Reconstruction Of Bone Defects Research Articles

Surgical wound healing quantitative assessment method: the case of dental implant placement using a modified guided bone regeneration technique. Part II

Relevance. The guided bone regeneration (GBR) technique during dental implant treatment, if alveolar bone/part of the jaws is lost, stands out for its effective potential, the main factor of which is the possibility of the necessary bone volume restoration having morphofunctional signs of organotypicity. The prognosis effectiveness of such reconstruction outcome directly depends on the wound process characteristics. The variability of the latter, subject to an unbiased quantitative assessment, can be essential for predictive analysis and prognosis.Aim. The study aimed to develop a technique for quantitative assessment of surgical wound healing (exemplified with an extracted tooth socket), described in the first part of the publication.Materials and methods. The clinical study involved 20 patients of both sexes diagnosed with the condition after dental implantation and reconstruction of the alveolar bone volume using the GBR technique modified by the formation of a situational vicryl framework (SVF). We determined the following parameters: independent and dependent variables, with their indirect mutually dependent influence on a favourable, compromised or unfavourable treatment outcome, based on the wound healing process follow-up and assessment of immediate results in the early, middle and late postoperative period − up to 1 month, and the analysis of delayed – from 1 month to 1 year, and long-term – over one year. These variables are characterized as quantitative indicators – biomarkers, processed by the correlation and regression analysis using the Gretl statistical package.Results. The study revealed a direct correlation regarding all parameters as independent (factor) and dependent (effect) variables necessary for quantifying the wound healing process variability. The created linear regression model confirmed the empirically observed and theoretically substantiated idea of the reciprocal influence of normal and pathological variations of wound healing process on an outcome of dental implantation in the reconstruction of the alveolar bone defect. The correlation and regression analysis for an unbiased quantitative assessment of surgical wound healing demonstrated the statistically explicable behaviour of dependent variables at a 95% le vel.Conclusion. The correlation and regression analysis performed using the presented data indicates a direct correlation between the parameters of a favourable, compromised and unfavourable outcome of dental implantation during the reconstruction of the alveolar bone volume using the GBR technique modified by the formation of SVF and variables expressed by biomarkers, such as the initial complexity of clinical conditions, duration of surgery, mechanical load of the wound, bio-reactive properties of the additional materials required in the w ound.

Deproteinized Bone Tissue as a Matrix for Tissue-Engineered Construction: Experimental Study

Background. At present, for a number of reasons the complete bone defect replacement with autogenous bone is not always possible. Bone substitute materials are used as an alternative to autogenous bone tissue and can be of either biological or non-biological origin. One of the ways of development of reconstructive technologies is the use of tissue-engineered constructs that fully imitate autogenous bone tissue in the required volume.
 Aim of study to define in vivo the possibility of using deproteinized human cancellous bone tissue as a matrix for creating tissue-engineered constructs.
 Methods. An in vivo study was carried out on NZW rabbits. To create a construct, we used the fragments of deproteinized cancellous bone tissue of the human femoral head and stromal vascular fraction of rabbit adipose tissue as a matrix. Bone defect modeling with its subsequent replacement was performed to evaluate the efficacy of reparative osteogenesis during bone defects reconstruction. Study groups were defined: group 1 (control) surgical modeling of a bone defect of the femur without its reconstruction; group 2 surgical modeling of a bone defect of the femur with its reconstruction using fragments of deproteinized cancellous bone matrix; group 3 surgical modeling of a bone defect of the femur with its reconstruction using fragments of deproteinized cancellous bone matrix in combination with stromal vascular fraction of adipose tissue (according to ACP SVF technology).
 Results. Comparative analysis of reparative processes in case of applying tissue-engineered constructs based on deproteinized human cancellous bone matrix in combination with adipose tissue-derived stromal vascular fraction on in vivo experimental model revealed that the use of these bone substitute materials contributes not only to an early activation of reparative regeneration of main structural elements of the bone tissue in the area of the bone defect replacement, but also to its well-timed differentiation. This determines the restoration of structural and functional viability of the bone tissue at the damage site without developing discernible reactive inflammation. Moreover, the effect of the selected tissue-engineered construct with the combined influence of several factors (ACP SVF) in its composition turned out to be more effective in stimulating bone tissue repair and differentiation.
 Conclusion. Combination of SVF and deproteinized bone matrix for creating tissue-engineered constructs enables to engage several regeneration mechanisms and accelerate the process of bone defect replacement in comparison with isolated deproteinized bone matrix without bone defect reconstruction.

Bovine Serum Albumin-Coated Ceria Nanoparticles Activate the TGF-β Signaling Pathway for Periodontal Bone Regeneration

Heterogeneous human periodontal ligament cells (hPDLCs) are the key seed cells to address the regeneration of periodontal bone defects, and nanomaterials b ring strategies for periodontal bone regeneration. Herein, we synthesized cerium-based nanoparticles by a convenient, green, and efficient bovine serum albumin (BSA) culture strategy. The results of in vitro experiments showed that CeO2@BSA had a significant ability to promote osteogenesis in hPDLCs at lower concentrations, which was mediated through TGF-β signaling pathway. However, this ability was diminished at high concentrations, which may be caused by excessive activation of autophagy. Notably, the osteogenic potential of hPDLCs was inhibited after autophagy was blocked. The construction of tissue-engineered membranes confirmed that CeO2@BSA facilitated reconstruction of periodontal bone defects in Sprague–Dawley (SD) rats. Our work demonstrated that CeO2@BSA exhibited efficient therapeutic effects in osteogenic differentiation and periodontal bone defect repair, while greatly expanding the application of CeO2@BSA in disease treatment.

Treatment of Fracture-Related Infections with Bone Abscess Formation after K-Wire Fixation of Pediatric Distal Radius Fractures in Adolescents—A Report of Two Clinical Cases

Closed reduction and K-wire fixation of displaced distal radius fractures in children and adolescents is an established and successful surgical procedure. Fracture-related infections after K-wire fixation are rare but can have significant consequences for the patient. There is a lack of literature on the treatment of K-wire-associated fracture-related infections in children and adolescents. Herein, we report two cases of fracture-related infection after initial closed reduction and Kirschner wire fixation in two adolescents. One 13-year-old boy and one 11-year-old girl were seen for fracture-related infections 4 and 8 weeks after closed reduction and percutaneous K-wire fixation of a distal radius, respectively. X-ray and magnetic resonance imaging (MRI) revealed a healed fracture with osteolytic changes in the metaphyseal radius with periosteal reaction and abscess formation of the surrounding soft tissue structures. A two-staged procedure was performed with adequate debridement of the bone and dead space management with an antibiotic-loaded polymethyl methacrylate (PMMA) spacer at stage 1. After infection control, the spacer was removed and the defect was filled with autologous bone in one case and with a calcium sulphate-hydroxyapatite biomaterial in the other case. In each of the two patients, the infection was controlled and a stable consolidation of the distal radius in good alignment was achieved. In one case, the epiphyseal plate was impaired by the infection and premature closure of the epiphyseal plate was noted resulting in a post-infection ulna plus variant. In conclusion, a fracture-related infection after Kirschner wire fixation of pediatric distal radius fractures is a rare complication but can occur. A two-stage procedure with infection control and subsequent bone defect reconstruction was successful in the presented two cases. Premature closure of the epiphyseal growth plate of the distal radius is a potential complication.

Regenerative Potential of Hydroxyapatite-Based Ceramic Biomaterial on Mandibular Cortical Bone: An In Vivo Study.

Reconstruction of bone defects and maintaining the continuity of the mandible is still a challenge in the maxillofacial surgery. Nowadays, the biomedical research within bone defect treatment is focussed on the therapy of using innovative biomaterials with specific characteristics consisting of the body's own substances. Hydroxyapatite ceramic scaffolds have fully acceptable phase compositions, microstructures and compressive strengths for their use in regenerative medicine. The innovative hydroxyapatite ceramics used by us were prepared using the tape-casting method, which allows variation in the shape of samples after packing hydroxyapatite paste to 3D-printed plastic form. The purpose of our qualitative study was to evaluate the regenerative potential of the innovative ceramic biomaterial prepared using this method in the therapy of the cortical bone of the lower jaw in four mature pigs. The mandible bone defects were evaluated after different periods of time (after 3, 4, 5 and 6 months) and compared with the control sample (healthy cortical bone from the opposite side of the mandible). The results of the morphological, clinical and radiological investigation and hardness examination confirmed the positive regenerative potential of ceramic implants after treatment of the mandible bone defects in the porcine mandible model.

Closed-incision negative-pressure wound therapy (ciNPWT) to minimize wound-related complications in lower limb reconstruction after bone tumor resection: preliminary proof-of-concept study.

The purpose of this study was to compare the impact of postoperative closed-incision negative-pressure wound therapy (ciNPWT) and conventional dressings in wound-related complications after bone tumor resection and reconstruction. A total of 50 patients with bone tumors and clinical indication for wide resection and reconstruction were included and divided into two groups (A and B). Bone defect reconstructions were achieved with modular endoprosthesis or biologic techniques, mainly involving allografts with free vascularized fibula. Group A received ciNPWT, and Group B conventional dressings. Wound-related complications, including wound dehiscence, persistent wound leakage, surgical site infections (SSIs), and causes for surgical revision, were assessed. Nineteen patients were included in Group A and 31 in Group B. No significant differences were found between groups regarding epidemiologic and clinical presentation features, contrarily to reconstructive options, which were significantly different between both (Fisher = 10,100; p = 0.005). Additionally, Group A presented lower wound dehiscence rate (0 vs. 19.4%; χ2(1) = 4.179; p = 0.041), SSI rate (0 vs. 19.4%; χ2(1) = 4.179; p = 0.041), and surgical revision rate (5.3% vs. 32.3%; χ2(1) = 5.003; p = 0.025) compared to Group B. This is the first study reporting the impact of ciNPWT after bone tumor resection and reconstruction, and its results support a potential role for this technique in diminishing postoperative wound complications and SSIs. A multicentric randomized controlled trial may help clarify the role and impact of ciNPWT after bone tumor resection and reconstruction.

Follow-up of biological reconstruction of epiphysis preserving osteosarcoma around the knee in children: A retrospective cohort study.

Limb salvage treatment for malignant bone tumors in children includes prosthetic and biological reconstruction. Early function following prosthesis reconstruction is satisfactory; however, there are several complications. Biological reconstruction is another way to treat bone defects. We evaluated the effectiveness of reconstruction of bone defects by liquid nitrogen inactivation of autologous bone with preserving epiphysis in 5 cases of periarticular osteosarcoma of the knee. We retrospectively selected 5 patients with articular osteosarcoma of the knee who underwent epiphyseal-preserving biological reconstruction in our department between January 2019 and January 2020. Femur involvement occurred in 2 cases and tibia involvement occurred in 3 cases, with an average defect of 18 cm (12-30 cm). The 2 patients with femur involvement were treated with inactivated autologous bone by liquid nitrogen with vascularized fibula transplantation. Among the patients with tibia involvement, 2 were treated with inactivated autologous bone with ipsilateral vascularized fibula transplantation and 1 was treated with autologous inactivated bone with contralateral vascularized fibula transplantation. Bone healing was evaluated by regular X-ray examination. At the end of the follow-up, lower limb length, knee flexion, and extension function were evaluated. Patients were followed up for 24 to 36 months. Average bone-healing time was 5.2 months (3-8 months). All patients achieved bone healing with no tumor recurrence and no distant metastasis and all patients survived. The lengths of both lower limbs were equal in 2 cases, with shortening by ≤1 cm in 1 case and shortening by 2 cm in 1 case. Knee flexion was >90° in 4 cases and between 50 and 60° in 1 case. The Muscle and Skeletal Tumor Society score was 24.2 (range 20-26). Inactivation of autogenous bone with the epiphysis preserved by liquid nitrogen combined with vascularized fibula reconstruction for periarticular osteosarcoma of the knee in children is safe and effective. This technique supports bone healing. Postoperative limb length and function, and short-term effects were satisfactory.

Piezoelectric Bioactive Glasses Composite Promotes Angiogenesis by the Synergistic Effect of Wireless Electrical Stimulation and Active Ions.

Insufficient angiogenesis frequently occurs after the implantation of orthopedic materials, which greatly increases the risk of bone defect reconstruction failure. Therefore, the development of bone implant with improved angiogenic properties is of great importance. Mimicking the extracellular matrix clues provides a more direct and effective strategy to modulate angiogenesis. Herein, inspired by the bioelectrical characteristics of the bone microenvironment, a piezoelectric bioactive glasses composite (P-KNN/BG) based on the incorporation of polarized potassium sodium niobate is constructed, which could effectively promote angiogenesis. It is found that P-KNN/BG has exceptional wireless electrical stimulation performance and sustained active ions release. In vitro cell experiments reveal that P-KNN/BG enhances endothelial cell adhesion, migration, and differentiation via activating the eNOS/NO signaling pathway, which might be contributed to cell membrane hyperpolarization induced by wireless electrical stimulation increase the influx of active ions into the cells. In vivo chick chorioallantoic membrane experiment demonstrates that P-KNN/BG shows excellent pro-angiogenic capacity and biocompatibility. This work broadens the current understanding of bioactive materials with bionic electrical properties, which brings new insights into the clinical treatment of bone defect repair.

Treatment of Refractory Congenital Pseudoarthrosis of Tibia with Contralateral Vascularized Fibular Bone Graft and Anatomic Distal Tibial Locking Plate: A Case Series and Literature Review

Congenital pseudoarthrosis of the tibia (CPT) remains a challenge for physicians. Several treatment options have been proposed, but the standard of care remains inconclusive. In this study, we present three patients for whom the failure of prior treatments was managed with a contralateral vascularized fibular bone graft (VFG) and an anatomic distal tibial locking plate. Between 2017 and 2021, three patients were referred for failed treatment of CPT. All patients had undergone multiple prior surgeries, including tumor excision and fixation with ring external fixators, plates, and screws. We performed radical tumor resection and reconstruction of bone defects with a VFG. The construct was fixed with an anatomic locking plate, and the patients were followed up for a mean of 45.7 months. All three patients were able to obtain graft union at 19.3 weeks. At the final follow-up, all grafts achieved bony hypertrophy without evidence of bone resorption or local tumor recurrence. There was a mean leg length difference of 8.5 cm preoperatively, compared with 6.3 cm postoperatively. The average lower leg angulation was 7.4 degrees and the average ankle range of motion was 58.3 degrees. The mean VAS score was 0 and the mean AOFAS score was 88.3. No significant complications were noted. Implantation of a VFG and an anatomic distal tibia locking plate can be considered an option for treatment-refractory CPT. Patients can expect to achieve bone consolidation, ambulate as tolerated, and have a low complication rate.

Research progress on surface modification of three-dimensional printing porous titanium alloys

Three-dimensional (3D) printed porous titanium alloy has good mechanical and physical properties and chemical stability. It is widely used in the field of additive manufacturing to realize the personalized customization of complex structures, such as industry, military, aerospace, and medicine, especially in the customization of personalized orthopedic implants and the repair and reconstruction of bone defects. However, due to the biological inertia of titanium alloy, the cell adhesion of the untreated metal surface is poor. Therefore, surface modification to enhance the biocompatibility and promote bone activity and antibacterial activity of 3D printed porous titanium alloy has become a research hotspot. In this article, the surface modification technology of 3D printing porous titanium alloys is reviewed from four aspects: physical modification, chemical modification, biochemical modification, and metal ion coating.

Reconstruction of infected long bone defects: Issues and Challenges

Reconstruction of infected long bone defects: Issues and Challenges

Development of a novel regenerative therapy for malignant bone tumors using an autograft containing tumor inactivated by high hydrostatic pressurization (HHP).

Surgical resection of malignant bone tumors leads to significant defects in the normal surrounding tissues that should be reconstructed to avoid amputation. Our research aimed to inactivate osteosarcoma (OS)-affected bone to obtain autologous bone grafts for bone defect reconstruction using a novel therapy called high hydrostatic pressurization (HHP) therapy. The key points are complete tumor death and preservation of the non-denatured native extracellular matrix (ECM) and bone tissue by HHP. Previously, we found that HHP at 200MPa for 10min can completely inactivate cells in normal skin and skin tumors, including malignant melanoma and squamous cell carcinoma while maintaining their original biochemical properties and biological components. Based on our previous research, this study used HHP at 200MPa for 10min to eradicate OS. We prepared an OS cell line (LM8), pressurized it at 200MPa for 10min, and confirmed its inactivation through morphological observation, WST-8 assay, and live/dead assay. We then injected OS cells with or without HHP into the bone marrow of the murine tibia, after which we implanted tumor tissues with or without HHP into the anterior surface of the tibia. After HHP, OS cells did not proliferate and were assessed using a live/dead assay. The pressurized cells and tumors did not grow after implantation. The pressurized bone was well prepared as tumor-free autologous bone tissues, resulting in the complete eradication of OS. This straightforward and short-pressing treatment was proven to process the tumor-affected bone to make a transplantable and tumor-free autologous bone substitute.

The optimal strategy for 3D-printed uncemented endoprosthesis for the bone defect reconstruction of the distal radius, based on biomechanical analysis and retrospective cohort study.

Prosthetic reconstruction after resecting giant cell tumor of bone (GCTB) of the distal radius has been proposed. However, this is generally associated with various complications. To improve the functional outcomes, we designed a three-dimensional (3D)-printed uncemented endoprosthesis. Meanwhile, using finite-element analysis and clinical observation, an optimization strategy was explored. We retrospectively analyzed patients with Campanacci III or recurrent GCTB of the distal radius who underwent 3D-printed uncemented endoprosthesis reconstruction. Clinically, according to the different palmar tilts of the endoprosthesis, patients were divided into the biological angle (BA) group and the zero-degree (ZD) group. We recorded and evaluated the differences in functional outcomes and complications between the two groups. Biomechanically, four 3D finite-element models (normal and customized endoprostheses with three different implemented palmar tilts) were developed. We analyzed 22 patients (12 males and 10 females). The median follow-up period was 60 (range, 19-82) months. Of the 22 patients, 11 patients were included in the BA group and the remaining 11 patients were in the ZD group. Both groups showed no significant differences in the range of motion, Mayo score, and disabilities of the arm, shoulder, and hand scores postoperatively. The subluxation rate was significantly lower in the ZD group than in the BA group. The biomechanical results showed similar stress and displacement distribution patterns in the normal and prosthetic reconstruction models. Additionally, the endoprosthesis with 0° palmar tilt showed better biomechanical performance. 3D-printed uncemented endoprosthesis provides acceptable midterm outcomes in patients undergoing distal radius reconstruction. Optimizing the design by decreasing the palmar tilt may be beneficial for decreasing the risk of wrist joint subluxation.

Synthetic biodegradable polymer materials in the repair of tumor-associated bone defects.

The repair and reconstruction of bone defects and the inhibition of local tumor recurrence are two common problems in bone surgery. The rapid development of biomedicine, clinical medicine, and material science has promoted the research and development of synthetic degradable polymer anti-tumor bone repair materials. Compared with natural polymer materials, synthetic polymer materials have machinable mechanical properties, highly controllable degradation properties, and uniform structure, which has attracted more attention from researchers. In addition, adopting new technologies is an effective strategy for developing new bone repair materials. The application of nanotechnology, 3D printing technology, and genetic engineering technology is beneficial to modify the performance of materials. Photothermal therapy, magnetothermal therapy, and anti-tumor drug delivery may provide new directions for the research and development of anti-tumor bone repair materials. This review focuses on recent advances in synthetic biodegradable polymer bone repair materials and their antitumor properties.

Resistencia mecánica de matrices óseas de ácido poliláctico desarrolladas por impresión 3D para la reconstrucción de defectos óseos

IntroductionBone defects are one of the main limitations in orthopedic surgery and traumatology. For this reason, multiple bone replacement systems have been developed, either by prosthetic implant or by substitution with osteoforming substances, whose limitations are their survival and lack of structurality, respectively. The objective of this work is the generation of a new material for the creation of biologically active structures that have sufficient tensile strength to maintain the structure during remodeling. Material and methodsA new filament based on the fusion of natural polylactide acid (PLA) powder was designed for the generation of pieces by means of fused deposition modeling (FDM) on which to carry out tensile mechanical tests of osteosynthesis material. A total of 13 groups with different cortical thickness, filling and layer height were carried out, with 10 tensile tests in each group, defining the tensile breaking limit for each group. The regression lines for each group and their mechanical resistance to traction on the filament used were determined. ResultsThe filament ratio per contact surface unit with the osteosynthesis used was the main determinant of the mechanical resistance to traction, either at the expense of the increase in cortical thickness or by the increase in the percentage of cancellous bone filling. Layer height had a minor effect on tensile strength. The regression value was high for cortical thickness and cancellous filling, being elements with a predictable biomechanical behavior. ConclusionsThe new methodology allows the creation of personalized neutral and implantable PLA bone matrices for the reconstruction of large bone defects by means of 3D printing by FDM with a mechanical resistance to traction greater than that of current biological support structures.

Research Progress of Macrophages in Bone Regeneration

Bone tissue regeneration plays an increasingly important role in contemporary clinical treatment. The reconstruction of bone defects remains a huge challenge for clinicians. Bone regeneration is regulated by the immune system, in which inflammation is an important regulating factor in bone formation and remodeling. As the main cells involved in inflammation, macrophages play a key role in osteogenesis by polarizing into different phenotypes during different stages of bone regeneration. Considering this, this review mainly summarizes the function of macrophage in bone regeneration based on mesenchymal stem cells (MSCs), osteoblasts, osteoclasts, and vascular cells. In conclusion, anti-inflammatory macrophages (M2) have a greater potentiality to promote bone regeneration than M0 and classically activated proinflammatory macrophages (M1). In the fracture and bone defect models, tissue engineering materials can induce the transition from M1 to M2, alter the bone microenvironment, and promote bone regeneration through interactions with bone-related cells and blood vessels. The review provides a further understanding of macrophage polarization behavior in the evolving field of bone immunology.

Engineering mussel-inspired multifunctional nanocomposite hydrogels to orchestrate osteoimmune microenvironment and promote bone healing

The reconstruction of large bone defects by bioactive materials without exogenous cells, cytokines or growth factors remains a substantial clinical challenge. Herein, we present the rational design of injectable and adhesive (GMAD/LP) hydrogels composed of gelatin-methacryloyl (GelMA), dopamine-grafted alginate (AD), and polydopamine-functionalized Laponite (Lap@PDA) nanosheets that can act as osteoimmune regulators to engineer the pro-regenerative microenvironment for personalized bone regeneration. The as-fabricated GMAD/LP hydrogel with excellent tissue adhesion, self-healing, injectability, and improved mechanical strength can fill irregular bone defects in a minimally invasive manner. Moreover, the hydrogel exhibited outstanding osteogenic potential and osteoimmunomodulatory functions in vitro, significantly promoting the adhesion, proliferation, spreading, and osteogenic differentiation of bone mesenchymal stem cells (BMSCs), which was further augmented by hydrogel-induced macrophage M2-phenotype polarization and effective M2 macrophage-BMSC crosstalk. In vivo experiments in a cranial defect model demonstrated that the GMAD/LP hydrogel induced a reparative microenvironment similar to that in normal cranium, as characterized by an increased percentage of anti-inflammatory M2 macrophages and endogenous stem cells and high-level neovascularization, consequently accelerating bone healing. This strategy not only achieves a bioactive hydrogel for bone defect reconstruction but also provides a feasible methodology to recover injured bone tissue through integrated design with diverse functions.

Porous surface with fusion peptides embedded in strontium titanate nanotubes elevates osteogenic and antibacterial activity of additively manufactured titanium alloy

It is still a big challenge in orthopedics to treat infected bone defects properly using medical metals. The use of three-dimensional (3D) scaffold materials that simultaneously mimic the skeletal hierarchy and induce sustainable osteogenic and antibacterial functions are a promising solution with an increasing appeal. In this study, we first designed a bifunctional fusion peptide (HHC36-RGD, HR) by linking antimicrobial peptide (HHC36) and arginine-glycine-aspartate (RGD) peptide via 6-aminohexanoic acid. Then the 3D scaffold was fabricated by additive manufacturing, and the strontium titanate nanotube structure (3D-STN) was constructed on its surface. Finally, the HR was anchored to the 3D-STN with the aid of polydopamine (PDA, P), forming the 3D-STN-P-HR scaffold. The results showed that the scaffold exhibited an ordered 3D porous structure, and that the surface was covered by a dense HHC36-RGD layer. Expectedly, the adsorption of PDA effectively slowed down the release of HR. Moreover, the functionalized scaffold had a significant inhibitory effect on Staphylococcus aureus and Escherichia coli, and its antibacterial rate could reach more than 95%. The results of in vitro cell culture experiments demonstrated that the 3D-STN-P-HR scaffold possessed excellent cytocompatibility and could promote the transcription of osteogenic differentiation-related genes and the expression of related proteins. In conclusion, the functionally modified 3D porous titanium alloy scaffold (3D-STN-P-HR) has a balanced antibacterial and osteogenic function, which bodes well for future potential in the customized functional reconstruction of complex-shaped infected bone defects.

A Mechanically Reinforced Super Bone Glue Makes a Leap in Hard Tissue Strong Adhesion and Augmented Bone Regeneration.

Existing bone tissue engineering strategies aim to achieve minimize surgical trauma, stabilize the injured area, and establish a dynamic osteogenic microenvironment. The cutting-edge bone glue developed in this study satisfies these criteria. Inspired by the excellent adhesive properties of mussels, herein, a super osteogenic glue (L-DPZ) that integrates poly(vinyl alcohol), L-dopa amino acid, and zeolitic imidazolate framework-8 characterized by catechol-metal coordination is used to successfully adhere to hard tissue with a maximum adhesive strength of 10MPa, which is much higher than those of commercial and previously reported bone glues. The stable hard tissue adhesion also enables it to adhere strongly to luxated or broken teeth, Bio-Oss (a typical bone graft material), and splice fragments from comminuted fractures of the rabbit femur. Then, it is testified that the L-DPZ hydrogels exhibit satisfactory biocompatibility, stable degradability, and osteogenic ability in vitro. Moreover, the ability to anchor Bio-Oss and sustained osteogenesis of L-DPZ result in satisfactory healing in calvarial bone defect models in rabbits, as observed by increased bone thickness and the ingrowth of new bone tissue. These results are expected to demonstrate solutions to clinical dilemmas such as comminuted bone fracture fixation, bone defect reconstruction, and teeth dislocation replantation.

Reconstruction of massive bone defects after femoral tumor resection using two new-designed 3D-printed intercalary prostheses: a clinical analytic study with the cooperative utilization of multiple technologies

BackgroundTo reconstruct massive bone defects of the femoral diaphysis and proximal end with limited bilateral cortical bone after joint-preserving musculoskeletal tumor resections, two novel 3D-printed customized intercalary femoral prostheses were applied.MethodsA series of nine patients with malignancies who received these novel 3D-printed prostheses were retrospectively studied between July 2018 and November 2021. The proximal and diaphyseal femur was divided into three regions of interest (ROIs) according to anatomic landmarks, and anatomic measurements were conducted on 50 computed tomography images showing normal femurs. Based on the individual implant-involved ROIs, osteotomy level, and anatomical and biomechanical features, two alternative 3D-printed prostheses were designed. In each patient, Hounsfield Unit (HU) value thresholding and finite element analysis were conducted to identify the bone trabecula and calcar femorale and to determine the stress distribution, respectively. We described the characteristics of each prosthesis and surgical procedure and recorded the intraoperative data. All patients underwent regular postoperative follow-up, in which the clinical, functional and radiographical outcomes were evaluated.ResultsWith the ROI division and radiographic measurements, insufficient bilateral cortical bones for anchoring the traditional stem were verified in the normal proximal femur. Therefore, two 3D-printed intercalary endoprostheses, a Type A prosthesis with a proximal curved stem and a Type B prosthesis with a proximal anchorage-slot and corresponding locking screws, were designed. Based on HU value thresholding and finite element analysis, the 3D-printed proximal stems in all prostheses maximally preserved the trabecular bone and calcar femorale and optimized the biomechanical distribution, as did the proximal screws. With the 3D-printed osteotomy guide plates and reaming guide plates, all patients underwent the operation uneventfully with a satisfactory duration (325.00 ± 62.60 min) and bleeding volume (922.22 ± 222.36 ml). In the follow-up, Harris Hip and Musculoskeletal Tumor Society scores were ameliorated after surgery (P < 0.001 and P < 0.001, respectively), reliable bone ingrowth was observed, and no major complications occurred.ConclusionsTwo novel 3D-printed femoral intercalary prostheses, which achieved acceptable overall postoperative outcomes, were used as appropriate alternatives for oncologic patients with massive bone defects and limited residual bone and increased the opportunities for joint‐preserving tumor resection. Several scientific methodologies utilized in this study may promote the clinical design proposals of 3D-printed implants.