Allogeneic Bone Transplantation Research Articles

Establishing a bone bank within a hospital setting in India: early insights from a tertiary care center in Northern India-a review article.

When addressing bone defects resulting from trauma, infection, or tumors, the use of allogenic bone is often necessary. While autografts are considered the standard, they have limitations and can lead to donor site morbidity. Consequently, there has been exploration into the feasibility of utilizing allogenic bone and bone graft replacements. Allogenic bone transplants are acquired from donors following rigorous procurement, sterile processing, and donor screening procedures. To ensure the safe storage and effective utilization of allograft material, a bone banking system is employed. Establishing and managing an orthopedic bone bank, entails navigating complex legal and medical organizational aspects. This paper examines the establishment and operation of bone banks in India, drawing upon our first-hand experience in managing one at a tertiary care center in Northern India.Level of evidence: Level IV.

Preliminary study on the preparation of antler powder/chitosan/β-glycerophosphate sodium/polyvinyl alcohol porous hydrogel scaffolds and their osteogenic effects.

Introduction: The production of bone-like structural scaffolds through bone tissue engineering technology is a promising method for bone regeneration to repair bone defects. Deer antler, an easily harvested and abundantly sourced initial bone tissue structure, resembles the composition and structure of human cancellous bone and can serve as a new material for allogeneic bone transplantation. Methods: This study involved the preparation and characterization of antler powder/chitosan/β-glycerophosphate sodium/polyvinyl alcohol (AP/CS/β-GP/PVA) porous hydrogel scaffolds to verify their material properties and osteogenic mechanisms. The microstructure, hydrophilicity, and mechanical properties of the scaffolds were studied using Scanning Electron Microscopy (SEM), contact angle measurement, and a universal material testing machine. The interactions between the various components were investigated using Fourier-Transform Infrared Spectroscopy (FTIR). Biocompatibility, osteogenic properties, and expression of osteogenesis-related proteins of the scaffolds were evaluated through Cell Counting Kit-8 (CCK-8) assays, alkaline phosphatase staining, Alizarin Red staining, live/dead cell staining, and Western blot analysis. Results: The results showed that as the content of deer antler powder increased, both the hydrophilicity and mechanical properties of the scaffold materials improved, while the porosity slightly decreased with an increase in deer antler powder content. Cell culture experiments demonstrated that scaffolds with a higher proportion of deer antler powder were beneficial for the proliferation and differentiation of mouse pre-osteoblast (MC3T3-E1) cells, with the scaffolds containing 10% and 8% deer antler powder showing the best effects. The upregulation of RUNX2, OCN, OSX, and OPN protein expression may promote differentiation. Discussion: Therefore, the AP/CS/β-GP/PVA hydrogel scaffolds have the potential to become a promising biomaterial for bone tissue engineering.

Biofunctionalisation strategies of material surface and the inspired biological effects for bone repair

AbstractDue to trauma and disease, bone defects endanger the healthy life of human beings. At present, the gold standard for bone defect repair is still autologous bone transplantation and allogeneic bone transplantation. However, its insufficient source, potential disease transmission and immune rejection limit its clinical application. Therefore, the development of bone repair materials plays an important role in promoting bone repair. As the interface between material and tissue, the surface of the material plays an important role in the reaction after implantation, which determines the effectiveness of defect repair treatment. With the development of surface engineering and technology, bone repair materials have developed from biological inertia to biological activity by endowing various biological functions by controlling the composition, topological morphology and structure of the material surface etc. The inspired biofunctionalisation of material surface includes the capacities of inducing osteogenesis, promoting angiogenesis, antibacterial, immune regulation etc., as well as integration of postoperative repair and treatment. The authors review the biofunctionalisation of biomaterial surface and the inspired biological effects for bone repair, mainly including physical and chemical properties of material surface to regulate osteogenesis, and functional strategy of bone repair material surface.

Biomechanical Investigation of the Osseointegration of Titanium Implants With Different Surfaces Placed With Allogeneic Bone Transfer.

Allogeneic grafts can be preferred to autogenous grafts in plastic and oral-maxillofacial surgery for vertical and horizontal bone deficiencies. Implant surface properties are an important factor in osseointegration. This study aims to evaluate the osseointegration levels of titanium implants with machined, sand-blasted, and acid-etched (SLA) and resorbable blast material (RBM) surfaces placed together with allogeneic bone tissue transplantations obtained from the tibia bone using biomechanical method. Twenty-five female Sprague-Dawley rats were included in the study. The rats were divided into groups in which machined (n=7), SLA (n=7), and RBM (n=7) surface implants were placed with the transplantation of bone taken from the tibia. Four rats (both left and right tibias) were used as donors. Grafts and implants were surgically placed in the corticocancellous part of the metaphyseal area of the tibia bones of rats. At the end of the 4-week experimental setup, all rats were killed, and the implants and surrounding bone tissue were subjected to biomechanical reverse torque analysis (N/cm). Sand-blasted acid-etched surface implants were observed to have higher biomechanical osseointegration levels than RBM and machined surface implants ( P <0.05). No statistical difference could be detected between the RBM and machined surface implants ( P >0.05). On the basis of the limited results of this study, it can be concluded that the osseointegration levels of SLA surface implants placed with allogeneic bone transplantation may be better than those of machined and RBM surface implants.

Individualized surgical treatment of sarcomas of the extremities

Sarcomas of the extremities are rare entities, the treatment of which requires special expertise. Even if the treatment of patients is always interdisciplinary, the surgical R0 resection is the key point of each curatively intended treatment. In addition to resection in sano, the aim is to preserve the extremities and function, so that defect reconstruction after resection plays adecisive role. Due to the heterogeneity of tumors as well as their localization and extent, reconstruction is always an individually adapted treatment. Modular tumor endoprostheses are often used in this context, which can be constructed according to the size of the defect. The transplantation of autologous or allogeneic bone is also frequently used alone or as an additive procedure. Patient-specific (mega)prostheses are used particularly for pelvic tumors. Defect reconstruction using scaffold-based procedures from the field of tissue engineering is being tested as apromising procedure for the future. This article provides an overview of the treatment principles for sarcomas of the extremities and their individual reconstruction options.

CK1ε drives osteogenic differentiation of bone marrow mesenchymal stem cells via activating Wnt/β-catenin pathway.

The treatment of bone defects is a difficult problem in orthopedics. At present, the treatment mainly relies on autologous or allogeneic bone transplantation, which may lead to some complications such as foreign body rejection, local infection, pain, or numbness at the bone donor site. Local injection of conservative therapy to treat bone defects is one of the research hotspots at present. Bone marrow mesenchymal stem cells (BMSCs) can self-renew, significantly proliferate, and differentiate into various types of cells. Although it has been reported that CK1ε could mediate the Wnt/β-catenin pathway, leading to the development of the diseases, whether CK1ε plays a role in bone regeneration through the Wnt/β-catenin pathway has rarely been reported. The purpose of this study was to investigate whether CK1ε was involved in the osteogenic differentiation (OD) of BMSCs through the Wnt/β-catenin pathway and explore the mechanism. We used quantitative reverse transcription-polymerase chain reaction (qRT-qPCR), Western blots, immunofluorescence, alkaline phosphatase, and alizarin red staining to detect the effect of CK1ε on the OD of BMSCs and the Wnt/β-catenin signaling pathway. CK1ε was highly expressed in BMSCs with OD, and our study further demonstrated that CK1ε might promote the OD of BMSCs by activating DLV2 phosphorylation, initiating Wnt signaling downstream, and activating β-catenin nuclear transfer. In addition, by locally injecting a CK1ε-carrying adeno-associated virus (AAV5- CK1ε) into a femoral condyle defect rat model, the overexpression of CK1ε significantly promoted bone repair. Our data show that CK1ε was involved in the regulation of OD by mediating Wnt/β-catenin. This may provide a new strategy for the treatment of bone defects.

Research Progress on the Osteogenesis-Related Regulatory Mechanisms of Human Umbilical Cord Mesenchymal Stem Cells.

In recent years, research on human umbilical cord mesenchymal stem cells (hUCMSCs) derived from human umbilical cord tissue has accelerated and entered clinical application research. Compared with mesenchymal stem cells (MSCs) from other sources, hUCMSCs can be extracted from different parts of umbilical cord or from the whole umbilical cord. It has the characteristics of less ethical controversy, high differentiation potential, strong proliferation ability, efficient expansion in vitro, avoiding immune rejection and immune privilege, and avoids the limitations of lack of embryonic stem cells, heterogeneity, ethical and moral constraints. hUCMSCs avoid the need for embryonic stem cell sources, heterogeneity, and ethical and moral constraints. Bone defects are very common in clinical practice, but completely effective bone tissue regeneration treatment is challenging. Currently, autologous bone transplantation and allogeneic bone transplantation are main treatment approaches in clinical work, but each has different shortcomings, such as limited sources, invasiveness, immune rejection and insufficient osteogenic ability. Therefore, to solve the bottleneck of bone tissue regeneration and repair, a great amount of research has been carried out to explore the clinical advantages of hUCMSCs as seed cells to promote osteogenesis.However, the regulation of osteogenic differentiation of hUCMSCs is an extremely complex process. Although a large number of studies have demonstrated that the role of hUCMSCs in enhancing local bone regeneration and repair through osteogenic differentiation and transplantation into the body involves multiple signaling pathways, there is no relevant article that summarize the findings. This article discusses the osteogenesis-related regulatory mechanisms of hUCMSCs, summarizes the currently known related mechanisms, and speculates on the possible signals.

Advances in osseointegration of biomimetic mineralized collagen and inorganic metal elements of natural bone for bone repair.

At this stage, bone defects caused by trauma, infection, tumor, or congenital diseases are generally filled with autologous bone or allogeneic bone transplantation, but this treatment method has limited sources, potential disease transmission and other problems. Ideal bone-graft materials remain continuously explored, and bone defect reconstruction remains a significant challenge. Mineralized collagen prepared by bionic mineralization combining organic polymer collagen with inorganic mineral calcium phosphate can effectively imitate the composition and hierarchical structure of natural bone and has good application value in bone repair materials. Magnesium, strontium, zinc and other inorganic components not only can activate relevant signaling pathways to induce differentiation of osteogenic precursor cells but also stimulate other core biological processes of bone tissue growth and play an important role in natural bone growth, and bone repair and reconstruction. This study reviewed the advances in hydroxyapatite/collagen composite scaffolds and osseointegration with natural bone inorganic components, such as magnesium, strontium and zinc.

Application of Graphene-Based Nanomaterials Combined with Early Exercise Rehabilitation Training in the Treatment of Patients with Infectious Bone Defects

Methods of treating bone defects include autogenous bone and allogeneic bone transplantation, tissue engineering technology, gene therapy, growth factor and adjuvant therapy of physical therapy, etc. However, most treatment schemes have obvious disadvantages. The purpose of this paper is to study the application of graphene-based nanomaterials combined with early exercise rehabilitation training in the treatment of patients with infectious bone defects. The biomedical properties and biomedical applications of graphene are briefly introduced through literature research and investigation, and bone defect diseases and commonly used treatment methods are analyzed. Graphene is used in many biomedical fields, such as disease diagnosis, biosensing, antibacterial and antiviral materials, cancer targeting, photothermal therapy, drug delivery, cell electrical stimulation, tissue engineering, stem cell technology, DNA sequencing and fluorescent (FL) tracking molecular probes. The effects of graphene-based nanomaterials and rehabilitation exercise on the treatment of infectious bone defects were compared through controlled experiments. The results show that although the repair effect of graphene-based nano-materials is not as good as that of autogenous bone, the difference is not significant, and it is better than calcium phosphate cement. After rehabilitation exercise, the curative effect of graphene experimental group was improved. In the 12th week, the tensile strength reached 5.78 N, and the torsional strength reached 0.93 N m, which exceeded the group of autogenous bone without rehabilitation exercise. This paper discusses the strength-related repair effect, but the in vivo toxicity of graphene needs further study.

Composite bone and skin flap transplantation combined with bone lengthening for repairing lower limb burn with soft tissue and bone defect

To compare the effect of traditional fibula flap combined with allogeneic bone transplantation and composite bone flap transplantation combined with bone lengthening in staged repair of severe soft tissue and bone defect caused by lower limb burn. Total 68 patients with severe soft tissue and bone defect caused by lower limb burn from March 2015 to January 2018 were retrospectively analyzed, and they were divided into control group (34 cases) and study group (34 cases) according to the treatment plan. All patients had different degrees of soft tissue and bone tissue defects. In the study group, 34 patients were treated with composite bone flap transplantation combined with bone lengthening. There were 22 males and 12 females; the age ranged from 32 to 46(39.18±6.01) years; the time from injury to treatment was (16.69±5.11) h;28 cases were caused by explosion injury and 6 cases were caused by firearm burn; the length of bone defect was (12.10± 2.34) cm;and 16 cases were on the left side of affected limb 18 cases were on the right side. In the control group, there were 24 males and 10 females, aged 31 to 47 (38.93 ± 5.81) years;the time from injury to treatment was(17.10±5.63) h;the causes of injury were explosive injury in 30 cases and firearm burn in 4 cases; the length of bone defect was (11.96±2.51) cm;19 cases were on the left side and 15 cases on the right side. All patients were followed up for 6 months. The FMA scores before operation and 3 and 6 months after operation, treatment satisfaction, curative effect and complications of the two groups were recorded. Limb function:there was no significant difference in FMA scores between the two groups before operation (P> 0.05), and the FMA scores of the two groups were higher than those before operation 3 and 6 months after operation(P<0.05), and the FMA scores of the studygroup were higher than those of the control group (P<0.05). At 6 months after operation:the excellent and good rate of the study group (94.12%) was higher than that of the control group (76.47%)(P<0.05), the treatment satisfaction of the study group (94.12%) was higher than that of the control group(76.47%)(P<0.05). Complications:the incidence of complications in the study group (14.71%) was higher than that in the control group (26.47%) (P>0.05). the combined use of composite bone flap transplantation and bone lengthening staged repair in the treatment of severe soft tissue and bone defect caused by lower limb burn can achieve good therapeutic effect, improve limb function, and have high treatment satisfaction and certain safety.

Bone transplantation or biomaterials? : An analysis of 99,863 surgical procedures in orthopedic and trauma surgery in Germany from 2018

FragestellungZiel der Arbeit war es, (1) die Gesamtzahl der operativen Eingriffe mit autologer bzw. allogener Knochentransplantation sowie Biomaterialien zu analysieren. (2) Es sollten die unterschiedlichen Arten von Biomaterialien, autologen und allogenen Knochentransplantationen untersucht und (3) die zusätzliche Anwendung eines Antibiotikumzusatzes bei Biomaterialien analysiert werden.MethodikDaten wurden vom Statistischen Bundesamt für das Jahr 2018 bezogen. Durch die Operationen- und Prozedurenschlüssel 5‑784 „Knochentransplantation und -transposition“ und 5‑785 „Implantation von alloplastischem Knochenersatz“ konnten die Prozedurhäufigkeit der Implantation von Biomaterialien, wie Kalziumphosphatkeramiken, Kalziumsulfate, Kalziumphosphatzemente und Polymethylmethacrylat, sowie autologem und allogenem Knochen zur Defektrekonstruktion an Extremitäten und Becken analysiert werden.ErgebnisseIm Jahr 2018 wurden insgesamt 99.863 Prozeduren unter Verwendung von Autografts (54.784, 55 %). Biomaterialien (23.838, 24 %) und Allografts (21.241, 21 %) durchgeführt. Sowohl bei Autografts als auch bei Allografts kamen am häufigsten Spongiosaplastiken (77 % resp. 79 %) zum Einsatz. Bei den Biomaterialien wurden Keramiken (42 %) häufiger als Knochenzemente (37 %) benutzt (sonstige Biomaterialien 21 %). Bei 16.027 (67 %) der Biomaterialien wurde kein Antibiotikumzusatz verwendet. Antibiotikumzusatz kam v. a. bei Knochenzementen zum Einsatz (6612 Fälle, 75 %).SchlussfolgerungIm Jahr 2018 wurden insgesamt bei einer beträchtlichen Anzahl von 99.863 Eingriffen zur Knochendefektrekonstruktion Knochentransplantate bzw. Biomaterialien eingesetzt. Bei mehr als der Hälfte der Fälle wurde autologer Knochen (55 %), ungefähr einem Viertel Biomaterialien (24 %) und etwa einem Fünftel (21 %) allogener Knochen eingesetzt. Als Biomaterial wurden Keramiken (42 %) öfter als Zemente (37 %) verwendet. Antibiotikumzusatz kam v. a. bei Zementen zum Einsatz (75 %).

Study of PLGA microspheres loaded with pOsx/PEI nanoparticles for repairing bone defects in vivo and in vitro.

Autogenous or allogenic bone transplantation is the main treatment for bone defects and nonunions. However, the shortcomings of autogenous or allogenic bone transplantation limit its wide application in clinical use. This study investigated the effect of poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with pOsterix (pOsx)/polyethylenimine (PEI) nanoparticles in repairing bone defects and explored its mechanism. Poly(lactic-co-glycolic acid) microspheres loaded with pOsx/PEI nanoparticles were constructed. The Osx transfection effect was detected by fluorescence quantitative PCR and western blotting methods. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-diphenytetrazoliumromide (MTT) and flow cytometry methods were used to detect cell proliferation. The collagen I (Col-1), osteopontin (OPN) and osteocalcin (OC) expression levels were detected using real-time polymerase chain reaction (RT-PCR) and western blotting methods. Bone defect model was constructed. Bone repair was detected using X-ray, hematoxylin and eosin (H&E) staining, and Mason staining methods. PLGA@pOsx/PEI has transfection effect both in vitro and in vivo, does not affect cell proliferation and is safe for cells. PLGA@pOsx/PEI could promote the expression of Col-1, OPN and OC in vitro and in vivo. PLGA@pOsx/PEI could promote osteogenesis in vivo. PLGA@pOsx/PEI with high Osx expression could promote the expression of OC, OPN, and COL-I. PLGA@pOsx/PEI can be used as a material for repairing bone defects and can promote bone formation. These results provide a theoretical and practical basis for its further clinical application.

Human amniotic fluid stem cells attract osteoprogenitor cells in bone healing.

Current treatments of large bone defects are based on autologous or allogenic bone transplantation. Human amniotic fluid stem cells (hAFSCs) were evaluated for their potential in bone regenerative medicine. In this study, hAFSCs were transduced with lentiviral vector harboring red fluorescent protein to investigate their role in the regeneration of critical-size bone defects in calvarial mouse model. To distinguish donor versus recipient cells, a transgenic mouse model carrying GFP fluorescent reporter was used as recipient to follow the fate of hAFSCs transplanted in vivo into Healos® scaffold. Our results showed that transduced hAFSCs can be tracked in vivo directly at the site of transplantation. The presence of GFP positive cells in the scaffold at 3 and 6 weeks after transplantation indicates that donor hAFSCs can recruit host cells during the repair process. These observations help clarify the role of hAFSCs in bone tissue repair.

Endoprosthetic replacement following intercalary resection

Endoprosthetic replacement is avaluable treatment option following intercalary resection of bone tumours in the diaphysis. To identify indication, operative technique, implants currently available, literature results and alternative procedures for the alloplastic reconstruction of segmental bone defects. This review article summarizes the authors' own experiences and relevant clinical studies focussing on this topic. According to the literature, 10-year-survival rates of intercalary endoprostheses range between 64 and 80%. Yet, comparisons between different publications are difficult due to the limited number of cases, different implants, follow-up periods and the heterogeneous patient populations. Biological alternatives for reconstruction are autologous bone transplantation, distraction osteogenesis and bone transport, allogenic bone transplantation, and the induced membrane technique. Innovative tissue engineering approaches are still limited to preclinical testing. Short- to mid-term results for segmental endoprostheses following intercalary resections are satisfactory and may be regarded as superior to those of biological reconstructions due to the immediate full weight-bearing capability. However, they are mainly applied for elderly patients and in palliative situations because of potential long-term complications.

Impact of Day 14 Peripheral Blood Chimerism after Allogeneic Hematopoietic Stem Cell Bone Transplantation on the Treatment Outcome of Non-Malignant Disease.

BackgroundThe impact of early peripheral blood chimerism on the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is unclear. We aimed to determine whether day 14 peripheral blood chimerism after allo-HSCT predicts outcomes in patients with non-malignant diseases.MethodsData from 56 patients who received allo-HSCT between April 2007 and March 2016 were retrospectively analyzed. Chimerism was evaluated using short-tandem repeat polymerase chain reaction, with mixed chimerism (MC) defined as greater than 1% recipient cells which was further categorized into low-level MC (> 1% and < 15% of recipient-derived cells) and high-level MC (≥ 15% of the recipient-derived cells).ResultsThirty-six patients showed complete donor chimerism (CC), 14 low-level MC, and 6 high-level MC at day 14 post-transplant. The estimated 5-year event-free survival (EFS) was higher in the CC or low-level MC groups than in the high-level MC group (86.1% vs. 71.4% vs. 33.3%; P = 0.001). In BM or peripheral blood stem cell (BM/PBSC) transplants, the 5-year EFS was higher in the CC or low-level MC group than in the high-level MC group (93.1% vs. 66.7% vs. 0%; P < 0.001). However, in cord blood transplants, the 5-year OS and EFS according to the day 14 peripheral blood chimerism did not reach statistical significance.ConclusionAlthough CC is not always necessary after allo-HSCT for non-malignant diseases, our data suggest that day 14 peripheral blood chimerism may predict outcomes in patients with non-malignant diseases who underwent BM/PBSC transplants.

Allogeneic transplants for biological reconstruction of bone defects

A combination of allogeneic and autologous bone transplants is frequently used for the biological reconstruction of bone defects. Autologous bone transplants can be used either in the form of structural or cancellous bone transplants. The osteogenic potential of autologous cancellous bone is well-known and is still the gold standard with respect to osteoinduction and remodelling. Structural transplants, such as fibular and tricortical iliac crest grafts can be transplanted either free, i.e. non-vascularized or vascularized with anastomosed vessels. Allogeneic bone transplants can be used in a spongiose or structural form. In revision endoprosthetics the use of allogeneic bone transplants has essentially been reduced to impaction grafting, due to the introduction of trabecular metal as a permanently stable substitute. Allogeneic transplants have been restricted due to 3D-printing and the associated individually adapted reconstruction. In individual cases combined reconstruction consisting of allograft and endoprosthesis provide the advantage of safe load transmission and permanent reconstruction by the endoprosthesis and the possibility of soft tissue insertion of the allograft.

Artificial Bone via Bone Tissue Engineering: Current Scenario and Challenges.

Bone provides mechanical support, and flexibility to the body as a structural frame work along with mineral storage, homeostasis, and blood pH regulation. The repair and/or replacement of injured or defective bone with healthy bone or bone substitute is a critical problem in orthopedic treatment. Recent advances in tissue engineering have shown promising results in developing bone material capable of substituting the conventional autogenic or allogenic bone transplants. In the present review, we have discussed natural and synthetic scaffold materials such as metal and metal alloys, ceramics, polymers, etc. which are widely being used along with their cellular counterparts such as stem cells in bone tissue engineering with their pros and cons.

Biological downsizing : Acetabular defect reconstruction in revision total hip arthroplasty

Periacetabular bony defects remain agreat challenge in revision total hip arthroplasty. After assessment and classification of the defect and selection of asuitable implant the primary stable fixation and sufficient biological reconstitution of asustainable bone stock are essential for long term success in acetabular revision surgery. Biological defect reconstruction aims for the down-sizing of periacetabular defects for later revision surgeries. In the field of biological augmentation several methods are currently available. Autologous transplants feature aprofound osseointegrative capacity. However, limitations such as volume restrictions and secondary complications at the donor site have to be considered. Structural allografts show little weight bearing potential in the long term and high failure rates. In clinical practice, the usage of spongious chips implanted via impaction bone grafting technique in combination with antiprotrusio cages for the management of contained defects have shown promising long time results. Nevertheless, when dealing with craniolateral acetabular and dorsal column defects, the additional implantation of macroporous metal implants or augments should be considered since biological augmentation has shown little clinical success in these particular cases. This article provides an overview of the current clinically available biological augmentation methods of peri-acetabular defects. Due to the limitations of autologous and allogeneic bone transplants in terms of size and availability, the emerging field of innovative implantable tissue engineering constructs gains interest and will also be discussed in this article.

A bioresorbable polylactide implant used in bone cyst filling

The aims in treating patients diagnosed with critical-sized bone defects resulting from bone cysts are to replace the lost bone mass after its removal and to restore function. The standard treatment is autologous or allogeneic bone transplantation, notwithstanding the known consequences and risks due to possible bone infection, donor site morbidity, bleeding and nerve injury and possible undesirable immune reactions. Additionally, allogeneic grafts are inhomogeneous, with a mosaic of components with difficult-to-predict regenerative potential, because they consist of cancellous bone obtained from different bones from various cadavers. In the present study, a 22-year-old patient with a history of right humerus fracture due to bone cysts was diagnosed with recurrent cystic lesions based on X-ray results. The patient qualified for an experimental program, in which he was treated with the application of a bioresorbable polylactide hybrid sponge filled with autologous platelet-rich plasma. Computed tomography and magnetic resonance imaging performed 3, 6, and 36months after surgery showed progressive ossification and bone formation inside the defect cavity in the humerus. Three years after treatment with the bone substitute, the patient is pain free, and the cystic lesions have not reoccurred.

Bacterial infections associated with allogenic bone transplantation.

Bone allografts are frequently used in orthopedic reconstructive procedures carrying a high risk for recipients. To assess the nature and frequency of allograft contamination and associated surgical infection the case records from our institutional bone bank were reviewed. We retrospectively analyzed the microbiology of discarded bone allografts and the surgical site of the recipients. A case series of patients who acquired surgical site infection after allogenic bone transplantation was presented. Swab culturing was conducted on 309 femoral heads from living donors who underwent partial and total hip arthroplasty between January 2007 and December 2013. To prevent potential bone allograft contamination we used saline solution of 2.0 mg/ml of amikacin during thawing. The overall infection rate was analyzed in 197 recipients. Of the 309 donated femoral heads, 37 were discarded due to bacterial contamination, giving the overall contamination rate of 11.97%. The postoperative survey of 213 bone allotransplantations among 197 recipients showed the infection rate of 2.03%. The coagulase-negative Staphylococcus was the most commonly identified contaminant of bone allografts and recipient surgical sites. The allograft contamination rate and the infection rate among recipients in our institution are in accordance with the international standards. The coagulase-negative Staphylococcus was the most commonly identified contaminant of bone allografts,and recipient surgical sites. There is no strong evidence that surgical site infections were associated with bone allograft utilization. We plan further improvements in allograft handling and decontamination with highly concentrated antibiotic solutions in order to reduce infection risk for recipients.