Autologous Bone Transplantation Research Articles

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.

Meta-analysis of autologous bone grafts and bone substitute for the treatment of tibial plateau fractures

To explore clinical efficacy of autologous bone grafts and bone substitute for the treatment of tibial plateau fractures by Meta analysis. Controlled clinical studies on autogenous bone transplantation and bone substitutes in treating tibial plateau fractures published on PubMed,Web of Science,CNKI,Wanfang and other databases from January 2005 to August 2022 were searched by computer. Literature screening and data extraction were performed according to randomized controlled trial(RCT),and the quality of RCT were evaluated by using intervention meta-analysis criteria in Cochrane manual. Meta-analysis of joint depression,secondary collapse rate of articular surface,blood loss,operative time and infection rate between two methods were performed by Rev Man 5.3 software. Seven RCT studies (424 patients) were included,296 patients in bone replacement group and 128 patients in autograft group. Operative time [MD=-16.79,95%CI(-25.72,-7.85),P=0.000 2] and blood loss[MD=-70.49,95%CI(-79.34,-61.65),P<0.000 01] between two groups had statistically differences,while joint depression[MD=-0.17,95%CI(-0.91,0.58),P=0.66],secondary collapse rate of joint surface[RR=-0.74, 95%CI(0.35,1.57),P=0.43],infection rate [RR=1.21,95%CI(0.31,4.70),P=0.78] between two groups had no differences. The effects of bone substitute and autograft for the treatment of tibial plateau fracture have similar effects in terms of joint depression,secondary articular surface collapse rate and infection rate. However,compared with autologous bone transplantation,bone replacement could reduce blood loss and shorten operation time.

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.

Retrospective study on the effect of adipose stem cell transplantation on jaw bone regeneration

PurposeIn patients with jaw bone atrophy, dental implant therapy requires bone augmentation on the alveolar ridge. Common methods are autologous bone transplantation or bone substitutes. The latter technique is less surgically invasive because it does not require bone harvesting; however, blood supply from the surrounding tissues and local differentiation of osteoblasts are not guaranteed, so adequate bone regeneration for dental implant therapy is often not achieved. Therefore, at our hospital we introduced a bone regenerative medicine technique that uses adipose stem cells (ASCs) from adipose tissue. The new approach is less surgically invasive and appears to have a better effect on bone regeneration. The current retrospective study aimed to demonstrate the efficacy of ASC transplantation in patients who underwent alveolar ridge bone augmentation at our hospital.MethodsWe compared medical records, postoperative radiographic findings, and histological results from patients treated between January 2018 and March 2022 by augmentation of the jaw bone with bone substitutes (carbonate apatite) mixed with ASCs (ASCs+ group) and those treated with bone substitutes (carbonate apatite) alone (ASCs− group).ResultsAfter 6 months, the survival rate of augmented bone and the gray scale value in dental cone beam computed tomography (a bone density index) were significantly higher in the ASCs+ group than in the ASCs− group. Histological analysis at 6 months showed more adequate bone tissue regeneration in the ASCs+ group.ConclusionsThe findings suggest the effectiveness of using ASCs in bone augmentation on the alveolar ridge in patients with jaw bone atrophy.

Analysis of risk factors for the recurrence of osteomyelitis of the limb after treatment with antibiotic-loaded calcium sulfate and autologous bone graft.

We aimed to evaluate the efficacy of antibiotic-loaded calcium sulfate combined with autologous iliac bone transplantation in the treatment of limb-localized osteomyelitis (Cierny-Mader type III) and analyze the causes and risk factors associated with infection recurrence. Clinical data of 163 patients with localized osteomyelitis of the extremities treated with antibiotic-loaded calcium sulfate combined with autologous iliac bone transplantation in Xi'an Honghui Hospital from January 2017 to December 2022 were retrospectively analyzed. All patients were diagnosed with localized osteomyelitis through clinical examination and treated with antibiotic-loaded calcium sulfate combined with autologous iliac bone. Based on the infection recurrence status, the patients were divided into the recurrence group and the non-recurrence group. The clinical data of the two groups were compared using univariate analysis. Subsequently, the distinct datasets were included in the binary logistic regression analysis to determine the risk and protective factors. This study included 163 eligible patients, with an average age of 51.0 years (standard deviation: 14.9). After 12 months of follow-up, 25 patients (15.3%) experienced infection recurrence and were included in the recurrence group; the remaining 138 patients were included in the non-recurrence group. Among the 25 patients with recurrent infection, 20 required reoperation, four received antibiotic treatment alone, and one refused further treatment. Univariate analysis showed that education level, smoking, hypoproteinemia, open injury-related infection, and combined flap surgery were associated with infection recurrence (p < 0.05). Logistic regression analysis showed that open injury-related infection (odds ratio [OR] = 35.698; 95% confidence interval [CI]: 5.997-212.495; p < 0.001) and combined flap surgery (OR = 41.408; 95% CI: 5.806-295.343; p < 0.001) were independent risk factors for infection recurrence. Meanwhile, high education level (OR = 0.009; 95% CI: 0.001-0.061; p < 0.001) was a protective factor for infection recurrence. Antibiotic-loaded calcium sulfate combined with autologous iliac bone transplantation is an effective method for treating limb-localized osteomyelitis. Patients without previous combined flap surgery and non-open injury-related infections have a relatively low probability of recurrence of infection after treatment with this surgical method. Additionally, patients with a history of smoking and hypoproteinemia should pay attention to preventing the recurrence of infection after operation. Providing additional guidance and support, particularly in patients with lower education levels and compliance, could contribute to the reduction of infection recurrence.

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.

Comparison of the 3D-microstructure of human alveolar and fibula bone in microvascular autologous bone transplantation: a synchrotron radiation μ-CT study.

Introduction: Autologous bone transplantation is successfully used in reconstructive surgery of large/critical-sized bone defects, whereby the microvascular free fibula flap is still regarded as the gold standard for the reconstruction of such defects in the head and neck region. Here, we report the morphological and lacunar properties of patient-paired bone samples from eight patients from the jaw (AB; recipient site) and the fibula (FB; donor site) on the micron length-scale using Synchrotron µ-CT. Insights into differences and similarities between these bone structures could offer a better understanding of the underlying mechanism for successful surgical outcomes and might clear the path for optimized, nature-inspired bone scaffold designs. Methods: Spatial vessel-pore arrangements, bone morphology, fluid-simulation derived permeability tensor, osteocyte lacunar density, and lacunar morphology are compared. Results: The orientation of the vessel system indicates a homogenous vessel orientation for AB and FB. The average mineral distance (50%) to the closest vessel boundary is higher in AB than in FB (the mean is 96μm for AB vs. 76μm for FB; p = 0.021). Average osteocyte lacunar density is found to be higher in AB than in FB (mean 22,874mm3 vs. 19,376mm3 for FB; p = 0.038), which might compensate for the high distance from the mineral to the nearest vessel. No significant differences in lacunar volume are found between paired AB and FB. Discussion: A comparable vessel network and similar distribution of vessel porosity between AB and FB may allow the FB graft to exhibit a high regeneration potential when connected to AB, and this might correlate with a high osteoinductive and osteoconductive potential of FB when connected to AB. Since widely used and potent synthetic bone grafts exist, new insight into the bone structure of well-established autologous bone grafts, such as the free fibula flap, could help to improve the performance of such materials and therefore the design of 3D scaffolds.

Mechanical and Functional Improvement of β-TCP Scaffolds for Use in Bone Tissue Engineering.

Autologous bone transplantation is still considered as the gold standard therapeutic option for bone defect repair. The alternative tissue engineering approaches have to combine good hardiness of biomaterials whilst allowing good stem cell functionality. To become more useful for load-bearing applications, mechanical properties of calcium phosphate materials have to be improved. In the present study, we aimed to reduce the brittleness of β-tricalcium phosphate (β-TCP). For this purpose, we used three polymers (PDL-02, -02a, -04) for coatings and compared resulting mechanical and degradation properties as well as their impact on seeded periosteal stem cells. Mechanical properties of coated and uncoated β-TCP scaffolds were analyzed. In addition, degradation kinetics analyses of the polymers employed and of the polymer-coated scaffolds were performed. For bioactivity assessment, the scaffolds were seeded with jaw periosteal cells (JPCs) and cultured under untreated and osteogenic conditions. JPC adhesion/proliferation, gene and protein expression by immunofluorescent staining of embedded scaffolds were analyzed. Raman spectroscopy measurements gave an insight into material properties and cell mineralization. PDL-coated β-TCP scaffolds showed a significantly higher flexural strength in comparison to that of uncoated scaffolds. Degradation kinetics showed considerable differences in pH and electrical conductivity of the three different polymer types, while the core material β-TCP was able to stabilize pH and conductivity. Material differences seemed to have an impact on JPC proliferation and differentiation potential, as reflected by the expression of osteogenic marker genes. A homogenous cell colonialization of coated and uncoated scaffolds was detected. Most interesting from a bone engineer's point of view, the PDL-04 coating enabled detection of cell matrix mineralization by Raman spectroscopy. This was not feasible with uncoated scaffolds, due to intercalating effects of the β-TCP material and the JPC-formed calcium phosphate. In conclusion, the use of PDL-04 coating improved the mechanical properties of the β-TCP scaffold and promoted cell adhesion and osteogenic differentiation, whilst allowing detection of cell mineralization within the ceramic core material.

Computer-Assisted and Hip Arthroscopy for Avascular Necrosis of the Femoral Head With Femoroacetabular Impingement

Avascular necrosis of the femoral head with femoroacetabular impingement is a disabling disease. Without early treatment and intervention, its further development will even lead to hip osteoarthritis and hip dysfunction. This technical note aims to introduce a computer-assisted precise core decompression of the femoral head, followed by injection of platelet-rich plasma and bone marrow aspirate concentrate. Then, the autologous ipsilateral iliac bone is transplanted to the core decompression area. Thereafter, under hip arthroscopy, the injured glenoid lip of the hip joint is repaired, and the cam deformity of the femoral head/neck junction is polished and formed. The advantages of this technique include accurately locating the core decompression area, combined with autologous cells and bone transplantation, being able to delay the process of avascular necrosis of the femoral head, and evaluating articular cartilage injury, subchondral collapse, and guidance during reaming and curettage.

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.

Intrinsic antibacterial and osteoinductive sterosomes promote infected bone healing

Open fractures and internal fixation implants are often accompanied by bacterial infection, leading to osteomyelitis, characterized by intractable bone infection and sequestrum formation, and can result in lifelong disability or fatal sepsis. As common clinical treatment strategies, high-dose antibiotic application and autologous bone transplantation face the risk of recurrence and donor site injury. Herein, we designed and prepared a novel drug delivery system by rational selection of the antibacterial single-chain amphiphile (cetylpyridinium chloride, CPC) and osteoinductive sterol (20S-hydroxycholesterol, Oxy) to formulate CPC/Oxy sterosomes. We demonstrate their excellent biocompatibility and antibacterial ability through 2D and 3D settings in vitro. In addition, the osteogenic differentiation of bone marrow mesenchymal stem cells was investigated in cell monolayers and a hydrogel environment. Moreover, a rat infected critical-sized calvarial defect model was employed to illustrate the effects of antibacterial and osteogenic CPC/Oxy sterosomes in vivo. Our results showed that CPC/Oxy sterosomes not only exterminated bacterial infections, but also enhanced calvarial healing without additional antibiotics, bone formation promoters or exogenous cells. This research provides a promising and effective multifunctional sterosomal platform for the treatment of infected bone defects, with the potential to be combined with therapeutic genes, and small molecule drugs.

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.

Research status and progress of bone marrow mesenchymal stem cells for osteonecrosis of femoral head

Osteonecrosis of femoral head (ONFH) is a progressive, destructive disorder with no targeted treatment currently available. The etiology of this disease is complex and the pathogenesis is not clear. The main clinical manifestations are hip pain and mobility dysfunction, which threatens human health to a large extent. If not timely intervention and treatment in the early and middle stages of ONFH, femoral head deformation and even collapse are easy to occur, seriously affecting the prognosis of patients. Therefore, early identification and treatment of ONFH is very important. With the development and maturity of regenerative medicine and tissue engineering technologies, studies have shown that Bone marrow mesenchymal stem cells (BMSCs) combined with cardiac decompression, autologous bone transplantation, arterial interventional therapy, and tissue engineering techniques, it has certain curative effect on early and middle stage ONFH. This paper mainly discusses the research status and progress of BMSCs in the treatment of ONFH, in order to provide theoretical basis for the treatment of ONFH with BMSCs.

A novel decellularized matrix of Wnt signaling-activated osteocytes accelerates the repair of critical-sized parietal bone defects with osteoclastogenesis, angiogenesis, and neurogenesis.

Cell source is the key to decellularized matrix (DM) strategy. This study compared 3 cell types, osteocytes with/without dominant active Wnt/β-catenin signaling (daCO and WTO) and bone marrow stromal cells (BMSCs) for their DMs in bone repair. Decellularization removes all organelles and >95% DNA, and retained >74% collagen and >71% GAG, maintains the integrity of cell basement membrane with dense boundaries showing oval and honeycomb structure in osteocytic DM and smooth but irregular shape in the BMSC-DM. DM produced higher cell survival rate (90%) and higher proliferative activity. In vitro, daCO-DM induces more and longer stress fibers in BMSCs, conducive to cell adhesion, spreading, and osteogenic differentiation. 8-wk after implantation of the critical-sized parietal bone defect model, daCO-DM formed tight structures, composed of a large number of densely-arranged type-I collagen under polarized light microscope, which is similar to and integrated with host bone. BV/TV (>54%) was 1.5, 2.9, and 3.5 times of WTO-DM, BMSC-DM, and none-DM groups, and N.Ob/T.Ar (3.2 × 102/mm2) was 1.7, 2.9, and 3.3 times. At 4-wk, daCO-DM induced osteoclastogenesis, 2.3 times higher than WTO-DM; but BMSC-DM or none-DM didn't. daCO-DM increased the expression of RANKL and MCSF, Vegfa and Angpt1, and Ngf in BMSCs, which contributes to osteoclastogenesis, angiogenesis, and neurogenesis, respectively. daCO-DM promoted H-type vessel formation and nerve markers β3-tubulin and NeuN expression. Conclusion: daCO-DM produces metabolic and neurovascularized organoid bone to accelerate the repair of bone defects. These features are expected to achieve the effect of autologous bone transplantation, suitable for transformation application.

Transcriptomic analysis and biological evaluation reveals that LMO3 regulates the osteogenic differentiation of human adipose derived stem cells via PI3K/Akt signaling pathway.

Autologous bone transplantation which is a common treatment method for bone defects needs a large quantity of bone cells. In order to develop new treatments to regenerating bone tissues, this research aimed at identifying the key genes and finding their mechanism in human adipose-derived stem cells (hADSCs) osteogenesis. GSE63754, GSE89330 and GSE72429 were downloaded to perform GO functional and KEGG pathway analyses, construct a competing endogenous RNA (ceRNA) network, construct a PPI network and identify hub genes. The expression level of LMO3 during the osteogenesis of hADSCs was examined by quantitative reverse transcription polymerase chain reaction and western blot. Lentivirus transfection was used to knock down or overexpress LMO3, which enabled us to investigate the effect of LMO3 on osteogenic differentiation of hADSCs. Wortmannin were used to identify the mechanism of the LMO3/PI3K/Akt axis in regulating osteogenic differentiation of hADSCs. Moreover, ectopic bone formation in nude mice was used to investigate the effect of LMO3 on osteogenesis in vivo. In this study, we found the expression of LMO3 was significantly upregulated during the osteogenic differentiation of hADSCs. LMO3 knockdown remarkably suppressed osteogenic differentiation of hADSCs, while LMO3 overexpression promoted osteogenic differentiation of hADSCs both in vitro and in vivo. Moreover, we discovered that the enhancing effect of LMO3 overexpression on osteogenic differentiation was related to the activation of PI3K/Akt signaling pathway. Inhibition of PI3K/Akt signaling pathway with wortmannin effectively blocked the stimulation of osteogenic differentiation induced by LMO3 overexpression. In conclusion, based on transcriptomic analysis, we identified key genes involved in regulating the osteogenic differentiation of hADSCs. In addition, we found that LMO3 might act as a positive modulator of hADSC osteogenic differentiation by mediating PI3K/Akt signaling pathway. Manipulating the expression of LMO3 and its associated pathways might contribute to advances in bone regeneration and tissue engineering.

Comparison of Clinical Effects of the Modified Masquelet Technique and Kirschner Wire External Fixation-Assisted Autogenous Bone Transplantation in the Treatment of Segmental Metacarpophalangeal Bone Defects.

ObjectiveThe present study aims to explore the (1) clinical effects of the modified Masquelet technique, whose improved Masquelet technique innovates the in vitro plasticity of the bone cement module and prefabricated hollow design, and the Kirschner wire external fixation-assisted autologous bone transplantation technique in the treatment of segmental metacarpophalangeal bone defects and (2) the differences between the two techniques.MethodsThe clinical data of 32 patients with segmental metacarpophalangeal bone defects (15 patients treated with the modified Masquelet technique and 17 patients treated with the self-made Kirschner wire external fixation technique) admitted to our department between January 2012 and January 2020 were retrospectively analyzed. The postoperative bone healing time, hand function, and complications were compared between the two groups.ResultsThe two groups were comparable; there were no significant differences in age, sex, length of bone defect, and time from injury to operation between the two groups (P > 0.05). All patients were followed up with for 6–24 months (average = 13.7 months), and all patients with segmental metacarpophalangeal bone defects achieved fracture healing. The postoperative hospital stay, fracture healing time, functionary scores of the affected limb, and incidence of severe complications were better in the modified group than in the external fixation group (P < 0.05).ConclusionCompared with the Kirschner wire external fixation stent assisted autologous bone transplantation, the improved Masquelet technique has the advantages of simple operation, fast healing, accurate effect, wide indications, and less complications, making it more worthy of clinical promotion.

THE RELEVANCE OF BONE GRAFTS AND THE RELATIONSHIP OF BOHLER'S ANGLE IN INTRA-ARTICULAR CALCANEAL FRACTURES' PROGNOSIS

Background: The most frequently broken tarsal bone is the calcaneum. Even if the rehabilitation process can take a while and the treatment is challenging, the results are still very unexpected. As a result, calcaneal fractures place a significant socioeconomic strain on society. As a result, we looked for a factor, such as Bohler's angle, that we might link to the functional result of patients with intra-articular calcaneal fractures. Method: A calcaneum intra-articular fracture was present in 40 individuals. X-rays and CT scans were used to assess each patient before to surgery. With the use of a goniometer, Bohler's angle was manually determined on the lateral radiograph, and a record was created for future use. All patients were treated using open reductions and intermaxillary fixation with a plate, accompanied by or without bone transplant, according to a randomization process. Following surgery, Bohler's angle was assessed at follow-up visits at 2, 4, and 6 weeks as well as 2, 4, and 6 months. The American Orthopedic Foot and Ankle Score (AOFAS) was used to evaluate the patient's functional recovery at least 5 months following the injury. Results: Our analysis of 40 calcaneal fractures demonstrates that there was a statistically significant distinction in the functional outcomes of patients according to the surgically corrected Bohler's angle. Less comorbidities and statistically significant better outcomes were seen in surgical calcaneus fractures when Bohler's angle was restored within normal bounds. The benefit of autologous bone transplant in restoring calcaneal elevation and anatomic minimization was also proven by our research. Conclusion: We recommend using Bohler's angle as a key to achieving outstanding results in displaced calcaneal fractures as well as the use of autologous bone graft in attaining and maintaining normal Bohler's angle in light of the great results gained with Bohler's angle rehabilitation.

Three-Dimensional Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells Promotes Matrix Metallopeptidase 13 (MMP13) Expression in Type I Collagen Hydrogels.

Autologous bone transplantation is the principal method for reconstruction of large bone defects. This technique has limitations, such as donor site availability, amount of bone needed and morbidity. An alternative to this technique is tissue engineering with bone marrow-derived mesenchymal stem cells (BMSCs). In this study, our aim was to elucidate the benefits of culturing BMSCs in 3D compared with the traditional 2D culture. In an initial screening, we combined BMSCs with four different biogels: unmodified type I collagen (Col I), type I collagen methacrylate (ColMa), an alginate and cellulose-based bioink (CELLINK) and a gelatin-based bioink containing xanthan gum (GelXA-bone). Col I was the best for structural integrity and maintenance of cell morphology. Osteogenic, adipogenic, and chondrogenic differentiations of the BMSCs in 2D versus 3D type I collagen gels were investigated. While the traditional pellet culture for chondrogenesis was superior to our tested 3D culture, Col I hydrogels (i.e., 3D) favored adipogenic and osteogenic differentiation. Further focus of this study on osteogenesis were conducted by comparing 2D and 3D differentiated BMSCs with Osteoimage® (stains hydroxyapatite), von Kossa (stains anionic portion of phosphates, carbonates, and other salts) and Alizarin Red (stains Ca2+ deposits). Multivariate gene analysis with various covariates showed low variability among donors, successful osteogenic differentiation, and the identification of one gene (matrix metallopeptidase 13, MMP13) significantly differentially expressed in 2D vs. 3D cultures. MMP13 protein expression was confirmed with immunohistochemistry. In conclusion, this study shows evidence for the suitability of type I collagen gels for 3D osteogenic differentiation of BMSCs, which might improve the production of tissue-engineered constructs for treatment of bone defects.

Effect of High Hydrostatic Pressure on Human Trabecular Bone Regarding Cell Death and Matrix Integrity.

The reconstruction of critical size bone defects is still clinically challenging. Even though the transplantation of autologous bone is used as gold standard, this therapy is accompanied by donor site morbidities as well as tissue limitations. The alternatively used allografts, which are devitalized due to thermal, chemical or physical processing, often lose their matrix integrity and have diminished biomechanical properties. High Hydrostatic Pressure (HHP) may represent a gentle alternative to already existing methods since HHP treated human osteoblasts undergo cell death and HHP treated bone cylinders maintain their mechanical properties. The aim of this study was to determine the biological effects caused by HHP treatment regarding protein/matrix integrity and type of cell death in trabecular bone cylinders. Therefore, different pressure protocols (250 and 300 MPa for 10, 20 and 30 min) and end point analysis such as quantification of DNA-fragmentation, gene expression, SDS-PAGE, FESEM analysis and histological staining were performed. While both protein and matrix integrity was preserved, molecular biological methods showed an apoptotic differentiation of cell death for lower pressures and shorter applications (250 MPa for 10 and 20 min) and necrotic differentiation for higher pressures and longer applications (300 MPa for 30 min). This study serves as a basis for further investigation as it shows that HHP successfully devitalizes trabecular bone cylinders.

Reparative effect of super active platelet combined with allogeneic bone for large bone defects.

In clinical practice, autologous bone transplantation is usually used to treat large-scale bone defects. However, autologous bone can cause complications such as secondary injury to patients, the scarcity of autografts. In this study, the study of using super active platelet lysate (sPL) and allogeneic bone to treat the 15mm long bone defect in right radius of rabbits, and provide an experimental basis for the next step of clinical bone defect treatment. The critical-size defect of New Zealand white rabbits was made and divided into three groups: autologous bone group, allogeneic bone group, and sPL group. They were euthanized 1, 2, and 3months after the operation, perform imaging and histological observation on the repair of bone defect area. The results showed that there were varying degrees of new bone in the bone defect. CT data showed that the bone defect repair rate and new bone mass in each group increased month by month (P<.05). Bone tissue (BV) and bone tissue to the total volume (BV/TV, %) in the sPL group > allogeneic bone group, autologous bone group > allogeneic bone group, with statistical significance (P<.05). Compared with the allogeneic bone group, the sPL group can significantly promote the healing of bone defects, enhance the bone density after fracture healing. The repair effect after 3months was similar to that of the autogenous bone group. The use of allogeneic bone and sPL therapy may become part of a comprehensive strategy for tissue engineering to treat bone defects.