-term (sixth to fourteenth day after grafting), low dose of cyclosporine. Total body irradiation was able merely to delay rejection of grafts across a strong histocompatibility barrier for one to two weeks, when compared to nonirradiated allografts. The combination of donor irradiation plus cyclosporine did not delay the immune response, and the rejection score was similar to that observed for control allografts. Consequently, allograft viability was quickly impaired, leading to irreversible bone damage. This study suggest that 10 Gy of donor total body irradiation delivered six days prior to grafting cannot circumvent the immune rejection in a vascularized allograft of bone across a strong histocompatibility barrier.

  18. Surgical Guides (Patient-Specific Instruments) for Pediatric Tibial Bone Sarcoma Resection and Allograft Reconstruction

    PubMed Central

    Bellanova, Laura; Paul, Laurent; Docquier, Pierre-Louis

    2013-01-01

    To achieve local control of malignant pediatric bone tumors and to provide satisfactory oncological results, adequate resection margins are mandatory. The local recurrence rate is directly related to inappropriate excision margins. The present study describes a method for decreasing the resection margin width and ensuring that the margins are adequate. This method was developed in the tibia, which is a common site for the most frequent primary bone sarcomas in children. Magnetic resonance imaging (MRI) and computerized tomography (CT) were used for preoperative planning to define the cutting planes for the tumors: each tumor was segmented on MRI, and the volume of the tumor was coregistered with CT. After preoperative planning, a surgical guide (patient-specific instrument) that was fitted to a unique position on the tibia was manufactured by rapid prototyping. A second instrument was manufactured to adjust the bone allograft to fit the resection gap accurately. Pathologic evaluation of the resected specimens showed tumor-free resection margins in all four cases. The technologies described in this paper may improve the surgical accuracy and patient safety in surgical oncology. In addition, these techniques may decrease operating time and allow for reconstruction with a well-matched allograft to obtain stable osteosynthesis. PMID:23533326

  19. Percutaneous Vertebral Augmentation with Polyethylene Mesh and Allograft Bone for Traumatic Thoracolumbar Fractures

    PubMed Central

    Schulz, C.; Kunz, U.; Mauer, U. M.; Mathieu, R.

    2015-01-01

    Purpose. In cases of traumatic thoracolumbar fractures, percutaneous vertebral augmentation can be used in addition to posterior stabilisation. The use of an augmentation technique with a bone-filled polyethylene mesh as a stand-alone treatment for traumatic vertebral fractures has not yet been investigated. Methods. In this retrospective study, 17 patients with acute type A3.1 fractures of the thoracic or lumbar spine underwent stand-alone augmentation with mesh and allograft bone and were followed up for one year using pain scales and sagittal endplate angles. Results. From before surgery to 12 months after surgery, pain and physical function improved significantly, as indicated by an improvement in the median VAS score and in the median pain and work scale scores. From before to immediately after surgery, all patients showed a significant improvement in mean mono- and bisegmental kyphoses. During the one-year period, there was a significant loss of correction. Conclusions. Based on this data a stand-alone approach with vertebral augmentation with polyethylene mesh and allograft bone is not a suitable therapy option for incomplete burst fractures for a young patient collective. PMID:25688302

  20. Bone grafting and one-stage revision of THR - biological reconstruction and effective antimicrobial treatment using antibiotic impregnated allograft bone.

    PubMed

    Winkler, Heinz

    2012-01-01

    Infection of a total hip replacement (THR) is considered one of the most serious complications in orthopaedic surgery. Problems derive from the presence of biofilms with inherent resistance to usual antibiotic treatment and bone defects resulting from infection induced osteolysis. Discussions on the choice of treatment mainly focus on the chance of eradicating the infection in either one or more stages. The advantages of only one operation with regard to patients' satisfaction, functional results and economical burden are evident. However, the fear of re-infection usually leads surgeons to multiple stage procedures, mostly using antibiotic loaded spacers in the interval. Spacers have no effect on biofilms and are associated with a high rate of complications such as breakage or dislocation. Cemented revisions show several disadvantages like reduction of biomechanical properties through added antibiotics, inferior long term results, difficulties of removal in case of recurrence etc. Uncemented implants appear more advantageous but are at risk of becoming colonised by remaining biofilm fragments. To overcome this risk higher local concentrations of antibiotics are needed. Allograft bone may be impregnated with high loads of antibiotics using special incubation techniques, resulting in an antibiotic bone compound (ABC). ABC provides local concentrations exceeding those of cement by more than a 100-fold and efficient release is prolonged for several weeks. At the same time it is likely to restore bone stock, which is usually compromised after removal of an infected endoprosthesis. Based on these considerations new protocols for one-stage exchange of infected THR have been established. Bone voids may be filled with ABC, uncemented implants may be fixed in original healthy bone. Recent studies indicate an overall success rate of more than 90% with one operation, without any adverse side effects. Incorporation of allografts appears as after grafting with unimpregnated bone

  1. Histologic Evaluation of Bone Healing Capacity Following Application of Inorganic Bovine Bone and a New Allograft Material in Rabbit Calvaria

    PubMed Central

    Paknejad, Mojgan; Rokn, AmirReza; Rouzmeh, Nina; Heidari, Mohadeseh; Titidej, Azadehzeinab; Kharazifard, Mohammad Javad; Mehrfard, Ali

    2015-01-01

    Objectives: Considering the importance of bone augmentation prior to implant placement in order to obtain adequate bone quality and quantity, many studies have been conducted to evaluate different techniques and materials regarding new bone formation. In this study, we investigated the bone healing capacity of two different materials deproteinized bovine bone mineral (DBBM with the trade name of Bio-Oss) and demineralized freeze-dried bone allograft (DFDBA with the trade name of DynaGraft). Materials and Methods: This randomized blinded prospective study was conducted on twelve New Zealand white rabbits. Three cranial defects with an equal diameter were created on their calvarium. Subsequently, they were distributed into three groups: 1. The control group without any treatment; 2. The Bio-Oss group; 3. The DynaGraft group. After 30 days, the animals were sacrificed for histologic and histomorphometric analysis. Results: Substantial new bone formation was observed in both groups. DynaGraft: 56/1 % ± 15/1 and Bio-Oss: 53/55 % ± 13/5 compared to the control group: 28/6 % ± 11/2. All groups showed slight inflammation and a small amount of residual biomaterial was observed. Conclusion: Considerable new bone formation was demonstrated in both DynaGraft and Bio-Oss groups in comparison with the control group. Both materials are considered biocompatible regarding the negligible foreign body reaction. PMID:26005452

  2. Total Knee Arthroplasty for Post-Traumatic Proximal Tibial Bone Defect: Three Cases Report

    PubMed Central

    Tigani, D; Dallari, D; Coppola, C; Ben Ayad, R; Sabbioni, G; Fosco, M

    2011-01-01

    Bone stock deficiency in primary as well as in revision total knee arthroplasty (TKA) represents a difficult problem to surgeon with regard to maintaining proper alignment of the implant components and in establishing a stable bone-implant interface. Different surgical procedures are available in these situations, for instances the use of bone cement, prosthetic augments, custom implant, and wire mesh with morsellized bone grafting and structural bone allograft. Structural allograft offers a numerous advantages as easy remodeling and felling cavitary or segmental defects, excellent biocompatibility, bone stock restoration and potential for ligamentous reattachment. In this article we report a short term result of three cases affected by severe segmental medial post/traumatic tibial plateau defect in arthritic knee, for which massive structural allograft reconstruction and primary total knee replacement were carried. The heights of the bone defect were between 27-33 mm and with moderate medio-lateral knee instability. Pre-operative AKS score in three cases was 30, 34 and 51 points consecutively and improved at the last follow-up to 83, 78 and 85 consecutively. No acute or chronic complication was observed. Last radiological exam referred no signs of prosthetic loosening, no secondary resorption of bone graft and well integrated graft to host bone. These results achieved in our similar three cases have confirmed that the structural bone allograft is a successful biological material to restore hemi-condylar segmental tibial bone defect when total knee replacement is indicated. PMID:21584202

  3. Enhancement by dimethyl myleran of donor type chimerism in murine recipients of bone marrow allografts

    SciTech Connect

    Lapidot, T.; Terenzi, A.; Singer, T.S.; Salomon, O.; Reisner, Y. )

    1989-05-15

    A major problem in using murine models for studies of bone marrow allograft rejection in leukemia patients is the narrow margin in which graft rejection can be analyzed. In mice irradiated with greater than 9 Gy total body irradiation (TBI) rejection is minimal, whereas after administration of 8 Gy TBI, which spares a significant number of clonable T cells, a substantial frequency of host stem cells can also be detected. In current murine models, unlike in humans, bone marrow allograft rejection is generally associated with full autologous hematopoietic reconstitution. In the present study, we investigated the effect of the myeloablative drug dimethyl myleran (DMM) on chimerism status following transplantation of T cell-depleted allogenic bone marrow (using C57BL/6 donors and C3H/HeJ recipients, conditioned with 8 Gy TBI). Donor type chimerism 1 to 2 months post-transplant of 1 to 3 x 10(6) bone marrow cells was markedly enhanced by using DMM one day after TBI and prior to transplantation. Conditioning with cyclophosphamide instead of DMM, in combination with 8 Gy TBI, did not enhance engraftment of donor type cells. Artificial reconstitution of T cells, after conditioning with TBI plus DMM, by adding mature thymocytes, or presensitization with irradiated donor type spleen cells 1 week before TBI and DMM, led to strong graft rejection and consequently to severe anemia. The anti-donor responses in these models were proportional to the number of added T cells and to the number of cells used for presensitization, and they could be neutralized by increasing the bone marrow inoculum.

  4. Extraction site preservation using new graft material that combines mineralized and demineralized allograft bone: a case series report with histology.

    PubMed

    Holtzclaw, Dan

    2014-02-01

    This retrospective case series reports on the use of a new allograft bone product composed of a 70 to 30 ratio of mineralized to demineralized cortical bone particles to preserve the alveolar ridge dimensions of patients requiring tooth extraction with plans for future dental implant placement. Ten patients received atraumatic tooth extractions with subsequent placement of the blended bone allograft. All sites were covered with a single layer of amnion-chorion, which was intentionally left exposed. After an average healing time of 14 weeks, the surgical sites were accessed for placement of dental implants. Prior to implant placement, trephine core samples were taken for histologic analysis. Dental implants were successfully placed in all previously grafted surgical sites; no sites required any additional bone augmentation. Histologic analysis of trephined bone core samples revealed bone compositions similar to those described in previously published site preservation studies. The results of this case series suggest that blended bone allograft containing a 70 to 30 ratio of mineralized to demineralized cortical bone particles can be successfully used to facilitate future placement of dental implants with as little as 14 weeks of healing. PMID:24571560

  5. Biomechanical properties of canine cortical bone allografts: effects of preparation and storage.

    PubMed

    Roe, S C; Pijanowski, G J; Johnson, A L

    1988-06-01

    The effects of various preparation and storage procedures and of different storage times on structural properties of canine cortical bone allografts were determined by evaluation of the compressive load to failure of a whole diaphyseal segment, the ability of a screw to resist being pulled from a cortical segment, and the torque required to strip the threads of a screw hole in a cortical segment. Preparation and storage procedures evaluated were sterile collection and storage at -20 C; ethylene oxide sterilization and storage at room temperature (22 C); chemical sterilization (methanol and chloroform, then iodoacetic acid) and storage at -20 C; and chemical sterilization, partial decalcification, and storage at -20 C. Storage times were 1, 16, and 32 weeks for each procedure. After 1 week of storage, aseptically collected frozen bone and ethylene oxide-sterilized bone had an increase, compared with matched controls, in load to failure in compression, but pullout load or screw-stripping torque did not change. Chemically sterilized bone had not changed after 1 week of storage, whereas chemically sterilized and partially decalcified bone had a 40% to 60% decrease in compressive load to failure, pullout load, and screw-stripping torque. Chemically sterilized and partially decalcified bone remained weak after 16 and 32 weeks of storage. Significant structural alterations were not detected in aseptically collected bone after 16 or 32 weeks of storage. Ethylene oxide-sterilized bone had a reduced pullout load after 32 weeks of storage. Chemically sterilized bone had significantly reduced compressive load to failure and pullout load after 16 and 32 weeks of storage.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3041883

  6. Engineering nanocages with polyglutamate domains for coupling to hydroxyapatite biomaterials and allograft bone.

    PubMed

    Culpepper, Bonnie K; Morris, David S; Prevelige, Peter E; Bellis, Susan L

    2013-03-01

    Hydroxyapatite (HA) is the principal constituent of bone mineral, and synthetic HA is widely used as a biomaterial for bone repair. Previous work has shown that polyglutamate domains bind selectively to HA and that these domains can be utilized to couple bioactive peptides onto many different HA-containing materials. In the current study we have adapted this technology to engineer polyglutamate domains into cargo-loaded nanocage structures derived from the P22 bacteriophage. P22 nanocages have demonstrated significant potential as a drug delivery system due to their stability, large capacity for loading with a diversity of proteins and other types of cargo, and ability to resist degradation by proteases. Site-directed mutagenesis was used to modify the primary coding sequence of the P22 coat protein to incorporate glutamate-rich regions. Relative to wild-type P22, the polyglutamate-modified nanocages (E2-P22) exhibited increased binding to ceramic HA disks, particulate HA and allograft bone. Furthermore, E2-P22 binding was HA selective, as evidenced by negligible binding of the nanocages to non-HA materials including polystyrene, agarose, and polycaprolactone (PCL). Taken together these results establish a new mechanism for the directed coupling of nanocage drug delivery systems to a variety of HA-containing materials commonly used in diverse bone therapies. PMID:23312905

  7. Engineering nanocages with polyglutamate domains for coupling to hydroxyapatite biomaterials and allograft bone

    PubMed Central

    Culpepper, Bonnie K.; Morris, David S.; Prevelige, Peter E.; Bellis, Susan L.

    2013-01-01

    Hydroxyapatite (HA) is the principal constituent of bone mineral, and synthetic HA is widely used as a biomaterial for bone repair. Previous work has shown that polyglutamate domains bind selectively to HA and that these domains can be utilized to couple bioactive peptides onto many different HA-containing materials. In the current study we have adapted this technology to engineer polyglutamate domains into cargo-loaded nanocage structures derived from the P22 bacteriophage. P22 nanocages have demonstrated significant potential as a drug delivery system due to their stability, large capacity for loading with a diversity of proteins and other types of cargo, and ability to resist degradation by proteases. Site-directed mutagenesis was used to modify the primary coding sequence of the P22 coat protein to incorporate glutamate-rich regions. Relative to wild-type P22, the polyglutamate-modified nanocages (E2-P22) exhibited increased binding to ceramic HA disks, particulate HA and allograft bone. Furthermore, E2-P22 binding was HA selective, as evidenced by negligible binding of the nanocages to non-HA materials including polystyrene, agarose, and polycaprolactone (PCL). Taken together these results establish a new mechanism for the directed coupling of nanocage drug delivery systems to a variety of HA-containing materials commonly used in diverse bone therapies. PMID:23312905

  8. Long-term survival of intestinal allografts induced by costimulation blockade, busulfan and donor bone marrow infusion.

    PubMed

    Guo, Zhong; Wang, Jun; Dong, Ying; Adams, Andrew B; Shirasugi, Nozomu; Kim, Oliver; Hart, John; Newton-West, Marvin; Pearson, Thomas C; Larsen, Christian P; Newell, Kenneth A

    2003-09-01

    Tolerance-inducing strategies that infuse donor bone marrow cells in conjunction with costimulation blockade have not been applied to intestinal transplantation. Intestines from BALB/c mice were transplanted into C57BL/6 recipients treated with anti-CD40L mAb, CTLA4-Ig, donor bone marrow, and busulfan. The majority of mice transplanted after completion of this regimen developed hematopoietic macrochimerism, although the degree of chimerism varied widely between recipients, and experienced long-term allograft survival. T cells from these mice demonstrated donor-specific hyporesponsiveness in vitro. However, T cells from chimeric mice proliferated to donor alloantigen in vivo. Furthermore, chimeric mice bearing intestinal allografts were capable of rejecting subsequently placed donor-strain skin grafts. These data suggest that although long-term allograft survival occurs in the absence of acute or chronic rejection, recipient mice are not completely unresponsive to donor alloantigens. When intestinal transplantation was performed at the time of initial bone marrow infusion (initiation of the chimerism protocol), most recipients failed to develop chimerism and promptly rejected the intestinal allograft. Although this is the most effective protocol that we have tested using this stringent model of transplantation, our observations suggest that modifications will be necessary before it can be reliably applied to the transplantation of highly immunogeneic organs like the intestine. PMID:12919088

  9. The Enhancement of Bone Allograft Incorporation by the Local Delivery of the Sphingosine 1-phosphate Receptor Targeted Drug FTY720

    PubMed Central

    Aronin, Caren E Petrie; Shin, Soo J; Naden, Kimberly B; Rios, Peter D; Sefcik, Lauren S; Zawodny, Sarah R; Bagayoko, Namory D; Cui, Quanjun; Khan, Yusuf

    2010-01-01

    Poor vascularization coupled with mechanical instability is the leading cause of post-operative complications and poor functional prognosis of massive bone allografts. To address this limitation, we designed a novel continuous polymer coating system to provide sustained localized delivery of pharmacological agent, FTY720, a selective agonist for sphingosine 1-phosphate receptors, within massive tibial defects. In vitro drug release studies validated 64% loading efficiency with complete release of compound following 14 days. Mechanical evaluation following six weeks of healing suggested significant enhancement of mechanical stability in FTY720 treatment groups compared with unloaded controls. Furthermore, superior osseous integration across the host-graft interface, significant enhancement in smooth muscle cell investment, and reduction in leukocyte recruitment was evident in FTY720 treated groups compared with untreated groups. Using this approach, we can capitalize on the existing mechanical and biomaterial properties of devitalized bone, add a controllable delivery system while maintaining overall porous structure, and deliver a small molecule compound to constitutively target vascular remodeling, osseous remodeling, and minimize fibrous encapsulation within the allograft-host bone interface. Such results support continued evaluation of drug-eluting allografts as a viable strategy to improve functional outcome and long-term success of massive cortical allograft implants. PMID:20621764

  10. Fractionated sublethal total body irradiation and donor bone marrow infusion for induction of specific allograft tolerance

    SciTech Connect

    Pierce, G.E.; Kimler, B.F.; Thomas, J.H.; Watts, L.M.; Kinnaman, M.L.

    1981-03-01

    Fractionated total lymphoid irradiation (FT-lymphoid-I) plus donor bone marrow (BM) can induce tolerance to skin allografts. In the present study, fractionated total body irradiation (FT-body-I) was studied as an alternative to FT-lymphoid-I. FT-body-I produces less pulmonary and gastrointestinal injury than does single exposure total body irradiation, but because of the decreased capacity of lymphoid tissues to recover from the effects of irradiation between fractions, the effect of FT-body-I on lymphoid cells, when delivered within 24 h, is approximately the same as an equivalent single exposure of total body irradiation. Therefore, FT-body-I, like FT-lymphoid-I, has some selectivity for lymphoid tissues and has the advantage that it can be delivered within the time constraints of ex vivo organ preservation.

  11. Histological evaluation of an impacted bone graft substitute composed of a combination of mineralized and demineralized allograft in a sheep vertebral bone defect.

    PubMed

    Fujishiro, Takaaki; Bauer, Thomas W; Kobayashi, Naomi; Kobayashi, Hideo; Sunwoo, Moon Hae; Seim, Howard B; Turner, A Simon

    2007-09-01

    Demineralized bone matrix (DBMs) preparations are a potential alternative or supplement to autogenous bone graft, but many DBMs have not been adequately tested in clinically relevant animal models. The aim of current study was to compare the efficacy of a new bone graft substitute composed of a combination of mineralized and demineralized allograft, along with hyaluronic acid (AFT Bone Void Filler) with several other bone graft materials in a sheep vertebral bone void model. A drilled defect in the sheep vertebral body was filled with either the new DBM preparation, calcium sulfate (OsteoSet), autologous bone graft, or left empty. The sheep were euthanized after 6 or 12 weeks, and the defects were examined by histology and quantitative histomorphometry. The morphometry data were analyzed by one-way analysis of variance with the post hoc Tukey-Kramer test or the Student's t-test. All of the bone defects in the AFT DBM preparation group showed good new bone formation with variable amounts of residual DBM and mineralized bone graft. The DBM preparation group at 12 weeks contained significantly more new bone than the defects treated with calcium sulfate or left empty (respectively, p < 0.05, p < 0.01). There was no significant difference between the DBM and autograft groups. No adverse inflammatory reactions were associated with any of the three graft materials. The AFT preparation of a mixture of mineralized and demineralized allograft appears to be an effective autograft substitute as tested in this sheep vertebral bone void model. PMID:17309059

  12. Arthroscopic Treatment for Shoulder Instability with Glenoid Bone Loss Using Distal Tibia Allograft Augmentation - Short Term Results

    PubMed Central

    Wong, Ivan; Amar, Eyal; Coady, Catherine M.; Dilman, Daryl B.; Smith, Ben

    2016-01-01

    Objectives: Background: The results of arthroscopic anterior labral (Bankart) repair have been shown to have high failure rate in patients with significant glenoid bone loss. Several reconstruction procedures using bone graft have been described to overcome the bone loss, including autogenous coracoid transfer to the anterior glenoid (Latarjet procedure) as well as iliac crest autograft and tibial allografts. In recent years, trends toward minimally invasive shoulder surgery along with improvements in technology and technique have led surgeons to expand the application of arthroscopic treatment. Purpose: This study aims to perform a retrospective analysis of prospectively collected data to evaluate the clinical and radiological follow up of patient who underwent anatomic glenoid reconstruction using distal tibia allograft for the treatment of shoulder instability with glenoid bone loss at 1-year post operation time point. Methods: Between December 2011 and January 2015, 55 patients underwent arthroscopic stabilization of the shoulder by means of capsule-labral reattachment to glenoid ream and bony augmentation of glenoid bone loss with distal tibial allograft for recurrent instability of the shoulder. Preoperative and postoperative evaluation included general assessment by the western Ontario shoulder instability index (WOSI) questionnaire, preoperative and postoperative radiographs and CT scans. Results: Fifty-five patients have been evaluated with mean age of 29.73 years at time of the index operation. There were 40 males (mean age of 29.66) and 15 female (mean age of 29.93). Minimum follow up time was 12 months. The following adverse effects were recorded: none suffered from recurrent dislocation, 2 patients suffered from bone resorption but without overt instability, 1 patient had malunion due to screw fracture, none of the patients had nonunion. The mean pre-operative WOSI score was 36.54 and the mean postoperative WOSI score was 61.0. Conclusion: Arthroscopic

  13. Repair of peripheral nerve defects with chemically extracted acellular nerve allografts loaded with neurotrophic factors-transfected bone marrow mesenchymal stem cells

    PubMed Central

    Zhang, Yan-ru; Ka, Ka; Zhang, Ge-chen; Zhang, Hui; Shang, Yan; Zhao, Guo-qiang; Huang, Wen-hua

    2015-01-01

    Chemically extracted acellular nerve allografts loaded with brain-derived neurotrophic factor-transfected or ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells have been shown to repair sciatic nerve injury better than chemically extracted acellular nerve allografts alone, or chemically extracted acellular nerve allografts loaded with bone marrow mesenchymal stem cells. We hypothesized that these allografts compounded with both brain-derived neurotrophic factor- and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells may demonstrate even better effects in the repair of peripheral nerve injury. We cultured bone marrow mesenchymal stem cells expressing brain-derived neurotrophic factor and/or ciliary neurotrophic factor and used them to treat sciatic nerve injury in rats. We observed an increase in sciatic functional index, triceps wet weight recovery rate, myelin thickness, number of myelinated nerve fibers, amplitude of motor-evoked potentials and nerve conduction velocity, and a shortened latency of motor-evoked potentials when allografts loaded with both neurotrophic factors were used, compared with allografts loaded with just one factor. Thus, the combination of both brain-derived neurotrophic factor and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells can greatly improve nerve injury. PMID:26604913

  14. Repair of peripheral nerve defects with chemically extracted acellular nerve allografts loaded with neurotrophic factors-transfected bone marrow mesenchymal stem cells.

    PubMed

    Zhang, Yan-Ru; Ka, Ka; Zhang, Ge-Chen; Zhang, Hui; Shang, Yan; Zhao, Guo-Qiang; Huang, Wen-Hua

    2015-09-01

    Chemically extracted acellular nerve allografts loaded with brain-derived neurotrophic factor-transfected or ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells have been shown to repair sciatic nerve injury better than chemically extracted acellular nerve allografts alone, or chemically extracted acellular nerve allografts loaded with bone marrow mesenchymal stem cells. We hypothesized that these allografts compounded with both brain-derived neurotrophic factor- and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells may demonstrate even better effects in the repair of peripheral nerve injury. We cultured bone marrow mesenchymal stem cells expressing brain-derived neurotrophic factor and/or ciliary neurotrophic factor and used them to treat sciatic nerve injury in rats. We observed an increase in sciatic functional index, triceps wet weight recovery rate, myelin thickness, number of myelinated nerve fibers, amplitude of motor-evoked potentials and nerve conduction velocity, and a shortened latency of motor-evoked potentials when allografts loaded with both neurotrophic factors were used, compared with allografts loaded with just one factor. Thus, the combination of both brain-derived neurotrophic factor and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells can greatly improve nerve injury. PMID:26604913

  15. Effects of gamma irradiation on the initial mechanical and material properties of goat bone-patellar tendon-bone allografts

    SciTech Connect

    Gibbons, M.J.; Butler, D.L.; Grood, E.S.; Bylski-Austrow, D.I.; Levy, M.S.; Noyes, F.R. )

    1991-03-01

    The effects of {sup 60}Co gamma irradiation on the initial mechanical properties of the composite bone-patellar tendon-bone unit (CU) and the tendon midsubstance (TM) were studied. Frozen specimens were exposed to either 2 or 3 Mrad of gamma irradiation. Paired frozen specimens served as intraanimal controls. Treatment effects on the CU were assessed using four mechanical parameters. Effects on the TM were assessed using four material parameters measured using an optical surface-strain analysis system. The maximum force and strain energy to maximum force of the composite unit were significantly reduced 27% and 40%, respectively, after 3 Mrad of irradiation (p less than .05). Mechanical properties of the CU were not significantly altered, however, following 2 Mrad of irradiation. Based on individual paired contrasts between treatment and control, significant differences were also found in the material properties of the tendon midsubstance. The maximum stress, maximum strain, and strain energy density to maximum stress were significantly reduced following 3 Mrad, but not 2 Mrad, of irradiation. The results provide important time zero material property data, which will be useful for later anterior cruciate ligament reconstruction studies using irradiated allograft patellar tendons in the goat model and other animal models as well.

  16. Socket preservation and sinus augmentation using a medical grade calcium sulfate hemihydrate and mineralized irradiated cancellous bone allograft composite.

    PubMed

    Bagoff, Robert; Mamidwar, Sachin; Chesnoiu-Matei, Ioana; Ricci, John L; Alexander, Harold; Tovar, Nick M

    2013-06-01

    Regeneration and preservation of bone after the extraction of a tooth are necessary for the placement of a dental implant. The goal is to regenerate alveolar bone with minimal postoperative pain. Medical grade calcium sulfate hemihydrate (MGCSH) can be used alone or in combination with other bone grafts; it improves graft handling characteristics and particle containment of particle-based bone grafts. In this case series, a 1:1 ratio mix of MGCSH and mineralized irradiated cancellous bone allograft (MICBA) was mixed with saline and grafted into an extraction socket in an effort to maintain alveolar height and width for future implant placement. MGCSH can be used in combination with other bone grafts and can improve handling characteristics and graft particle containment of particle-based bone grafts. In the cases described, we found that an MGCSH:MICBA graft can potentially be an effective bone graft composite. It has the ability to act as a space maintainer and as an osteoconductive trellis for bone cells, thereby promoting bone regeneration in the extraction socket. MGCSH, a cost-effective option, successfully improved MICBA handling characteristics, prevented soft tissue ingrowth, and assisted in the regeneration of bone. PMID:21905884

  17. Computed Tomography and Optical Imaging of Osteogenesis-angiogenesis Coupling to Assess Integration of Cranial Bone Autografts and Allografts.

    PubMed

    Cohn Yakubovich, Doron; Tawackoli, Wafa; Sheyn, Dmitriy; Kallai, Ilan; Da, Xiaoyu; Pelled, Gadi; Gazit, Dan; Gazit, Zulma

    2015-01-01

    A major parameter determining the success of a bone-grafting procedure is vascularization of the area surrounding the graft. We hypothesized that implantation of a bone autograft would induce greater bone regeneration by abundant blood vessel formation. To investigate the effect of the graft on neovascularization at the defect site, we developed a micro-computed tomography (µCT) approach to characterize newly forming blood vessels, which involves systemic perfusion of the animal with a polymerizing contrast agent. This method enables detailed vascular analysis of an organ in its entirety. Additionally, blood perfusion was assessed using fluorescence imaging (FLI) of a blood-borne fluorescent agent. Bone formation was quantified by FLI using a hydroxyapatite-targeted probe and µCT analysis. Stem cell recruitment was monitored by bioluminescence imaging (BLI) of transgenic mice that express luciferase under the control of the osteocalcin promoter. Here we describe and demonstrate preparation of the allograft, calvarial defect surgery, µCT scanning protocols for the neovascularization study and bone formation analysis (including the in vivo perfusion of contrast agent), and the protocol for data analysis. The 3D high-resolution analysis of vasculature demonstrated significantly greater angiogenesis in animals with implanted autografts, especially with respect to arteriole formation. Accordingly, blood perfusion was significantly higher in the autograft group by the 7(th) day after surgery. We observed superior bone mineralization and measured greater bone formation in animals that received autografts. Autograft implantation induced resident stem cell recruitment to the graft-host bone suture, where the cells differentiated into bone-forming cells between the 7(th) and 10(th) postoperative day. This finding means that enhanced bone formation may be attributed to the augmented vascular feeding that characterizes autograft implantation. The methods depicted may serve

  18. Efficacy of Combined Therapy of Periosteum and Bone Allograft in a Critical-Sized Defect Model in New Zealand White Rabbits

    PubMed Central

    Zhang, Dawei; Huang, Dong; Huang, Yongjun; Liu, Yuanhang; Lin, Bochuan; Yu, Chaoqun; Mou, Yong; Wu, Weichi; Zhang, Huiru; Lin, Hao

    2014-01-01

    Background Large segmental bone defects caused by trauma, infection, or bone tumor resection are difficult to cure and have been a problem in the field of bone repair for decades. The objective of this study was to discuss the efficacy of combined therapy of free periosteum and bone allograft in treating bone defects and to provide a theoretical basis for clinical application of this therapy. Material/Methods A unilateral tibia cortical defect model in New Zealand white rabbits was established according to Girolamo method. Total 48 rabbits were randomized into 3 groups: a simple bone defect group (n=16), an autogenous bone graft group (n=16), and a periosteum and bone allograft combined therapy group (n=16). The efficacy was evaluated by imaging inspections and scoring, HE staining, and RT-PCR in postoperative weeks 2, 4, 8, and 12. Results The results of imaging and histopathological inspections in the study indicated that in postoperative weeks 4, 8, and 12 the experimental and control groups had statistically significant differences in Lane-Sandhu radiographic scoring and relative bone density when compared with the simple bone defect group (P<0.05). The RT-PCR results suggested that the expression of SPP-1, BMP-2, and VEGF in the experimental group was higher than in the control group (P<0.05) and the expression of Col Iα1 in the control group was higher than in the experimental group (P<0.05). Conclusions Efficacies of the combined therapy (periosteum combined with bone allografting) and the criterion standard therapy (autogenous bone grafting) are equivalent in treating bone defects in New Zealand white rabbits. PMID:25417209

  19. Placement of implants in an ossifying fibroma defect obliterated with demineralized, freeze-dried bone allograft and Plasma-rich growth factor

    PubMed Central

    Pal, Umashankar; Mishra, Niraj

    2012-01-01

    There has been considerable clinical interest in combining the grafts, particularly bone allografts for support for dental implants, soft-tissue support, periodontal maintenance, and ovate pontic formation. The use of demineralized, freeze-dried bone allograft (DFDBA) offers certain advantages over other graft materials and can avoid the need for a second-site surgery for autogenous donor bone. The advantages of DFDBA include handling properties, osteoinductivity, membrane tenting, and less susceptibility to migration after placement. This article will review available grafting materials and demonstrate a case of ossifying fibroma of the mandible, which was treated by curettage and hollow cavity filled with DFDBA. Six months follow-up period showed successful graft result and this grafted bone form was utilized for implant supported prosthesis. PMID:23633812

  20. The effect of sterilization methods on the osteoconductivity of allograft bone in a critical-sized bilateral tibial defect model in rabbits.

    PubMed

    Russell, Nicholas; Oliver, Rema A; Walsh, William R

    2013-11-01

    Clinically, allogeneic bone graft is used extensively because it avoids the donor site morbidity associated with autograft. However, there are concerns over the optimal sterilization method to eliminate immunological risks whilst maintaining the biological efficacy of the graft. This study compared the effect of Supercritical fluid (SCF) treatment and gamma irradiation at 25 kGy on the osteoconductivity of allograft bone in a bilateral critical sized defect rabbit model. Osteoconductivity was evaluated at 2 and 4 weeks using X-ray, CT, histology (qualitative and quantitative) and immunohistochemistry (Alkaline Phosphatase and Cathepsin-K). Both grafts were well tolerated and osteoconductive. At 2 weeks, there was decreased bone volume and density in the gamma irradiated graft compared to the SCF treated graft, corresponding with a greater inflammatory response histologically and increased Cathepsin-K expression. Catabolic activity predominated at 4 weeks, with both grafts undergoing significant resorption and remodeling inside the defect. Alkaline Phosphatase expression was greater in the SCF group at both time points indicative of a more anabolic response. Allograft bone sterilized with either gamma irradiation or SCF treatment was osteoconductive and capable of healing a critical sized tibial defect in a rabbit. Gamma irradiated allografts elicited an acute inflammatory reaction when implanted which may increase the amount of graft resorption compared to the SCF treated bone. PMID:23891084

  1. Bone Cysts After Osteochondral Allograft Repair of Cartilage Defects in Goats Suggest Abnormal Interaction Between Subchondral Bone and Overlying Synovial Joint Tissues

    PubMed Central

    Pallante-Kichura, Andrea L.; Cory, Esther; Bugbee, William D.; Sah, Robert L.

    2013-01-01

    The efficacy of osteochondral allografts (OCA) may be affected by osseous support of the articular cartilage, and thus affected by bone healing and remodeling in the OCA and surrounding host. Bone cysts, and their communication pathways, may be present in various locations after OCA insertion and reflect distinct pathogenic mechanisms. Previously, we analyzed the effect of OCA storage (FRESH, 4°C/14d, 4°C/28d, FROZEN) on cartilage quality in fifteen adult goats after 12 months in vivo. The objectives of this study were to further analyze OCA and contralateral non-operated (Non-Op) CONTROLS from the medial femoral condyle to (1) determine the effect of OCA storage on local subchondral (ScB) and trabecular (TB) bone structure, (2) characterize the location and structure of bone cysts and channels, and (3) assess the relationship between cartilage and bone properties. (1) Overall bone structure after OCA was altered compared to Non-Op, with OCA samples displaying bone cysts, ScB channels, and ScB roughening. ScB BV/TV in FROZEN OCA was lower than Non-Op and other OCA. TB BV/TV in FRESH, 4°C/14d, and 4°C/28d OCA did not vary compared to Non-Op, but BS/TV was lower. (2) OCA contained “basal” cysts, localized to deeper regions, some “subchondral” cysts, localized near the bone-cartilage interface, and some ScB channels. TB surrounding basal cysts exhibited higher BV/TV than Non-Op. (3) Basal cysts occurred (a) in isolation, (b) with subchondral cysts and ScB channels, (c) with ScB channels, or (d) with subchondral cysts, ScB channels, and ScB erosion. Deterioration of cartilage gross morphology was strongly associated with abnormal μCT bone structure. Evidence of cartilage-bone communication following OCA repair may favor fluid intrusion as a mechanism for subchondral cyst formation, while bone resorption at the graft-host interface without affecting overall bone and cartilage structure may favor bony contusion mechanism for basal cyst formation. These

  2. Analysis of new bone, cartilage, and fibrosis tissue in healing murine allografts using whole slide imaging and a new automated histomorphometric algorithm

    PubMed Central

    Zhang, Longze; Chang, Martin; Beck, Christopher A; Schwarz, Edward M; Boyce, Brendan F

    2016-01-01

    Histomorphometric analysis of histologic sections of normal and diseased bone samples, such as healing allografts and fractures, is widely used in bone research. However, the utility of traditional semi-automated methods is limited because they are labor-intensive and can have high interobserver variability depending upon the parameters being assessed, and primary data cannot be re-analyzed automatically. Automated histomorphometry has long been recognized as a solution for these issues, and recently has become more feasible with the development of digital whole slide imaging and computerized image analysis systems that can interact with digital slides. Here, we describe the development and validation of an automated application (algorithm) using Visiopharm’s image analysis system to quantify newly formed bone, cartilage, and fibrous tissue in healing murine femoral allografts in high-quality digital images of H&E/alcian blue-stained decalcified histologic sections. To validate this algorithm, we compared the results obtained independently using OsteoMeasureTM and Visiopharm image analysis systems. The intraclass correlation coefficient between Visiopharm and OsteoMeasure was very close to one for all tissue elements tested, indicating nearly perfect reproducibility across methods. This new algorithm represents an accurate and labor-efficient method to quantify bone, cartilage, and fibrous tissue in healing mouse allografts. PMID:26816658

  3. Balancing the Rates of New Bone Formation and Polymer Degradation Enhances Healing of Weight-Bearing Allograft/Polyurethane Composites in Rabbit Femoral Defects

    PubMed Central

    Dumas, Jerald E.; Prieto, Edna M.; Zienkiewicz, Katarzyna J.; Guda, Teja; Wenke, Joseph C.; Bible, Jesse; Holt, Ginger E.

    2014-01-01

    There is a compelling clinical need for bone grafts with initial bone-like mechanical properties that actively remodel for repair of weight-bearing bone defects, such as fractures of the tibial plateau and vertebrae. However, there is a paucity of studies investigating remodeling of weight-bearing bone grafts in preclinical models, and consequently there is limited understanding of the mechanisms by which these grafts remodel in vivo. In this study, we investigated the effects of the rates of new bone formation, matrix resorption, and polymer degradation on healing of settable weight-bearing polyurethane/allograft composites in a rabbit femoral condyle defect model. The grafts induced progressive healing in vivo, as evidenced by an increase in new bone formation, as well as a decrease in residual allograft and polymer from 6 to 12 weeks. However, the mismatch between the rates of autocatalytic polymer degradation and zero-order (independent of time) new bone formation resulted in incomplete healing in the interior of the composite. Augmentation of the grafts with recombinant human bone morphogenetic protein-2 not only increased the rate of new bone formation, but also altered the degradation mechanism of the polymer to approximate a zero-order process. The consequent matching of the rates of new bone formation and polymer degradation resulted in more extensive healing at later time points in all regions of the graft. These observations underscore the importance of balancing the rates of new bone formation and degradation to promote healing of settable weight-bearing bone grafts that maintain bone-like strength, while actively remodeling. PMID:23941405

  4. Extramedullary hematopoiesis in renal allograft

    PubMed Central

    Chen, Guilan; Ali, Reza; Shuldberg, Mark M.; Bastani, Bahar; Brink, David S.

    2013-01-01

    Extramedullary hematopoiesis (EMH), defined as the presence of hematopoietic elements outside of the medullary cavity of bone, has been reported in patients with various hematopoietic neoplasms including myelofibrosis. EMH commonly occurs in the liver and spleen (resulting in hepatosplenomegaly) and uncommonly involves the kidney. EMH involving the allograft kidney has not been reported in English literature. Herein, we report the first case of EMH in allograft kidney in a patient with myelofibrosis. The clinical and pathological findings are described. Through comparison of the medullary neoplastic infiltrate with the renal allograft infiltrate, we postulate the neoplastic nature of the infiltrate in the allograft kidney. PMID:26120442

  5. Post-operative infection with fresh frozen allograft: reported outcomes of a hospital-based bone bank over 14 years.

    PubMed

    Man, Wing Yum; Monni, Toni; Jenkins, Ruth; Roberts, Paul

    2016-06-01

    Femoral head bone allografts have traditionally been used to provide mechanical stability to areas of bony deficiency, or for its osteoinductive and osteoconductive properties. Concerns have been raised over increased infection rates following the use of fresh-frozen graft tissue. This retrospective study aims to investigate the outcomes of fresh frozen femoral heads kept in a regulated, non-commercial bone bank at a university teaching hospital.The local bone bank database was used to identify released femoral heads during a 14 year study period (September 1999-December 2013) whereby a retrospective review of patient records was undertaken to determine clinical outcome. During the observed study period, 427 femoral heads were released from cold storage. Of these, 270 femoral heads had a mean follow-up of 347 days. 157 femoral heads were excluded due to insufficient follow-up data (n = 132) or discarded due to breaks in the cold chain prior to use (n = 25). Of the 270 included femoral heads, 231 (85.6 %) had no reported complications with good graft incorporation. In the remaining 39 with reported complications, only 5 (2.6 %) developed a postoperative infection. Our findings suggest that the use of fresh frozen allograft does not materially increase the risk of post-operative bacterial infection. Our reported post-operative infection rates are comparable with infection rates of other similar studies on fresh frozen allograft use. PMID:26910111

  6. Biomechanical comparison between CentraLoc and Intrafix fixation of quadrupled semitendinosus-gracilis allografts in cadaveric tibiae with low bone mineral density.

    PubMed

    Krupp, R; Nyland, J; Smith, C; Nawab, A; Burden, R; Caborn, D N M

    2007-08-01

    Supplementary or back-up tibial tunnel fixation of a quadruple semitendinosus-gracilis (STG) graft is often performed when the knee surgeon questions the integrity of intra-tunnel fixation. Back-up fixation devices such as staples however may contribute to increased knee pain and dysfunction. Both primary extra-tunnel and intra-tunnel fixation devices may provide sufficient quadruple STG graft fixation in a tibial tunnel to preclude the need for back-up fixation. This biomechanical study compared the fixation of quadruple STG allografts in standard drilled tunnels prepared in low apparent bone mineral density (BMD) cadaveric tibiae using either an Intrafix device with primary intra-tunnel fixation in a region of predominantly cancellous trabecular bone, or a CentraLoc device with primary extra-tunnel fixation in a region of predominantly cortical bone. The study hypothesis was that the CentraLoc device would display superior fixation in these low apparent BMD cadaveric tibiae. Matched pair tibiae and quadruple STG allografts were divided into two groups of seven specimens each. Extraction drilled tunnels matched allograft diameter. Constructs were pretensioned on a servo hydraulic device between 10 and 50 N for 10 cycles and isometric pretensioned at 50 N for 1 min prior to undergoing 500 loading cycles (50-250 N) and load to failure testing (20 mm/min). The CentraLoc group displayed superior load at failure (448.4+/-171 N vs. 338.4+/-119 N, P=0.04) and survived more loading cycles (410+/-154 cycles vs. 196+/-230 cycles, P=0.04) than the Intrafix group. Most CentraLoc group specimens (6/7, 85.7%) failed by device pullout with intact quadruple STG allograft strands while all Intrafix group specimens (7/7, 100%) failed by slippage of one or more strands (P=0.005). PMID:17490882

  7. Socket Preservation Therapy with Acellular Dermal Matrix and Mineralized Bone Allograft After Tooth Extraction in Humans: A Clinical and Histomorphometric Study.

    PubMed

    Fernandes, Patricia Garani; Muglia, Valdir Antonio; Reino, Danilo Maeda; Maia, Luciana Prado; de Moraes Grisi, Marcio Fernando; de Souza, Sergio Luís; Taba, Mario; Palioto, Daniela Bazan; de Almeida, Adriana G; Novaes, Arthur Belém

    2016-01-01

    The aim of this study was to analyze through clinical and histomorphometric parameters the use of acellular dermal matrix (ADM) with or without mineralized bone allograft (AB) on bone formation in human alveoli after a 6- to 8-month healing period. A total of 19 patients in need of extraction of the maxillary anterior teeth were selected and randomly assigned to the test group (ADM plus AB) or to the control group (ADM only). Clinical and histomorphometric measurements and histologic analysis were recorded 6 to 8 months after ridge preservation procedures. Clinical parameters and amount of mineralized and nonmineralized tissue were measured and analyzed. In the clinical measurements, the test group showed reduced bone loss in the buccopalatal dimension after 6 to 8 months (intragroup analysis P < .01). Histologic findings showed higher percentages of mineralized tissue and lower percentages of nonmineralized tissue in the test group when compared with the control group (P < .05). In this randomized controlled clinical and histomorphometric study in humans, acellular dermal matrix in association with mineralized bone allograft reduced alveolar bone loss in the anterior maxillae both in height and width after a follow-up period of 6 to 8 months. PMID:26901306

  8. Multipotent adult progenitor cells on an allograft scaffold facilitate the bone repair process

    PubMed Central

    LoGuidice, Amanda; Houlihan, Alison; Deans, Robert

    2016-01-01

    Multipotent adult progenitor cells are a recently described population of stem cells derived from the bone marrow stroma. Research has demonstrated the potential of multipotent adult progenitor cells for treating ischemic injury and cardiovascular repair; however, understanding of multipotent adult progenitor cells in orthopedic applications remains limited. In this study, we evaluate the osteogenic and angiogenic capacity of multipotent adult progenitor cells, both in vitro and loaded onto demineralized bone matrix in vivo, with comparison to mesenchymal stem cells, as the current standard. When compared to mesenchymal stem cells, multipotent adult progenitor cells exhibited a more robust angiogenic protein release profile in vitro and developed more extensive vasculature within 2 weeks in vivo. The establishment of this vascular network is critical to the ossification process, as it allows nutrient exchange and provides an influx of osteoprogenitor cells to the wound site. In vitro assays confirmed the multipotency of multipotent adult progenitor cells along mesodermal lineages and demonstrated the enhanced expression of alkaline phosphatase and production of calcium-containing mineral deposits by multipotent adult progenitor cells, necessary precursors for osteogenesis. In combination with a demineralized bone matrix scaffold, multipotent adult progenitor cells demonstrated enhanced revascularization and new bone formation in vivo in an orthotopic defect model when compared to mesenchymal stem cells on demineralized bone matrix or demineralized bone matrix–only control groups. The potent combination of angiogenic and osteogenic properties provided by multipotent adult progenitor cells appears to create a synergistic amplification of the bone healing process. Our results indicate that multipotent adult progenitor cells have the potential to better promote tissue regeneration and healing and to be a functional cell source for use in orthopedic applications

  9. Multipotent adult progenitor cells on an allograft scaffold facilitate the bone repair process.

    PubMed

    LoGuidice, Amanda; Houlihan, Alison; Deans, Robert

    2016-01-01

    Multipotent adult progenitor cells are a recently described population of stem cells derived from the bone marrow stroma. Research has demonstrated the potential of multipotent adult progenitor cells for treating ischemic injury and cardiovascular repair; however, understanding of multipotent adult progenitor cells in orthopedic applications remains limited. In this study, we evaluate the osteogenic and angiogenic capacity of multipotent adult progenitor cells, both in vitro and loaded onto demineralized bone matrix in vivo, with comparison to mesenchymal stem cells, as the current standard. When compared to mesenchymal stem cells, multipotent adult progenitor cells exhibited a more robust angiogenic protein release profile in vitro and developed more extensive vasculature within 2 weeks in vivo. The establishment of this vascular network is critical to the ossification process, as it allows nutrient exchange and provides an influx of osteoprogenitor cells to the wound site. In vitro assays confirmed the multipotency of multipotent adult progenitor cells along mesodermal lineages and demonstrated the enhanced expression of alkaline phosphatase and production of calcium-containing mineral deposits by multipotent adult progenitor cells, necessary precursors for osteogenesis. In combination with a demineralized bone matrix scaffold, multipotent adult progenitor cells demonstrated enhanced revascularization and new bone formation in vivo in an orthotopic defect model when compared to mesenchymal stem cells on demineralized bone matrix or demineralized bone matrix-only control groups. The potent combination of angiogenic and osteogenic properties provided by multipotent adult progenitor cells appears to create a synergistic amplification of the bone healing process. Our results indicate that multipotent adult progenitor cells have the potential to better promote tissue regeneration and healing and to be a functional cell source for use in orthopedic applications. PMID

  10. Osseous healing with a composite of allograft and demineralized bone matrix: adverse effects of smoking.

    PubMed

    Ziran, Bruce H; Hendi, Pooneh; Smith, Wade R; Westerheide, Kenneth; Agudelo, Juan F

    2007-04-01

    We report on our use of a composite graft of lyophilized cancellous allogenic chips and demineralized bone matrix (DBM; Grafton; Osteotech, Eatontown, NJ) to manage traumatic osseous defects and nonunions. Data were prospectively collected from all patients who received this composite bone graft between 1996 and 2000. Only acute fractures with bone loss resulting in a uncontained defect and atrophic non-unions were included in the present study. Demographic data and complications related to composite use, tobacco use, and other comorbidities that could affect healing were evaluated. One hundred seven patients (112 bone graft sites) were followed up for a mean of 32 months (range, 12-60 months). Graft sites included the forearm, femur and tibia. Of the 112 patients, there were 56 smokers (25 non-unions and 31 fractures) and 56 non-smokers (28 fractures and 28 non-unions). Healing occured in 38/56 smokers compared with 49/56 non-smokers. In failed cases, smoking was characteristic in 7/9 non-unions and 11/16 fractures. There were 26 acute uncontained injuries, 29 acute contained defects, and 67 nonunions. Grafting sites were radius/ulna (13 cases), humerus (17), femur (31), and tibia/fibula (51). Significant comorbidities were diabetes mellitus (4 cases), fungal osteomyelitis (1), and pulmonary alveolar proteinosis (1). Eight (73%) of the 11 patients with graft failure had a significant smoking history. This composite graft is an option for managing osseous defects and nonunions traditionally treated with autologous bone grafting but should be used with caution when treating patients who are smokers. PMID:17515188

  11. A randomized controlled evaluation of alveolar ridge preservation following tooth extraction using deproteinized bovine bone mineral and demineralized freeze-dried bone allograft

    PubMed Central

    Sadeghi, Rokhsareh; Babaei, Maryam; Miremadi, S. Asghar; Abbas, Fatemeh Mashadi

    2016-01-01

    Background: Alveolar ridge preservation could be performed immediately following tooth extraction to limit dimensional changes of alveolar process due to bone resorption. The aim of this study was to compare the clinical and histologic outcomes of socket preservation using two different graft materials; deproteinized bovine bone mineral (DBBM) and demineralized freeze-dried bone allograft (DFDBA) with absorbable collagen membrane. Materials and Methods: Twenty extraction sockets in 20 patients were randomly divided into 2 treatment groups: 10 sockets were augmented with DBBM and collagen membrane whereas 10 sockets were filled with DFDBA and covered by collagen membrane. Primary closure was achieved over extraction sockets by flap advancement. Horizontal and vertical ridge dimensional changes were assessed at baseline and after 4-6 months at the time of implant placement. For histological and histomorphometrical analysis, bone samples were harvested from the augmented sites with trephine during implant surgery. All data were analyzed using SPSS version 18 (α=0.05). Results: Clinical measurements revealed that average horizontal reduction was 2.3 ± 0.64 mm for DFDBA and 2.26 ± 0.51 mm for DBBM. Mean vertical ridge resorption at buccal side was 1.29 ± 0.68 mm for DFDBA and 1.1 ± 0.17 mm for DBBM. Moreover, mean vertical ridge reduction at lingual site was 0.41 ± 0.38 mm and 0.35 ± 0.34 mm for DFDBA and DBBM, respectively. No significant differences were seen between two groups in any of those clinical parameters. Histologic analysis showed statistically significant more new bone deposition for DFDBA compared to DBBM (34.49 ± 3.19 vs. 18.76 ± 3.54) (P < 0.01). Residual graft particles were identified significantly more in DBBM (12.77 ± 1.85) than DFDBA (6.06 ± 1.02). Conclusion: Based on the findings of this study, both materials have positive effect on alveolar ridge preservation after tooth extraction, but there was more new bone formation and less

  12. Properties of the "Orgamax" osteoplastic material made of a demineralized allograft bone

    NASA Astrophysics Data System (ADS)

    Podorognaya, V. T.; Kirilova, I. A.; Sharkeev, Yu. P.; Uvarkin, P. V.; Zhelezny, P. A.; Zheleznaya, A. P.; Akimova, S. E.; Novoselov, V. P.; Tupikova, L. N.

    2016-08-01

    We investigated properties of the "Orgamax" osteoplastic material, which was produced from a demineralized bone, in the treatment of extensive caries, in particular chronic pulpitis of the permanent teeth with unformed roots in children. The "Orgamax" osteoplastic material consists of demineralized bone chips, a collagen additive, and antibiotics. The surface morphology of the "Orgamax" osteoplastic material is macroporous, with the maximum pore size of 250 µm, whereas the surface morphology of the major component of "Orgamax", demineralized bone chips, is microporous, with a pore size of 10-20 µm. Material "Orgamax" is used in the treatment of complicated caries, particularly chronic pulpitis of permanent teeth with unformed roots in children. "Orgamax" filling a formed cavity exhibits antimicrobial properties, eliminates inflammation in the dental pulp, and, due to its osteoconductive and osteoinductive properties, undergoes gradual resorption, stimulates regeneration, and provides replacement of the defect with newly formed tissue. The dental pulp viability is completely restored, which ensures the complete formation of tooth roots with root apex closure in the long-term period.

  13. The haemopoietic and immunogenic capacities of living hybrid bone marrow cells tested in tumour allograft rejection.

    PubMed Central

    Kerckhaert, J A; Hofhuis, F M; Willers, J M

    1975-01-01

    In irradiated mice the capacity to reject allogenic tumours can be reconstituted with syngeneic lymphoid cells if the transferred cells are primed with the allogenicantigen. Living semi-allogeneic cells proved to be 30-100-times more acitve as priming antigen than cell membrane fractions. The tumour-suppressive activity of primed lymphoid cells increased in the following order: bone marrow less than Peyer's patches less than thymus less than spleen less than lymph node cells. Even bone marrowcells showed a considerable suppressing activity after priming with live antigen. It was a great advantage that 2 times 10-6 semi-allogeneic bone marrow cells could be used both for the restoration of the haemopoietic system after irradiation and for stimulation of the transferred parental lymphocytes. Priming with large numbers of semi-allogeneic spleen cells abolished the tumour-suppressive activity of the transferred lymphoid cells. This tolerogenic effect disappeared when the priming cells were pretreated with mitomycin. Tolerance could be induced when the cell donors were treated with cyclophosphamide in combination with the living cells. Cell membranes were not effective. PMID:1150311

  14. A Clinical Comparison of Cenobone (A Decalcified Freeze-dried Bone Allograft) with Autogenous Bone Graft in the Treatment of Two- and Three-wall Intrabony Periodontal Defects: A Human Study with Six-month Reentry

    PubMed Central

    Abolfazli, Nader; Saleh Saber, Fariba; Lafzi, Ardeshir; Eskandari, Amir; Mehrasbi, Sarah

    2008-01-01

    Background and aims Complete and predictable regeneration of tissue lost as a result of infection or trauma is the ultimate goal of periodontal therapy. Various graft materials have been successfully used in the treatment of intrabony defects. The purpose of this study was to evaluate the use of a decalcified freeze-dried bone allograft (Cerabone) with the autogenous bone graft as a gold standard in the treatment of human two- or three-wall intrabony periodontal defects. Materials and methods This split-mouth study was done on 10 pairs of matched two- or three-wall intrabony periodontal defects with 5 mm or more probing depth and 3 mm or more depth of intrabony component following phase I therapy. In the control sites autogenous bone graft and in the test sites decalcified freeze-dried bone allograft were used. Results At baseline, no significant differences were found in terms of oral hygiene and defect charac-teristics. At six months, analysis showed a significant improvement in soft and hard tissue parameters for both treatment groups as compared to preoperative measurements. There were no statistical differ-ences in clinically-measured parameters between treatment groups after 6 months except for crestal resorption that increased significantly in control group (P = 0.25). Defect resolution and bone fill in the test and control groups were 2.5 ± 0.46 mm versus 2.7 ± 0.73 mm and 2 ± 0.62 mm versus 2.20 ± 0.52 mm, respectively. Conclusion The results of this study demonstrated that both graft materials improved clinical parameters. The comparison of the two treatment groups did not show any significant differences in clinical parameters after six months. However, because of the limited amount of intra-oral donor bone, it is preferable to use decalcified freeze-dried bone allograft. PMID:23285322

  15. Improved in vitro biocompatibility of surface-modified hydroxyapatite sponge scaffold with gelatin and BMP-2 in comparison against a commercial bone allograft.

    PubMed

    Carpena, Nathaniel T; Min, Young-Ki; Lee, Byong-Taek

    2015-01-01

    This study aims to demonstrate the morphology and in vitro biocompatibility of neat and surface-modified hydroxyapatite sponge scaffold (SM-HASS) which was fabricated using a sponge replica method, and compared with the commercially available demineralized freeze-dried bone allograft (DFDBA). Surface-modifications were done by coating the surface area of the neat hydroxyapatite sponge scaffold (HASS) with either gelatin alone (HASS/G) or gelatin and BMP-2 growth factor (HASS/G+B). Scanning electron microscope (SEM), Fourier transform infrared (FTIR), porosity, pore size distribution, and compressive strength analyses showed that the addition of gelatin in HASS/G produced a morphologically and structurally similar scaffold to that of the allograft. The addition of BMP-2 improved the biocompatibility of the HASS/G+B in vitro using MC3T3-E1 cells which showed better cell viability, proliferation, and cell adhesion than on the allograft. Therefore, hydroxyapatite scaffold coated with gelatin polymer and gelatin with BMP-2 growth factor showed comparable performance against commercially available DFDBA from cadaver with regards to structure and in vitro biocompatibility. PMID:25248041

  16. A comparative evaluation of extraction socket preservation with demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin: A clinical and radiographic study

    PubMed Central

    Thakkar, Dhaval J.; Deshpande, Neeraj C.; Dave, Deepak H.; Narayankar, Suraj D.

    2016-01-01

    Aims: To investigate clinically and radiographically, the bone fill in extraction sockets using demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin (PRF). Materials and Methods: A randomized controlled clinical trial was carried out on 36 nonrestorable single-rooted teeth sites. Sites were randomized into demineralized freeze-dried bone allograft (DFDBA) combined with PRF - test and DFDBA - control groups using a coin toss method. After the placement of graft material, collagen membrane was used to cover it. The clinical parameters recorded were ridge width and ridge height. All the parameters were recorded at baseline and at 90 and 180 days. Statistical Analysis Used: Independent t-test and paired t-test. Results: In both groups, there is significant reduction in loss of ridge width and ridge height from baseline to 90 days (P < 0.001), baseline to 180 days (P < 0.001), and 90–180 days (P < 0.001). However, when both the groups were compared the test group favored in the reduction of ridge width while there was no statistical difference in reduction of ridge height among at different intervals. Conclusions: Although DFDBA is considered as an ideal graft material, PRF can be used as an adjunctive with DFDBA for socket preservation.

  17. Combination of bone allograft, barrier membrane and doxycycline in the treatment of infrabony periodontal defects: A comparative trial

    PubMed Central

    Agarwal, Ashish; Gupta, N.D.

    2015-01-01

    Aim The purpose of the present study was to compare the regenerative potential of noncontained periodontal infrabony defects treated with decalcified freeze-dried bone allograft (DFDBA) and barrier membrane with or without local doxycycline. Methods This study included 48 one- or two-wall infrabony defects from 24 patients (age: 30–65 years) seeking treatment for chronic periodontitis. Defects were randomly divided into two groups and were treated with a combination of DFDBA and barrier membrane, either alone (combined treatment group) or with local doxycycline (combined treatment + doxycycline group). At baseline (before surgery) and 3 and 6 months after surgery, the pocket probing depth (PPD), clinical attachment level (CAL), radiological bone fill (RBF), and alveolar height reduction (AHR) were recorded. Analysis of variance and the Newman–Keuls post hoc test were used for statistical analysis. A two-tailed p-value of less than 0.05 was considered to be statistically significant. Results In the combined treatment group, the PPD reduction was 2.00 ± 0.38 mm (32%), CAL gain was 1.25 ± 0.31 mm (17.9%), and RBF was 0.75 ± 0.31 mm (20.7%) after 6 months. In the combined treatment + doxycycline group, these values were 2.75 ± 0.37 mm (44%), 1.5 ± 0.27 mm (21.1%), and 1.13 ± 0.23 mm (28.1%), respectively. AHR values for the groups without and with doxycycline were 12.5% and 9.4%, respectively. Conclusion There was no significant difference in the regeneration of noncontained periodontal infrabony defects between groups treated with DFDBA and barrier membrane with or without doxycycline. PMID:26236130

  18. Systemic zoledronate treatment both prevents resorption of allograft bone and increases the retention of new formed bone during revascularization and remodelling. A bone chamber study in rats

    PubMed Central

    Åstrand, Jörgen; Harding, Anna Kajsa; Aspenberg, Per; Tägil, Magnus

    2006-01-01

    Background In osteonecrosis the vascular supply of the bone is interrupted and the living cells die. The inorganic mineral network remains intact until ingrowing blood vessels invade the graft. Accompanying osteoclasts start to resorb the bone trabeculae and gradually replace the bone. If the osteonecrosis occurs in mechanically loaded parts, like in the subchondral bone of a loaded joint, the remodelling might lead to a weakening of the bone and, in consequence to a joint collapse. Systemic bisphosphonate treatment can reduce the resorption of necrotic bone. In the present study we investigate if zoledronate, the most potent of the commercially available bisphosphonates, can be used to reduce the amount or speed of bone graft remodeling. Methods Bone grafts were harvested and placed in a bone chamber inserted into the tibia of a rat. Host tissue could grow into the graft through openings in the chamber. Weekly injections with 1.05 μg zoledronate or saline were given subcutaneously until the rats were harvested after 6 weeks. The specimens were fixed, cut and stained with haematoxylin/eosin and used for histologic and histomorphometric analyses. Results By histology, the control specimens were almost totally resorbed in the remodeled area and the graft replaced by bone marrow. In the zoledronate treated specimens, both the old graft and new-formed bone remained and the graft trabeculas were lined with new bone. By histomorphometry, the total amount of bone (graft+ new bone) within the remodelled area was 35 % (SD 13) in the zoledronate treated grafts and 19 % (SD 12) in the controls (p = 0.001). Also the amount of new bone was increased in the treated specimens (22 %, SD 7) compared to the controls (14 %, SD 9, p = 0.032). Conclusion We show that zoledronate can be used to decrease the resorption of both old graft and new-formed bone during bone graft remodelling. This might be useful in bone grafting procedure but also in other orthopedic conditions, both where

  19. Clinical and radiographic outcomes of the treatment of adolescent idiopathic scoliosis with segmental pedicle screws and combined local autograft and allograft bone for spinal fusion: a retrospective case series

    PubMed Central

    2010-01-01

    Background High morbidity has been reported with iliac crest bone graft harvesting; however, donor bone is typically necessary for posterior spinal fusion. Autograft bone combined with allograft may reduce the morbidity associated with iliac crest bone harvesting and improve the fusion rate. Our aim in this study was to determine the presence of complications, pseudarthrosis, non-union, and infection using combined in situ local autograft bone and freeze-dried cancellous allograft bone in patients undergoing posterior spinal fusion for the treatment of adolescent idiopathic scoliosis. Methods A combination of in situ local autograft bone and freeze-dried cancellous allograft blocks were used in 50 consecutive patients with adolescent idiopathic scoliosis treated by posterior fusion and Moss Miami pedicle screw instrumentation. Results were assessed clinically and radiographically and quality of life and functional outcome was evaluated by administration of a Chinese version of the SRS-22 survey. Results There were 41 female and 9 male patients included for analysis with an average age of 14.7 years (range, 12-17). All patients had a minimum follow-up of 18 months (range, 18 to 40 months). The average preoperative Cobb angle was 49.8° (range, 40° to 86°). The average number of levels fused was 9.8 (range, 6-15). Patients had a minimum postoperative follow-up of 18 months. At final follow-up, the average Cobb angle correction was 77.8% (range, 43.4 to 92.5%). There was no obvious loss in the correction, and the average loss of correction was 1.1° (range, 0° to 4°). There was no pseudarthrosis and no major complications. Conclusions In situ autograft bone combined with allograft bone may be a promising method enhances spinal fusion in AIS treated with pedicle screw placement. By eliminating the need for iliac crest bone harvesting, significant morbidity may be avoided. PMID:20630050

  20. Role of Demineralized Allograft Subchondral Bone in the Treatment of Shoulder Lesions of the Talus: Clinical Results With Two-Year Follow-Up.

    PubMed

    Galli, Melissa M; Protzman, Nicole M; Bleazey, Scott T; Brigido, Stephen A

    2015-01-01

    Cystic osteochondral lesions of the talus present a considerable challenge for foot and ankle surgeons. The purpose of the present study was to evaluate the effect of a medial malleolar osteotomy and implantation of demineralized allograft subchondral bone on pain and function 2 years after surgery. For inclusion, patients demonstrated radiographic evidence of a medial cystic full-thickness osteochondral defect of the talus and previously failed microfracture (N = 12). We hypothesized that improvements in pain and disability would be maintained across time. Compared with the preoperative values, 2 years after surgery, pain and disability had significantly reduced (p < .001). Significant reductions had occurred in postoperative pain from 6 months to 1 year (p = .001) and from 6 months to 2 years (p = .005). Similarly, significant reductions had occurred in postoperative disability from 6 months to 1 year (p = .008) and from 6 months to 2 years (p = .03). The reductions in postoperative pain and disability were maintained from 1 year to 2 years (p ≥ .79). Multiple regression analyses identified depression as a predictor of 2-year postoperative pain (R(2) = 0.36, p = .04). No variables were identified as significant predictors of postoperative disability at 2 years. Other than 1 previously reported peroneal deep venous thrombosis, no additional complications occurred. With successful graft incorporation, no inflammatory response, and no additional complications, the allograft subchondral plug appears to successfully treat osteochondral lesions of the talus and maintain improvements in pain and disability at intermediate follow-up. PMID:25022615

  1. Biomechanical Evaluation of Different Fixation Methods for Mandibular Anterior Segmental Osteotomy Using Finite Element Analysis, Part Two: Superior Repositioning Surgery With Bone Allograft.

    PubMed

    Kilinç, Yeliz; Erkmen, Erkan; Kurt, Ahmet

    2016-01-01

    In this study, the biomechanical behavior of different fixation methods used to fix the mandibular anterior segment following various amounts of superior repositioning was evaluated by using Finite Element Analysis (FEA). The three-dimensional finite element models representing 3 and 5 mm superior repositioning were generated. The gap in between segments was assumed to be filled by block bone allograft and resignated to be in perfect contact with the mandible and segmented bone. Six different finite element models with 2 distinct mobilization rate including 3 different fixation configurations, double right L (DRL), double left L (DLL), or double I (DI) miniplates with monocortical screws, correspondingly were created. A comparative evaluation has been made under vertical, horizontal and oblique loads. The von Mises and principal maximum stress (Pmax) values were calculated by finite element solver programme. The first part of our ongoing Finite Element Analysis research has been addressed to the mechanical behavior of the same fixation configurations in nongrafted models. In comparison with the findings of the first part of the study, it was concluded that bone graft offers superior mechanical stability without any limitation of mobilization and less stress on the fixative appliances as well as in the bone. PMID:26703029

  2. A Comparision of Two Types of Decalcified Freeze-Dried Bone Allograft in Treatment of Dehiscence Defects around Implants in Dogs

    PubMed Central

    Abed, Ahmad Moghareh; Pestekan, Rasool Heidari; Yaghini, Jaber; Razavi, Seyed Mohammad; Tavakoli, Mohammad; Amjadi, Mohammad

    2011-01-01

    Background: Decalcified freeze-dried bone allograft (DFDBA) may have the potential to enhance bone formation around dental implants. Our aim in this study was the evaluation and comparison of two types of DFDBA in treatment of dehiscence defects around Euroteknika® implants in dogs. Methods: In this prospective clinical trial animal study, all mandibular premolars of three Iranian dogs were extracted. After 3 months of healing, fifteen SLA type Euroteknika® dental implants (Natea) with 4.1mm diameter and 10mm length were placed in osteotomy sites with dehiscence defects of 5mm length, 4 mm width, and 3mm depth. Guided bone regeneration (GBR) procedures were performed using Cenobone and collagen membrane for six implants, the other six implants received Dembone and collagen membrane and the final three implants received only collagen membrane. All implants were submerged. After 4 months of healing, implants were uncovered and stability (Implant Stability Quotient) of all implants was measured. Then, block biopsies of each implant site were taken and processed for ground sectioning and histomorphometric analysis. The data was analyzed by ANOVA and Pearson tests. P value less than 0.05 was considered to be significant. Results: All implants osseointegrated after 4 months. The mean values of bone to implant contact for histomorphometric measurements of Cenobone, Denobone, and control groups were 77.36 ± 9.96%, 78.91 ± 11.9% and 71.56 ± 5.61% respectively, with no significant differences among the various treatment groups. The correlation of Implant Stability Quotient and histomorphometric techniques was 0.692. Conclusion: In treating of dehiscence defects with GBR technique in this study, adding DFDBA did not significantly enhance the percentages of bone-to-implant contact measurements; and Implant Stability Quotient Resonance Frequency Analysis appeared to be a precise technique. PMID:22013476

  3. The relevance of Choukroun's platelet-rich fibrin and metronidazole during complex maxillary rehabilitations using bone allograft. Part II: implant surgery, prosthodontics, and survival.

    PubMed

    Simonpieri, Alain; Del Corso, Marco; Sammartino, Gilberto; Dohan Ehrenfest, David M

    2009-06-01

    Extensive bone grafting remains a delicate procedure, due to the slow and difficult integration of the grafted material into the physiological architecture. The recent use of platelet concentrates aims to improve this process of integration by accelerating bone and mucosal healing. Choukroun's platelet-rich fibrin (PRF) is a healing biomaterial that concentrates in a single autologous fibrin membrane, most platelets, leukocytes, and cytokines from a 10-mL blood harvest, without artificial biochemical modification (no anticoagulant, no bovine thrombin). In this second part, we describe the implant and prosthetic phases of a complex maxillary rehabilitation, after preimplant bone grafting using allograft, Choukroun's PRF membranes, and metronidazole. Twenty patients were treated using this new technique and followed up during 2.1 years (1-5 years). Finally, 184 dental implants were placed, including 54 classical screw implants (3I, Palm Beach Gardens, FL) and 130 implants with microthreaded collar (46 from AstraTech, Mölndal, Sweden; 84 from Intra-Lock, Boca Raton, FL). No implant or graft was lost in this case series, confirming the validity of this reconstructive protocol. However, the number of implants used per maxillary rehabilitation was always higher with simple screw implants than with microthreaded implants, the latter presenting a stronger initial implant stability. Finally, during complex implant rehabilitations, PRF membranes are particularly helpful for periosteum healing and maturation. The thick peri-implant gingiva is related to several healing phases on a PRF membrane layer and could explain the low marginal bone loss observed in this series. Microthreaded collar and platform-switching concept even improved this result. Multiple healing on PRF membranes seems a new opportunity to improve the final esthetic result. PMID:19509532

  4. Reconstruction with fascia lata allograft of the posterior vertebra elements after resection for aneurysmal bone cyst in a child

    PubMed Central

    Schuster, Sergio; Biagini, Roberto; Casadei, Roberto; De Paolis, Massimiliano; Bertoni, Franco; Boriani, Stefano; Mercuri, Mario

    2007-01-01

    We report a case of ABC in a child where, after resection of the posterior spinal column of L1, we did a biological reconstruction using a posterior tension band with a segment of fascia lata allograft in tension between T12 and L2. After the long term follow up, X-ray and MRI controls showed a satisfactory alignment of the spine and no local recurrence. The patient now has no sign of spinal instability or deviation, with no kind of discomfort or pain, and has a normal life. In our experience this biological tension band interferes minimally with the growth of the spine, and has a less number of complications in comparison with other more aggressive methods and so is a good option for restoring the stability in young patients with benign spinal tumors that arises on the posterior column without having any kind of potential deviations. PMID:17426986

  5. Reconstruction with fascia lata allograft of the posterior vertebra elements after resection for aneurysmal bone cyst in a child.

    PubMed

    Errani, Costantino; Schuster, Sergio; Biagini, Roberto; Casadei, Roberto; De Paolis, Massimiliano; Bertoni, Franco; Boriani, Stefano; Mercuri, Mario

    2007-09-01

    We report a case of ABC in a child where, after resection of the posterior spinal column of L1, we did a biological reconstruction using a posterior tension band with a segment of fascia lata allograft in tension between T12 and L2. After the long term follow up, X-ray and MRI controls showed a satisfactory alignment of the spine and no local recurrence. The patient now has no sign of spinal instability or deviation, with no kind of discomfort or pain, and has a normal life. In our experience this biological tension band interferes minimally with the growth of the spine, and has a less number of complications in comparison with other more aggressive methods and so is a good option for restoring the stability in young patients with benign spinal tumors that arises on the posterior column without having any kind of potential deviations. PMID:17426986

  6. A Novel Approach for Treatment of an Unusual Presentation of Radicular Cysts Using Autologous Periosteum and Platelet-Rich Fibrin in Combination with Demineralized Freeze-Dried Bone Allograft

    PubMed Central

    Patil, Veena A.; Desai, Manthan H.; Patil, Veerendra S.; Reddy Kaveti, Hanisha; Ganji, Kiran Kumar; Danappanavar, Prasanna M.

    2013-01-01

    Radicular cysts are the most common cystic lesions affecting the jaws. They are most commonly found at the apices of the involved teeth. This condition is usually asymptomatic but can result in a slow-growth tumefaction in the affected region. The following case report presents the successful treatment of radicular cysts using autologous periosteum and platelet-rich fibrin with demineralized freeze-dried bone allograft. PMID:23984115

  7. Aneurysmal bone cyst involving the metacarpal bone in a child.

    PubMed

    Song, Kwang Soon; Lee, Si Wook; Bae, Ki Cheor; Sohn, Eun Seok

    2015-03-01

    Aneurysmal bone cysts associated with tubular bones of the hand occur rarely and require particular diagnostic and therapeutic management techniques. While optimal treatment has not been established, accepted treatments range from aggressive radical treatment, including en bloc resection and excision diaphysectomy with strut bone grafting, to relatively simple techniques, such as thorough curettage followed by bone graft. Aggressive treatment approaches may be optimal for the cases with articular surface involvement, full-bone invasion of the phalanx or metacarpal, or more than 1 recurrence. We report a monocentric case of aneurysmal bone cysts involving metacarpal bone in a child who achieved favorable outcome with curettage and morselized cancellous bone grafts. PMID:25750953

  8. Abrogation of bone marrow allograft resistance in mice by increased total body irradiation correlates with eradication of host clonable T cells and alloreactive cytotoxic precursors

    SciTech Connect

    Schwartz, E.; Lapidot, T.; Gozes, D.; Singer, T.S.; Reisner, Y.

    1987-01-15

    Host-vs-graft activity presents a major obstacle for transplantation of T cell-depleted bone marrow in HLA-mismatched patients. In a primate model, conditioned exactly like leukemia patients, it was shown that residual host clonable T cells, as well as alloreactive cytotoxic precursors, were present in peripheral blood and spleen after completion of cytoreduction. We have now extended this study in a mouse model for allogeneic bone marrow transplantation. C/sub 3/H/HeJ mice were treated by 9 Gy total body irradiation (TBI), and 24 hr later their spleen cells were cultured in the presence of T cell growth factor and phytohemagglutinin according to the limit dilution procedure. After 7 days of culture the average frequency of clonable cells was 2.5 X 10(-3) compared with 37 X 10(-3) in the spleens of normal mice. The T cell derivation of the growing cells was ascertained by complement-mediated cytotoxicity with anti-Thy-1 as well as with anti-Lyt-2 and anti-Ly-3T4. In parallel, we found that the initial engraftment rate of bone marrow allograft in mice given 9 Gy TBI was lower than that found in recipients of syngeneic marrow. The initial engraftment rate was measured by the number of colony-forming units in the spleen and by splenic uptake of /sup 125/IUdR. A slight increase in TBI from 9 Gy to 11 Gy markedly reduced the difference in the number of spleen colony-forming units or the IUdR uptake between recipients of allogeneic and syngeneic bone marrow. This increase in TBI also coincided with eradication of detectable clonable T cells. Moreover, in mice transplanted with T cell-depleted bone marrow after 9 Gy TBI, we also demonstrate that cytotoxicity against donor-type target cells is present in the spleen 10 to 14 days posttransplantation, whereas in mice treated by 11 Gy TBI such alloreactivity could not be detected.

  9. A clinical and radiological evaluation of the relative efficacy of demineralized freeze-dried bone allograft versus anorganic bovine bone xenograft in the treatment of human infrabony periodontal defects: A 6 months follow-up study

    PubMed Central

    Blaggana, Vikram; Gill, Amarjit Singh; Blaggana, Anshu

    2014-01-01

    Background: The ultimate goal of periodontal therapy entails regeneration of the periodontal tissues lost as a consequence of periodontitis. Predictable correction of vertical osseous defects has however posed as a constant therapeutic challenge. The aim of our present study is to evaluate the relative efficacy of demineralized freeze-dried bone allograft (DFDBA) vs anorganic bovine bone xenograft (ABBX) in the treatment of human infrabony periodontal defects. Materials and Methods: 15 patients with 30 bilaterally symmetrical defect sites in either of the arches, in the age group of 25-50 years were selected as part of split-mouth study design. Defect-A (right side) was grafted with DFDBA while Defect-B (left side) was grafted with ABBX. Various clinical and radiographic parameters viz. probing depth(PD), clinical attachment level(CAL) and linear bone fill were recorded preoperatively, 12- & 24-weeks postoperatively. Results: Both defect-A & defect-B sites exhibited a highly significant reduction in probing depth, and gain in clinical attachment level and linear bone fill at 12-weeks & at the end of 24-weeks. Comparative evaluation between the study groups revealed a statistically non-significant reduction in probing depth (P<0.1) and mean gain in linear bone fill (P<0.1). However, there was a statistically significant gain in clinical attachment level (P<0.05) in Defect-A (CD=0.356) as compared to Defect-B (CD=0.346). Conclusions: Within the limits of this study, both the materials viz. ABBX and DFDBA are beneficial for the treatment of periodontal infrabony defects. Both the materials were found to be equally effective in all respects except the gain in attachment level, which was found to be more with DFDBA. Long-term studies are suggested to evaluate further the relative efficacy of the two grafts. PMID:25425822

  10. Radiation sterilization of tissue allografts: A review

    PubMed Central

    Singh, Rita; Singh, Durgeshwer; Singh, Antaryami

    2016-01-01

    Tissue substitutes are required in a number of clinical conditions for treatment of injured and diseased tissues. Tissues like bone, skin, amniotic membrane and soft tissues obtained from human donor can be used for repair or reconstruction of the injured part of the body. Allograft tissues from human donor provide an excellent alternative to autografts. However, major concern with the use of allografts is the risk of infectious disease transmission. Therefore, tissue allografts should be sterilized to make them safe for clinical use. Gamma radiation has several advantages and is the most suitable method for sterilization of biological tissues. This review summarizes the use of gamma irradiation technology as an effective method for sterilization of biological tissues and ensuring safety of tissue allografts. PMID:27158422

  11. Radiation sterilization of tissue allografts: A review.

    PubMed

    Singh, Rita; Singh, Durgeshwer; Singh, Antaryami

    2016-04-28

    Tissue substitutes are required in a number of clinical conditions for treatment of injured and diseased tissues. Tissues like bone, skin, amniotic membrane and soft tissues obtained from human donor can be used for repair or reconstruction of the injured part of the body. Allograft tissues from human donor provide an excellent alternative to autografts. However, major concern with the use of allografts is the risk of infectious disease transmission. Therefore, tissue allografts should be sterilized to make them safe for clinical use. Gamma radiation has several advantages and is the most suitable method for sterilization of biological tissues. This review summarizes the use of gamma irradiation technology as an effective method for sterilization of biological tissues and ensuring safety of tissue allografts. PMID:27158422

  12. Informed consent is not routinely documented for procedures using allografts.

    PubMed

    Porter, Scott E; Stull, Douglass; Kneisl, Jeffrey S; Frick, Steven L

    2004-06-01

    Patients who receive musculoskeletal allografts may have severe postoperative infections develop. Media reports have heightened public awareness of the risk of allograft use. Explaining these risks to patients preoperatively has become more important as attention to informed consent issues has increased. This study retrospectively investigated the patterns of informed consent for allograft bone used during elective orthopaedic procedures at a major teaching hospital. Forty-seven (32%) of 148 patients had preoperative discussions of allograft risks and benefits documented with a signed preoperative consent. In nearly 70% of the cases in which structural allograft was used, preoperative consent was documented. Only 8% of cases in which nonstructural, highly processed allograft was used had documented preoperative consent. Forty-eight (32%) of 148 patients were treated with allograft and autograft. Consent was obtained for the harvesting and use of autograft from 90% of these patients. In none of these patients was consent obtained for the allograft used. Although risks of disease transmission vary widely with the degree of allograft processing and the source of its procurement, informed consent for any allograft use should be a routine part of preoperative discussions of risks and benefits in elective orthopaedic surgeries. PMID:15232464

  13. Osteogenic Scaffolds for Bone Reconstruction

    PubMed Central

    Li, Ling-jiang; Liu, Ning; Liu, Qing; Jia, Lian-shun; Yuan, Wen

    2012-01-01

    Abstract A highly osteogenic hybrid bioabsorbable scaffold was developed for bone reconstruction/augmentation. Through the use of a solid free-form fabrication technology, a bioabsorbable polycaprolactone (PCL) cage scaffold with a desired size and shape was produced and then filled with osteogenic bone graft particles, that is, morselized autologous bone chips. A rabbit total lamina defect model was chosen to demonstrate its efficacy in regenerating bone with a complicated anatomic shape. Both iliac bone and morselized iliac bone grafts were used in this study for comparison purposes. Serum osteocalcin and collagen type I cross-linked C-terminal telopeptide (CTx) determination showed that active bone remodeling occurred after bone grafts were implanted. X-ray images showed that the bony defects were completely filled with bone mass in all the groups with bone grafts. However, biomechanical tests showed that only the iliac bone and hybrid scaffold groups could restore the mechanical properties to the normal level after 10 weeks of implantation. A histology study showed that both iliac and hybrid scaffold groups had extensive new bone formation, and no adhesion and fibrosis were found. These results indicated that this osteogenic hybrid scaffold can be a good alternative to autologous iliac bone, because it does not need a second iliac bone-harvesting surgery, and thus the morbidity and the possible infections that are often associated with the bone harvesting surgery can be avoided. PMID:23515416

  14. Morselized Amniotic Membrane Tissue for Refractory Corneal Epithelial Defects in Cicatricial Ocular Surface Diseases

    PubMed Central

    Cheng, Anny M. S.; Chua, Lorraine; Casas, Victoria; Tseng, Scheffer C. G.

    2016-01-01

    Purpose To evaluate the clinical efficacy of morselized amniotic membrane and umbilical cord tissue (MAU) in treating refractory corneal epithelial defect in ocular cicatricial diseases. Methods Retrospective review of four patients with ocular cicatricial diseases treated with topical MAU for corneal epithelial defects refractory to conventional treatments including topical lubricants, autologous serum, bandage contact lens, and tarsorraphy. Their symptoms, corneal staining, conjunctival inflammation, and visual acuity were compared before and after treatment. Results After topical application of MAU twice daily, two patients demonstrated rapid corneal epithelialization with prompt visual acuity improvement at the first day. All patients showed corneal epithelialization in 7.3 ± 2.6 days accompanied by a significant relief of symptoms, reduction of ocular surface inflammation, and improvement of visual acuity. Conclusion This pilot study suggests topical MAU can be developed into a novel treatment for treating refractory corneal epithelial defects. Translational Relevance Topical MAU can be an effective novel treatment for refractory corneal epithelial defects. PMID:27226933

  15. Localized bone marrow transplantation leads to skin allograft acceptance in nonmyeloablated recipients: comparison of intra-bone marrow and isolated limb perfusion.

    PubMed

    Askenasy, Nadir

    2002-01-01

    It has been shown that engraftment of allogeneic bone marrow cells (BMC) induces tolerance to antigen-matched organs, and infusion of a megadose of cells improves the success of engraftment of T-cell-depleted BMC. This study explores intra-bone marrow injection (IB) and isolated limb perfusion (IL) as means of localized bone marrow transplantation (BMT) and assesses their tolerogenic effect. Intravenous (i.v.), IB, and IL infusion of syngeneic and allogeneic whole BMC rescued 90%-100% of myeloablated recipients. Tracing of PKH-labeled cells revealed early systemic dissipation after IB injection, indicating that it was equivalent to i.v. transplantation. In contrast, IL perfusion led to initial localization of donor BMC. BALB/c recipients conditioned with 70 microg/g busulfan had 58% +/- 5% and 44% +/- 4% donor lymphocytes at 4 weeks after i.v. and IL infusion, respectively, of 10(7) whole BMC from B10 donors. This suggests that cells migrated out of the IL femur and seeded other bones. All recipients accepted donor-matched skin grafts and acutely rejected third party grafts. T-cell depletion lowered the engraftment efficiency of i.v.-BMT by 35% (p < 0.001 versus whole BMC), but not when infused IL (p < 0.001). It is concluded that IL-BMT is a procedure for initial localization of donor cells, which is as efficient as i.v.- and IB-BMT in rescue of myeloablated mice, induction of hemopoietic chimerism, and donor-specific immune nonresponsiveness to secondary skin grafts without myeloablative conditioning. The megadose effect achieved by inoculation of a small hemopoietic space improved engraftment of T-cell-depleted BMC. This approach may have clinical applications. PMID:11796926

  16. Reconstruction of an atrophied posterior mandible with the inlay technique and allograft block versus allograft particulate: a case report.

    PubMed

    Checchi, Vittorio; Mazzoni, Annalisa; Breschi, Lorenzo; Felice, Pietro

    2015-01-01

    This case report describes the bilateral reconstruction of a severely atrophic posterior mandible in a 30-year-old woman using allograft block versus particulate grafting in the inlay technique. Three months later, four dental implants were placed and bone core biopsy specimens were taken for histologic evaluation. During implant placement, the grafted sites were stable with good clinical osseointegration. The histologic analysis showed the presence of compact bone revealing areas of demarcation between grafted bone, newly formed bone, and bone-regenerated areas. Allografts might serve as an alternative to autogenous and heterologous grafting in posterior mandible augmentation using the inlay technique. PMID:25738350

  17. Induction of donor-type chimerism in murine recipients of bone marrow allografts by different radiation regimens currently used in treatment of leukemia patients

    SciTech Connect

    Salomon, O.; Lapidot, T.; Terenzi, A.; Lubin, I.; Rabi, I.; Reisner, Y. )

    1990-11-01

    Three radiation protocols currently used in treatment of leukemia patients before bone marrow transplantation (BMT) were investigated in a murine model (C57BL/6----C3H/HeJ) for BM allograft rejection. These include (a) a single dose of total body irradiation (8.5 Gy TBI delivered at a dose rate of 0.2 Gy/min), (b) fractionated TBI 12 Gy administered in six fractions, 2 Gy twice a day in 3 days, delivered at a dose rate of 0.1 Gy/min, and (c) hyperfractionated TBI (14.4 Gy administered in 12 fractions, 1.2 Gy three times a day in 3 days, delivered at a dose rate of 0.1 Gy/min). Donor-type chimerism 6 to 8 weeks after BMT and hematologic reconstitution on day 12 after BMT found in these groups were compared with results obtained in mice conditioned with 8 Gy TBI delivered at a dose rate of 0.67 Gy/min, routinely used in this murine model. The results in both parameters showed a marked advantage for the single dose 8.5 Gy TBI over all the other treatments. This advantage was found to be equivalent to three- to fourfold increment in the BM inoculum when compared with hyperfractionated radiation, which afforded the least favorable conditions for development of donor-type chimerism. The fractionated radiation protocol was equivalent in its efficacy to results obtained in mice irradiated by single-dose 8 Gy TBI, both of which afforded a smaller but not significant advantage over the hyperfractionated protocol. This model was also used to test the effect of radiation dose rate on the development of donor-type chimerism. A significant enhancement was found after an increase in dose rate from 0.1 to 0.7 Gy/min. Further enhancement could be achieved when the dose rate was increased to 1.3 Gy/min, but survival at this high dose rate was reduced.

  18. Bone banking and sterilization of bones

    NASA Astrophysics Data System (ADS)

    Minamisawa, I.; Itoman, M.; Maehara, H.; Kobayashi, A.; Watanabe, T.

    1995-08-01

    The use of banked bone (preserved allograft bone) is various and essential, because it has numerous advantages including the relative ease in retrieval a large amount of bone material and requisite shape and size. But bone banking and allografting must be promoted under obligation to stably supply safe and high-quality bone. To avoid transferring disease perfectly, irradiation sterilization is especially recommended at the present time.

  19. ACL reconstruction with BPTB autograft and irradiated fresh frozen allograft*

    PubMed Central

    Sun, Kang; Tian, Shao-qi; Zhang, Ji-hua; Xia, Chang-suo; Zhang, Cai-long; Yu, Teng-bo

    2009-01-01

    Objective: To analyze the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction with irradiated bone-patellar tendon-bone (BPTB) allograft compared with non-irradiated allograft and autograft. Methods: All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 mrad of irradiation prior to distribution. A total of 68 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into one of the two groups (autograft and irradiated allograft groups). The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months of follow-up (ranging from 24 to 47 months), patients were evaluated by the same observer according to objective and subjective clinical evaluations. Results: Of these patients, 65 (autograft 33, irradiated allograft 32) were available for full evaluation. When the irradiated allograft group was compared to the autograft group at the 31-month follow-up by the Lachman test, the anterior drawer test (ADT), the pivot shift test, and KT-2000 arthrometer test, statistically significant differences were found. Most importantly, 87.8% of patients in the autograft group and just only 31.3% in the irradiated allograft group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%). The anterior and rotational stabilities decreased significantly in the irradiated allograft group. According to the overall International Knee Documentation Committee (IKDC), functional and subjective evaluations, and activity level testing, no statistically significant differences were found between the two groups. Besides, patients in the irradiated allograft group had a shorter operation time and a longer duration of postoperative fever. When the patients had a fever, the

  20. Autograft Versus Nonirradiated Allograft Tissue for Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Mariscalco, Michael W.; Magnussen, Robert A.; Mehta, Divyesh; Hewett, Timothy E.; Flanigan, David C.; Kaeding, Christopher C.

    2014-01-01

    Background An autograft has traditionally been the gold standard for anterior cruciate ligament reconstruction (ACLR), but the use of allograft tissue has increased in recent years. While numerous studies have demonstrated that irradiated allografts are associated with increased failure rates, some report excellent results after ACLR with nonirradiated allografts. The purpose of this systematic review was to determine whether the use of nonirradiated allograft tissue is associated with poorer outcomes when compared with autografts. Hypothesis Patients undergoing ACLR with autografts versus nonirradiated allografts will demonstrate no significant differences in graft failure risk, laxity on postoperative physical examination, or differences in patient-oriented outcome scores. Study Design Systematic review. Methods A systematic review was performed to identify prospective or retrospective comparative studies (evidence level 1, 2, or 3) of autografts versus nonirradiated allografts for ACLR. Outcome data included graft failure based on clinical findings and instrumented laxity, postoperative laxity on physical examination, and patient-reported outcome scores. Studies were excluded if they did not specify whether the allograft had been irradiated. Quality assessment and data extraction were performed by 2 examiners. Results Nine studies comparing autografts and nonirradiated allografts were included. Six of the 9 studies compared bone– patellar tendon–bone (BPTB) autografts with BPTB allografts. Two studies compared hamstring tendon autografts to hamstring tendon allografts, and 1 study compared hamstring tendon autografts to tibialis anterior allografts. The mean patient age in 7 of 9 studies ranged from 24.5 to 32 years, with 1 study including only patients older than 40 years and another not reporting patient age. The mean follow-up duration was 24 to 94 months. Six of 9 studies reported clinical graft failure rates, 8 of 9 reported postoperative instrumented

  1. Enhancement of bone marrow allografts from nude mice into mismatched recipients by T cells void of graft-versus-host activity

    SciTech Connect

    Lapidot, T.; Lubin, I.; Terenzi, A.; Faktorowich, Y.; Erlich, P.; Reisner, Y. )

    1990-06-01

    Transplantation of 8 x 10(6) C57BL/6-Nu+/Nu+ (nude) bone marrow cells into C3H/HeJ recipients after conditioning with 8 Gy of total body irradiation has resulted in a markedly higher rate of graft rejection or graft failure compared to that found in recipients of normal C57BL/6 or C57BL/6-Bg+/Bg+ (beige) T-cell-depleted bone marrow. Mixing experiments using different numbers of nude bone marrow cells with or without mature thymocytes (unagglutinated by peanut agglutinin) revealed that engraftment of allogeneic T-cell-depleted bone marrow is T-cell dependent. To ensure engraftment, a large inoculum of nude bone marrow must be supplemented with a trace number of donor T cells, whereas a small bone marrow dose from nude donors requires a much larger number of T cells for engraftment. Marked enhancement of donor type chimerism was also found when F1 thymocytes were added to nude bone marrow cells, indicating that the enhancement of bone marrow engraftment by T cells is not only mediated by alloreactivity against residual host cells but may rather be generated by growth factors, the release of which may require specific interactions between T cells and stem cells or between T cells and bone marrow stroma cells.

  2. Kidney allograft survival in dogs treated with total lymphoid irradiation

    SciTech Connect

    Howard, R.J.; Sutherland, D.E.R.; Lum, C.T.; Lewis, W.I.; Kim, T.H.; Slavin, S.; Najarian, J.S.

    1981-02-01

    Total lymphoid irradiation (TLI) is immunosuppressive and, in rodents, can induce a state where transplantation of allogenic bone marrow results in chimerism and permanent acceptance of organ allografts from the donor strain. Twelve splenectomized dogs were treated with TLI (150 rads per fraction, total dose 1950 to 3000 rads) before bilateral nephrectomy and renal allotransplantation. Eight dogs received bone marrow from the kidney donor. In 13 untreated control dogs renal allografts functioned for a mean +- (SE) of 4.7 +- 0.3 days. In the four TLI treated dogs who did not receive bone marrow the renal allografts functioned for 15 to 76 days (two dogs died with functioning grafts). In the eight TLI treated dogs who received donor bone marrow, two died immediately after transplantation, two rejected at 3 and 13 days, one died at 13 days with a functioning graft, and two have had the grafts function for longer than 500 days. Chimerism was not detected in the one dog tested. The response of peripheral blood lymphocytes to stimulation with phytohemaglutinin and in mixed lymphocyte culture was suppressed for at least one month after TLI. The results confirm the immunosuppressive effect of TLI. The absence of kidney rejection in two recipients of donor bone marrow show the potential of this approach to induce long-term immunologic unresponsiveness as to an organ allograft, but the outcome is unpredictable and further experiments are needed to define the optimal conditions for administration of TLI and bone marrow to the recipients.

  3. Healing properties of allograft from alendronate-treated animal in lumbar spine interbody cage fusion.

    PubMed

    Xue, Qingyun; Li, Haisheng; Zou, Xuenong; Bünger, Mathias; Egund, Niels; Lind, Martin; Christensen, Finn Bjarke; Bünger, Cody

    2005-04-01

    This study investigated the healing potential of allograft from bisphosphonate-treated animals in anterior lumbar spine interbody fusion. Three levels of anterior lumbar interbody fusion with Brantigan cages were performed in two groups of five landrace pigs. Empty Brantigan cages or cages filled with either autograft or allograft were located randomly at different levels. The allograft materials for the treatment group were taken from the pigs that had been fed with alendronate, 10 mg daily for 3 months. The histological fusion rate was 2/5 in alendronate-treated allograft and 3/5 in non-treated allograft. The mean bone volume was 39% and 37.2% in alendronate-treated or non-treated allograft (NS), respectively. No statistical difference was found between the same grafted cage comparing two groups. The histological fusion rate was 7/10 in all autograft cage levels and 5/10 in combined allograft cage levels. No fusion was found at all in empty cage levels. With the numbers available, no statistically significant difference was found in histological fusion between autograft and allograft applications. There was a significant difference of mean bone volume between autograft (49.2%) and empty cage (27.5%) (P<0.01). In conclusion, this study did not demonstrate different healing properties of alendronate-treated and non-treated allograft for anterior lumbar interbody fusion in pigs. PMID:15248057

  4. Radioprotection provides functional mechanics but delays healing of irradiated tendon allografts after ACL reconstruction in sheep.

    PubMed

    Seto, Aaron U; Culp, Brian M; Gatt, Charles J; Dunn, Michael

    2013-12-01

    Successful protection of tissue properties against ionizing radiation effects could allow its use for terminal sterilization of musculoskeletal allografts. In this study we functionally evaluate Achilles tendon allografts processed with a previously developed radioprotective treatment based on (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) crosslinking and free radical scavenging using ascorbate and riboflavin, for ovine anterior cruciate ligament reconstruction. Arthroscopic anterior cruciate ligament (ACL) reconstruction was performed using double looped allografts, while comparing radioprotected irradiated and fresh frozen allografts after 12 and 24 weeks post-implantation, and to control irradiated grafts after 12 weeks. Radioprotection was successful at preserving early subfailure mechanical properties comparable to fresh frozen allografts. Twelve week graft stiffness and anterior-tibial (A-T) translation for radioprotected and fresh frozen allografts were comparable at 30 % of native stiffness, and 4.6 and 5 times native A-T translation, respectively. Fresh frozen allograft possessed the greatest 24 week peak load at 840 N and stiffness at 177 N/mm. Histological evidence suggested a delay in tendon to bone healing for radioprotected allografts, which was reflected in mechanical properties. There was no evidence that radioprotective treatment inhibited intra-articular graft healing. This specific radioprotective method cannot be recommended for ACL reconstruction allografts, and data suggest that future efforts to improve allograft sterilization procedures should focus on modifying or eliminating the pre-crosslinking procedure. PMID:23842952

  5. Results of 32 Allograft-prosthesis Composite Reconstructions of the Proximal Femur

    PubMed Central

    Larousserie, Frédérique; Thévenin, Fabrice; Piperno-Neumann, Sophie; Anract, Philippe

    2009-01-01

    The use of allograft-prosthesis composites for reconstruction after bone tumor resection at the proximal femur has generated considerable interest since the mid1980s on the basis that their use would improve function and survival, and restore bone stock. Although functional improvement has been documented, it is unknown whether these composites survive long periods and whether they restore bone stock. We therefore determined long-term allograft-prosthesis composite survival, identified major complications that led to revision, and determined whether allograft bone stock could be spared at the time of revision. We also compared the radiographic appearance of allografts sterilized by gamma radiation and fresh-frozen allografts. We retrospectively reviewed 32 patients with bone malignancy in the proximal femur who underwent reconstruction with a cemented allograft-prosthesis composite. The allograft-prosthesis composite was a primary reconstruction for 23 patients and a revision procedure for nine. The minimum followup was 2 months (median, 68 months; range, 2–232 months). The cumulative incidence of revision for any reason was 14% at 5 years (95% confidence interval, 1%–28%) and 19% at 10 years (95% confidence interval, 3%–34%). Nine patients (28%) had revision of the reconstruction during followup; four of these patients had revision surgery for infection. Allografts sterilized by gamma radiation showed worse resorption than fresh-frozen allografts. Based on reported results, allograft-composite prostheses do not appear to improve survival compared with megaprostheses. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. PMID:19851817

  6. Immune Privilege of Corneal Allografts

    PubMed Central

    Niederkorn, Jerry Y.; Larkin, D. Frank P.

    2013-01-01

    Corneal transplantation has been performed successfully for over 100 years. Normally, HLA typing and systemic immunosuppressive drugs are not utilized, yet 90% of corneal allografts survive. In rodents, corneal allografts representing maximal histoincompatibility enjoy >50% survival even without immunosuppressive drugs. By contrast, other categories of transplants are invariably rejected in such donor/host combinations. The acceptance of corneal allografts compared to other categories of allografts is called immune privilege. The cornea expresses factors that contribute to immune privilege by preventing the induction and expression of immune responses to histocompatibility antigens on the corneal allograft. Among these are soluble and cell membrane molecules that block immune effector elements and also apoptosis of T lymphocytes. However, some conditions rob the corneal allograft of its immune privilege and promote rejection, which remains the leading cause of corneal allograft failure. Recent studies have examined new strategies for restoring immune privilege to such high-risk hosts. PMID:20482389

  7. CT Lesion Model-Based Structural Allografts: Custom Fabrication and Clinical Experience

    PubMed Central

    Brune, Jan Claas; Hesselbarth, Uwe; Seifert, Philipp; Nowack, Dimitri; von Versen, Rüdiger; Smith, Mark David; Seifert, Dirk

    2012-01-01

    Summary Background Patients requiring knee and hip revision arthroplasty often present with difficult anatomical situations that limit options for surgery. Customised mega-implants may be one of few remaining treatment options. However, extensive damage to residual bone stock may also be present, and in such cases even customised prosthetics may be difficult to implant. Small quantities of lost bone can be replaced with standard allografts or autologous bone. Larger defects may require structural macro-allografts, sometimes in combination with implants (allograft-prosthesis composites). Methods Herein, we describe a process for manufacturing lesion-specific large structural allografts according to a 3D, full-scale, lithographically generated defect model. These macro-allografts deliver the volume and the mechanical stability necessary for certain complex revisions. They are patient-and implant-matched, negate some requirements for additional implants and biomaterials and save time in the operating theatre by eliminating the requirement for intra-operative sizing and shaping of standard allografts. Conclusion While a robust data set from long-term follow-up of patients receiving customised macro-allografts is not yet available, initial clinical experience and results suggest that lesion-matched macro-allografts can be an important component of revision joint surgery. PMID:23800856

  8. Allograft Pancreatectomy: Indications and Outcomes.

    PubMed

    Nagai, S; Powelson, J A; Taber, T E; Goble, M L; Mangus, R S; Fridell, J A

    2015-09-01

    This study evaluated the indications, surgical techniques, and outcomes of allograft pancreatectomy based on a single center experience. Between 2003 and 2013, 47 patients developed pancreas allograft failure, excluding mortality with a functioning pancreas allograft. Early graft loss (within 14 days) occurred in 16, and late graft loss in 31. All patients with early graft loss eventually required allograft pancreatectomy. Nineteen of 31 patients (61%) with late graft loss underwent allograft pancreatectomy. The main indication for early allograft pancreatectomy included vascular thrombosis with or without severe pancreatitis, whereas one recipient required urgent allograft pancreatectomy for gastrointestinal hemorrhage secondary to an arterioenteric fistula. In cases of late allograft pancreatectomy, graft failure with clinical symptoms such as abdominal discomfort, pain, and nausea were the main indications (13/19 [68%]), simultaneous retransplantation without clinical symptoms in 3 (16%), and vascular catastrophes including pseudoaneurysm and enteric arterial fistula in 3 (16%). Postoperative morbidity included one case each of pulmonary embolism leading to mortality, formation of pseudoaneurysm requiring placement of covered stent, and postoperative bleeding requiring relaparotomy eventually leading to femoro-femoral bypass surgery 2 years after allograftectomy. Allograft pancreatectomy can be performed safely, does not preclude subsequent retransplantation, and may be lifesaving in certain instances. PMID:25912792

  9. Influence of the volume of bone defect, bone grafting methods, and hook fixation on stress on the Kerboull-type plate and screw in total hip arthroplasty: three-dimensional finite element analysis.

    PubMed

    Kaku, Nobuhiro; Hara, Katsutoshi; Tabata, Tomonori; Tsumura, Hiroshi

    2015-02-01

    For total hip arthroplasty or revision surgery using acetabular reinforcement cross-plates, choosing between bulk and morselized bone grafts for filling acetabular defects is challenging. We used finite element model (FEM) analysis to clarify various stresses on the cross-plate based on bone defect size, bone graft type, and presence or absence of hook fixation to the bone. We constructed 12-pattern FEMs and calculated the maximum stress generated on the Kerboull-type (KT) plate and screw. Bone defects were classified into four patterns according to the volume. Regarding the bone graft type, bulk bone grafts were considered as cortical bone, and morselized bone grafts were considered to consist of cancellous bone. Models were compared based on whether hook fixation was used and whether a gap was present behind the plate. The upper surface of the host bone was fixed, and a 1,000-N load was imposed on the horizontal axis at 71°. Larger bone defects increased the stress on the KT plate and screws. This stress increased when no bone was grafted; it was lower when bulk cortical bone grafts were used for filling than when morselized cancellous bone grafts were used. For cortical bone grafts, the increased stress on the KT plate and screws was lowered with hook removal. Attaching the hook to the bone and filling the gap behind the KT plate with an adequate bone graft reduced the stress on the KT plate and screws, particularly for large bone defects filled by bulk bone grafting. PMID:24964969

  10. Quadriceps tendon allografts as an alternative to Achilles tendon allografts: a biomechanical comparison.

    PubMed

    Mabe, Isaac; Hunter, Shawn

    2014-12-01

    Quadriceps tendon with a patellar bone block may be a viable alternative to Achilles tendon for anterior cruciate ligament reconstruction (ACL-R) if it is, at a minimum, a biomechanically equivalent graft. The objective of this study was to directly compare the biomechanical properties of quadriceps tendon and Achilles tendon allografts. Quadriceps and Achilles tendon pairs from nine research-consented donors were tested. All specimens were processed to reduce bioburden and terminally sterilized by gamma irradiation. Specimens were subjected to a three phase uniaxial tension test performed in a custom environmental chamber to maintain the specimens at a physiologic temperature (37 ± 2 °C) and misted with a 0.9 % NaCl solution. There were no statistical differences in seven of eight structural and mechanical between the two tendon types. Quadriceps tendons exhibited a significantly higher displacement at maximum load and significantly lower stiffness than Achilles tendons. The results of this study indicated a biomechanical equivalence of aseptically processed, terminally sterilized quadriceps tendon grafts with bone block to Achilles tendon grafts with bone block. The significantly higher displacement at maximum load, and lower stiffness observed for quadriceps tendons may be related to the failure mode. Achilles tendons had a higher bone avulsion rate than quadriceps tendons (86 % compared to 12 %, respectively). This was likely due to observed differences in bone block density between the two tendon types. This research supports the use of quadriceps tendon allografts in lieu of Achilles tendon allografts for ACL-R. PMID:24414293

  11. A comparative evaluation of freeze-dried bone allograft with and without bioabsorbable guided tissue regeneration membrane Healiguide® in the treatment of Grade II furcation defects: A clinical study

    PubMed Central

    Jain, Deept; Deepa, Dhruvakumar

    2015-01-01

    Background: Furcation defects represent one of the most demanding therapeutic challenges for periodontal therapy. Various treatment modalities have been tried with different success rates. The present study was undertaken to evaluate the efficacy of freeze-dried bone allograft (FDBA) with and without bioabsorbable guided tissue regeneration (GTR) membrane Healiguide® in the treatment of Grade II furcation defects. Materials and Methods: Ten patients with bilateral Grade II furcation defects were selected for the study. After phase I therapy, subjects were divided into two arms and treated in a split-mouth design. Ten defects were treated with FDBA alone in the control arm. Ten defects were treated with FDBA in conjunction with bioabsorbable GTR membrane Healiguide® in test arm. Clinical parameters like plaque index, gingival index, vertical probing depth, horizontal probing depth, and relative attachment level (RAL) were assessed at baseline, 3 months, and 6 months postoperatively. Results: At 6 months, clinical improvement was seen in both the arms with mean pocket depth reduction of 1.2 ± 1.032 mm and 1.7 ± 0.948 mm and mean horizontal probing depth reduction being 2.1 ± 1.969 mm and 1.6 ± 1.264 mm in control and test arm, respectively. Both surgical procedures resulted in a statistically significant reduction in vertical and horizontal probing depths. Conclusion: Both the arms demonstrated a significant improvement in the probing depth, horizontal furcation depth, and RAL at 6 months postsurgery in the treatment of Grade II furcation defects. However, on the intergroup comparison, there was no statistically significant difference in the results achieved between two arms. PMID:26941515

  12. Evaluation of platelet-rich plasma alone or in combination with demineralized freeze dried bone allograft in treatment of periodontal infrabony defects: A comparative clinical trial

    PubMed Central

    Agarwal, Prerna; Chatterjee, Anirban; Gokhale, Shankar; Singh, Himanshu Pratap; Kandwal, Abhishek

    2016-01-01

    Aims: The use of platelet-rich plasma (PRP) alone in periodontal defects has been controversial and inconclusive. Hence, the present study was designed with the aim to assess the clinical and radiographic effectiveness of PRP alone in infrabony defects. Materials and Methods: Thirty infrabony defects were treated with either autologous PRP with open flap debridement (OFD) or autologous PRP + demineralized freeze dried bone graft (DFDBA) with OFD or OFD alone. Clinical parameters recorded were gingival index, plaque index, probing depth (PD), clinical attachment level (CAL), and gingival recession (REC). Radiographic parameters included defect depth reduction, defect resolution, and crestal bone level. All the parameters were recorded at baseline and 12 months postoperatively. Results: Mean PD reduction and CAL gain were greater in PRP + DFDBA (4.88 ± 1.12 mm and 4.26 ± 1.85 mm) and PRP (4.86 ± 2.12 mm and 4.10 ± 1.47 mm) groups than the control group (2.69 ± 1.37 mm and 1.27 ± 0.89 mm). Conclusions: Within the limits of the study, all the three groups showed significant improvement in clinical parameters from baseline to postoperative 12 months. The amount of defect depth reduction and defect resolution treated with PRP alone group were significantly < PRP + DFDBA. The results pertaining to these parameters were significantly better than the control group. PMID:27041837

  13. Regenerative Effects of Three Types of Allografts on Rabbit Calvarium: An Animal Study

    PubMed Central

    Rokn, Amir Reza; Shakeri, Abbas Seyed; Etemad-Moghadam, Shahroo; Alaeddini, Mojgan; Shamshiri, Ahmad Reza; Manasheof, Rebecca; Barikani, Hamidreza

    2015-01-01

    Objectives: The aim of this study was to histologically compare the regenerative properties of two allografts manufactured by two Iranian companies. Materials and Methods: In this study, four 8-mm defects were produced in the calvaria of 12 rabbits. In three defects, three types of allografts namely ITB, CenoBone and Grafton were placed and one defect served as control. Samples were prepared and histomorphometric evaluations were carried out after healing periods of four weeks (interval 1) and eight weeks (interval 2). Qualitative and quantities variables were compared and analyzed with SPSS software. Results: Mild inflammation was observed in 45% and 12.5% of the samples in the first and second intervals, respectively. Foreign body reaction was observed in only 5% of the samples. The quality of regenerated bone was immature, mixed and lamellar in 54.5%, 15.9% and 4.5% of the samples, respectively. The rate of allograft resorption was the highest and lowest in the CenoBone and Grafton samples, respectively. The mean amount of regenerated bone was higher in areas containing Grafton; however, the differences were not statistically significant. Conclusion: Despite the differences in the numerical values of bone regeneration, there were no statistically significant differences in bone generation among the material groups, and allografts manufactured in Iran can be suitable alternatives to Grafton with the same good properties. Further studies are necessary to clarify the efficacy of these allografts. PMID:27507993

  14. Impregnation of bone chips with alendronate and cefazolin, combined with demineralized bone matrix: a bone chamber study in goats

    PubMed Central

    2012-01-01

    Background Bone grafts from bone banks might be mixed with bisphosphonates to inhibit the osteoclastic response. This inhibition prevents the osteoclasts to resorb the allograft bone before new bone has been formed by the osteoblasts, which might prevent instability. Since bisphosphonates may not only inhibit osteoclasts, but also osteoblasts and thus bone formation, we studied different bisphosphonate concentrations combined with allograft bone. We investigated whether locally applied alendronate has an optimum dose with respect to bone resorption and formation. Further, we questioned whether the addition of demineralized bone matrix (DBM), would stimulate bone formation. Finally, we studied the effect of high levels of antibiotics on bone allograft healing, since mixing allograft bone with antibiotics might reduce the infection risk. Methods 25 goats received eight bone conduction chambers in the cortical bone of the proximal medial tibia. Five concentrations of alendronate (0, 0.5 mg/mL, 1 mg/mL, 2 mg/mL, and 10 mg/mL) were tested in combination with allograft bone and supplemented with cefazolin (200 μg/mL). Allograft not supplemented with alendronate and cefazolin served as control. In addition, allograft mixed with demineralized bone matrix, with and without alendronate, was tested. After 12 weeks, graft bone area and new bone area were determined with manual point counting. Results Graft resorption decreased significantly (p < 0.001) with increasing alendronate concentration. The area of new bone in the 1 mg/mL alendronate group was significantly (p = 0.002) higher when compared to the 10 mg/mL group. No differences could be observed between the group without alendronate, but with demineralized bone, and the control groups. Conclusions A dose-response relationship for local application of alendronate has been shown in this study. Most new bone was present at 1 mg/mL alendronate. Local application of cefazolin had no effect on bone remodelling. PMID:22443362

  15. Inhibition of the immune response to experimental fresh osteoarticular allografts

    SciTech Connect

    Rodrigo, J.J.; Schnaser, A.M.; Reynolds, H.M. Jr.; Biggart, J.M. 3d.; Leathers, M.W.; Chism, S.E.; Thorson, E.; Grotz, T.; Yang, Q.M. )

    1989-06-01

    The immune response to osteoarticular allografts is capable of destroying the cartilage--a tissue that has antigens on its cells identical to those on the bone and marrow cells. Osteoarticular allografts of the distal femur were performed in rats using various methods to attempt to temporarily inhibit the antibody response. The temporary systemic immunosuppressant regimens investigated were cyclophosphamide, azathioprine and prednisolone, cyclosporine A, and total lymphoid irradiation. The most successful appeared to be cyclosporine A, but significant side effects were observed. To specifically inhibit the immune response in the allograft antigens without systemically inhibiting the entire immune system, passive enhancement and preadministration of donor blood were tried. Neither was as effective as coating the donor bone with biodegradable cements, a method previously found to be successful. Cyclosporine A was investigated in dogs in a preliminary study of medial compartmental knee allografts and was found to be successful in inhibiting the antibody response and in producing a more successful graft; however, some significant side effects were similarly observed.

  16. The mechanical stability of allografts after a cleaning process: comparison of two preparation modes.

    PubMed

    Putzer, David; Huber, Debora Coraca; Wurm, Alexander; Schmoelz, Werner; Nogler, Michael

    2014-08-01

    In revision hip arthroplasty, bone loss can be compensated by impacting allograft material. Cleaning processes reduce the risk of bacterial and viral contamination. Cleaned allograft material was compared to native untreated allografts by using a uniaxial compression test. 30 measurements were performed for each group before and after compaction. Grain size distribution and weight loss were determined. A reduction in the amount of large bone fragments and a higher compaction rate were observed in the cleaned bone grafts. The cleaned bone chips presented with a better mechanical resistance to a compression force and a reduced flowability. The benefit of a cleaner and a mechanical stable graft material comes with the drawback that higher initial amounts of graft material are needed. PMID:24793889

  17. Sterilisation of canine anterior cruciate allografts by gamma irradiation in argon. Mechanical and neurohistological properties retained one year after transplantation.

    PubMed

    Goertzen, M J; Clahsen, H; Bürrig, K F; Schulitz, K P

    1995-03-01

    Bone-ACL-bone allograft transplantation is a potential solution to the problem of reconstruction of the anterior cruciate ligament (ACL), but sterilisation by gamma irradiation or ethylene oxide causes degradation of the graft. We have studied the biomechanical and histological properties of deep-frozen canine bone-ACL-bone allografts sterilised by gamma irradiation (2.5 Mrad) under argon gas protection. Particular attention was paid to their collagen structure and neuroanatomy compared with those of non-irradiated allografts. We used 60 skeletally mature foxhounds. In 30 animals one ACL was replaced by an irradiated allograft and in the other 30 a non-irradiated graft was used. In both groups the graft was augmented by a Kennedy Ligament Augmentation Device. Examination of the allografts at 3, 6 and 12 months after implantation included mechanical testing, histology, collagen morphometry, neuroanatomical morphology (silver and gold chloride stain) and studies of the microvasculature (modified Spalteholz technique). At 12 months the irradiated ACL allografts failed at a mean maximum load of 718.3 N, 63.8% of the strength of the normal canine ACL. The non-irradiated allografts failed at 780.1 N, 69.1% of normal. All the allografts showed a well-orientated collagen structure one year after transplantation and there was no difference between the irradiated grafts and the others. The silver staining technique demonstrated Golgi tendon organs and free nerve endings within both groups of allografts. As in the normal ACL these structures were most commonly found near the surface of the graft and at its bony attachments. At 12 months the irradiated allografts showed slight hypervascularity compared with the non-irradiated grafts.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7706332

  18. Donation FAQs (Bone and Tissue Allografts)

    MedlinePlus

    ... donor family services. Most organ, tissue and eye banks that are members of MTF send tissue to ... according to exact surgical specifications. Small, local tissue banks could not provide this level of quality in ...

  19. Aortic valve allografts in sheep

    PubMed Central

    Borrie, John; Hill, G. L.

    1968-01-01

    Some of the mechnical and biological problems surrounding the use of fresh allograft inverted aortic valves as mitral valve substitutes are described. Certain aspects of the problem have been studied experimentally. In three sheep `fresh' aortic valve allografts were inserted, using cardiopulmonary bypass, into the main pulmonary artery, and were observed from 5 to 7 months after operation. The animals survived normally. Their normal pulmonary valves remained in situ. The technique is described. At subsequent necropsy, macroscopically the valves were found to be free from vegetation, and the cusps were pliable and apparently normal. Microscopically, the supporting allograft myocardium showed necrosis and early calcification. The valve cusp showed hyalinization of collagen, although beneath the endocardium this hyalinized collagen contained moderate numbers of fibroblasts with no evidence of proliferation. The endocardium and arterial intima of the allograft showed evidence of ingrowth from adjacent normal host endocardial tissues. The allograft itself was invested in a loose layer of fibro-fatty tissue, which, in view of the necrotic state of the graft myocardium, could well have been a reparative reaction rather than a homograft reaction. It is concluded that, although the cusps could function normally, the necrosis of the myocardium might in time lead to late failure of the graft. Further studies with the valve inserted at mitral level are indicated. Images PMID:5656757

  20. Osteochondral Allograft of the Talus

    PubMed Central

    Bisicchia, Salvatore; Rosso, Federica; Amendola, Annunziato

    2014-01-01

    Osteochondral lesions of the talus are being recognized as an increasingly common injury. They are most commonly located postero-medially or antero-laterally, while centrally located lesions are uncommon. Large osteochondral lesions have significant biomechanical consequences and often require resurfacing with osteochondral autograft transfer, mosaicplasty, autologous chondrocyte implantation (or similar methods) or osteochondral allograft transplantation. Allograft procedures have become popular due to inherent advantages over other resurfacing techniques. Cartilage viability is one of the most important factors for successful clinical outcomes after transplantation of osteochondral allografts and is related to storage length and intra-operative factors. While there is abundant literature about osteochondral allograft transplantation in the knee, there are few papers about this procedure in the talus. Failure of non-operative management, initial debridement, curettage or microfractures are an indication for resurfacing. Patients should have a functional ankle motion, closed growth plates, absence of cartilage lesions on the tibial side. This paper reviews the published literature about osteochondral allograft transplantation of the talus focusing on indications, pre-operative planning, surgical approaches, postoperative management, results and complications of this procedure. PMID:25328456

  1. Review article: Treatments for bone loss in revision total knee arthroplasty.

    PubMed

    Qiu, Yi Yan; Yan, Chun Hoi; Chiu, Kwong Yuen; Ng, Fu Yuen

    2012-04-01

    Bone deficiency hinders implant alignment and stabilisation of the bone-implant interface in revision total knee arthroplasty (TKA). Treatments for bone defects include bone cement, bone cement with screw reinforcement, metal augments, impaction bone grafts, structural allografts, and tantalum, depending on the location and size of the defects. Small defects are usually treated with cement, cement plus screws, or impaction allograft bone. Large defects are repaired with structural allografts or metal augments. Recent developments involve the use of highly porous osteoconductive tantalum. We reviewed the pros and cons of each method for bone defect management in revision TKA. PMID:22535817

  2. Biology of cancellous bone grafts.

    PubMed

    Heiple, K G; Goldberg, V M; Powell, A E; Bos, G D; Zika, J M

    1987-04-01

    Despite 30 years of experimental bone grafting research, the fresh cancellous bone graft remains the most osteogenic and reliable bone grafting material. Recent experimental data suggest that modification of the graft-host interaction by antigen matching or immune manipulation may allow increasingly successful use of allografts. PMID:3550570

  3. Filgrastim-Stimulated Bone Marrow Compared with Filgrastim-Mobilized Peripheral Blood in Myeloablative Sibling Allografting for Patients with Hematologic Malignancies: A Randomized Canadian Blood and Marrow Transplant Group Study.

    PubMed

    Couban, Stephen; Aljurf, Mahmoud; Lachance, Sylvie; Walker, Irwin; Toze, Cynthia; Rubinger, Morel; Lipton, Jeffrey H; Lee, Stephanie J; Szer, Richard; Doocey, R; Lewis, Ian D; Huebsch, Lothar; Howson-Jan, Kang; Lalancette, Michel; Almohareb, Fahad; Chaudhri, Nadeem; Ivison, Sabine; Broady, Raewyn; Levings, Megan; Fairclough, Diane; Devins, Gerald; Szwajcer, David; Foley, Ronan; Smith, Clayton; Panzarella, Tony; Kerr, Holly; Kariminia, Amina; Schultz, Kirk R

    2016-08-01

    In adult hematopoietic cell transplantation (HCT), filgrastim-mobilized peripheral blood (G-PB) has largely replaced unstimulated marrow for allografting. Although the use of G-PB results in faster hematopoietic recovery, it is also associated with more chronic graft-versus-host disease (cGVHD). A potential alternative allograft is filgrastim-stimulated marrow (G-BM), which we hypothesized may be associated with prompt hematopoietic recovery but with less cGVHD. We conducted a phase 3, open-label, multicenter randomized trial of 230 adults with hematologic malignancies receiving allografts from siblings after myeloablative conditioning to compare G-PB with G-BM. The primary endpoint was time to treatment failure, defined as a composite of extensive cGVHD, relapse/disease progression, and death. With a median follow-up of 36 months (range, 9.6 to 48), comparing G-BM with G-PB, there was no difference between the 2 arms with respect to the primary outcome of this study (hazard ratio [HR], .91; 95% confidence interval [CI], .68 to 1.22; P = .52). However, the cumulative incidence of overall cGVHD was lower with G-BM (HR, .66; 95% CI, .46 to .95; P = .007) and there was no difference in the risk of relapse or progression (P = .35). The median times to neutrophil recovery (P = .0004) and platelet recovery (P = .012) were 3 days shorter for recipients allocated to G-PB compared with those allocated to G-BM, but there were no differences in secondary engraftment-related outcomes, such as time to first hospital discharge (P = .17). In addition, there were no graft failures in either arm. This trial demonstrates that, compared with G-PB, the use of G-BM allografts leads to a significantly lower rate of overall cGVHD without a loss of the graft-versus-tumor effect and comparable overall survival. Our findings suggest that further study of this type of allograft is warranted. PMID:27154847

  4. Massive allograft replacement of hemiarticular traumatic defects of the elbow.

    PubMed

    Breen, T; Gelberman, R H; Leffert, R; Botte, M

    1988-11-01

    Four elbow osteoarticular allografts were done for four patients as salvage procedures for unreconstructable elbow fracture malunions. With a mean follow-up of 60 months (range, 12 to 72 months) all elbows were stable, free of pain, and had mean motion of 130 degrees active flexion and 27 degrees of flexion deformity, 67 degrees pronation and 62 degrees supination (preoperative mean: 104 degrees flexion, 42 degrees flexion contracture, 20 degrees pronation, and 34 degrees supination). Complications occurred in two elbows. One had a deep infection necessitating graft removal and subsequent regrafting. The second had an olecranon osteotomy nonunion. Elbow allografting is recommended as a salvage procedure for massive posttraumatic articular defects, bone loss, or malunion when neither arthrodesis nor conventional arthroplasty is indicated. PMID:3066816

  5. Allograft pancreas: pale acinar nodules.

    PubMed

    Troxell, Megan L; Drachenberg, Cinthia

    2016-08-01

    Microscopic pale-staining acinar nodules were characterized in native pancreas in the 1980s under a variety of names but have been infrequently reported since. We retrospectively studied the frequency and characteristics of pale acinar nodules in allograft pancreas biopsies, as compared to a sampling of native pancreas specimens at our center. Pale acinar nodules were present in 13% (9/69) of allograft biopsies from 22% (7/32) of transplant patients, and 23% (5/22) of native pancreas surgical specimens, although more nodules per pancreas area were present in allograft needle biopsies. Acinar nodules had size of 100 to 700 μm, were periodic acid-Schiff pale, were synaptophysin negative, stained more weakly with keratin CAM 5.2 compared to surrounding parenchyma, and had a low proliferative rate. Ultrastructural evaluation revealed paucity of zymogen granules with dilated cistern-like structures. In our experience, pale acinar nodules have similar features in allograft and native pancreas specimens, yet remain of uncertain etiology and significance. PMID:27063474

  6. Emphysema in the renal allograft

    SciTech Connect

    Potter, J.L.; Sullivan, B.M.; Fluornoy, J.G.; Gerza, C.

    1985-04-01

    Two diabetic patients in whom emphysematous pyelonephritis developed after renal transplantation are described. Clinical recognition of this unusual and serious infection is masked by the effects of immunosuppression. Abdominal radiographic, ultrasound, and computed tomography findings are discussed. The clinical presentation includes urinary tract infection, sepsis, and acute tubular malfunction of the allograft in insulin-dependent diabetics.

  7. Comparison of Clinical Outcome of Autograft and Allograft Reconstruction for Anterior Cruciate Ligament Tears

    PubMed Central

    Jia, Yu-Hua; Sun, Peng-Fei

    2015-01-01

    Background: Hamstring (HS) autograft and bone-patellar tendon-bone allograft are the most common choice for reconstruction of anterior cruciate ligament (ACL). There was a little report about the clinical outcome and difference of arthroscopic ACL reconstruction using allograft and autograft. This study aimed to compare the clinical outcome of autograft and allograft reconstruction for ACL tears. Methods: A total of 106 patients who underwent surgery because of ACL tear were included in this study. The patients were randomly divided into two groups, including 53 patients in each group. The patients in group I underwent standard ACL reconstruction with HS tendon autografts, while others in group II underwent reconstruction with bone-patellar tendon-bone allograft. All the patients were followed up and analyzed; the mean follow-up was 81 months (range: 28–86 months). Clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC), Lysholm scores, physical instability tests, and patient satisfaction questionnaires. The complication rates of both groups were compared. Tibial and femoral tunnel widening were assessed using lateral and anteroposterior radiographs. Results: At the end of follow-up, no significant differences were found between the groups in terms of IKDC, Lysholm scores, physical instability tests, patient satisfaction questionnaires, and incidences of arthrofibrosis. Tibial and femoral tunnel widening was less in the HS tendon autografts. This difference was more significant on the tibial side. Conclusions: In the repair of ACL tears, allograft reconstruction is as effective as the autograft reconstruction, but the allograft can lead to more tunnel widening evidently in the tibial tunnel, particularly. PMID:26612290

  8. Comparative evaluation of pelvic allograft selection methods.

    PubMed

    Bousleiman, Habib; Paul, Laurent; Nolte, Lutz-Peter; Reyes, Mauricio

    2013-05-01

    This paper presents a firsthand comparative evaluation of three different existing methods for selecting a suitable allograft from a bone storage bank. The three examined methods are manual selection, automatic volume-based registration, and automatic surface-based registration. Although the methods were originally published for different bones, they were adapted to be systematically applied on the same data set of hemi-pelvises. A thorough experiment was designed and applied in order to highlight the advantages and disadvantages of each method. The methods were applied on the whole pelvis and on smaller fragments, thus producing a realistic set of clinical scenarios. Clinically relevant criteria are used for the assessment such as surface distances and the quality of the junctions between the donor and the receptor. The obtained results showed that both automatic methods outperform the manual counterpart. Additional advantages of the surface-based method are in the lower computational time requirements and the greater contact surfaces where the donor meets the recipient. PMID:23299829

  9. Strontium doping of bone graft extender

    PubMed Central

    2011-01-01

    Background and purpose Allografts are often used during revision hip replacement surgery for stabilization of the implant. Resorption of the allograft may exceed new bone formation, and instability of the prosthesis can develop. We investigated whether strontium could regulate the imbalance of fast resorption of allograft and slower formation of new bone, because it is both an anabolic and an anticatabolic agent. Method Strontium was added to the implant interface environment by doping a hydroxyapatite bone graft extender. 10 dogs each received 2 experimental titanium implants. The implants were inserted within a 2.7-mm concentric gap in cancellous bone. The gap was filled with 50% (v/v) allograft mixed with 50% bone graft extender. The extender either had 5% strontium doping (SrHA) or was undoped (HA). After 4 weeks, osseointegration and mechanical fixation were evaluated by histomorphometry and by push-out test. Results SrHA bone graft extender induced a 1.2-fold increase in volume of new bone, a 1.2-fold increase in allograft remaining in the gap, and a 1.4-fold increase in surface area of the bone graft extender material in contact with new bone compared to HA bone graft extender. All these increases were statistically significant. SrHA bone graft extender did not significantly improve ongrowth of bone onto the implants or improve any of the mechanical push-out parameters compared to HA bone graft extender. Interpretation Doping of the HA bone graft extender with 5% strontium increased gap healing, preserved more of the allograft in the gap, and increased the ongrowth of bone onto the bone graft extender material, but did not improve mechanical fixation. PMID:21895497

  10. An audit of consent for allograft use in elective orthopaedic surgery.

    PubMed

    Mullan, C J; Pagoti, R; Davison, H; McAlinden, M G

    2016-04-01

    Introduction Patients receiving musculoskeletal allografts may be at risk of postoperative infection. The General Medical Council guidelines on consent highlight the importance of providing patients with the information they want or need on any proposed investigation or treatment, including any potential adverse outcomes. With the increased cost of defending medicolegal claims, it is paramount that adequate, clear informed patient consent be documented. Methods We retrospectively examined the patterns of informed consent for allograft bone use during elective orthopaedic procedures in a large unit with an onsite bone bank. The initial audit included patients operated over the course of 1 year. Following a feedback session, a re-audit was performed to identify improvements in practice. Results The case mix of both studies was very similar. Revision hip arthroplasty surgery constituted the major subgroup requiring allograft (48%), followed by foot and ankle surgery (16.3%) and revision knee arthroplasty surgery (11.4%) .On the initial audit, 17/45 cases (38%) had either adequate preoperative documentation of the outpatient discussion or an appropriately completed consent form on the planned use of allograft. On the re-audit, 44/78 cases (56%) had adequate pre-operative documentation. There was little correlation between how frequently a surgeon used allograft and the adequacy of consent (Correlation coefficient -0.12). Conclusions Although the risk of disease transmission with allograft may be variable, informed consent for allograft should be a routine part of preoperative discussions in elective orthopaedic surgery. Regular audit and feedback sessions may further improve consent documentation, alongside the targeting of high volume/low compliance surgeons. PMID:26924483

  11. Reconstruction of large traumatic segmental defects of the femur using segmental allograft with vascularized fibula inlay.

    PubMed

    Ridha, Hyder; Bernard, Jason; Gateley, David; Vesely, Martin J

    2011-07-01

    Segmental defects of the distal femur following trauma pose a reconstructive challenge. A stable reconstruction capable of withstanding high forces while allowing early mobility is paramount. The Capanna technique of reconstruction combining allograft with vascularized bone graft provides such a construct and has been described for oncological resection. We describe a modified Capanna technique, the "inlay" construct. Three reconstructions were performed for distal femoral segmental loss following trauma. One patient had bilateral reconstructions. Bone defects measuring 11, 9, and 8 cm were reconstructed using a large segmental allograft and free fibular flap inlay assembly. Both patients made uneventful recoveries and achieved full weight-bearing without walking aids 6 months postreconstruction. Range of movement of each knee joint achieved at least 90 degrees of active flexion. We have shown that large segmental traumatic defects of the femur can be successfully reconstructed using segmental allograft with vascularized fibula inlay. This reconstruction provides early mechanical stability, protecting the fibula from fracturing and allowing axial loading of healing bone. The inlay assembly allows a large area of bony contact between allograft and vascularized bone, optimizing bony healing. It is a good alternative to other established techniques of managing significant segmental defects of the distal femur. PMID:21717390

  12. Functional Outcomes of Primary Anterior Cruciate Ligament Reconstruction with Tibialis Anterior Allograft

    PubMed Central

    Başar, Selda; Büyükafşar, Enes; Hazar, Zeynep; Ataoğlu, Baybars; Kanatlı, Ulunay

    2014-01-01

    Objectives: Allografts have potential advantages in primary anterior cruciate ligament reconstruction (ACLR), including the absence of donor site morbidity, shorter operative times, improved cosmesis, and easier rehabilitation. There is limited and conflicting outcome data for ACLR with tibialis anterior allograft. The purpose of this study was to evaluate the functional outcomes of ACLR with tibialis anterior allograft. Methods: We retrospectively evaluated patients underwent ACLR using with tibialis anterior allograft between 2005 and 2013. Totally 12 patients who were performed suspensory fixation technique were included in this study (range: 25-43 years). Exclusion criteria included double bundle, bone tendon bone technique and revision surgery. Clinical outcomes were measured by subject part of International Knee Documentation Committee (IKDC) and Lysholm scores. Results: A significant increase was reported in all the clinical scores. In particular, the IKDC-subjective score increased from a basal value of 45.5±12.7 to 84.3±5.50 at the 12 months' evaluation (p<0.05). The Lysholm score revealed a significant improvement from 49.7±14.2 to 83.5±20.5 at the 12 months' evaluation (p<0.05). Conclusion: ACLR with tibialis anterior allograft is an effective treatment for correcting loss of function and increasing quality of life.

  13. Effect of Low-Level Laser Therapy on Incorporation of Block Allografts

    PubMed Central

    Valiati, Renato; Paes, Jefferson Viapiana; de Moraes, Aury Nunes; Gava, Aldo; Agostini, Michelle; Masiero, Anelise Viapiana; de Oliveira, Marilia Gerhardt; Pagnoncelli, Rogério Miranda

    2012-01-01

    Objective To assess the effect of low-level laser therapy (LLLT) on the incorporation of deep-frozen block allografts in a rabbit model. Background Data Studies have shown that LLLT has beneficial effects on tissue repair and new bone formation. Methods Bone tissue was harvested from two rabbits, processed by deep-freezing and grafted into the calvaria of 12 animals, which were then randomly allocated into two groups: experimental (L) and control (C). Rabbits in group L were irradiated with an aluminum gallium arsenide diode laser (AlGaAs; wavelength 830 nm, 4 J/cm2), applied to four sites on the calvaria, for a total dose of 16 J/cm2 per session. The total treatment dose after eight sessions was 128 J/cm2. Animals were euthanized at 35 (n = 6) or 70 days (n = 6) postoperatively. Results Deep-freeze-processed block allografts followed by LLLT showed incorporation at the graft-host interface, moderate bone remodeling, partial filling of osteocyte lacunae, less inflammatory infiltrate in the early postoperative period, and higher collagen deposition than the control group. Conclusion Optical microscopy and scanning electron microscopy showed that allograft bone processed by deep-freezing plus LLLT is suitable as an alternative for the treatment of bone defects. Use of the deep-freezing method for processing of bone grafts preserves the structural and osteoconductive characteristics of bone tissue. PMID:23155359

  14. Increased Risk of Revision after ACL Reconstruction with Soft Tissue Allograft Compared to Autograft

    PubMed Central

    Maletis, Gregory; Chen, Jason; Inacio, Maria Carolina Secorun; Love, Rebecca; Funahashi, Tadashi Ted

    2016-01-01

    Objectives: The use of allograft tissue for anterior cruciate ligament reconstruction (ACLR) remains controversial. Numerous meta-analysis and systematic reviews of small clinical studies have not found differences between autograft and allograft outcomes but large registry studies have shown an increased risk of revision with allografts. The purpose of this study was to compare the risk of aseptic revision between bone-patellar tendon-bone (BPTB) autografts, hamstring tendon autografts and soft tissue allografts. Methods: A retrospective cohort study of prospectively collected data was conducted using an US ACLR Registry. A cohort of primary unilateral ACLR cases reconstructed with BPTB autografts, hamstring autografts and soft tissue allografts (from any site) was identified. Aseptic revision was the end point of the study. Type of graft and allograft processing methods (non-processed, <1.8Mrads with and without chemical processing (Allowash or AlloTrue methods), >1.8 Mrads irradiation with and without chemical processing, and chemical processing alone (BioCleanse)) were the exposures of interest evaluated. Time from surgery was evaluated as an effect modifier. All analyses were adjusted for age, gender, and race. Kaplan-Meier curves and Cox proportional hazard models were employed. Hazard ratios (HR), 95% confidence intervals (CI) are provided. Results: The cohort had 14015 cases, 8924 (63.7%) were male, 6397 (45.6%) were White, 4557 (32.5%) cases used BPTB autograft, 3751 (26.8%) cases used soft tissue allograft and 5707 (40.7%) cases used hamstring autograft. The median age was 34.6 years-old (IQR 24.1-43.2) for allograft cases and 24.3 years-old (IQR 17.7-33.8) for hamstring autograft cases, and 22.0 years-old (IQR 17.6-30.0) for BPTB autograft cases. Compared to hamstring tendon autografts, an increased risk of revision was found in allografts processed with >1.8Mrads without chemical processing after 2.5 years (HR: 3.88 95%CI 1.48-10.12), and >1.8Mrads with

  15. Leiomyoma in a Renal Allograft.

    PubMed

    Li, Yan Jun; Siriwardana, Amila Rohan; Symons, James Lawrence Penn; O'Neill, Gordon Francis; Qiu, Min Ru; Furlong, Timothy John

    2016-01-01

    Leiomyomas are smooth muscle tumours that are rarely found in the kidney. There is one report of a leiomyoma in a kidney transplant in a paediatric recipient. Here, we report an adult renal transplant recipient who developed an Epstein-Barr virus-positive leiomyoma in his allograft 15 years after transplantation. The patient was converted to everolimus for posttransplant immunosuppression management and there was no sign of progression over a year. PMID:27195169

  16. Leiomyoma in a Renal Allograft

    PubMed Central

    Li, Yan Jun; Siriwardana, Amila Rohan; Symons, James Lawrence Penn; O'Neill, Gordon Francis; Qiu, Min Ru; Furlong, Timothy John

    2016-01-01

    Leiomyomas are smooth muscle tumours that are rarely found in the kidney. There is one report of a leiomyoma in a kidney transplant in a paediatric recipient. Here, we report an adult renal transplant recipient who developed an Epstein-Barr virus-positive leiomyoma in his allograft 15 years after transplantation. The patient was converted to everolimus for posttransplant immunosuppression management and there was no sign of progression over a year. PMID:27195169

  17. Hearing Benefit in Allograft Tympanoplasty Using Tutoplast Processed Malleus

    PubMed Central

    Issing, Wolfgang

    2014-01-01

    Objectives. Tutoplast processed human cadaveric ossicular allografts are a safe alternative for ossicular reconstruction where there is insufficient material suitable for autograft ossiculoplasty. We present a series of 7 consecutive cases showing excellent air-bone gap closure following canal-wall-down mastoidectomy for cholesteatoma and reconstruction of the middle ear using Tutoplast processed malleus. Patients and Methods. Tympanoplasty with Tutoplast processed malleus was performed in seven patients to reconstruct the middle ear following canal-wall-down mastoidectomy in a tertiary ENT centre. Main Outcome Measures. Hearing improvement and recurrence-free period were assessed. Pre-and postoperative audiograms were performed. Results. The average pre operative hearing loss was 50 ± 13 dB, with an air-bone gap of 33 ± 7 dB. Post operative audiograms at 25 months demonstrated hearing thresholds of 29 ± 10 dB, with an air-bone gap of 14 ± 6 dB. No prosthesis extrusion was observed, which compares favourably to other commercially available prostheses. Conclusions. Tutoplast processed allografts restore conductive hearing loss in patients undergoing mastoidectomy and provide an excellent alternative when there is insufficient material suitable for autograft ossiculoplasty. PMID:24688548

  18. Bone Allografts: What Is the Risk of Disease Transmission with Bone Allografts?

    MedlinePlus

    ... Sample Device Evaluation Form Instructions for Using the Sample Screening Form Glossary Research & Publications Oral Health In America: Summary of the Surgeon General's Report Journal Articles Oral Health Data Tools Water Fluoridation Reporting System Water Fluoridation Reporting System Data ...

  19. Allografts in Soft Tissue Reconstructive Procedures

    PubMed Central

    Giedraitis, Andrius; Arnoczky, Steven P.; Bedi, Asheesh

    2014-01-01

    Context Allografts offer several important advantages over autografts in musculoskeletal reconstructive procedures, such as anterior cruciate ligament reconstruction. Despite growing widespread use of allograft tissue, serious concerns regarding safety and functionality remain. We discuss the latest knowledge of the potential benefits and risks of allograft use and offer a critical review of allograft tissue regulation, management, and sterilization to enable the surgeon to better inform athletes considering reconstructive surgery options. Evidence Acquisition A review of sources published in the past 10 years is the primary basis of this research. Study Design: Observational analysis (cohort study). Level of Evidence: Level 3. Results Comparable outcome data for autografts and allografts do not support universal standards for anterior cruciate ligament reconstruction, and physician recommendation and bias appear to significantly influence patient preference and satisfaction. Sterilization by gamma and electron-beam irradiation diminishes the biomechanical integrity of allograft tissue, but radioprotective agents such as collagen cross-linking and free radical scavengers appear to have potential in mitigating the deleterious effects of irradiation and preserving tissue strength and stability. Conclusion Allografts offer greater graft availability and reduced morbidity in orthopaedic reconstructive procedures, but greater expansion of their use by surgeons is challenged by the need to maintain tissue sterility and biomechanical functionality. Advances in the radioprotection of irradiated tissue may lessen concerns regarding allograft safety and structural stability. PMID:24790696

  20. Allograft Replacement for Absent Native Tissue

    PubMed Central

    Chaudhury, Salma; Wanivenhaus, Florian; Fox, Alice J.; Warren, Russell F.; Doyle, Maureen; Rodeo, Scott A.

    2013-01-01

    Context: Structural instability due to poor soft tissue quality often requires augmentation. Allografts are important biological substitutes that are used for the symptomatic patient in the reconstruction of deficient ligaments, tendons, menisci, and osteochondral defects. Interest in the clinical application of allografts has arisen from the demand to obtain stable anatomy with restoration of function and protection against additional injury, particularly for high-demand patients who participate in sports. Traditionally, allografts were employed to reinforce weakened tissue. However, they can also be employed to substitute deficient or functionally absent tissue, particularly in the sports medicine setting. Objective: This article presents a series of 6 cases that utilized allografts to restore functionally deficient anatomic architecture, rather than just simply augmenting the degenerated or damaged native tissue. Detailed discussions are presented of the use of allografts as a successful treatment strategy to replace functionally weakened tissue, often after failed primary repairs. PMID:24427387

  1. Osteochondral Allografts in the Ankle Joint

    PubMed Central

    Vannini, Francesca; Buda, Roberto; Ruffilli, Alberto; Cavallo, Marco; Giannini, Sandro

    2013-01-01

    Purpose: The aim of this systematic review is to report about the clinical use of partial and total fresh osteochondral allograft in the ankle joint. The state of the art of allografts with regard to basic science, procurement and storage methods, immunogenicity, generally accepted indications and contraindications, and the rationale of the allografting procedure have been described. Methods: All studies published in PubMed from 2000 to January 2012 addressing fresh osteochondral allograft procedures in the ankle joint were identified, including those that fulfilled the following criteria: (a) level I-IV evidence addressing the areas of interest outlined above; (b) measures of functional, clinical, or imaging outcome; and (c) outcome related to ankle cartilage lesions or ankle arthritis treated by allografts. Results: The analysis showed a progressively increasing number of articles from 2000. The number of selected articles was 14; 9 of those focused on limited dimension allografts (plugs, partial) and 5 on bipolar fresh osteochondral allografts. The evaluation of evidence level showed 14 case series and no randomized studies. Conclusions: Fresh osteochondral allografts are now a versatile and suitable option for the treatment of different degrees of osteochondral disease in the ankle joint and may even be used as total joint replacement. Fresh osteochondral allografts used for total joint replacement are still experimental and might be considered as a salvage procedure in otherwise unsolvable situations. A proper selection of the patients is therefore a key point. Moreover, the patients should be adequately informed about the possible risks, benefits, and alternatives to the allograft procedure. PMID:26069666

  2. Fresh osteochondral allografts in the knee: only a salvage procedure?

    PubMed

    Gobbi, Alberto; Scotti, Celeste; Lane, John G; Peretti, Giuseppe M

    2015-07-01

    The role of fresh allogeneic osteochondral allograft transplantation (OCA) in the cartilage repair algorithm has been long debated and this procedure is primarily considered as a salvage procedure, to be used when other, simple, techniques have failed. Gracitelli et al. in a retrospective comparison of patients who received OCA as primary treatment or as a salvage procedure, demonstrates that the outcome of this procedure is minimally influenced by a previous failed treatment and that OCA represents an effective solution for both primary and revision surgery of chondral and osteochondral lesions of the knee. In particular, optimal indications for OCA seem to be revision of previously failed bone marrow stimulation techniques with an impaired subchondral bone plate and primary treatment of large osteochondral defects. PMID:26261835

  3. Radiation sterilization of skin allograft

    NASA Astrophysics Data System (ADS)

    Kairiyama, E.; Horak, C.; Spinosa, M.; Pachado, J.; Schwint, O.

    2009-07-01

    In the treatment of burns or accidental loss of skin, cadaveric skin allografts provide an alternative to temporarily cover a wounded area. The skin bank facility is indispensable for burn care. The first human skin bank was established in Argentina in 1989; later, 3 more banks were established. A careful donor selection is carried out according to the national regulation in order to prevent transmissible diseases. As cadaveric human skin is naturally highly contaminated, a final sterilization is necessary to reach a sterility assurance level (SAL) of 10 -6. The sterilization dose for 106 batches of processed human skin was determined on the basis of the Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control (2004) and ISO 11137-2 (2006). They ranged from 17.6 to 33.4 kGy for bioburdens of >10-162.700 CFU/100 cm 2. The presence of Gram negative bacteria was checked for each produced batch. From the analysis of the experimental results, it was observed that the bioburden range was very wide and consequently the estimated sterilization doses too. If this is the case, the determination of a tissue-specific dose per production batch is necessary to achieve a specified requirement of SAL. Otherwise if the dose of 25 kGy is preselected, a standardized method for substantiation of this dose should be done to confirm the radiation sterilization process.

  4. Meniscal allograft transplantation in rabbit.

    PubMed

    Vilela, Liana M; Del Carlo, Ricardo J; Melo Filho, Edson V; Favarato, Lukiya S C; Duarte, Tatiana S; Pontes, Kelly C S; Cunha, Daise N Q

    2015-01-01

    This study evaluated the technique for meniscal allograft transplantation using allografts preserved in glycerin 98% in rabbits. Euthanasia was performed at 70 days to compare the transplanted (TM1 to TM16) versus the contralateral meniscus (OM1 to OM16). Sixteen menisci, 8 transplanted and 8 contralateral, were submitted to gross examination, histomorphometric analysis for identification and quantification of cellular type, and for quantification and distribution of collagen fibers. A revascularization study was conducted in all of the other samples. Lengths of the OM varied from 0.9 to 1.0 cm and two TM were smaller. All TM were completely attached to the synovial membrane, except for one case that presented partial fixation. Both, TM and OM had similar amounts of chondrocytes, fibroblasts and fibrocytes, and at the horns, chondrocytes were predominant. The collagen fibers in TM were well organized throughout the body, and disorganized at the horns. These fibers in OM were organized. The amounts of collagen type I and III, and the vascularization of the perimeniscal tissue and of the edge were similar in OM and TM. These results demonstrated graft integration and thus this transplantation technique and preservation method may be recommended. PMID:26648544

  5. Preserved saphenous vein allografts for vascular access.

    PubMed

    Piccone, V A; Sika, J; Ahmed, N; LeVeen, H H; DiScala, V

    1978-09-01

    Preserved venous allografts were used as an alternate access procedure in 70 patients receiving dialysis during a three year period. The clinical experience with allograft fistulas revealed an extremely high initial patency rate; absence of infection postoperatively and during three years of dialysis; suitability for dialysis a week after implantation, thus greatly obviating the need for Silastic shunts; a low long term thrombosis rate and the weakly antigenic allograft veins produced no accelerated rejection of subsequently transplanted kidneys. Surviving patients average 172 dialysis treatments per allograft. Allograft fistulas constituted 45 per cent of the last 100 vascular procedures, an indication of the extent of usage. Microscopic examination of grafts retrieved from patients who died during the late follow-up period demonstrated that structural components of the wall of the vein were still identifiable. Allograft venous fistulas offer dependable, safe vascular access, especially in the infection prone patient with diabetes who is receiving dialysis treatment. The clinical results of allograft fistulas suggests a major role for this technique in vascular access operations. PMID:684591

  6. Future of allografts in sports medicine.

    PubMed

    Harner, Christopher D; Lo, Marvin Y

    2009-04-01

    Allografts play a prominent role in sports medicine, and their usage has increased dramatically over the past few decades, but the role of allograft in the future of sports medicine largely depends on several factors: (1) the ability of the tissue banking industry to convince both surgeons and the general population that tissue procurement is safe and nearly disease-free, (2) the ability to sterilize tissue with minimal compromise to tissue integrity, (3) successful clinical outcomes with allograft, and (4) the advent of artificial scaffolds and ligaments that function as well. PMID:19306738

  7. Infectious Triggers of Chronic Lung Allograft Dysfunction.

    PubMed

    Gregson, Aric L

    2016-07-01

    Survival after lung transplantation is limited in large part due to the high incidence of chronic rejection, known as chronic lung allograft dysfunction (CLAD). Pulmonary infections are a frequent complication in lung transplant recipients, due both to immunosuppressive medications and constant exposure of the lung allograft to the external environment via the airways. Infection is a recognized risk factor for the development of CLAD, and both acute infection and chronic lung allograft colonization with microorganisms increase the risk for CLAD. Acute infection by community acquired respiratory viruses, and the bacteria Pseudomonas aeruginosa and Staphylococcus aureus are increasingly recognized as important risk factors for CLAD. Colonization by the fungus Aspergillus may also augment the risk of CLAD. Fostering this transition from healthy lung to CLAD in each of these infectious episodes is the persistence of an inflammatory lung allograft environment. PMID:27221821

  8. Renal allograft rejection: sonography and scintigraphy

    SciTech Connect

    Singh, A.; Cohen, W.N.

    1980-07-01

    A total of 30 renal allograft patients who had sonographic B scanning and radionuclide studies of the transplant was studied as to whether: (1) the allograft rejection was associated with any consistent and reliable sonographic features and (2) the sonograms complemented the radionuclide studies. Focal areas of decreased parenchymal echogenicity were the most striking and consistent sonographic finding in chymal echogenicity were the most striking and consistens sonographic finding in allograft rejection. This was observed in most of the patients exhibiting moderate or severe rejection, but was frequently absent with mild rejection. Areas of decreased parenchymal echogenicity were not seen during episodes of acute tubular necrosis. Therefore, sonography showing zones of decreased parenchymal echogenicity was complementary to radionuclide studies in the diagnosis of allograft rejection versus acute tubular necrosis. Corticomedullary demarcation was difficult to interpret because of technical variables, and was inconsistently related to rejection in this series.

  9. Penetrating Blast Injury to the Knee of a United States Soldier Treated with Allograft Mosaicplasty

    PubMed Central

    Eichinger, Maj. Josef K.; Bluman, Eric M.; Arrington, Col. Edward D.

    2011-01-01

    Objective: This is the first report of successful allograft mosaicplasty treatment of a large osteochondral lesion of the knee caused by a blast fragment sustained during combat operations. The patient was able to return to active duty following rehabilitation. Methods: An active-duty infantryman sustained an osteochondral lesion of the medial femoral condyle caused by a metallic fragment of an explosively formed projectile. Initial treatment consisted of removal of the foreign body and primary closure. The patient continued to experience pain, mechanical symptoms, and repeated effusions after initial nonoperative treatment. Allograft mosaicplasty of the lesion utilizing two 18-mm-diameter fresh allograft osteochondral plugs was performed at 6 months post-injury. Results: At 2-year follow-up, the patient remains on active duty with marked improvement in symptoms. Two years postoperatively, his outcome scores are 72 of 100 on the Western Ontario and McMaster University osteoarthritis scoring index (WOMAC) and 60 of 100 on the Knee Injury and Osteoarthritis Outcome Score (KOOS). His follow-up x-rays and MRI demonstrate intact articular cartilage and subchondral bone incorporation. Conclusion: Penetrating injuries to joints are commonplace in the battlefield environment. Combat injuries to the knee are frequently associated with articular cartilage injury. While numerous cartilage restoration techniques have been used with success for the treatment of osteochondral injuries to the femoral condyles, no published reports describe the use of allograft mosaicplasty in this location for open, penetrating injuries with focal cartilage loss. This is the first documented use of allograft mosaicplasty for a traumatic osteochondral defect of the medial femoral condyle caused by a metallic projectile. The patient was able to return to active duty following rehabilitation. We demonstrate a high level of functioning is possible following allograft mosaicplasty of a large

  10. Bone grafts and their substitutes.

    PubMed

    Fillingham, Y; Jacobs, J

    2016-01-01

    The continual cycle of bone formation and resorption is carried out by osteoblasts, osteocytes, and osteoclasts under the direction of the bone-signaling pathway. In certain situations the host cycle of bone repair is insufficient and requires the assistance of bone grafts and their substitutes. The fundamental properties of a bone graft are osteoconduction, osteoinduction, osteogenesis, and structural support. Options for bone grafting include autogenous and allograft bone and the various isolated or combined substitutes of calcium sulphate, calcium phosphate, tricalcium phosphate, and coralline hydroxyapatite. Not all bone grafts will have the same properties. As a result, understanding the requirements of the clinical situation and specific properties of the various types of bone grafts is necessary to identify the ideal graft. We present a review of the bone repair process and properties of bone grafts and their substitutes to help guide the clinician in the decision making process. PMID:26733632

  11. Is there significant variation in the material properties of four different allografts implanted for ACL reconstruction.

    PubMed

    Penn, David; Willet, Thomas L; Glazebrook, Mark; Snow, Martyn; Stanish, William D

    2009-03-01

    The aims of our study were to: (1) determine if there are differences in the material properties of tendon obtained from implanted tibialis anterior, achilles, bone-patella- bone and tibialis posterior allografts; (2) determine the variability in material properties between the implanted specimens. A total of 60 specimens were collected from fresh frozen allografts implanted at ACL reconstruction. Specimens collected included 15 tibialis anterior, 15 tibialis posterior, 15 achilles and 15 bone-patella-bone tendons. Each specimen was mounted in a custom made cryogrip. The mounted specimens were loaded onto a MTS Testline servo-hydraulic testing machine in a uni-axial tensile test configuration. Specimens were subjected to a strain rate of 5% per second until the ultimate tensile stress (UTS), failure strain and high strain modulus was calculated for each specimen after being normalized for specimen dimensions. Individual material properties were tested using one way analysis of variance (ANOVA) and post hoc Tukey's B test with a P value of <0.05 considered significant. Homogeneity of variance was assessed using the Levene's test. As a result, no significant difference was found between all four grafts with regards to UTS, failure strain or high strain linear modulus. The UTS was plotted against the modulus demonstrating a linear relationship which is typical of soft tissues. Significant variability in the results were observed. In conclusion, there was no significant statistical difference between the material properties of the four tendon allografts tested. But significant variability in results was observed within groups and between groups, which may provide one explanation for the range of results in allograft ACL reconstruction reported in the literature. PMID:19039574

  12. The beginning of clinical tolerance in solid organ allografts.

    PubMed

    Monaco, Anthony P

    2004-06-01

    Development of effective multidrug immunosuppressive regimens and improvements in the management of chronically immunosuppressed patients have produced extraordinary patient and allograft survival in clinical organ transplantation. Unfortunately, significant problems of morbidity and mortality related to chronic immunosuppression remain. Thus, there is an enormous motivation and interest in inducing specific unresponsiveness (tolerance) to clinical solid organ allografts. Operational clinical tolerance may be defined as stable, normal graft function in the total absence of a requirement for maintenance immunosuppression. Alternatively, the concept of employing tolerogenic strategies to permit graft acceptance with dramatically reduced immunosuppression requirements is referred to as prope' or minimal immunosuppression tolerance. There have been isolated examples of clinical tolerance, usually in the context of spontaneous or induced donor chimerism, excellent HLA matching, and/or drug weaning or patient noncompliance. The various attempts that are currently being employed to induce some type of clinical tolerance are reviewed in this manuscript. Strategies in which all immunosuppression was to be withdrawn from the recipient (donor-specific unresponsiveness) are first discussed. These include strategies that utilize initial immunoablation with varying doses of irradiation and/or lymphocytic antibodies with or without donor-specific bone marrow infusion and short-term standard immunosuppressive therapy. Strategies to induce prope' or minimal immunosuppression tolerance that utilize induction lymphoablation with polyclonal or monoclonal antilymphocyte antibodies, with or without donor bone marrow infusion, followed by limited low-dose immunosuppressive therapy are also discussed. The ethical considerations in testing clinical tolerance strategies and protocols are discussed in detail. The limited number of clinical tolerance studies already available affirms that

  13. Implant Site Development Using Ti-Mesh and Cellular Allograft in the Esthetic Zone for Restorative-Driven Implant Placement: A Case Report.

    PubMed

    Levine, Robert A; McAllister, Bradley S

    2016-01-01

    This article presents a case report of implant site development in a healthy, nonsmoking 62-year-old man using titanium mesh (Ti-mesh) in conjunction with human cellular allograft for ridge augmentation of a type 4 alveolar ridge defect. The patient presented initially with a severely periodontally abscessed maxillary right central incisor probing to the apex. The tooth was extracted, and after 8 weeks a bone reconstructive procedure was completed using a well-stabilized Ti-mesh and cellular allograft that was covered with a quickly resorbing collagen matrix. After 7 months of undisturbed healing, cone beam computed tomographic evaluation demonstrated a horizontal bone increase of 7 mm and a vertical bone increase of 2.3 mm. This case report demonstrates the benefits of predictable regenerative space maintenance using Ti-mesh in conjunction with a cellular allograft to allow for prosthetically driven implant placement in the esthetic zone. PMID:27100807

  14. Clinical, Histological, and Histomorphometric Evaluation of Demineralized Freeze-Dried Cortical Block Allografts for Alveolar Ridge Augmentation.

    PubMed

    Aslan, Elcin; Gultekin, Alper; Karabuda, Cuneyt; Mortellaro, Carmen; Olgac, Vakur; Mijiritsky, Eitan

    2016-07-01

    Autogenous bone-block grafts are the "gold standard" for block bone grafting, but have several disadvantages. Allografts have the potential to overcome these disadvantages. The purpose of this study was to evaluate the clinical and histomorphometric features of demineralized freeze-dried cortical block allografts (DCBA) used for ridge augmentation. Eleven patients who showed bone deficiencies of <5 mm in the horizontal plane were included in this study. The recipient sites were reconstructed with DCBA. The primary outcomes of interest were bone-width measurements, postoperative clinical evaluations, and histomorphometric analysis of the biopsy samples collected during the implant surgery. Clinical analysis showed that the mean gain in horizontal bone was 1.65 ± 0.14 mm, and that the mean percentage of graft resorption was 5.39 ± 2.18%. On postoperative day 7, edema, pain, and bruising were observed in 18.2%, 0%, and 9.1% of the patients, respectively. In the biopsy samples, the mean percentages of newly formed bone, residual block allograft, and marrow and connective tissue were 40.30 ± 24.59%, 40.39 ± 21.36%, and 19.30 ± 15.07%, respectively. All of the block grafts were successfully integrated into the recipient sites. DCBA may be a viable alternative for treating both deficient maxillary and mandibular alveolar ridges. PMID:27380561

  15. Induced regulatory T cells in allograft tolerance via transient mixed chimerism

    PubMed Central

    Hotta, Kiyohiko; Aoyama, Akihiro; Oura, Tetsu; Yamada, Yohei; Tonsho, Makoto; Huh, Kyu Ha; Kawai, Kento; Schoenfeld, David; Allan, James S.; Madsen, Joren C.; Benichou, Gilles; Smith, Rex-Neal; Colvin, Robert B.; Sachs, David H.; Cosimi, A. Benedict; Kawai, Tatsuo

    2016-01-01

    Successful induction of allograft tolerance has been achieved in nonhuman primates (NHPs) and humans via induction of transient hematopoietic chimerism. Since allograft tolerance was achieved in these recipients without durable chimerism, peripheral mechanisms are postulated to play a major role. Here, we report our studies of T cell immunity in NHP recipients that achieved long-term tolerance versus those that rejected the allograft (AR). All kidney, heart, and lung transplant recipients underwent simultaneous or delayed donor bone marrow transplantation (DBMT) following conditioning with a nonmyeloablative regimen. After DBMT, mixed lymphocyte culture with CFSE consistently revealed donor-specific loss of CD8+ T cell responses in tolerant (TOL) recipients, while marked CD4+ T cell proliferation in response to donor antigens was found to persist. Interestingly, a significant proportion of the proliferated CD4+ cells were FOXP3+ in TOL recipients, but not in AR or naive NHPs. In TOL recipients, CD4+FOXP3+ cell proliferation against donor antigens was greater than that observed against third-party antigens. Finally, the expanded Tregs appeared to be induced Tregs (iTregs) that were converted from non-Tregs. These data provide support for the hypothesis that specific induction of iTregs by donor antigens is key to long-term allograft tolerance induced by transient mixed chimerism. PMID:27446989

  16. Repair of massively defected hemi-joints using demineralized osteoarticular allografts with protected cartilage.

    PubMed

    Li, Siming; Yang, Xiaohong; Tang, Shenghui; Zhang, Xunmeng; Feng, Zhencheng; Cui, Shuliang

    2015-08-01

    Surgical replacement of massively defected joints necessarily relies on osteochondral grafts effective to both of bone and cartilage. Demineralized bone matrix (DBM) retains the osteoconductivity but destroys viable chondrocytes in the cartilage portion essential for successful restoration of defected joints. This study prepared osteochondral grafts of DBM with protected cartilage. Protected cartilage portions was characterized by cellular and molecular biology and the grafts were allogenically used for grafting. Protected cartilage showed similar histomorphological structure and protected proteins estimated by total proteins and cartilage specific proteins as in those of fresh controls when DBMs were generated in bone portions. Such grafts were successfully used for simultaneously repair of bone and cartilage in massively defected osteoarticular joints within 16 weeks post-surgery. These results present an allograft with clinical potential for simultaneous restoration of bone and cartilage in defected joints. PMID:26319778

  17. The effectiveness of bone banking in Central Serbia: audit of the first seven years.

    PubMed

    Stepanovic, Zeljko Lj; Ristic, Branko M

    2014-12-01

    We analyzed the incidence and predisposing factors for overall discard rate after retrieval of 295 femoral head allografts. The aim of the present study was to evaluate the quality system of institutional bone banking and to ensure that we can provide high standard allografts with low infection rate. Audit of bone banking was conducted on 295 donors and 180 recipients. Of the 295 donated femoral heads 77 were discarded, giving an overall discard rate of 26.1 %. At retrieval, 37 allografts were positive, giving an overall contamination rate of 12.54 %. The organism most commonly identified was Staphylococcus species. Seven (2.37 %) of the 295 allografts failed the blood screening tests. Twelve allografts (4.06 %) were discarded because of suspected damage of the packaging or disuse during surgery. Due to donor death or inability to perform serology retests, 21 (7.11 %) allografts were discarded. In the postoperative survey an infection rate of 2.22 % was found. After 7 years of bone banking, our results show that overall discard rate and allograft related infection rate are in accordance with the international standards. The leading cause of allograft discarding was bacterial contamination influenced by the surgical team. We suggest stringent aseptic allograft handling during harvesting and thawing within highly concentrated antibiotic solution to reduce a possibility of its contamination. PMID:24549703

  18. Radionuclide surveillance of the allografted pancreas

    SciTech Connect

    George, E.A.; Salimi, Z.; Carney, K.; Castaneda, M.; Garvin, P.J.

    1988-04-01

    To determine the value of scintigraphy to detect posttransplantation complications of the allografted pancreas, we retrospectively reviewed 209 scintigrams obtained with /sup 99m/Tc-sulfur colloid (/sup 99m/Tc-SC) and /sup 99m/Tc-glucoheptonate (/sup 99m/Tc-GH). The scintigraphic studies were performed in 37 recipients of simultaneous renal and pancreatic allografts harvested from the same donor. /sup 99m/Tc-SC was used as an indicator of thrombotic vasculitis; pancreatic perfusion and blood-pool parameters were monitored with /sup 99m/Tc-GH. In 11 of the 37 recipients, scintigraphic abnormalities suggested posttransplantation infarction. Recurrent episodes of acute rejection of the pancreatic allograft, which always coincided with acute rejection of the renal allograft, were monitored in 24 recipients. Rejection-induced ischemic pancreatitis was suggested in 12 of the 24 recipients and persisted in 10 recipients for several weeks after improvement of renal allograft rejection. Pancreatic atrophy was suggested scintigraphically in 16 of the 24 recipients with recurrent episodes of rejection. Spontaneous pancreatic-duct obstruction and obstructive pancreatitis were associated with a scintigraphic pattern similar to that of rejection-induced ischemic pancreatitis. We concluded that the specific radionuclides used in this series are useful for the surveillance and assessment of posttransplantation pancreatic infarction, acute rejection, pancreatitis, and atrophy

  19. Adipose-Derived Stromal Cells Promote Allograft Tolerance Induction

    PubMed Central

    Anam, Khairul; Lazdun, Yelena; Gimble, Jeffrey M.; Elster, Eric A.

    2014-01-01

    Amputations and unsalvageable injuries with devastating tissue loss are common in the combat wounded. Reconstructive transplantation in the civilian setting using vascular composite allotransplants (VCAs) with multiple tissues (skin, muscle, nerve, bone) combined with long-term multidrug immunosuppression has been encouraging. However, skin rejection remains a critical complication. Adipose-derived stromal/stem cells (ASCs) are easily obtained from normal individuals in high numbers, precluding ex vivo expansion. The reparative function and paracrine immunomodulatory capacity of ASCs has gained considerable attention. The present study investigated whether ASCs facilitate long-term skin allograft survival. ASCs were isolated from fresh human subcutaneous adipose lipoaspirate. Full-thickness skin grafts from BALB/c mice were transplanted onto the dorsal flanks of C57BL/6 mice treated with five doses of anti-CD4/CD8 monoclonal antibodies (10 mg/kg) on days 0, +2, +5, +7, and +14 relative to skin grafting. A single nonmyeloablative low dose of busulfan (5 mg/kg) was given on day +5. Seven days after skin transplantation, ASCs (3 × 106) were infused i.v. with or without donor bone marrow cells (BMCs; 5 × 105). ASC+BMC coinfusion with minimal conditioning led to stable lymphoid and myeloid macrochimerism, deletion of alloreactive T cells, expansion of regulatory T cells, and long-term allograft survival (>200 days). ASCs constitutively produced high levels of anti-inflammatory/immunoregulatory factors such as prostaglandin E2, indoleamine 2,3-dioxygenase, APO-1/Fas (CD95), and programmed cell death-1 ligand-2. These findings serve as a foundation for developing a translational advanced VCA protocol, embodying both ASCs and low-dose donor BMCs, in nonhuman primates, with the goal of enhancing functional outcomes and eliminating the complications associated with long-term immunosuppression. PMID:25411475

  20. Preliminary Results of Bioactive Amniotic Suspension with Allograft for Achieving One and Two-Level Lumbar Interbody Fusion

    PubMed Central

    Kerr, Eubulus J.; Utter, Philip A.; Cavanaugh, David A.; Frank, Kelly A.; Moody, Devan; McManus, Brian; Stone, Marcus B.

    2016-01-01

    Background Bone graft material for lumbar fusion was historically autologous bone graft (ABG). In recent years alternatives such as allograft, demineralized bone matrix (DBM), ceramics, and bone morphogenetic protein (BMP) have gained favor, although the complications of these are not fully understood. Bioactive amniotic suspension (BAS) with allograft is a new class of material derived from human amniotic tissue. Methods Eligible patients receiving a one or two level lumbar interbody fusion with Nucel, a BAS with allograft, were contacted and scheduled for a mininmim 12 month follow-up visit. Patients were evaluated for fusion using CT's and plain radiographs. Clincal outcomes, including ODI, VAS back and leg were collected, as well as comorbidities including BMI, smoking status, diabetes and previous lumbar surgery. Results One-level patients (N=38) were 71.1% female with mean age of 58.4 ± 12.7 and mean BMI of 30.6 ± 6.08. Two-level patients (N=34) were 58.8% female with mean age of 49.3 ±10.9 and mean BMI of 30.1 ± 5.82. Kinematic fusion was achieved in 97.4% of one-level patients and 100% of two-level patients. Baseline comorbidities were present in 89.5% of one-level patients and 88.2% of two-level patients. No adverse events related to BAS were reported in this study. Conclusion Fusion status is evaluated with many different biologics and varying methods in the literature. BAS with allograft in this study demonstrated high fusion rates with no complications within a largely comorbid population. Although a small population, BAS with allograft results were encouraging for one and two-level lumbar interbody fusion in this study. Further prospective studies should be conducted to investigate safety and efficacy in a larger population. PMID:27162714

  1. Risk factors of cardiac allograft vasculopathy

    PubMed Central

    Szczurek, Wioletta; Gąsior, Mariusz; Zembala, Marian

    2015-01-01

    Despite advances in prevention and treatment of heart transplant rejection, development of cardiac allograft vasculopathy (CAV) remains the leading factor limiting long-term survival of the graft. Cardiac allograft vasculopathy etiopathogenesis is not fully understood, but a significant role is attributed to endothelial cell damage, caused by immunological and non-immunological mechanisms. Immunological factors include the differences between the recipient's and the donor's HLA systems, the presence of alloreactive antibodies and episodes of acute rejection. Among the non-immunological factors the most important are the age of the donor, ischemia-reperfusion injury and cytomegalovirus infection. The classical cardiovascular risk factors (diabetes, hypertension, obesity and hyperlipidemia) are also important. This study presents an up-to-date overview of current knowledge on the vasculopathy etiopathogenesis and the role played by endothelium and inflammatory processes in CAV, and it also investigates the factors which may serve as risk markers of cardiac allograft vasculopathy. PMID:26855649

  2. Assessing bone banking activities at University of Malaya medical centre.

    PubMed

    Mohd, Suhaili; Samsuddin, Sharifah Mazni; Ramalingam, Saravana; Min, Ng Wuey; Yusof, Norimah; Zaman, T Kamarul; Mansor, Azura

    2015-12-01

    The main advantage of establishing in-house bone banks is its ability to readily provide allograft bones for local surgeries. Bone procurement activities of our university bone bank during the 10 years of operation were reviewed. Socio-demographic data of donors, types of bone procured, cases of rejected bones and types of allograft bones transplanted are presented. From 179 potential donors, 73 % were accepted with 213 procured bones. Femoral head was the common bone transplanted (45 %), as it was also the most common procured (82 %). Bones were rejected mainly due to non-technical reasons (83 %) rather than positive results of microbiological (13 %) and serological (4 %) tests. Comprehensive data could not be obtained for further analysis due to difficulties in retrieving information. Therefore, quality assurance system was improved to establish more systematic documentations, as the basis of good banking practice with process control hence allowing traceability. PMID:25656787

  3. Endoscopic versus transcranial procurement of allograft tympano-ossicular systems: a prospective double-blind randomized controlled audit.

    PubMed

    Caremans, Jeroen; Hamans, Evert; Muylle, Ludo; Van de Heyning, Paul; Van Rompaey, Vincent

    2016-06-01

    Allograft tympano-ossicular systems (ATOS) have proven their use over many decades in tympanoplasty and reconstruction after resection of cholesteatoma. The transcranial bone plug technique has been used in the past 50 years to procure en bloc ATOS (tympanic membrane with malleus, incus and stapes attached). Recently, our group reported the feasibility of the endoscopic procurement technique. The aim of this study was to assess whether clinical outcome is equivalent in ATOS acquired by using the endoscopic procurement technique compared to ATOS acquired by using the transcranial technique. A double-blind randomized controlled audit was performed in a tertiary referral center in patients that underwent allograft tympanoplasty because of chronic otitis media with and without cholesteatoma. Allograft epithelialisation was evaluated at the short-term postoperative visit by microscopic examination. Failures were reported if reperforation was observed. Fifty patients underwent allograft tympanoplasty: 34 received endoscopically procured ATOS and 16 received transcranially procured ATOS. One failed case was observed, in the endoscopic procurement group. We did not observe a statistically significant difference between the two groups in failure rate. This study demonstrates equivalence of the clinical outcome of allograft tympanoplasty using either endoscopic or transcranial procured ATOS and therefore indicates that the endoscopic technique can be considered the new standard procurement technique. Especially because the endoscopic procurement technique has several advantages compared to the former transcranial procurement technique: it avoids risk of prion transmission and it is faster while lacking any noticeable incision. PMID:26342932

  4. Autograft Substitutes: Conduits and Processed Nerve Allografts.

    PubMed

    Safa, Bauback; Buncke, Gregory

    2016-05-01

    Manufactured conduits and allografts are viable alternatives to direct suture repair and nerve autograft. Manufactured tubes should have gaps less than 10 mm, and ideally should be considered as an aid to the coaptation. Processed nerve allograft has utility as a substitute for either conduit or autograft in sensory nerve repairs. There is also a growing body of evidence supporting their utility in major peripheral nerve repairs, gap repairs up to 70 mm in length, as an alternative source of tissue to bolster the diameter of a cable graft, and for the management of neuromas in non-reconstructable injuries. PMID:27094886

  5. Meniscal allograft transplantation: rationale for treatment.

    PubMed

    Smith, N A; Costa, M L; Spalding, T

    2015-05-01

    The anatomy and microstructure of the menisci allow the effective distribution of load across the knee. Meniscectomy alters the biomechanical environment and is a potent risk factor for osteoarthritis. Despite a trend towards meniscus-preserving surgery, many tears are irreparable, and many repairs fail. Meniscal allograft transplantation has principally been carried out for pain in patients who have had a meniscectomy. Numerous case series have reported a significant improvement in patient-reported outcomes after surgery, but randomised controlled trials have not been undertaken. It is scientifically plausible that meniscal allograft transplantation is protective of cartilage, but this has not been established clinically to date. PMID:25922450

  6. Allograft rejection in cattle with bovine leukocyte adhesion deficiency.

    PubMed

    Müller, K E; Rutten, V P; Becker, C K; Hoek, A; Bernadina, W E; Wentink, G H; Figdor, C G

    1995-09-01

    In the present investigation cell-mediated immunity in animals with bovine leukocyte adhesion deficiency (BLAD) was studied by means of skin transplantation experiments. Autograft and allograft behaviour in animals with BLAD was compared with the behaviour of simultaneously transplanted autografts and allografts in healthy controls. Allograft survival time was prolonged in three BLAD cattle (28, 30, and 72 days) compared to six healthy controls (12-14 days). When transplantations were repeated on one animal with BLAD using skin grafts from the same donor, accelerated rejection was observed (allograft survival time decreased from 72 days at primary to 35 days at secondary and to 21 days at tertiary transplantation), suggesting the development of immunological memory. Graft-infiltrating lymphocytes that were obtained from allograft biopsies during the period of rejection, were shown to be from recipient origin (beta 2-integrin negative). Our findings demonstrate that, although prolonged allograft survival is observed in cattle with BLAD, skin allografts are ultimately rejected. PMID:8533316

  7. The Impact of Infection on Chronic Allograft Dysfunction and Allograft Survival After Solid Organ Transplantation.

    PubMed

    Martin-Gandul, C; Mueller, N J; Pascual, M; Manuel, O

    2015-12-01

    Infectious diseases after solid organ transplantation (SOT) are a significant cause of morbidity and reduced allograft and patient survival; however, the influence of infection on the development of chronic allograft dysfunction has not been completely delineated. Some viral infections appear to affect allograft function by both inducing direct tissue damage and immunologically related injury, including acute rejection. In particular, this has been observed for cytomegalovirus (CMV) infection in all SOT recipients and for BK virus infection in kidney transplant recipients, for community-acquired respiratory viruses in lung transplant recipients, and for hepatitis C virus in liver transplant recipients. The impact of bacterial and fungal infections is less clear, but bacterial urinary tract infections and respiratory tract colonization by Pseudomonas aeruginosa and Aspergillus spp appear to be correlated with higher rates of chronic allograft dysfunction in kidney and lung transplant recipients, respectively. Evidence supports the beneficial effects of the use of antiviral prophylaxis for CMV in improving allograft function and survival in SOT recipients. Nevertheless, there is still a need for prospective interventional trials assessing the potential effects of preventive and therapeutic strategies against bacterial and fungal infection for reducing or delaying the development of chronic allograft dysfunction. PMID:26474168

  8. Meniscal Allograft Transplantation: State of the Art.

    PubMed

    Trentacosta, Natasha; Graham, William C; Gersoff, Wayne K

    2016-06-01

    Meniscal allograft transplantation has evolved over the years to provide a state-of-the-art technique for the sports medicine surgeon to utilize in preserving contact mechanics and function of the knee in irreparable meniscal pathology. However, this procedure continues to spark considerable debate on proper tissue processing techniques, acceptable indications, methods of implantation, and potential long-term outcomes. PMID:27135295

  9. The Safety and Efficacy of Cadaveric Allografts and Titanium Cage as a Fusion Substitutes in Pyogenic Osteomyelitis

    PubMed Central

    Kim, Hyun Woo; Ryu, Je-il

    2011-01-01

    Objective The safety and efficacy of various fusion substitutes in pyogenic osteomyelitis has not been investigated. We evaluated and compared the cadaveric allograft and titanium cages used to reconstruct, maintain alignment and achieve fusion in the management of pyogenic spinal infection. Methods There were 33 patients with pyogenic osteomyelitis underwent fusion in this study. Fifteen of the 33 patients were operated on by fusion with allografts (cadaveric patella bones) and 18 of those were operated with titanium mesh cages filled with autologous cancellous iliac bone. After the affected disc and vertebral body resection with pus drainage, cadaveric allograft or titanium cages were inserted into the resected space. Posterior transpedicular screw fixation and rod compression in resected space, where cadaveric allograft or titanium cages were inserted, was performed to prevent the malposition in all patients except in 1 case. Recurrent infection was identified by serial erythrocyte sedimentation rate and cross reactive protein follow-up. Osseous union and recurred infection available at a minimum of 2 years following operation was identified. The amount of kyphosis correction and the subsidence were measured radiographically. Results Spinal fusion was achieved in 29 of 33 patients. In the cadaveric allograft group, 93.3% of patient (14 of 15) showed the osseous union while 83.3% of patient (15 of 18) in the titanium cage group showed union. Subsidence was noted in 12 of the patients. Twelve patients (36.3%) showed unsettling amounts of subsidence postoperatively whereas 46.6% of patients in the cadaveric allograft group and 37.7% of patients in the titanium cage group showed similar subsidence, respectively. There were statistical difference in the fusion rate (p=0.397) and subsidence rate (p=0.276) between the two groups. There was significant statistical difference in the postoperative improvement of segmental kyphosis between the two groups (p=0.022), that is

  10. Demineralized bone matrix and human cancellous bone enhance fixation of porous-coated titanium implants in sheep.

    PubMed

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2016-03-01

    Allogenic bone graft has been considered the gold standard in connection with bone graft material in revision joint arthroplasty. However, the lack of osteogenic potential and the risk of disease transmission are clinical challenges. The use of osteoinductive materials, such as demineralized bone matrix (DBM), alone or in combination with allograft or commercially available human cancellous bone (CB), may replace allografts, as they have the capability of inducing new bone and improving implant fixation through enhancing bone ongrowth. The purpose of this study was to investigate the effect of DBM alone, DBM with CB, or allograft on the fixation of porous-coated titanium implants. DBM100 and CB produced from human tissue were included. Both materials are commercially available. DBM granules are placed in pure DBM and do not contain any other carrier. Titanium alloy implants, 10 mm long × 10 mm diameter, were inserted bilaterally into the femoral condyles of eight skeletally mature sheep. Thus, four implants with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: (a) DBM; (b) DBM:CB at a ratio of 1:3; (c) DBM:allograft at a ratio of 1:3; or (d) allograft (gold standard), respectively. A standardized surgical procedure was used. At sacrifice 6 weeks after implantation, both distal femurs were harvested. The implant fixation was evaluated by mechanical push-out testing to test shear mechanical properties between implant and the host bone and by histomorphometry. Non-parametric tests were applied; p < 0.05 was considered significant. Mechanical fixation showed that the strengths among the DBM/CB, DBM/allograft and allograft groups were not statistically different. The strength of the DBM group was 0.01 MPa, which was statistical significantly lower than the other three groups (p < 0.05). Histomorphometry results showed that the bone ongrowth in the DBM group was statistically significantly lower than the other three groups

  11. Localized maxillary ridge augmentation with a block allograft for dental implant placement: case reports.

    PubMed

    Leonetti, Joseph A; Koup, Richard

    2003-01-01

    Autogenous block bone grafts have been highly successful in treating human periodontal defects, restoring esthetics, and developing adequate bone volume for dental implant placement. Limitations in available donor bone, the need for an added surgical procedure, and other potential complications have made the use of allogenic bone graft materials an important alternative. One patient described in this report presented with fractured root syndrome of the right maxillary incisor with severe resorption of the buccal plate. After atraumatic tooth extraction, a staged treatment approach involving localized ridge augmentation with an allogenic iliac bone block material and dental implant placement was used. The host bone completely incorporated the graft with only minor resorption, which enabled the implant to be placed. The allogenic bone block material used in this study was an effective alternative to harvesting and grafting autogenous bone for implant site development. The cases presented in this article clinically demonstrate the efficacy of using a block allograft in generating effective new bone fill for dental implant placement. PMID:14560481

  12. Interprosthetic humeral fracture revision using a tibial allograft total elbow prosthetic composite in a patient with hemophilia A : a case report

    PubMed Central

    2012-01-01

    Introduction Interprosthetic fractures of the humerus are rare. Revisions of total elbow arthroplasty components in these cases are difficult. We report the first case of a patient with hemophilia who underwent a revision with a tibial allograft prosthetic composite without the need for hardware augmentation. Case presentation A 43-year-old Caucasian man with a history of hemophilia and transfusion-related human immunodeficiency virus and hepatitis B and C presented with an interprosthetic fracture of his humerus after months of pain between his total elbow and total shoulder arthroplasties. Because of the poor remaining bone stock available in his distal humerus, a revision using a barrel-staved tibial allograft prosthetic composite was performed. Our patients’ factor VIII level was optimized before the operation and he suffered no major long-term complications at 28 months. His only complication was an incomplete radial nerve palsy that ultimately recovered and left him with some numbness on the dorsum of his hand. Conclusion Careful use of an allograft prosthetic composite is a very reasonable option when a patient experiences an interprosthetic fracture. We have successfully performed revision total elbow arthroplasty for a patient with hemophilia with an interprosthetic fracture using a tibial allograft and no additional fixation, which resulted in his return to full activities of daily living, minimal pain and full incorporation of the allograft to host bone. PMID:23009283

  13. The clinical and radiological evaluation of the use of an allograft-prosthesis composite in the treatment of proximal femoral giant cell tumours.

    PubMed

    Malhotra, R; Kiran Kumar, G N; K Digge, V; Kumar, V

    2014-08-01

    Giant cell tumour is the most common aggressive benign tumour of the musculoskeletal system and has a high rate of local recurrence. When it occurs in proximity to the hip, reconstruction of the joint is a challenge. Options for reconstruction after wide resection include the use of a megaprosthesis or an allograft-prosthesis composite. We performed a clinical and radiological study to evaluate the functional results of a proximal femoral allograft-prosthesis composite in the treatment of proximal femoral giant cell tumour after wide resection. This was an observational study, between 2006 and 2012, of 18 patients with a mean age of 32 years (28 to 42) and a mean follow-up of 54 months (18 to 79). We achieved excellent outcomes using Harris Hip Score in 13 patients and a good outcome in five. All allografts united. There were no complications such as infection, failure, fracture or resorption of the graft, or recurrent tumour. Resection and reconstruction of giant cell tumours with proximal femoral allograft-prosthesis composite is a better option than using a prosthesis considering preservation of bone stock and excellent restoration of function. A good result requires demanding bone banking techniques, effective measures to prevent infection and stability at the allograft-host junction. PMID:25086128

  14. Factors Predicting Meniscal Allograft Transplantation Failure

    PubMed Central

    Parkinson, Ben; Smith, Nicholas; Asplin, Laura; Thompson, Peter; Spalding, Tim

    2016-01-01

    Background: Meniscal allograft transplantation (MAT) is performed to improve symptoms and function in patients with a meniscal-deficient compartment of the knee. Numerous studies have shown a consistent improvement in patient-reported outcomes, but high failure rates have been reported by some studies. The typical patients undergoing MAT often have multiple other pathologies that require treatment at the time of surgery. The factors that predict failure of a meniscal allograft within this complex patient group are not clearly defined. Purpose: To determine predictors of MAT failure in a large series to refine the indications for surgery and better inform future patients. Study Design: Cohort study; Level of evidence, 3. Methods: All patients undergoing MAT at a single institution between May 2005 and May 2014 with a minimum of 1-year follow-up were prospectively evaluated and included in this study. Failure was defined as removal of the allograft, revision transplantation, or conversion to a joint replacement. Patients were grouped according to the articular cartilage status at the time of the index surgery: group 1, intact or partial-thickness chondral loss; group 2, full-thickness chondral loss 1 condyle; and group 3, full-thickness chondral loss both condyles. The Cox proportional hazards model was used to determine significant predictors of failure, independently of other factors. Kaplan-Meier survival curves were produced for overall survival and significant predictors of failure in the Cox proportional hazards model. Results: There were 125 consecutive MATs performed, with 1 patient lost to follow-up. The median follow-up was 3 years (range, 1-10 years). The 5-year graft survival for the entire cohort was 82% (group 1, 97%; group 2, 82%; group 3, 62%). The probability of failure in group 1 was 85% lower (95% CI, 13%-97%) than in group 3 at any time. The probability of failure with lateral allografts was 76% lower (95% CI, 16%-89%) than medial allografts at

  15. Development of a Comprehensive Osteochondral Allograft MRI Scoring System (OCAMRISS) With Histopathologic, Micro–Computed Tomography, and Biomechanical Validation

    PubMed Central

    Pallante-Kichura, Andrea L.; Bae, Won C.; Du, Jiang; Statum, Sheronda; Wolfson, Tanya; Gamst, Anthony C.; Cory, Esther; Amiel, David; Bugbee, William D.; Sah, Robert L.; Chung, Christine B.

    2014-01-01

    Objective: To describe and apply a semiquantitative MRI scoring system for multifeature analysis of cartilage defect repair in the knee by osteochondral allografts and to correlate this scoring system with histopathologic, micro–computed tomography (µCT), and biomechanical reference standards using a goat repair model. Design: Fourteen adult goats had 2 osteochondral allografts implanted into each knee: one in the medial femoral condyle and one in the lateral trochlea. At 12 months, goats were euthanized and MRI was performed. Two blinded radiologists independently rated 9 primary features for each graft, including cartilage signal, fill, edge integration, surface congruity, calcified cartilage integrity, subchondral bone plate congruity, subchondral bone marrow signal, osseous integration, and presence of cystic changes. Four ancillary features of the joint were also evaluated, including opposing cartilage, meniscal tears, synovitis, and fat-pad scarring. Comparison was made with histologic and µCT reference standards as well as biomechanical measures. Interobserver agreement and agreement with reference standards was assessed. Cohen’s κ, Spearman’s correlation, and Kruskal-Wallis tests were used as appropriate. Results: There was substantial agreement (κ > 0.6, P < 0.001) for each MRI feature and with comparison against reference standards, except for cartilage edge integration (κ = 0.6). There was a strong positive correlation between MRI and reference standard scores (ρ = 0.86, P < 0.01). Osteochondral allograft MRI scoring system was sensitive to differences in outcomes between the types of allografts. Conclusions: We have described a comprehensive MRI scoring system for osteochondral allografts and have validated this scoring system with histopathologic and µCT reference standards as well as biomechanical indentation testing. PMID:24489999

  16. [Extensor mechanism allograft reconstruction after total knee replacement].

    PubMed

    Bürde, C; Sweeney, Patrick

    2007-04-01

    We present three cases in which we used a complete extensor mechanism allograft for the reconstruction of an insufficient extensor mechanism after total knee arthroplasty (and failed reconstruction with local tissue in two of these cases). Early results are encouraging. Allograft reconstruction can be taken into consideration as an alternative to arthrodesis in those "worst-case scenarios". Late failure may occur in about 20%, probably due to a lack of revitalisation in the centre of the allograft. PMID:17262182

  17. Bone regeneration with autologous biomaterial; rapid induction of vital new bone in maxillary sinus floor by platelet concentrate alone at 23x baseline (PRP23x): a case report.

    PubMed

    Smith, Astley E; Prasad, Hari S; Rohrer, Michael D

    2009-06-01

    To date, most clinicians and researchers have been using platelet concentrate within the range of 4x to 8x baseline. In this case report a new procedure involving strategic pooling and triple spin was developed and used to concentrate platelets to 23x baseline. The concentrate alone was infused into morselized resorbable collagen sponge, activated with calcium chloride and autologous thrombin, then placed as an autologous graft into the left sinus floor of a healthy 80-year-old woman. The floor of the sinus had approximately 2 mm of bony height. A computed tomography scan taken after 5 months showed that new bone was formed and it was as dense as native bone around the surgical site. From the computed tomography scan bone density analysis using Hounsfield Units revealed that the bone formed was D3 bone (518.3 +/- 224.9 Hounsfield Units) and it was as dense as native bone on the axial, coronal and sagittal slices. Histomorphometric analysis of 2 bone core biopsies taken after 6 months showed that 1 core had 34% bone of which 98% was vital new bone and the other core had 39% bone of which 100% was vital new bone. The height of the bone formed in the sinus floor was 12 mm. It was also characterized by good trabecular pattern and connectivity. The quality of the bone generated was such that 2 endosseous implants were placed and torqued to 30 N cm after the cores were removed. PMID:19509531

  18. Comparison of Fusion Rates between Glycerol-Preserved and Frozen Composite Allografts in Cervical Fusion

    PubMed Central

    Rodway, Ian; Gander, Julie

    2014-01-01

    Background. This retrospective, two cohort series study was designed to compare a room temperature, glycerol-preserved composite pinned bone allograft (G-CPBA) with the same graft type provided in a frozen state (F-CPBA) for use as a cervical interbody spacer in anterior cervical discectomy and fusion (ACDF). Methods. A comprehensive chart review was performed for 67 sequential patients that received either a F-CPBA or a G-CPBA and had at least one-year follow-up. Twenty-eight patients had received G-CPBA grafts and 37 patients had received F-CPBA grafts. Two additional 2-level patients had received one of each type of grafts. Results. At 3 months, 45.3% (29 of 64) of glycerol-preserved and 41.4% (29 of 70) of frozen allografts, respectively, were considered to be fused radiographically. At 12 months, 100% of both treatment groups (41 glycerol-preserved and 45 frozen) were considered fused. Fusion rates for G-CPBA were statistically similar to F-CPBA at both 3 and 12 months (P = 0.6535 and >0.999, resp.). There were no allograft related complications in either treatment group. Conclusions. 100% fusion rates were attained by both treatment groups at 12 months and were similar at short-term follow-up for all comparable levels. Level of Evidence. Level of evidence is III.

  19. Mechanisms of allograft rejection of corneal endothelium

    SciTech Connect

    Tagawa, Y.; Silverstein, A.M.; Prendergast, R.A.

    1982-07-01

    The local intraocular graft-vs.-host (GVH) reaction, involving the destruction of the corneal endothelial cells of the rabbit host by sensitized donor lymphoid cells, has been used to study the mechanism of corneal allograft rejection. Pretreatment of donor cells with a specific mouse monoclonal hybridoma anti-T cell antibody and complement suppresses the destructive reaction, suggesting that a cellular-immune mechanism is primarily involved. Pretreatment of donor cells with mitomycin-C completely abolishes the local GVH reaction, indicating that the effector lymphocytes must undergo mitosis within the eye before they can engage in target cell destruction. Finally, studies of the local GVH reaction in irradiated leukopenic recipients or in preinflamed rabbit eyes suggest that host leukocytes may contribute nonspecifically to enhance the destructive process. These studies show that the local ocular GVH reaction may provide a useful model for the study of the mechanisms involved in the rejection of corneal allografts.

  20. Urinary Calprotectin and Posttransplant Renal Allograft Injury

    PubMed Central

    Bistrup, Claus; Marcussen, Niels; Pagonas, Nikolaos; Seibert, Felix S.; Arndt, Robert; Zidek, Walter; Westhoff, Timm H.

    2014-01-01

    Objective Current methods do not predict the acute renal allograft injury immediately after kidney transplantation. We evaluated the diagnostic performance of urinary calprotectin for predicting immediate posttransplant allograft injury. Methods In a multicenter, prospective-cohort study of 144 incipient renal transplant recipients, we postoperatively measured urinary calprotectin using an enzyme-linked immunosorbent assay and estimated glomerular filtration rate (eGFR) after 4 weeks, 6 months, and 12 months. Results We observed a significant inverse association of urinary calprotectin concentrations and eGFR 4 weeks after transplantation (Spearman r = −0.33; P<0.001). Compared to the lowest quartile, patients in the highest quartile of urinary calprotectin had an increased risk for an eGFR less than 30 mL/min/1.73 m2 four weeks after transplantation (relative risk, 4.3; P<0.001; sensitivity, 0.92; 95% CI, 0.77 to 0.98; specificity, 0.48; 95% CI, 0.31 to 0.66). Higher urinary calprotectin concentrations predicted impaired kidney function 4 weeks after transplantation, as well as 6 months and 12 months after transplantation. When data were analyzed using the urinary calprotectin/creatinine-ratio similar results were obtained. Urinary calprotectin was superior to current use of absolute change of plasma creatinine to predict allograft function 12 months after transplantation. Urinary calprotectin predicted an increased risk both in transplants from living and deceased donors. Multivariate linear regression showed that higher urinary calprotectin concentrations and older donor age predicted lower eGFR four weeks, 6 months, and 12 months after transplantation. Conclusions Urinary calprotectin is an early, noninvasive predictor of immediate renal allograft injury after kidney transplantation. PMID:25402277

  1. Procurement of hand and arm allografts.

    PubMed

    Cetrulo, Curtis L; Kovach, Stephen J

    2013-12-01

    Upper extremity transplantation has been at the forefront of vascularized composite allotransplantation. There have been more hand and upper extremity transplants than any other kinds of vascularized composite allotransplantation. However, it is a new and evolving field. Reconstructive surgeons are relative newcomers to the field of transplantation, and the procurement of upper extremity allografts has many subtleties that will differ depending on the intended recipient. However, there are certain principles that can be adhered to that this review serves to elucidate. PMID:24310234

  2. Zygomycosis in a renal allograft recipient

    PubMed Central

    Lakshminarayana, G.; Rajesh, R.; Kurian, G.; Unni, V. N.

    2009-01-01

    Invasive fungal infections can cause considerable morbidity and mortality in immunocompromised patients. Zygomycosis is a type of invasive fungal infection with a rapid course and grave prognosis. Renal transplant recipients with concomitant diabetes mellitus are most susceptible to this infection. We report here a case of disseminated zygomycosis (Rhizopus sp.) in a renal allograft recipient with posttransplant diabetes mellitus (PTDM). This is the first reported case of zygomycosis caused by Rhizopus species. PMID:20352010

  3. Experiences using IAEA Code of practice for radiation sterilization of tissue allografts: Validation and routine control

    NASA Astrophysics Data System (ADS)

    Hilmy, N.; Febrida, A.; Basril, A.

    2007-11-01

    Problems of tissue allografts in using International Standard (ISO) 11137 for validation of radiation sterilization dose (RSD) are limited and low numbers of uniform samples per production batch, those are products obtained from one donor. Allograft is a graft transplanted between two different individuals of the same species. The minimum number of uniform samples needed for verification dose (VD) experiment at the selected sterility assurance level (SAL) per production batch according to the IAEA Code is 20, i.e., 10 for bio-burden determination and the remaining 10 for sterilization test. Three methods of the IAEA Code have been used for validation of RSD, i.e., method A1 that is a modification of method 1 of ISO 11137:1995, method B (ISO 13409:1996), and method C (AAMI TIR 27:2001). This paper describes VD experiments using uniform products obtained from one cadaver donor, i.e., cancellous bones, demineralized bone powders and amnion grafts from one life donor. Results of the verification dose experiments show that RSD is 15.4 kGy for cancellous and demineralized bone grafts and 19.2 kGy for amnion grafts according to method A1 and 25 kGy according to methods B and C.

  4. The biomechanical behavior on the interface of tumor arthrosis/allograft prosthetic composite by finite element analysis

    NASA Astrophysics Data System (ADS)

    Chen, H. Z.; Jiang, W.; Zou, W.; Luo, J. M.; Chen, J. Y.; Tu, C. Q.; Xing, B. B.; Gu, Z. W.; Zhang, X. D.

    2008-11-01

    The biomechanical behavior of the uniting interface between the allograft bone and the autogenetic bone plays an important role in the treatment of the proximal femur massive defects with artificial tumor arthrosis/allograft prosthetic composite (TAAPC). According to the CT data of a patient, a 3D medical treatment model of TAAPC was established. Under the loads of 1.5 and 2.5 times standard body weight (70 kg), the mechanical behavior of the treatment model was analyzed by finite element analysis (FEA) for three typical healing periods. The results show that there are significant differences in the stress values and distribution in different healing periods. With healing of osteotomy, the hardness of the tissue of the uniting interface increases, the stress in uniting area was increased greatly and the stress concentration decreased. After cured the stress almost reached the level of normal bone. In the initial stage of healing, the healing training is not encouraged because there is an obvious risk of fracture of prosthesis and bone cement. In addition, porous hydroxyapatite (HA) ceramic used as bone tissue scaffold for this case, not only facilitates the generation of new bone, but also can avoid this risk caused by the non-uniting interface.

  5. Articular Cartilage Repair Using Marrow Stimulation Augmented with a Viable Chondral Allograft: 9-Month Postoperative Histological Evaluation

    PubMed Central

    Hoffman, James K.; Geraghty, Sandra; Protzman, Nicole M.

    2015-01-01

    Marrow stimulation is frequently employed to treat focal chondral defects of the knee. However, marrow stimulation typically results in fibrocartilage repair tissue rather than healthy hyaline cartilage, which, over time, predisposes the repair to failure. Recently, a cryopreserved viable chondral allograft was developed to augment marrow stimulation. The chondral allograft is comprised of native viable chondrocytes, chondrogenic growth factors, and extracellular matrix proteins within the superficial, transitional, and radial zones of hyaline cartilage. Therefore, host mesenchymal stem cells that infiltrate the graft from the underlying bone marrow following marrow stimulation are provided with the optimal microenvironment to undergo chondrogenesis. The present report describes treatment of a trochlear defect with marrow stimulation augmented with this novel chondral allograft, along with nine month postoperative histological results. At nine months, the patient demonstrated complete resolution of pain and improvement in function, and the repair tissue consisted of 85% hyaline cartilage. For comparison, a biopsy obtained from a patient 8.2 months after treatment with marrow stimulation alone contained only 5% hyaline cartilage. These outcomes suggest that augmenting marrow stimulation with the viable chondral allograft can eliminate pain and improve outcomes, compared with marrow stimulation alone. PMID:25628907

  6. Articular cartilage repair using marrow stimulation augmented with a viable chondral allograft: 9-month postoperative histological evaluation.

    PubMed

    Hoffman, James K; Geraghty, Sandra; Protzman, Nicole M

    2015-01-01

    Marrow stimulation is frequently employed to treat focal chondral defects of the knee. However, marrow stimulation typically results in fibrocartilage repair tissue rather than healthy hyaline cartilage, which, over time, predisposes the repair to failure. Recently, a cryopreserved viable chondral allograft was developed to augment marrow stimulation. The chondral allograft is comprised of native viable chondrocytes, chondrogenic growth factors, and extracellular matrix proteins within the superficial, transitional, and radial zones of hyaline cartilage. Therefore, host mesenchymal stem cells that infiltrate the graft from the underlying bone marrow following marrow stimulation are provided with the optimal microenvironment to undergo chondrogenesis. The present report describes treatment of a trochlear defect with marrow stimulation augmented with this novel chondral allograft, along with nine month postoperative histological results. At nine months, the patient demonstrated complete resolution of pain and improvement in function, and the repair tissue consisted of 85% hyaline cartilage. For comparison, a biopsy obtained from a patient 8.2 months after treatment with marrow stimulation alone contained only 5% hyaline cartilage. These outcomes suggest that augmenting marrow stimulation with the viable chondral allograft can eliminate pain and improve outcomes, compared with marrow stimulation alone. PMID:25628907

  7. The combined effect of parathyroid hormone and bone graft on implant fixation

    PubMed Central

    Daugaard, H.; Elmengaard, B.; Andreassen, T. T.; Baas, J.; Bechtold, J. E.; Søballe, K.

    2013-01-01

    Impaction allograft is an established method of securing initial stability of an implant in arthroplasty. Subsequent bone integration can be prolonged, and the volume of allograft may not be maintained. Intermittent administration of parathyroid hormone has an anabolic effect on bone and may therefore improve integration of an implant. Using a canine implant model we tested the hypothesis that administration of parathyroid hormone may improve osseo-integration of implants surrounded by bone graft. In 20 dogs a cylindrical porous-coated titanium alloy implant was inserted into normal cancellous bone in the proximal humerus and surrounded by a circumferential gap of 2.5 mm. Morsellised allograft was impacted around the implant. Half of the animals were given daily injections of human parathyroid hormone (1-34) 5 μg/kg for four weeks and half received control injections. The two groups were compared by mechanical testing and histomorphometry. We observed a significant increase in new bone formation within the bone graft in the parathyroid hormone group. There were no significant differences in the volume of allograft, bone-implant contact or in the mechanical parameters. These findings suggest that parathyroid hormone improves new bone formation in impacted morsellised allograft around an implant and retains the graft volume without significant resorption. Fixation of the implant was neither improved nor compromised at the final follow-up of four weeks. PMID:21196558

  8. Use of local allograft irradiation following renal transplantation

    SciTech Connect

    Halperin, E.C.; Delmonico, F.L.; Nelson, P.W.; Shipley, W.U.; Cosimi, A.B.

    1984-07-01

    Over a 10 year period, 67 recipients of 71 renal allografts received graft irradiation following the diagnosis of rejection. The majority of kidneys were treated with a total dose of 600 rad, 150 rad per fraction, in 4 daily fractions. Fifty-three kidneys were irradiated following the failure of standard systemic immunosuppression and maximally tolerated antirejection measures to reverse an episode of acute rejection. Twenty-two (42%) of these allografts were noted to have stable (i.e. no deterioration) or improved function 1 month following the treatment with irradiation. Eleven (21%) of these allografts maintained function 1 year following transplantation. Biopsies were obtained of 41 allografts. Of the 24 renal allografts with predominantly cellular rejection, 10 (42%) had the process reversed or stabilized at 1 month following irradiation. Five (21%) of these allografts were functioning at 1 year following irradiation. Rejection was reversed or stabilized in 6 of 17 (35%) allografts at 1 month when the histologic features of renal biopsy suggested predominantly vascular rejection. Local graft irradiation has helped maintain a limited number of allografts in patients whose rejection has failed to respond to systemic immunosuppression. Irradiation may also benefit patients with ongoing rejection in whom further systemic immunosuppression is contra-indicated.

  9. Disruption of Murine Cardiac Allograft Acceptance by Latent Cytomegalovirus

    PubMed Central

    Cook, Charles H.; Bickerstaff, Alice A.; Wang, Jiao-Jing; Zimmerman, Peter D.; Forster, Meghan R.; Nadasdy, Tibor; Colvin, Robert B.; Hadley, Gregg A.; Orosz, Charles G.

    2008-01-01

    Cytomegalovirus (CMV) reactivation is a well described complication of solid organ transplantation. These studies were performed to 1.) determine if cardiac allograft transplantation of latently infected recipients results in reactivation of CMV, and 2.) determine what impact CMV might have on development of graft acceptance/tolerance. BALB/c cardiac allografts were transplanted into C57BL/6 mice with/without latent murine CMV (MCMV). Recipients were treated with gallium nitrate induction and monitored for graft survival, viral immunity, and donor reactive DTH responses. Latently infected allograft recipients had ∼80% graft loss by 100 days after transplant, compared with ∼8% graft loss in naïve recipients. PCR evaluation demonstrated that MCMV was transmitted to cardiac grafts in all latently infected recipients, and 4/8 allografts had active viral transcription compared to 0/6 isografts. Latently infected allograft recipients showed intragraft IFN-α expression consistent with MCMV reactivation, but MCMV did not appear to negatively influence regulatory gene expression. Infected allograft recipients had disruption of splenocyte DTH regulation, but recipient splenocytes remained unresponsive to donor antigen even after allograft losses. These data suggest that transplantation in an environment of latent CMV infection may reactivate virus, and that intragraft responses disrupt development of allograft acceptance. PMID:18976295

  10. Surgical techniques and radiological findings of meniscus allograft transplantation.

    PubMed

    Lee, Hoseok; Lee, Sang Yub; Na, Young Gon; Kim, Sung Kwan; Yi, Jae Hyuck; Lim, Jae Kwang; Lee, So Mi

    2016-08-01

    Meniscus allograft transplantation has been performed over the past 25 years to relieve knee pain and improve knee function in patients with an irreparable meniscus injury. The efficacy and safety of meniscus allograft transplantation have been established in numerous experimental and clinical researches. However, there is a lack of reviews to aid radiologists who are routinely interpreting images and evaluating the outcome of the procedures, and also meniscus allograft transplantation is not widely performed in most hospitals. This review focuses on the indications of the procedure, the different surgical techniques used for meniscus allograft transplantation according to the involvement of the lateral and medial meniscus, and the associated procedures. The postoperative radiological findings and surgical complications of the meniscus allograft transplantation are also described in detail. PMID:27423673

  11. Comparison of structural allograft and traditional autograft technique in occipitocervical fusion: radiological and clinical outcomes from a single institution.

    PubMed

    Godzik, Jakub; Ravindra, Vijay M; Ray, Wilson Z; Schmidt, Meic H; Bisson, Erica F; Dailey, Andrew T

    2015-08-01

    OBJECT The authors' objectives were to compare the rate of fusion after occipitoatlantoaxial arthrodesis using structural allograft with the fusion rate from using autograft, to evaluate correction of radiographic parameters, and to describe symptom relief with each graft technique. METHODS The authors assessed radiological fusion at 6 and 12 months after surgery and obtained radiographic measurements of C1-2 and C2-7 lordotic angles, C2-7 sagittal vertical alignments, and posterior occipitocervical angles at preoperative, postoperative, and final follow-up examinations. Demographic data, intraoperative details, adverse events, and functional outcomes were collected from hospitalization records. Radiological fusion was defined as the presence of bone trabeculation and no movement between the graft and the occiput or C-2 on routine flexion-extension cervical radiographs. Radiographic measurements were obtained from lateral standing radiographs with patients in the neutral position. RESULTS At the University of Utah, 28 adult patients underwent occipitoatlantoaxial arthrodesis between 2003 and 2010 using bicortical allograft, and 11 patients were treated using iliac crest autograft. Mean follow-up for all patients was 20 months (range 1-108 months). Of the 27 patients with a minimum of 12 months of follow-up, 18 (95%) of 19 in the allograft group and 8 (100%) of 8 in the autograft group demonstrated evidence of bony fusion shown by imaging. Patients in both groups demonstrated minimal deterioration of sagittal vertical alignment at final follow-up. Operative times were comparable, but patients undergoing occipitocervical fusion with autograft demonstrated greater blood loss (316 ml vs 195 ml). One (9%) of 11 patients suffered a significant complication related to autograft harvesting. CONCLUSIONS The use of allograft in occipitocervical fusion allows a high rate of successful arthrodesis yet avoids the potentially significant morbidity and pain associated with

  12. Comparison of structural allograft and traditional autograft technique in occipitocervical fusion: radiological and clinical outcomes from a single institution

    PubMed Central

    Godzik, Jakub; Ravindra, Vijay M.; Ray, Wilson Z.; Schmidt, Meic H.; Bisson, Erica F.; Dailey, Andrew T.

    2016-01-01

    Object The authors' objectives were to compare the rate of fusion after occipitoatlantoaxial arthrodesis using structural allograft with the fusion rate from using autograft, to evaluate correction of radiographic parameters, and to describe symptom relief with each graft technique. Methods The authors assessed radiological fusion at 6 and 12 months after surgery and obtained radiographic measurements of C1–2 and C2–7 lordotic angles, C2–7 sagittal vertical alignments, and posterior occipitocervical angles at preoperative, postoperative, and final follow-up examinations. Demographic data, intraoperative details, adverse events, and functional outcomes were collected from hospitalization records. Radiological fusion was defined as the presence of bone trabeculation and no movement between the graft and the occiput or C-2 on routine flexion-extension cervical radiographs. Radiographic measurements were obtained from lateral standing radiographs with patients in the neutral position. Results At the University of Utah, 28 adult patients underwent occipitoatlantoaxial arthrodesis between 2003 and 2010 using bicortical allograft, and 11 patients were treated using iliac crest autograft. Mean follow-up for all patients was 20 months (range 1–108 months). Of the 27 patients with a minimum of 12 months of follow-up, 18 (95%) of 19 in the allograft group and 8 (100%) of 8 in the autograft group demonstrated evidence of bony fusion shown by imaging. Patients in both groups demonstrated minimal deterioration of sagittal vertical alignment at final follow-up. Operative times were comparable, but patients undergoing occipitocervical fusion with autograft demonstrated greater blood loss (316 ml vs 195 ml). One (9%) of 11 patients suffered a significant complication related to autograft harvesting. Conclusions The use of allograft in occipitocervical fusion allows a high rate of successful arthrodesis yet avoids the potentially significant morbidity and pain associated

  13. Effect of Er:YAG laser holes on osteoinduction in demineralized rat calvarial allografts.

    PubMed

    O'Donnell, R J; Deutsch, T F; Flotte, R J; Lorente, C A; Tomford, W W; Mankin, H J; Schomacker, K T

    1996-01-01

    Massive cortical autografts and allografts have been found to incorporate into host bone very slowly and thus are subject to complications such as fatigue fracture and infection. In order to understand and improve the process of osteogenesis in these types of bone grafts, a new experimental model was developed using bone discs from rat calvaria prepared by demineralization and drilling of 0.5 mm diameter holes with a pulsed, 2.94 microns wavelength Erbium:Yttrium-Aluminum-Garnet laser. Four types of bone discs were analyzed: untreated (Type I), demineralized (Type II), laser-ablated (Type III), and laser-ablated then demineralized (Type IV). The discs were transplanted into a subcutaneous site in adult Sprague-Dawley rats and followed for as long as 6 weeks. Histologic analysis of the discs at weekly intervals with use of hematoxylin and eosin staining confirmed the presence of new bone growth in Type-II and Type-IV discs. The amount of new bone growth in each disc was estimated by determining the mineral x-ray attenuation coefficient, which is proportional to mineral density, from digitized radiographs of the discs. The results showed that the processes of demineralization (P < 0.001) and laser ablation with demineralization (p < 0.05) were both significant in enhancing new bone growth in this model. This study demonstrated that osteoinduction can be fostered in cortical bone through the processes of demineralization and laser ablation. To the extent that laser ablation may allow maintenance of structural integrity while altering the surface geometry in such a way as to promote ingrowth of new bone, this experimental model represents an advance in understanding how osteogenesis in cortical bone grafts might be improved. PMID:8618152

  14. Graft vasculopathy in the skin of a human hand allograft: implications for diagnosis of rejection of vascularized composite allografts.

    PubMed

    Kanitakis, Jean; Karayannopoulou, Georgia; Lanzetta, Marco; Petruzzo, Palmina

    2014-11-01

    Whereas vascularized composite allografts often undergo acute rejections early in the postgraft period, rejection manifesting with severe vascular changes (graft vasculopathy) has only been observed on three occasions in humans. We report a hand-allografted patient who developed severe rejection following discontinuation of the immunosuppressive treatment. It manifested clinically with erythematous maculopapules on the skin and pathologically with graft vasculopathy that affected both large vessels and smaller cutaneous ones. The observation that graft vasculopathy can affect skin vessels shows that it is amenable to diagnosis with usual skin biopsy as recommended for the follow-up of these allografts. Graft vasculopathy developing in the setting of vascularized composite allografts likely represents chronic rejection due to under-immunosuppression and, if confirmed, should be included in a future update of the Banff classification of vascularized composite allograft rejection. PMID:25041139

  15. Effect of Risedronate in a Minipig Cartilage Defect Model with Allograft

    PubMed Central

    Muehleman, Carol; Li, Jun; Abe, Yumiko; Pfister, Brian; Sah, Robert L.; Phipps, Roger; Masuda, Koichi

    2010-01-01

    Cartilage/chondrocyte transplantation is frequently utilized in the repair of focal chondral defects. It has been proposed that failure of subchondral bone maintenance or restoration is a factor contributing to the failure of cartilage-forming transplants. Some studies reveal that the transplant is associated with subchondral bone resorption, often leading to deep pits beneath the presumptive cartilage repair site. Thus, the question is raised as to the utility of agents, such as bisphosphonates, to inhibit bone remodeling at the transplant site. In the present study we show that oral administration (three times weekly) of the bisphosphonate, risedronate, inhibited the subchondral bone loss deep to the cultured allogeneic graft tissue site in attempted repair of surgically created chondral defects in a minipig model. In addition, the graft tissue, characterized by type II collagen was retained in the majority of treated animals. Untreated minipigs displayed a deep bone resorption pit, beneath the graft region, filled with type I collagen tissue as determined through immunohistochemical staining. This fibrous tissue appeared well integrated with the host tissue in the majority of cases. In the transplanted cartilage region, the overall histological score for tissue quality was significantly (p<0.05) better for the treated animals which displayed better matrix staining, cell clustering, tidemark integrity, and subchondral bone integrity (p<0.05 in each category). However, the integration of allograft with host tissue did not always occur completely. Thus, bisphosphonates might be considered in clinical treatment strategies for such procedures. PMID:18925648

  16. Mechanical strength of cortical allografts with gamma radiation versus ethylene oxide sterilization.

    PubMed

    Zhou, Zongke; Qin, Tingwu; Yang, Jing; Shen, Bin; Kang, Pengde; Peil, Fuxing

    2011-10-01

    We investigated the effects of gamma irradiation versus ethylene oxide (ETO) sterilization on the mechanical strength of cortical bone grafts. Tibias were collected from cadavers of mature goats. Sixty test specimens were randomized into four groups: fresh (no processing), frozen (freezing at -70 degrees C), gamma-irradiated, and ETO-sterilized specimens. Torsion, three-point bending, and compression testing were separately performed with a material testing machine. Parameters studied included maximum stress, strain, deflection, extension, load, shear modulus, and E-modulus. Compared with findings for the fresh specimens, findings were as follows for gamma-irradiated specimens: maximal shear modulus, reduced by 48%; shear stress, by 55%; deflection, by 71%; bending stress, by 51%; bending strain, by 74%; extension, by 60%; and compression strain, by 50%. However, there were no reductions in those parameters for the frozen specimens or the ETO-sterilized specimens. These findings confirm that shear, bending, and compression strength of cortical allografts are weakened by gamma irradiation at room temperature. To maintain optimum mechanical properties, ETO sterilization of allografts is better than gamma sterilization, especially for cortical bone, because it is usually used in load-bearing settings. PMID:22187845

  17. Radiographical and clinical evaluation of critical size defects in rabbit calvaria filled with allograft and autograft: a pilot study.

    PubMed

    Oporto V, Gonzalo H; Fuentes, Ramón; Borie, Eduardo; Del Sol, Mariano; Orsi, Iara Augusta; Engelke, Wilfried

    2014-01-01

    Regeneration of resorbed edentulous sites can be induced by bone grafts from the subject himself and/or by the use of biomaterials. At present, there has been an extensive search for biomaterials that are evaluated by artificially creating one or more critical defects. The aim of this work was to clinically and radiographically analyze bone formation by the use of some biomaterials in artificially created defects in the parietal bone of rabbits. Six rabbits were used, creating defects of 8 mm in diameter in parietal bones. One defect was maintained with coagulum only, and in others, freeze-dried bone allograft (FDBA), autologous bone, and a combination of autologous bone with FDBA respectively, were added. Animals were sacrificed at 15-90 days with 2 weeks interval each, and calvaria were analyzed macroscopically, measuring by digital caliper the lack of filling at the surface of defects, identifying limits at anteroposterior and coronal view, realizing a digital photograph register of their external surfaces. This was subsequently evaluated radiographically by occlusal film radiography used to quantify its density through software. In conclusion, autologous bone showed the best behavior, clinically as well as radiographically. However, FDBA is a good option as an alternative to autologous bone as its behavior was slightly lower over time. The combination of autologous bone and FDBA in the same defect showed results considerably inferior to grafts used separately. Low radiopacity and clear limits were observed through time for the control coagulum filled defect. PMID:25126163

  18. Radiographical and clinical evaluation of critical size defects in rabbit calvaria filled with allograft and autograft: a pilot study

    PubMed Central

    Oporto V, Gonzalo H; Fuentes, Ramón; Borie, Eduardo; del Sol, Mariano; Orsi, Iara Augusta; Engelke, Wilfried

    2014-01-01

    Regeneration of resorbed edentulous sites can be induced by bone grafts from the subject himself and/or by the use of biomaterials. At present, there has been an extensive search for biomaterials that are evaluated by artificially creating one or more critical defects. The aim of this work was to clinically and radiographically analyze bone formation by the use of some biomaterials in artificially created defects in the parietal bone of rabbits. Six rabbits were used, creating defects of 8 mm in diameter in parietal bones. One defect was maintained with coagulum only, and in others, freeze-dried bone allograft (FDBA), autologous bone, and a combination of autologous bone with FDBA respectively, were added. Animals were sacrificed at 15-90 days with 2 weeks interval each, and calvaria were analyzed macroscopically, measuring by digital caliper the lack of filling at the surface of defects, identifying limits at anteroposterior and coronal view, realizing a digital photograph register of their external surfaces. This was subsequently evaluated radiographically by occlusal film radiography used to quantify its density through software. In conclusion, autologous bone showed the best behavior, clinically as well as radiographically. However, FDBA is a good option as an alternative to autologous bone as its behavior was slightly lower over time. The combination of autologous bone and FDBA in the same defect showed results considerably inferior to grafts used separately. Low radiopacity and clear limits were observed through time for the control coagulum filled defect. PMID:25126163

  19. Socket repair utilizing collagen membrane and mineralized allograft in the esthetic zone: a case report.

    PubMed

    Minichetti, John C; D'Amore, Joseph C

    2010-01-01

    As the number of patients seeking implants increases, so do the esthetic challenges. Adequate bone is necessary to place an implant with an esthetically pleasing outcome. Failing teeth that require implant replacement often have bony deficiencies, and several surgical techniques have been advocated for maintaining bone volume at the time of extraction. This case report utilized a predictable conservative technique for treating a facial bony defect prior to implant surgery. Atraumatic flapless tooth extraction and the placement of a resorbable collagen membrane and mineralized allograft allowed for adequate regeneration of the alveolar socket prior to implant placement. The dentition was later restored with a zirconia abutment and crown. Socket repair utilizing this technique was a clinically acceptable method for obtaining an esthetic implant restoration. PMID:20829166

  20. Minimizing the risk of chronic allograft nephropathy.

    PubMed

    Weir, Matthew R; Wali, Ravinder K

    2009-04-27

    Chronic allograft nephropathy, now defined as interstital fibrosis and tubular atrophy not otherwise specified, is a near universal finding in transplant kidney biopsies by the end of the first decade posttransplantation. After excluding death with functioning graft, caused by cardiovascular disease or malignancy, chronic allograft nephropathy is the leading cause of graft failure. Original assumptions were that this was not a modifiable process but inexorable, likely due to past kidney injuries. However, newer understandings suggest that acute or subacute processes are involved, and with proper diagnosis, appropriate interventions can be instituted. Our method involved a review of the primary and secondary prevention trials in calcineurin inhibitor withdrawal. Some of the more important causes of progressive graft deterioration include subclinical cellular or humoral rejection, and chronic calcineurin inhibitor toxicity. Early graft biopsy, assessment of histology, and changes in immunosuppression may be some of the most important measures available to protect graft function. The avoidance of clinical inertia in pursuing subtle changes in graft function is critical. Modification in maintenance immunosuppression may benefit many patients with early evidence of graft deterioration. PMID:19384181

  1. Scaffold Design for Bone Regeneration

    PubMed Central

    Polo-Corrales, Liliana; Latorre-Esteves, Magda; Ramirez-Vick, Jaime E.

    2014-01-01

    The use of bone grafts is the standard to treat skeletal fractures, or to replace and regenerate lost bone, as demonstrated by the large number of bone graft procedures performed worldwide. The most common of these is the autograft, however, its use can lead to complications such as pain, infection, scarring, blood loss, and donor-site morbidity. The alternative is allografts, but they lack the osteoactive capacity of autografts and carry the risk of carrying infectious agents or immune rejection. Other approaches, such as the bone graft substitutes, have focused on improving the efficacy of bone grafts or other scaffolds by incorporating bone progenitor cells and growth factors to stimulate cells. An ideal bone graft or scaffold should be made of biomaterials that imitate the structure and properties of natural bone ECM, include osteoprogenitor cells and provide all the necessary environmental cues found in natural bone. However, creating living tissue constructs that are structurally, functionally and mechanically comparable to the natural bone has been a challenge so far. This focus of this review is on the evolution of these scaffolds as bone graft substitutes in the process of recreating the bone tissue microenvironment, including biochemical and biophysical cues. PMID:24730250

  2. Effortless effort in bone regeneration: a review.

    PubMed

    Nazirkar, Girish; Singh, Shailendra; Dole, Vinaykumar; Nikam, Akhilesh

    2014-06-01

    Since the beginning of the 20th century, the concept of osteoconduction in bony changes in the oral cavity showed a wide range of biomaterials and their osteoinductive potential that emerged gradually and has to a large extent improved the quality of the bone prior to the placement of an implant. Alveolar bone loss is a major concern after tooth extraction in patients and therefore atraumatic extraction procedures should be followed to avoid further bone loss. To overcome the alveolar bone loss and to augment support for placing dental implants, many bone regenerative substitutes are available such as allografts, autografts, xenografts, synthetic biomaterials and osteoactive agents. In light of the steady progress in bone grafting techniques and graft materials, it has become possible to improve the volume, width, and height of bone in deficient areas of the oral cavity. These advances in regenerative dentistry thus facilitate an easy and convenient placement of an implant in an ideal position and angulations resulting in superior esthetics and function. Bone grafting materials and their substitutes are the alternative filler materials, which facilitate to reduce additional surgical procedures, risks, chances of cross infection involved in placing autografts and allografts into the bony structures. This review literature highlights various biomaterials that are helpful in bone healing and thus create an anatomically favorable base for ideal implant placement. How to cite the article: Nazirkar G, Singh S, Dole V, Nikam A. Effortless effort in bone regeneration: A review. J Int Oral Health 2014;6(3):120-4. PMID:25083047

  3. Effortless Effort in Bone Regeneration: A Review

    PubMed Central

    Nazirkar, Girish; Singh, Shailendra; Dole, Vinaykumar; Nikam, Akhilesh

    2014-01-01

    Since the beginning of the 20th century, the concept of osteoconduction in bony changes in the oral cavity showed a wide range of biomaterials and their osteoinductive potential that emerged gradually and has to a large extent improved the quality of the bone prior to the placement of an implant. Alveolar bone loss is a major concern after tooth extraction in patients and therefore atraumatic extraction procedures should be followed to avoid further bone loss. To overcome the alveolar bone loss and to augment support for placing dental implants, many bone regenerative substitutes are available such as allografts, autografts, xenografts, synthetic biomaterials and osteoactive agents. In light of the steady progress in bone grafting techniques and graft materials, it has become possible to improve the volume, width, and height of bone in deficient areas of the oral cavity. These advances in regenerative dentistry thus facilitate an easy and convenient placement of an implant in an ideal position and angulations resulting in superior esthetics and function. Bone grafting materials and their substitutes are the alternative filler materials, which facilitate to reduce additional surgical procedures, risks, chances of cross infection involved in placing autografts and allografts into the bony structures. This review literature highlights various biomaterials that are helpful in bone healing and thus create an anatomically favorable base for ideal implant placement. How to cite the article: Nazirkar G, Singh S, Dole V, Nikam A. Effortless effort in bone regeneration: A review. J Int Oral Health 2014;6(3):120-4. PMID:25083047

  4. Targeting Sirtuin-1 prolongs murine renal allograft survival and function.

    PubMed

    Levine, Matthew H; Wang, Zhonglin; Xiao, Haiyan; Jiao, Jing; Wang, Liqing; Bhatti, Tricia R; Hancock, Wayne W; Beier, Ulf H

    2016-05-01

    Current immunosuppressive medications used after transplantation have significant toxicities. Foxp3(+) T-regulatory cells can prevent allograft rejection without compromising protective host immunity. Interestingly, inhibiting the class III histone/protein deacetylase Sirtuin-1 can augment Foxp3(+) T-regulatory suppressive function through increasing Foxp3 acetylation. Here we determined whether Sirtuin-1 targeting can stabilize biological allograft function. BALB/c kidney allografts were transplanted into C57BL/6 recipients with a CD4-conditional deletion of Sirtuin-1 (Sirt1(fl/fl)CD4(cre)) or mice treated with a Sirtuin-1-specific inhibitor (EX-527), and the native kidneys removed. Blood chemistries and hematocrit were followed weekly. Sirt1(fl/fl)CD4(cre) recipients showed markedly longer survival and improved kidney function. Sirt1(fl/fl)CD4(cre) recipients exhibited donor-specific tolerance, accepted BALB/c, but rejected third-party C3H cardiac allografts. C57BL/6 recipients of BALB/c renal allografts that were treated with EX-527 showed improved survival and renal function at 1, but not 10 mg/kg/day. Pharmacologic inhibition of Sirtuin-1 also improved renal allograft survival and function with dosing effects having relevance to outcome. Thus, inhibiting Sirtuin-1 can be a useful asset in controlling T-cell-mediated rejection. However, effects on non-T cells that could adversely affect allograft survival and function merit consideration. PMID:27083279

  5. Acute and Chronic Allograft Dysfunction in Kidney Transplant Recipients.

    PubMed

    Goldberg, Ryan J; Weng, Francis L; Kandula, Praveen

    2016-05-01

    Allograft dysfunction after a kidney transplant is often clinically asymptomatic and is usually detected as an increase in serum creatinine level with corresponding decrease in glomerular filtration rate. The diagnostic evaluation may include blood tests, urinalysis, transplant ultrasonography, radionuclide imaging, and allograft biopsy. Whether it occurs early or later after transplant, allograft dysfunction requires prompt evaluation to determine its cause and subsequent management. Acute rejection, medication toxicity from calcineurin inhibitors, and BK virus nephropathy can occur early or later. Other later causes include transplant glomerulopathy, recurrent glomerulonephritis, and renal artery stenosis. PMID:27095641

  6. Osteochondral Allograft Transplantation in the Knee.

    PubMed

    Zouzias, Ioannis C; Bugbee, William D

    2016-06-01

    The technique of osteochondral allograft (OCA) transplantation has been used to treat a wide spectrum of cartilage deficiencies in the knee. Its use has been supported by basic science and clinical studies that show it is a safe and effective treatment option. What sets fresh OCA transplantation apart from other cartilage procedures in the knee, is the ability to treat large defects with mature hyaline cartilage. Studies looking at transplantation of fresh OCAs in the general population have shown reliable pain relief and return to activities of daily living. Reports of cartilage injuries in athletes have risen over the years and more research is needed in evaluating the successfulness of OCA transplantation in the athletic population. PMID:27135291

  7. Dysplasia Epiphysealis Hemimelica Treated with Osteochondral Allograft: A Case Report

    PubMed Central

    Anthony, Chris A.; Wolf, Brian R.

    2015-01-01

    Background Dysplasia epiphysealis hemimelica (DEH), or Trevor's disease, is a developmental disorder of the pediatric skeleton characterized by asymmetric osteochondral overgrowth. Methods We present the case of a five year old boy with a two year history of right knee pain and evidence of DEH on imaging who underwent initial arthroscopic resection of his lesion with subsequent recurrence. The patient then underwent osteochondral allograft revision surgery and was asymptomatic at two year follow-up with a congruent joint surface. Results To our knowledge, this is the first reported case of a DEH lesion treated with osteochondral allograft and also the youngest reported case of osteochondral allograft placement in the literature. Conclusions Osteochondral allograft may be a viable option in DEH and other deformities of the pediatric knee. Level of Evidence Level V PMID:26361443

  8. Recurrent Hepatitis C in Liver Allografts

    PubMed Central

    Demetris, A. J.; Eghtesad, B.; Marcos, A.; Ruppert, K.; Nalesnik, M. A.; Randhawa, P.; Wu, T.; Krasinskas, A.; Fontes, P.; Cacciarelli, T.; Shakil, A. O.; Murase, N.; Fung, J. J.; Starzl, T. E.

    2010-01-01

    Rationale and Design The accuracy of a prospective histopathologic diagnosis of rejection and recurrent hepatitis C (HCV) was determined in 48 HCV RNA-positive liver allograft recipients enrolled in an “immunosuppression minimization protocol” between July 29, 2001 and January 24, 2003. Prospective entry of all pertinent treatment, laboratory, and histopathology results into an electronic database enabled a retrospective analysis of the accuracy of histopathologic diagnoses and the pathophysiologic relationship between recurrent HCV and rejection. Results Time to first onset of acute rejection (AR) (mean, 107 days; median, 83 days; range, 7–329 days) overlapped with the time to first onset of recurrent HCV (mean, 115 days; median, 123 days; range, 22–315 days), making distinction between the two difficult. AR and chronic rejection (CR) with and without co-existent HCV showed overlapping but significantly different liver injury test profiles. One major and two minor errors occurred (positive predictive values for AR = 91%; recurrent HCV = 100%); all involved an overdiagnosis of AR in the context of recurrent HCV. Retrospective analysis of the mistakes showed that major errors can be avoided altogether and the impact of unavoidable minor errors can be minimized by strict adherence to specific histopathologic criteria, close clinicopathologic correlation including examination of HCV RNA levels, and a conservative approach to the use of additional immunosuppression. In addition, histopathologic diagnoses of moderate and severe AR and CR were associated with relatively low HCV RNA levels, whereas relatively high HCV RNA levels were associated with a histopathologic diagnosis of hepatitis alone, particularly the cholestatic variant of HCV. Conclusions Liver allograft biopsy interpretation can rapidly and accurately distinguish between recurrent HCV and AR/CR. In addition, the histopathologic observations suggest that the immune mechanism responsible for HCV

  9. A Case of Intraparenchymal Pseudoaneurysms in Kidney Allograft.

    PubMed

    Lorentz, Liam Antony; Hlabangana, Linda Tebogo; Davies, Malcom

    2016-01-01

    BACKGROUND Percutaneous needle biopsy is routinely performed for renal allograft management. Vascular complications of the procedure include pseudoaneurysm and arterio-venous fistulae formation. Delayed diagnosis of these complications is due to their mostly asymptomatic and indolent nature. CASE REPORT We present a case of extensive intraparenchymal pseudoaneurysm formation within the inferior pole of the allograft, diagnosed two years following the most recent biopsy procedure. CONCLUSIONS Renal pseudoaneurysms may only be diagnosed years after their formation as they are typically asymptomatic. PMID:27510594

  10. Musculoskeletal allograft risks and recalls in the United States.

    PubMed

    Mroz, Thomas E; Joyce, Michael J; Steinmetz, Michael P; Lieberman, Isador H; Wang, Jeffrey C

    2008-10-01

    There have been several improvements to the US tissue banking industry over the past decade. Tissue banks had limited active government regulation until 1993, at which time the US Food and Drug Administration began regulatory oversight because of reports of disease transmission from allograft tissues. Reports in recent years of disease transmission associated with the use of allografts have further raised concerns about the safety of such implants. A retrospective review of allograft recall data was performed to analyze allograft recall by tissue type, reason, and year during the period from January 1994 to June 30, 2007. During the study period, more than 96.5% of all allograft tissues recalled were musculoskeletal. The reasons underlying recent musculoskeletal tissue recalls include insufficient or improper donor evaluation, contamination, recipient infection, and positive serologic tests. Infectious disease transmission following allograft implantation may occur if potential donors are not adequately evaluated or screened serologically during the prerecovery phase and if the implant is not sterilized before implantation. PMID:18832599

  11. Management of traumatic tibial diaphyseal bone defect by “induced-membrane technique”

    PubMed Central

    Gupta, Gaurav; Ahmad, Sohail; Mohd. Zahid; Khan, A H; Sherwani, M K A; Khan, Abdul Qayyum

    2016-01-01

    Background: Gap nonunion of long bones is a challenging problem, due to the limitation of conventional reconstructive techniques more so if associated with infection and soft tissue defect. Treatment options such as autograft with non-vascularized fibula and cancellous bone graft, vascularized bone graft, and bone transportation are highly demanding on the part of surgeons and hospital setups and have many drawbacks. This study aims to analyze the outcome of patients with wide diaphyseal bone gap treated with induced-membrane technique (Masquelet technique). Materials and Methods: This study included 9 patients (7 males and 2 females), all with tibial bone-gap. Eight of the 9 patients were infected and in 3 patients there was associated large soft tissue defect requiring flap cover. This technique is two-stage procedure. Stage I surgery included debridement, fracture stabilization, application of spacer between bone ends, and soft tissue reconstruction. Stage II surgery included removal of spacer with preservation of induced membrane formed at spacer surface and filling the bone-gap with morselized iliac crest bone-graft within the membrane sleeve. Average bone-gap of 5.2 cm was treated. The spacer was always found to be encapsulated by a thick glistening membrane which did not collapse after its removal. All patients were followed up for an average period of 21.5 months. Results: Serial Radiographs showed regular uptake of autograft and thus consolidation within themselves in the region of bone gap and also with host bone. Bone-union was documented in all patients and all patients are walking full weight-bearing without support. Conclusions: The study highlights that the technique provide effective and practical management for difficult gap nonunion. It does not require specialized equipment, investigations, and surgery. Thus, it provides a reasonable alternative to the developing infrastructures and is a reliable and reproducible technique. PMID:27293290

  12. The Macrophage-depleting Agent Clodronate Promotes Durable Hematopoietic Chimerism and Donor-specific Skin Allograft Tolerance in Mice

    PubMed Central

    Li, Zhanzhuo; Xu, Xin; Feng, Xingmin; Murphy, Philip M.

    2016-01-01

    Hematopoietic chimerism is known to promote donor-specific organ allograft tolerance; however, clinical translation has been impeded by the requirement for toxic immunosuppression and large doses of donor bone marrow (BM) cells. Here, we investigated in mice whether durable chimerism might be enhanced by pre-treatment of the recipient with liposomal clodronate, a macrophage depleting agent, with the goal of vacating BM niches for preferential reoccupation by donor hematopoietic stem cells (HSC). We found that liposomal clodronate pretreatment of C57BL/6 mice permitted establishment of durable hematopoietic chimerism when the mice were given a low dose of donor BM cells and transient immunosuppression. Moreover, clodronate pre-treatment increased durable donor-specific BALB/c skin allograft tolerance. These results provide proof-of-principle that clodronate is effective at sparing the number of donor BM cells required to achieve durable hematopoietic chimerism and donor-specific skin allograft tolerance and justify further development of a tolerance protocol based on this principle. PMID:26917238

  13. Osteochondral allograft transplantation in cartilage repair: Graft storage paradigm, translational models, and clinical applications.

    PubMed

    Bugbee, William D; Pallante-Kichura, Andrea L; Görtz, Simon; Amiel, David; Sah, Robert

    2016-01-01

    The treatment of articular cartilage injury and disease has become an increasingly relevant part of orthopaedic care. Articular cartilage transplantation, in the form of osteochondral allografting, is one of the most established techniques for restoration of articular cartilage. Our research efforts over the last two decades have supported the transformation of this procedure from experimental "niche" status to a cornerstone of orthopaedic practice. In this Kappa Delta paper, we describe our translational and clinical science contributions to this transformation: (1) to enhance the ability of tissue banks to process and deliver viable tissue to surgeons and patients, (2) to improve the biological understanding of in vivo cartilage and bone remodeling following osteochondral allograft (OCA) transplantation in an animal model system, (3) to define effective surgical techniques and pitfalls, and (4) to identify and clarify clinical indications and outcomes. The combination of coordinated basic and clinical studies is part of our continuing comprehensive academic OCA transplant program. Taken together, the results have led to the current standards for OCA processing and storage prior to implantation and also novel observations and mechanisms of the biological and clinical behavior of OCA transplants in vivo. Thus, OCA transplantation is now a successful and increasingly available treatment for patients with disabling osteoarticular cartilage pathology. PMID:26234194

  14. Segmental pancreatic allograft survival in baboons treated with combined irradiation and cyclosporine: a preliminary report

    SciTech Connect

    du Toit, D.F.; Heydenrych, J.J.; Smit, B.; Louw, G.; Zuurmond, T.; Laker, L.; Els, D.; Weideman, A.; Wolfe-Coote, S.; van der Merwe, E.A.

    1985-04-01

    The present study was undertaken to evaluate the effectiveness of cyclosporine (CS) alone, total lymphoid irradiation (TLI) alone, and CS in combination with total body irradiation (TBI) in suppressing segmental pancreatic allograft rejection in totally pancreatectomized outbred chacma baboons. The administration of CS 25 mg/kg/day and 50 mg/ kg/day resulted in mean graft survival of 21.5 days and 24.5 days, respectively. CS 85 mg/kg/day resulted in median graft survival of 9 days. There was a wide daily fluctuation of CS serum trough levels exhibited between primates receiving the same oral dose. TBI in excess of 300 rads resulted in irreversible bone marrow suppression. Modest results were achieved in recipients of TBI-76 rads (38 x 2 rads), with median graft survival of 21 days, results not different from recipients treated with CS. TLI recipients of 600 rads (150 x 4 rads) resulted in median pancreatic graft survival of 16 days. TBI together with oral CS administration exhibited no synergistic or additive effect and a single peroperative donor-specific blood transfusion did not enhance pancreatic allograft survival in this model. However, of 10 primates receiving TBI 100 rads (50 x 2 rads) and CS 25 mg/kg/day administered orally indefinitely, four remained normoglycemic for more than 60 days. TBI 100 rads (50 x 2 rads) together with oral and parenteral CS resulted in necrotizing enterocolitis in four of six recipients.

  15. Co-transplantation of autologous MSCs delays islet allograft rejection and generates a local immunoprivileged site

    PubMed Central

    Ben Nasr, Moufida; Vergani, Andrea; Avruch, James; Liu, Liye; Kefaloyianni, Eirini; D’Addio, Francesca; Tezza, Sara; Corradi, Domenico; Bassi, Roberto; Valderrama-Vasquez, Alessandro; Usuelli, Vera; Kim, James; Azzi, Jamil; Essawy, Basset El; Markmann, James; Abdi, Reza

    2016-01-01

    Aims Mesenchymal stem cells (MSCs) are multipotent cells with immunomodulatory properties. We tested the ability of MSCs to delay islet allograft rejection. Methods Mesenchymal stem cells were generated in vitro from C57BL/6 and BALB/c mice bone marrow, and their immunomodulatory properties were tested in vitro. We then tested the effect of a local or systemic administration of heterologous and autologous MSCs on graft survival in a fully allogeneic model of islet transplantation (BALB/c islets into C57BL/6 mice). Results In vitro, autologous, but not heterologous, MSCs abrogated immune cell proliferation in response to alloantigens and skewed the immune response toward a Th2 profile. A single dose of autologous MSCs co-transplanted under the kidney capsule with allogeneic islets delayed islet rejection, reduced graft infiltration, and induced long-term graft function in 30 % of recipients. Based on ex vivo analysis of recipient splenocytes, the use of autologous MSCs did not appear to have any systemic effect on the immune response toward graft alloantigens. The systemic injection of autologous MSCs or the local injection of heterologous MSCs failed to delay islet graft rejection. Conclusion Autologous, but not heterologous, MSCs showed multiple immunoregulatory properties in vitro and delayed allograft rejection in vivo when co-transplanted with islets; however, they failed to prevent rejection when injected systemically. Autologous MSCs thus appear to produce a local immunoprivileged site, which promotes graft survival. PMID:25808641

  16. Bone-grafting materials in implant dentistry.

    PubMed

    Misch, C E; Dietsh, F

    1993-01-01

    There are three classes of bone-grafting materials based upon the mode of action. Autogenous bone is an organic material and forms bone by osteogenesis, osteoinduction, and osteoconduction. Allografts such as demineralized freeze-dried bone are osteoinductive and osteoconductive and may be cortical and/or trabecular in nature. Alloplasts such as hydroxyapatite and tricalcium phosphate may be synthetic or natural, vary in size, and are only osteoconductive. They can be divided into three types based upon the porosity of the product and include dense, macroporous, and microporous materials. In addition, alloplastic materials may be crystalline or amorphous. These materials have different properties and therefore indications. The use of the three classes of materials in diverse combinations depends upon the size and topography of the bony defect. Small defects or defects with four walls of host bone can be repaired with alloplasts alone or allografts in combination with alloplasts. The loss of three or more bony walls mandates the addition of autogenous bone to the graft or the use of a small pore membrane. The larger the defect, the more autogenous bone is required. The different indications of bone substitutes are discussed as to their specific applications in implant dentistry. PMID:8142935

  17. Acetabular Reconstruction with the Burch-Schneider Antiprotrusio Cage and Bulk Allografts: Minimum 10-Year Follow-Up Results

    PubMed Central

    Sandri, Andrea

    2014-01-01

    Reconstruction of severe pelvic bone loss is a challenging problem in hip revision surgery. Between January 1992 and December 2000, 97 hips with periprosthetic osteolysis underwent acetabular revision using bulk allografts and the Burch-Schneider antiprotrusio cage (APC). Twenty-nine patients (32 implants) died for unrelated causes without additional surgery. Sixty-five hips were available for clinical and radiographic assessment at an average follow-up of 14.6 years (range, 10.0 to 18.9 years). There were 16 male and 49 female patients, aged from 29 to 83 (median, 60 years), with Paprosky IIIA (27 cases) and IIIB (38 cases) acetabular bone defects. Nine cages required rerevision because of infection (3), aseptic loosening (5), and flange breakage (1). The average Harris hip score improved from 33.1 points preoperatively to 75.6 points at follow-up (P < 0.001). Radiographically, graft incorporation and cage stability were detected in 48 and 52 hips, respectively. The cumulative survival rates at 18.9 years with removal for any reason or X-ray migration of the cage and aseptic or radiographic loosening as the end points were 80.0% and 84.6%, respectively. The use of the Burch-Schneider APC and massive allografts is an effective technique for the reconstructive treatment of extensive acetabular bone loss with long-lasting survival. PMID:24967339

  18. Maxillary sinus augmentation using recombinant bone morphogenetic protein-2/acellular collagen sponge in combination with a mineralized bone replacement graft: a report of three cases.

    PubMed

    Tarnow, Dennis P; Wallace, Stephen S; Testori, Tiziano; Froum, Stuart J; Motroni, Alessandro; Prasad, Hari S

    2010-04-01

    The objective of the following case reports was to assess whether mineralized bone replacement grafts (eg, xenografts and allografts) could be added to recombinant human bone morphogenetic protein-2/acellular collagen sponge (rhBMP-2/ACS) in an effective manner that would: (1) reduce the graft shrinkage observed when using rhBMP-2/ACS alone, (2) reduce the volume and dose of rhBMP-2 required, and (3) preserve the osteoinductivity that rhBMP-2/ACS has shown when used alone. The primary outcome measures were histomorphometric analysis of vital bone production and analysis of serial computed tomographic scans to determine changes in bone graft density and stability. Over the 6-month course of this investigation, bone graft densities tended to increase (moreso with the xenograft than the allograft). The increased density in allograft cases was likely the result of both compression of the mineralized bone replacement graft and vital bone formation, seen histologically. Loss of volume was greater with the four-sponge dose than the two-sponge dose because of compression and resorption of the sponges. Vital bone formation in the allograft cases ranged from 36% to 53% but, because of the small sample size, it was not possible to determine any significant difference between the 5.6 mL (four-sponge) dose and the 2.8 mL (two-sponge) dose. Histology revealed robust new woven bone formation with only minimal traces of residual allograft, which appeared to have undergone accelerated remodeling or rhBMP-2-mediated resorption. PMID:20228973

  19. Use of a Fibular Strut Allograft in an Osteoporotic Distal Humerus Fracture

    PubMed Central

    Hildebrand, Gregory R.; Wright, David M.; Marston, Scott B.; Switzer, Julie A.

    2012-01-01

    In 2004, nearly 120 000 fragility fractures of the humerus were reported. As the US population ages, this number is expected to increase. Fractures of the distal humerus can be treated in a closed or open fashion. Open treatment includes open reduction and internal fixation or total elbow arthroplasty. Open reduction and internal fixation typically involves dual plating for increased stability and early mobility. We present a case in which dual plating failed due to lack of screw purchase in osteoporotic bone. This patient’s fracture was then revised with the use of a fibular strut allograft for improved stability and screw purchase. This method of fixation has not previously been described in the distal humerus and may prove useful in open fixation of osteoporotic distal humerus fractures. PMID:23569712

  20. Predicting the development of cardiac allograft vasculopathy.

    PubMed

    Seki, Atsuko; Fishbein, Michael C

    2014-01-01

    Cardiac transplantation is a lifesaving therapy for patients with end-stage cardiovascular disease. There has been remarkable progress in controlling acute rejection, and the early survival rate after the heart transplantation has significantly improved. Cardiac allograft vasculopathy (CAV) is one of the common causes of death and a major limiting factor for long-term graft survival years after heart transplantation. CAV is a progressive occlusion of arteries and veins of the transplanted heart. CAV is often clinically silent because of the denervation of the transplanted heart. CAV tends to be found at an advanced stage of disease, including myocardial infarction (MI), congestive heart failure, arrhythmia, and/or sudden cardiac death. Because of the serious sequelae of CAV, risk factors, prevention, and prediction of CAV have been investigated. Despite the effort by many researchers, the pathogenesis is not yet completely understood. There are a number of both immune and nonimmune factors in the donor and recipient that are related to the development of CAV. In addition, several biomarkers in blood and tissue are found to correlate with the presence of CAV, and that may be able to predict CAV. Here, we review the pathology, pathogenesis, risk factors, diagnosis, and the potential for prediction of CAV. PMID:24972526

  1. Autophagy in allografts rejection: A new direction?

    PubMed

    Sun, Hukui; Cheng, Dayan; Ma, Yuanyuan; Wang, Huaiquan; Liang, Ting; Hou, Guihua

    2016-03-18

    Despite the introduction of new and effective immunosuppressive drugs, acute cellular graft rejection is still a major risk for graft survival. Modulating the dosage of immunosuppressive drugs is not a good choice for all patients, new rejection mechanisms discovery are crucial to limit the inflammatory process and preserve the function of the transplant. Autophagy, a fundamental cellular process, can be detected in all subsets of lymphocytes and freshly isolated naive T lymphocytes. It is required for the homeostasis and function of T lymphocytes, which lead to cell survival or cell death depending on the context. T cell receptor (TCR) stimulation and costimulator signals induce strong autophagy, and autophagy deficient T cells leads to rampant apoptosis upon TCR stimulation. Autophagy has been proved to be activated during ischemia-reperfusion (I/R) injury and associated with grafts dysfunction. Furthermore, Autophagy has also emerged as a key mechanism in orchestrating innate and adaptive immune response to self-antigens, which relates with negative selection and Foxp3(+) Treg induction. Although, the role of autophagy in allograft rejection is unknown, current data suggest that autophagy indeed sweeps across both in the graft organs and recipients lymphocytes after transplantation. This review presents the rationale for the hypothesis that targeting the autophagy pathway could be beneficial in promoting graft survival after transplantation. PMID:26876576

  2. Arthroscopic posterior cruciate ligament reconstruction with allograft versus autograft

    PubMed Central

    Sun, Xiujiang; Zhang, Jianfeng; Qu, Xiaoyi

    2015-01-01

    Introduction The aim of the study was to compare and analyze retrospectively the outcomes of arthroscopic posterior cruciate ligament reconstruction with autograft versus allograft. Material and methods Seventy-one patients who underwent arthroscopic posterior cruciate ligament reconstruction with an autograft or allograft met our inclusion criteria. There were 36 patients in the autograft group and 35 patients in the allograft group. All the patients were evaluated by physical examination and a functional ligament test. Comparative analysis was done in terms of operation time, incision length, fever time, postoperative infection rate, incidence of numbness and dysesthesia around the incision, as well as a routine blood test. Results The average follow-up of the autograft group was 3.2 ±0.2 years and that of the allograft group was 3.3 ±0.6 years; there was no significant difference (p > 0.05). No differences existed in knee range of motion, Lysholm scores, International Knee Documentation Committee standard evaluation form and Tegner activity score at final follow-up (p > 0.05), except that patients in the allograft group had a shorter operation time and incision length and a longer fever time (p < 0.05). We found a difference in posterior drawer test and KT-2000 arthrometer assessment (p < 0.05). The posterior tibia displacement averaged 3.8 ±1.5 mm in the autograft group and 4.8 ±1.7 mm in the allograft group (p < 0.05). The incidence of numbness and dysesthesia around the incision in the autograft group was higher than that in the allograft group (p < 0.05). There was no infection postoperatively. The white blood cells and neutrophils in the allograft group increased more than those in the autograft group postoperatively (p < 0.05). Conclusions Both groups of patients had satisfactory outcomes after the operation. However, in the instrumented posterior laxity test, the autograft gave better results than the allograft. No differences in functional scores

  3. Metaphyseal bone loss in revision knee arthroplasty.

    PubMed

    Ponzio, Danielle Y; Austin, Matthew S

    2015-12-01

    The etiology of bone loss encountered during revision total knee arthroplasty (TKA) is often multifactorial and can include stress shielding, osteolysis, osteonecrosis, infection, mechanical loss due to a grossly loose implant, and iatrogenic loss at the time of implant resection. Selection of the reconstructive technique(s) to manage bone deficiency is determined by the location and magnitude of bone loss, ligament integrity, surgeon experience, and patient factors including the potential for additional revision, functional demand, and comorbidities. Smaller, contained defects are reliably managed with bone graft, cement augmented with screw fixation, or modular augments. Large metaphyseal defects require more extensive reconstruction such as impaction bone grafting with or without mesh augmentation, prosthetic augmentation, use of bulk structural allografts, or use of metaphyseal cones or sleeves. While each technique has advantages and disadvantages, the most optimal method for reconstruction of large metaphyseal bone defects during revision TKA is not clearly established. PMID:26362647

  4. Allografts in the treatment of athletic injuries of the shoulder.

    PubMed

    Ho, Jason Y; Miller, Suzanne L

    2007-09-01

    As allogeneic musculoskeletal tissue is readily available, has minimal limitation in size or shape, and carries no donor site morbidity, it has become attractive for use in reconstructive shoulder surgery. Allograft is a viable option for treating osseous defects associated with glenohumeral instability and has been shown to achieve a stable shoulder with good clinical outcomes. Although there are mixed results on the use of allograft as rotator cuff augments or substitutes, new commercially processed materials such as GraftJacket are being tested to address the high failure rates associated with massive rotator cuff repair. Interposition arthroplasty as a treatment for glenohumeral arthritis in the young and active patient is a novel concept in which the arthritic glenoid is biologically resurfaced. Satisfactory results have been described using lateral meniscus and Achilles tendon allograft. Despite the promising reports on the use of allograft in reconstructive shoulder surgery, most of the published literature exists as retrospective, case reports. Additional large, controlled research is needed to prove the efficacy and safety of allograft tissue in the treatment of athletic injuries of the shoulder. PMID:17700375

  5. Monitoring of corneal allograft rejection using laser flare meter

    NASA Astrophysics Data System (ADS)

    Zarnowski, Tomasz; Haszcz, Dariusz; Rakowska, Ewa; Zagorski, Zbigniew

    1998-10-01

    The purpose of this study was to quantify noninvasively, with the use of laser-flare meter the alterations of the blood-aqueous barrier following penetrating keratoplasty. This could diagnose objectively disruption of this barrier in eyes with early allograft rejection, possible even before manifestation of the clinical signs and would help to monitor the efficacy of the treatment. We used the laser flare-meter (Kowa FM-500) to investigate alteration of the blood-aqueous barrier following uncomplicated penetrating keratoplasty (PK) and in corneal allograft rejection. Examination was performed in 50 eyes of 48 patients after uncomplicated PK (7 days to 12 months after PK), in 20 normal control eyes and in 8 patients with acute allograft rejection. Flare values after uncomplicated keratoplasty slowly decreased in time reaching nearly control values 6 - 12 months postoperatively. They were considerably higher for acute allograft rejection compared to eyes following uncomplicated PK and normal control group. Actually, they tended to diminish gradually after systemic and topical administration of steroids and/or immunosuppressants. Application of laser tyndalometry has been proven to be highly useful in the follow up of patients after perforating keratoplasty-especially high risk grafts, it helps to detect objectively early allograft rejection and is beneficial in monitoring the effectiveness of the treatment.

  6. Osteochondral and Meniscal Allograft Transplantation in the Football (Soccer) Player

    PubMed Central

    Williams, Riley J.; Gersoff, Wayne K.; Bugbee, William D.

    2012-01-01

    Knee injuries are common in football, frequently involving damage to the meniscus and articular cartilage. These injuries can cause significant disability, result in loss of playing time, and predispose players to osteoarthritis. Osteochondral allografting is an increasingly popular treatment option for osteoarticular lesions in athletes. Osteochondral allografts provide mature, orthotopic hyaline cartilage on an osseous scaffold that serves as an attachment vehicle, which is rapidly replaced via creeping substitution, leading to reliable graft integration that allows for simplified rehabilitation and accelerated return to sport. The indications for meniscal replacement in football players are currently still evolving. Meniscus allografts offer potential functional, analgesic, and chondroprotective benefits in the meniscectomized knee. In the player at the end of his or her professional/competitive career, meniscal allografts can play a role in averting progression of chondropenia and facilitating knee function and an active lifestyle. This article is intended to present a concise overview of the limited published results for osteochondral and meniscal allografting in the athletic population and to provide a practical treatment algorithm that is of relevance to the clinician as well as the patient/football player, based on current consensus of opinion. PMID:26069605

  7. Significant prolongation of segmental pancreatic allograft survival in two species

    SciTech Connect

    Du Toit, D.F.; Heydenrych, J.J.

    1988-06-01

    A study was conducted to assess the suppression of segmental pancreatic allograft rejection by cyclosporine (CSA) alone in baboons and dogs, and subtotal marrow irradiation (TL1) alone and TL 1 in combination with CSA in baboons. Total pancreatectomy in the dog and primate provided a reliable diabetic model, induced an absolute deficiency of insulin and was uniformly lethal if not treated. Continuous administration of CSA in baboons resulted in modest allograft survival. As in baboons, dogs receiving CSA 25 mg/kg/d rendered moderate graft prolongation but a dose of 40 mg/kg/d resulted in significant graft survival (greater than 100 days) in 5 of 8 allograft recipients. Irradiation alone resulted in minimal baboon pancreatic allograft survival of 20 baboons receiving TL1 1,000 rad and CSA, 3 had graft survival greater than of 100 days. Of 15 baboons receiving TL1 800 rad and CSA, 6 had graft survival of greater than 100 days. In conclusion, CSA administration in dogs and TL1 in combination with CSA in baboons resulted in highly significant segmental pancreatic allograft survival.

  8. Imaging mouse lung allograft rejection with 1H MRI

    PubMed Central

    Guo, Jinbang; Huang, Howard J.; Wang, Xingan; Wang, Wei; Ellison, Henry; Thomen, Robert P.; Gelman, Andrew E.; Woods, Jason C.

    2014-01-01

    Purpose To demonstrate that longitudinal, non-invasive monitoring via MRI can characterize acute cellular rejection (ACR) in mouse orthotopic lung allografts. Methods Nineteen Balb/c donor to C57BL/6 recipient orthotopic left lung transplants were performed, further divided into control-Ig vs anti-CD4/anti-CD8 treated groups. A two-dimensional multi-slice gradient-echo pulse sequence synchronized with ventilation was used on a small-animal MR scanner to acquire proton images of lung at post-operative days 3, 7 and 14, just before sacrifice. Lung volume and parenchymal signal were measured, and lung compliance was calculated as volume change per pressure difference between high and low pressures. Results Normalized parenchymal signal in the control-Ig allograft increased over time, with statistical significance between day 14 and day 3 post transplantation (0.046→0.789, P < 0.05), despite large inter-mouse variations; this was consistent with histopathologic evidence of rejection. Compliance of the control-Ig allograft decreased significantly over time (0.013→0.003, P < 0.05), but remained constant in mice treated with anti-CD4/anti-CD8 antibodies. Conclusion Lung allograft rejection in individual mice can be monitored by lung parenchymal signal changes and by lung compliance through MRI. Longitudinal imaging can help us better understand the time course of individual lung allograft rejection and response to treatment. PMID:24954886

  9. Guided bone regeneration around titanium implants: report of the treatment of 1,503 sites with clinical reentries.

    PubMed

    Fugazzotto, P A; Shanaman, R; Manos, T; Shectman, R

    1997-06-01

    Guided bone regeneration procedures were carried out around 1,503 implants, including 237 that were noted in a previous publication, using Gore-Tex membranes over demineralized freeze-dried bone allograft, freeze-dried bone allograft, an equal combination of these, or demineralized freeze-dried bone allograft combined with equal parts of resorbable tricalcium phosphate. Comparison of findings at the time of clinical reentry and preoperative photographs and measurements yielded an overall success rate of 97.0% in the treatment of dehisced or fenestrated implants or fixtures placed in immediate extraction sockets. Success was defined as the presence of regenerated hard tissue covering all previously exposed implant surfaces (complete success) or as the presence of two threads or 2 mm or less of residual dehiscence (partial success). PMID:9497721

  10. Septic arthritis with Staphylococcus lugdunensis following arthroscopic ACL revision with BPTB allograft.

    PubMed

    Mei-Dan, Omer; Mann, Gideon; Steinbacher, Gilbert; Ballester, Soleda J; Cugat, Ramon Bertomeu; Alvarez, Pedro Diaz

    2008-01-01

    Septic arthritis following anterior cruciate ligament reconstruction is an uncommon but a serious complication resulting in six times greater hospital costs than that of uncomplicated ACL surgery and an inferior postoperative activity level. Promptly initiating a specific antibiotic therapy is the most critical treatment, followed by open or arthroscopic joint decompression, debridement and lavage. Staphylococcus lugdunensis is a coagulase-negative staphylococcus predominantly infecting the skin and soft tissue. The few reported cases of bone and joint infections by S. lugdunensis indicate that the clinical manifestations were severe, the diagnosis elusive, and the treatment difficult. If the microbiology laboratory does not use the tube coagulase (long) test to confirm the slide coagulase test result, the organism might be misidentified as Staphylococcus aureus. S. lugdunensis is more virulent than other coagulase-negative staphylococcus; in many clinical situations it behaves like S. aureus, further increasing the confusion and worsening the expected outcome. S. lugdunensis is known to cause infective endocarditis with a worse outcome, septicemia, deep tissue infection, vascular and joint prosthesis infection, osteomyelitis, discitis, breast abscess, urine tract infections, toxic shock and osteitis pubis. We present the first case report in the literature of septic arthritis with S. lugdunensis following arthroscopic ACL revision with bone-patellar-tendon-bone allograft. PMID:17684731