Treatment Of Massive Bone Defects Research Articles

Implantation of bovine hydroxyapatite and secretome with different oxygen concentration may improve massive bone defect regeneration: An experimental study on animal model.

The most widely used biomaterials in the treatment of massive bone defects are allograft bone or metal implants. The current problem is that the availability of allographs is limited and metal implants are very expensive. Mass production of secretome can make bone reconstruction of massive bone defects using a scaffold more effective and efficient. This study aims to prove bone regeneration in massive bone defects using bovine hydroxyapatite reconstruction with normoxic and hypoxic secretome conditions using collagen type 1 (COL1), alkaline phosphate (ALP), osteonectin (ON), and osteopontin (OPN) parameters. This is an in vivo study using male New Zealand white rabbits aged 6-9 months. The research was carried out at the Biomaterials Center-Tissue Bank, Dr. Soetomo Hospital for the manufacturer of bovine hydroxyapatite (BHA) and secretome BM-MSC culture under normoxic and hypoxic conditions, and UNAIR Tropical Disease Institute for implantation in experimental animals. Data analysis was carried out with the one-way ANOVA statistical test and continued with the Post Hoc test LSD statistical test to determine whether or not there were significant differences between groups. There were significant differences between hypoxic to normoxic group and hypoxic to BHA group at day-30 observation using ALP, COL 1, ON, and OPN parameters. Meanwhile, there is only osteonectin parameter has significant difference at day-30 observation. At day-60 observation, only OPN parameter has significant differences between hypoxic to normoxic and hypoxic to BHA group. Between day-30 and day-60 observation, BHA and normoxic groups have a significant difference at all parameters, but in hypoxic group, there are only difference at ALP, COL 1, and ON parameters. Hypoxic condition BM-MSC secretome with BHA composite is superior and could be an option for treating bone defect.

Biomimetic Nanosilica-Collagen Scaffolds for In Situ Bone Regeneration: Toward a Cell-Free, One-Step Surgery.

Current approaches to fabrication of nSC composites for bone tissue engineering (BTE) have limited capacity to achieve uniform surface functionalization while replicating the complex architecture and bioactivity of native bone, compromising application of these nanocomposites for in situ bone regeneration. A robust biosilicification strategy is reported to impart a uniform and stable osteoinductive surface to porous collagen scaffolds. The resultant nSC composites possess a native-bone-like porous structure and a nanosilica coating. The osteoinductivity of the nSC scaffolds is strongly dependent on the surface roughness and silicon content in the silica coating. Notably, without the use of exogenous cells and growth factors (GFs), the nSC scaffolds induce successful repair of a critical-sized calvarium defect in a rabbit model. It is revealed that topographic and chemical cues presented by nSC scaffolds could synergistically activate multiple signaling pathways related to mesenchymal stem cell recruitment and bone regeneration. Thus, this facile surface biosilicification approach could be valuable by enabling production of BTE scaffolds with large sizes, complex porous structures, and varied osteoinductivity. The nanosilica-functionalized scaffolds can be implanted via a cell/GF-free, one-step surgery for in situ bone regeneration, thus demonstrating high potential for clinical translation in treatment of massive bone defects.

Near-Infrared Light-Triggered Porous AuPd Alloy Nanoparticles To Produce Mild Localized Heat To Accelerate Bone Regeneration.

The treatment of massive bone defects is still a significant challenge for orthopedists. Here we have engineered synthetic porous AuPd alloy nanoparticles (pAuPds) as a hyperthermia agent for in situ bone regeneration through photothermal therapy (PTT). After being swallowed by cells, pAuPds produced a mild localized heat (MLH) (40-43 °C) under the irradiation of a near-infrared laser, which can greatly accelerate cell proliferation and bone regeneration. Almost 97% of the cranial defect area (8 mm in diameter) was covered by the newly formed bone after 6 weeks of PTT. RNA sequencing analysis was used to obtain insight into the molecular mechanism of the MLH on cell proliferation and bone formation. These results demonstrated that the Wnt signaling pathway was involved in the MLH. This Letter provides a unique strategy with mild heat stimulation and high efficiency for in situ bone regeneration.

3D Printed Acetabular Cups for Total Hip Arthroplasty: A Review Article

Three-dimensional (3D) printed titanium orthopaedic implants have recently revolutionized the treatment of massive bone defects in the pelvis, and we are on the verge of a change from conventional to 3D printed manufacture for the mass production of millions of off-the-shelf (non-personalized) implants. The process of 3D printing has many adjustable variables, which taken together with the possible variation in designs that can be printed, has created even more possible variables in the final product that must be understood if we are to predict the performance and safety of 3D printed implants. We critically reviewed the clinical use of 3D printing in orthopaedics, focusing on cementless acetabular components used in total hip arthroplasty. We defined the clinical and engineering rationale of 3D printed acetabular cups, summarized the key variables involved in the manufacturing process that influence the properties of the final parts, together with the main limitations of this technology, and created a classification according to end-use application to help explain the controversial and topical issues. Whilst early clinical outcomes related to 3D printed cups have been promising, in-depth robust investigations are needed, partly because regulatory approval systems have not fully adapted to the change in technology. Analysis of both pristine and retrieved cups, together with long-term clinical outcomes, will help the transition to 3D printing to be managed safely.

Supercritical CO2 foamed composite scaffolds incorporating bioactive lipids promote vascularized bone regeneration via Hif-1α upregulation and enhanced type H vessel formation

Bone tissue engineering has substantial potential for the treatment of massive bone defects; however, efficient vascularization coupled with bone regeneration still remains a challenge in this field. In the current study, supercritical carbon dioxide (scCO2) foaming technique was adopted to fabricate mesoporous bioactive glasses (MBGs) particle-poly (lactic-co-glycolic acid) (PLGA) composite scaffolds with appropriate mechanical and degradation properties as well as in vitro bioactivity. The MBG-PLGA scaffolds incorporating the bioactive lipid FTY720 (designated as FTY/MBG-PLGA) exhibited simultaneously sustained release of the bioactive lipid and ions. In addition to providing a favorable microenvironment for cellular adhesion and proliferation, FTY/MBG-PLGA scaffolds significantly facilitated the in vitro osteogenic differentiation of rBMSCs and also markedly stimulated the upregulation of Hif-1α expression via the activation of the Erk1/2 pathway, which mediated the osteogenic and pro-angiogenic effects on rBMSCs. Furthermore, FTY/MBG-PLGA extracts induced superior in vitro angiogenic performance of HUVECs. In vivo evaluation of critical-sized rat calvarial bone defects indicated that FTY/MBG-PLGA scaffolds potently promoted vascularized bone regeneration. Notably, the significantly enhanced formation of type H vessels (CD31hiEmcnhi neo-vessels) was observed in newly formed bone tissue in FTY/MBG-PLGA group, strongly suggesting that FTY720 and therapeutic ions released from the scaffolds synergistically induced more type H vessel formation, which indicated the coupling of angiogenesis and osteogenesis to achieve efficiently vascularized bone regeneration. Overall, the results indicated that the foamed porous MBG-PLGA scaffolds incorporating bioactive lipids achieved desirable vascularization-coupled bone formation and could be a promising strategy for bone regenerative medicine. Statement of SignificanceEfficacious coupling of vascularizationandbone formation is critical for the restoration of large bone defects. Anoveltechnique was used to fabricate composite scaffolds incorporating bioactive lipids which possessedsynergistic cues of bioactive lipids and therapeutic ions to potently promotebone regenerationas well as vascularization. The underlying molecular mechanism for the osteogenic and pro-angiogenic effects of the compositescaffolds was unveiled. Interestingly, the scaffolds were furtherfoundto enhance the formation oftype H capillarieswithin the bone healing microenvironment to couple angiogenesis to osteogenesis to achieve satisfyingvascularizedbone regeneration.These findings provide a novel strategy to develop efficiently vascularized engineering constructs to treat massive bone defects.

Treatment with Vancomycin Loaded Calcium Sulphate and Autogenous Bone in an Improved Rabbit Model of Bone Infection

Bone infection results from bacterial invasion, which is extremely difficult to treat in clinical, orthopedic, and traumatic surgery. The bone infection may result in sustained inflammation, osteomyelitis, and eventual bone non-union. Establishment of a feasible, reproducible animal model is important to bone infection research and antibiotic treatment. As an in vivo model, the rabbit model is widely used in bone infection research. However, previous studies on rabbit bone infection models showed that the infection status was inconsistent, as the amount of bacteria was variable. This study presents an improved surgical method for inducing bone infection on a rabbit, by blocking the bacteria in the bone marrow. Then, multi-level evaluations can be carried out to verify the modelling method. In general, debriding necrotic tissue and implantation of vancomycin-loaded calcium sulphate (VCS) are predominant in antibiotic treatment. Although calcium sulphate in VCS benefits osteocyte crawling and new bone growth, massive bone defects occur after debriding. Autogenous bone (AB) is an appealing strategy to overcome bone defects for the treatment of massive bone defects after debriding necrotic bone. In this study, we used the tail bone as an autogenous bone implanted in the bone defect. Bone repair was measured using micro-computed-tomography (micro-CT) and histological analysis after animal sacrifice. As a result, in the VCS group, bone non-union was consistently obtained. In contrast, the bone defect areas in the VCS-AB group were decreased significantly. The present modeling method described a reproducible, feasible, stable method to prepare a bone infection model. The VCS-AB treatment resulted in lower bone non-union rates after antibiotic treatment. The improved bone infection model and the combination treatment of VCS and autogenous bone could be helpful in studying the underlying mechanisms in bone infection and bone regeneration pertinent to traumatology orthopedic applications.

Treatment with Vancomycin Loaded Calcium Sulphate and Autogenous Bone in an Improved Rabbit Model of Bone Infection.

Bone infection results from bacterial invasion, which is extremely difficult to treat in clinical, orthopedic, and traumatic surgery. The bone infection may result in sustained inflammation, osteomyelitis, and eventual bone non-union. Establishment of a feasible, reproducible animal model is important to bone infection research and antibiotic treatment. As an in vivo model, the rabbit model is widely used in bone infection research. However, previous studies on rabbit bone infection models showed that the infection status was inconsistent, as the amount of bacteria was variable. This study presents an improved surgical method for inducing bone infection on a rabbit, by blocking the bacteria in the bone marrow. Then, multi-level evaluations can be carried out to verify the modelling method. In general, debriding necrotic tissue and implantation of vancomycin-loaded calcium sulphate (VCS) are predominant in antibiotic treatment. Although calcium sulphate in VCS benefits osteocyte crawling and new bone growth, massive bone defects occur after debriding. Autogenous bone (AB) is an appealing strategy to overcome bone defects for the treatment of massive bone defects after debriding necrotic bone. In this study, we used the tail bone as an autogenous bone implanted in the bone defect. Bone repair was measured using micro-computed-tomography (micro-CT) and histological analysis after animal sacrifice. As a result, in the VCS group, bone non-union was consistently obtained. In contrast, the bone defect areas in the VCS-AB group were decreased significantly. The present modeling method described a reproducible, feasible, stable method to prepare a bone infection model. The VCS-AB treatment resulted in lower bone non-union rates after antibiotic treatment. The improved bone infection model and the combination treatment of VCS and autogenous bone could be helpful in studying the underlying mechanisms in bone infection and bone regeneration pertinent to traumatology orthopedic applications.

ScCO <sub>2</sub> Foamed Composite Scaffolds Incorporating Bioactive Lipids Promote Vascularized Bone Regeneration Via Hif-1α Upregulation and Enhanced Type H Vessel Formation

Bone tissue engineering has substantial potential for the treatment of massive bone defects; however, efficient vascularization coupled with bone regeneration still remains a challenge in this field. In the current study,supercritical carbon dioxide (scCO2) foaming technique was adopted to fabricate mesoporous bioactive glasses (MBGs) particle-poly (lactic-co-glycolic acid) (PLGA) composite scaffolds with appropriate mechanical and degradation properties as well as in vitro bioactivity. The MBG-PLGA scaffolds incorporating the bioactive lipid FTY720 (designated as FTY/MBG-PLGA) exhibited simultaneously sustained release of thebioactive lipid and ions. In addition to providing a favorable microenvironment for cellular adhesion and proliferation, FTY/MBG-PLGA scaffolds significantly facilitated the in vitro osteogenic differentiation of rBMSCs and also markedly stimulated the up regulation of Hif-1α expression via the activation of the Erk1/2 pathway, which mediated the osteogenic and pro-angiogenic effects on rBMSCs. Furthermore, FTY/MBG-PLGA extracts induced superior in vitro angiogenic performance of HUVECs. In vivo evaluation of critical-sized rat calvarial bone defects indicated that FTY/MBG-PLGA scaffolds potently promoted vascularized bone regeneration. Notably, the significantly enhanced formation of type Hvessels (CD31hiEmcnhineo-vessels) was observed in newly formed bone tissue in FTY/MBG-PLGA group, strongly suggesting that FTY720 and therapeutic ions released from the scaffolds synergistically induced moretype H vessel formation, which indicated the coupling of angiogenesis and osteogenesis to achieve efficiently vascularized bone regeneration. Overall,the results indicated that the foamed porous MBG-PLGA scaffolds incorporating bioactive lipids achieved desirable vascularization-coupled bone formation and could be a promising strategy for bone regenerative medicine.

Osteogenesis induced by a three-dimensional bioimplant composed of demineralised bone matrix, collagen, hydroxyapatite, and bone marrow-derived cells in massive bone defects: An experimental study

with bioimplants vs. bioimplant plus bone marrow nucleated cells (BMNCs) showed a notorious osteogenic effect, but with greater osteoid synthesis and cellularity in the latter. These results suggest that combined treatment with bioimplants and BMNCs have an additive effect on massive bone defects in lambs. These experimental results could be applied to repair damaged human bone.

Establishment of a Segmental Femoral Critical-size Defect Model in Mice Stabilized by Plate Osteosynthesis

The use of tissue-engineered bone constructs is an appealing strategy to overcome drawbacks of autografts for the treatment of massive bone defects. As a model organism, the mouse has already been widely used in bone-related research. Large diaphyseal bone defect models in mice, however, are sparse and often use bone fixation which fills the bone marrow cavity and does not provide optimal mechanical stability. The objectives of the current study were to develop a critical-size, segmental, femoral defect in nude mice. A 3.5-mm mid-diaphyseal femoral ostectomy (approximately 25% of the femur length) was performed using a dedicated jig, and was stabilized with an anterior located locking plate and 4 locking screws. The bone defect was subsequently either left empty or filled with a bone substitute (syngenic bone graft or coralline scaffold). Bone healing was monitored noninvasively using radiography and in vivo micro-computed-tomography and was subsequently assessed by ex vivo micro-computed-tomography and undecalcified histology after animal sacrifice, 10 weeks postoperatively. The recovery of all mice was excellent, a full-weight-bearing was observed within one day following the surgical procedure. Furthermore, stable bone fixation and consistent fixation of the implanted materials were achieved in all animals tested throughout the study. When the bone defects were left empty, non-union was consistently obtained. In contrast, when the bone defects were filled with syngenic bone grafts, bone union was always observed. When the bone defects were filled with coralline scaffolds, newly-formed bone was observed in the interface between bone resection edges and the scaffold, as well as within a short distance within the scaffold. The present model describes a reproducible critical-size femoral defect stabilized by plate osteosynthesis with low morbidity in mice. The new load-bearing segmental bone defect model could be useful for studying the underlying mechanisms in bone regeneration pertinent to orthopaedic applications.

Establishment of a Segmental Femoral Critical-size Defect Model in Mice Stabilized by Plate Osteosynthesis.

The use of tissue-engineered bone constructs is an appealing strategy to overcome drawbacks of autografts for the treatment of massive bone defects. As a model organism, the mouse has already been widely used in bone-related research. Large diaphyseal bone defect models in mice, however, are sparse and often use bone fixation which fills the bone marrow cavity and does not provide optimal mechanical stability. The objectives of the current study were to develop a critical-size, segmental, femoral defect in nude mice. A 3.5-mm mid-diaphyseal femoral ostectomy (approximately 25% of the femur length) was performed using a dedicated jig, and was stabilized with an anterior located locking plate and 4 locking screws. The bone defect was subsequently either left empty or filled with a bone substitute (syngenic bone graft or coralline scaffold). Bone healing was monitored noninvasively using radiography and in vivo micro-computed-tomography and was subsequently assessed by ex vivo micro-computed-tomography and undecalcified histology after animal sacrifice, 10 weeks postoperatively. The recovery of all mice was excellent, a full-weight-bearing was observed within one day following the surgical procedure. Furthermore, stable bone fixation and consistent fixation of the implanted materials were achieved in all animals tested throughout the study. When the bone defects were left empty, non-union was consistently obtained. In contrast, when the bone defects were filled with syngenic bone grafts, bone union was always observed. When the bone defects were filled with coralline scaffolds, newly-formed bone was observed in the interface between bone resection edges and the scaffold, as well as within a short distance within the scaffold. The present model describes a reproducible critical-size femoral defect stabilized by plate osteosynthesis with low morbidity in mice. The new load-bearing segmental bone defect model could be useful for studying the underlying mechanisms in bone regeneration pertinent to orthopaedic applications.

Healing of massive segmental femoral bone defects in minipigs by allogenic ASCs engineered with FLPo/Frt-based baculovirus vectors

Adipose-derived stem cells (ASCs) hold promise for bone regeneration but possess inferior osteogenesis potential. Allotransplantation of ASCs engineered with the BMP2/VEGF-expressing baculoviruses into rabbits healed critical-size segmental bone defects. To translate the technology to clinical applications, we aimed to demonstrate massive bone healing in minipigs that more closely mimicked the clinical scenarios, using a new hybrid baculovirus system consisting of BacFLPo expressing the codon-optimized FLP recombinase (FLPo) and the substrate baculovirus harboring the transgene flanked by Frt sequences. Co-transduction of minipig ASCs (pASCs) with BacFLPo and the substrate baculovirus enabled transgene cassette excision, recombination and minicircle formation in ≈73.7% of pASCs, which substantially prolonged the transgene (BMP2 and VEGF) expression to 28 days. When encoding BMP2, the FLPo/Frt-based system augmented the pASCs osteogenesis. Allotransplantation of the BMP2/VEGF-expressing pASCs into minipigs healed massive segmental bone defects (30 mm in length) at the mid-diaphysis of femora, as evaluated by computed tomography, positron emission tomography, histology, immunohistochemical staining and biochemical testing. The defect size was ≈15% of femoral length in minipigs and was equivalent to ≈60–70 mm of femoral defect in humans, thus the healing using pASCs engineered with the FLPo/Frt-based baculovirus represented a remarkable advance for the treatment of massive bone defects.

Compressive mechanical properties of the radial bone defects treated with nano-hydroxyapatite/yttria-stabilized zirconia in rabbits

The treatment of massive bone defects is one of the most challenging problems, and many researchers are trying to find materials or drugs that can improve bone healing. The aim of this study was to evaluate the biomechanical effect of nano-hydroxyapatite/yttria-stabilized zirconia on the healing of a radial cortical bone defect in a rabbit model. Thirty six adult male New Zealand rabbits were randomly allocated into two equal groups and three subgroups (1-, 2-, and 3-month duration) with six rabbits in each subgroup. Under general anesthesia, a segmental bone defect, 10 mm in length, was created in the middle of the right radial shaft in all rabbits. This was then stabilized using mini-plate with four screws. The defects in group I were left empty, whereas in group II, the bone defects were filled with nano-hydroxyapatite/yttria-stabilized zirconia. The mean load for fracturing radial bone in group II at 1, 2, and 3 months after surgery was significantly higher than group I (P < 0.05). Biomechanical analysis of the radial bone healing was shown to be significantly improved by the nano-hydroxyapatite/yttria-stabilized zirconia compared with the control group, suggesting that this material promotes the healing of cortical bone, presumably by acting as an osteoconductive agent.

P035 Adipocyte derived stem cells favour healing in a new minipig model of cutaneous radiation syndrome through reepithelialisation and neoangiogenesis

Adipose-derived stem cells (ASCs) hold promise for bone regeneration but possess inferior osteogenesis potential. Allotransplantation of ASCs engineered with the BMP2/VEGF-expressing baculoviruses into rabbits healed critical-size segmental bone defects. To translate the technology to clinical applications, we aimed to demonstrate massive bone healing in minipigs that more closely mimicked the clinical scenarios, using a new hybrid baculovirus system consisting of BacFLPo expressing the codon-optimized FLP recombinase (FLPo) and the substrate baculovirus harboring the transgene flanked by Frt sequences. Co-transduction of minipig ASCs (pASCs) with BacFLPo and the substrate baculovirus enabled transgene cassette excision, recombination and minicircle formation in ≈73.7% of pASCs, which substantially prolonged the transgene (BMP2 and VEGF) expression to 28 days. When encoding BMP2, the FLPo/Frt-based system augmented the pASCs osteogenesis. Allotransplantation of the BMP2/VEGF-expressing pASCs into minipigs healed massive segmental bone defects (30 mm in length) at the mid-diaphysis of femora, as evaluated by computed tomography, positron emission tomography, histology, immunohistochemical staining and biochemical testing. The defect size was ≈15% of femoral length in minipigs and was equivalent to ≈60–70 mm of femoral defect in humans, thus the healing using pASCs engineered with the FLPo/Frt-based baculovirus represented a remarkable advance for the treatment of massive bone defects.

SUCCESSFUL MANAGEMENT OF INTRACTABLE INFECTION AFTER LIMB-SAVING SURGERY: A CASE REPORT

Infections following limb-saving surgeries still happen frequently and are refractory to treatment, even though the treatment of massive bone defects caused by bone resection of bone tumors has improved gradually. Once infections become intractable, they generally result in amputations in spite of all kinds of treatment. We report the case of a patient who developed an intractable infection after limb-saving surgery utilizing a massive frozen autograft and a tumor prosthesis, but whose limb was finally successfully salvaged by multiple surgical interventions. We conclude that continued perseverance in treatment after infections may enable preservation of the limb and restoration of good function.

Structural bone allografts with intramedullary vascularized fibular autografts for the treatment of massive bone defects in extremities

Objective To report the clinical outcome of repairing massive bone defects biologically in limbs by homeochronous using structural bone allografts with intramedullary vascularized fibular auto-grafts. Methods From January 2001 to December 2005, large bone defects in 19 patients (11 men and 8 women, aged 6 to 35 years) were repaired by structural bone allografts with intramedullary vascularized fibular autografts in the homeochronous period. The range of the length of bone defects was 11 to 25 cm (mean 17.6 cm), length of vascularized free fibular was 15 to 29 cm (mean 19.2 cm), length of massive bone allografts was 11 to 24 cm (mean 17.1 cm). Location of massive bone defects was in humerus ( n = 1), in femur ( n = 9) and in tibia ( n = 9), respectively. Results After 9 to 69 months (mean 38.2 months) follow-up, wounds of donor and recipient sites were healed in I stage, monitoring-flaps were alive, eject reaction of massive bone allografts were slight, no complications in donor limbs. Fifteen patients had the evidence of radiographic union 3 to 6 months after surgery, 3 cases united 8 months later, and the remained one case of malignant synovioma in distal femur recurred and amputated the leg 2.5 months, post-operatively. Five patients had been removed internal fixation, complete bone unions were found one year postoperatively. None of massive bone allografts were absorbed or collapsed at last follow-up. Conclusion The homeochronous usage of structural bone allograft with an intramedullary vascularized fibular autograft can biologically obtain a structure with the immediate mechanical strength of the allograft, a potential result of revascularization through the vascularized fibula, and accelerate bone union not only between fibular autograft and the host but also between massive bone allograft and the host.