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Piezoelectric ceramics are piezoelectric materials with polycrystalline structure and have been widely used in many fields such as medical imaging and sound sensors. As knowledge about this kind of material develops, researchers find piezoelectric ceramics possess favorable piezoelectricity, biocompatibility, mechanical properties, porous structure and antibacterial effect and endeavor to apply piezoelectric ceramics to the field of bone tissue engineering. However, clinically no piezoelectric ceramics have been exercised so far. Therefore, in this paper we present a comprehensive review of the research and development of various piezoelectric ceramics including barium titanate, potassium sodium niobate and zinc oxide ceramics and aims to explore the application of piezoelectric ceramics in bone regeneration by providing a detailed overview of the current knowledge and research of piezoelectric ceramics in bone tissue regeneration. [ABSTRACT FROM AUTHOR]

Treatment of bone defects resulting after tumor surgeries, accidents, or non-unions is an actual problem linked to morbidity and the necessity of a second surgery and often requires a critical healthcare cost. Although the surgical technique has changed in a modern way, the treatment outcome is still influenced by patient age, localization of the bone defect, associated comorbidities, the surgeon approach, and systemic disorders. Three-dimensional magnesium-based scaffolds are considered an important step because they can have precise bone defect geometry, high porosity grade, anatomical pore shape, and mechanical properties close to the human bone. In addition, magnesium has been proven in in vitro and in vivo studies to influence bone regeneration and new blood vessel formation positively. In this review paper, we describe the magnesium alloy's effect on bone regenerative processes, starting with a short description of magnesium's role in the bone healing process, host immune response modulation, and finishing with the primary biological mechanism of magnesium ions in angiogenesis and osteogenesis by presenting a detailed analysis based on a literature review. A strategy that must be followed when a patient-adapted scaffold dedicated to bone tissue engineering is proposed and the main fabrication technologies are combined, in some cases with artificial intelligence for Mg alloy scaffolds, are presented with examples. We emphasized the microstructure, mechanical properties, corrosion behavior, and biocompatibility of each study and made a basis for the researchers who want to start to apply the regenerative potential of magnesium-based scaffolds in clinical practice. Challenges, future directions, and special potential clinical applications such as osteosarcoma and persistent infection treatment are present at the end of our review paper. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Black Phosphorus (BP) is a new semiconductor material with excellent biocompatibility, degradability, and optical and electrophysical properties. A growing number of studies show that BP has high potential applications in the biomedical field. This article aims to systematically review the research progress of BP composite medical materials in the field of tissue engineering, mining BP in bone regeneration, skin repair, nerve repair, inflammation, treatment methods, and the application mechanism. Furthermore, the paper discusses the shortcomings and future recommendations related to the development of BP. These shortcomings include stability, photothermal conversion capacity, preparation process, and other related issues. However, despite these challenges, the utilization of BP-based medical materials holds immense promise in revolutionizing the field of tissue repair. [ABSTRACT FROM AUTHOR]

PURPOSE OF THE STUDY The preclinical study aimed to compare the healing of segmental bone defects treated with biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel with the established autologous spongioplasty. Another aim was to evaluate the hydrogel as a scaffold for osteoinductive growth factor of bone morphogenetic protein-2 (BMP-2) and stem cells. MATERIAL AND METHODS The study was conducted in an in vivo animal model. A standardized rabbit model of a 15 mm long segmental bone defect of left radius was used. A total of 40 animals were divided into 5 groups of 8 individuals. In the KO- (negative control) group, the created defect was left to heal spontaneously. In the KO+ (positive control) group, the defect was filled with morselized bone autograft prepared from the resected segment. In the study group A, the defect was filled with hydrogel based on hyaluronic acid derivative and tricalcium phosphate. In the study group B, the defect was filled with hydrogel based on hyaluronic acid derivative, tricalcium phosphate and bone marrow aspirate. In the study group C, the defect was filled with hydrogel based on hyaluronic acid derivative, tricalcium phosphate, bone marrow aspirate and BMP-2. Healing was assessed using radiographs at 1, 6, and 12 weeks postoperatively and histology specimens were collected at 16 weeks postoperatively. RESULTS Altogether 35 rabbits survived (KO- 7, KO+ 7, A 7, B 6, C 8) until the end of the study. As concerns the radiographic assessment, the best results were achieved by the groups KO+ and C, where new bone formation across the entire width of the bone defect was clearly seen at 6 and 12 weeks and the osteotomy line was completely healed too. At 12 weeks, complete bone remodelling was observed in all animals in the group KO+, whereas in the group C, bone remodelling was fully completed in 5 animals and partially completed in 3 animals. In terms of histological assessment, however, the best results were achieved by the group C, where the bone defect was completely remodelled into lamellar bone in 7 specimens, while in 1 specimen it healed with bony callus formation. In the group KO+, the defect was healed in 4 specimens by cartilaginous callus with loci of remodelling into bony callus, in 2 specimens the bony callus was predominant with cartilaginous callus areas, and only one defect was completely remodelled into lamellar bone. DISCUSSION Compared to autografts that manifest osteogenic, osteoinductive and osteoconductive properties, the biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel has osteoconductive properties only. Thus, it was also tested in our study as a scaffold for bone marrow cells and BMP-2 osteoinductive growth factor. Thanks to its semi-liquid properties, the biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel is a promising material for use in 3D printing. CONCLUSIONS The preclinical study in an in vivo animal model confirmed the beneficial effect of the biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel on the healing of critical-size segmental bone defects. Better healing of these defects was also confirmed for filling composed of hydrogel and BMP-2 osteoinductive growth factor. The benefit of bone marrow aspirate mixed with hydrogel was not confirmed. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA)-based materials are widely used in the bone defect restoration field due to their stable physical properties, good biocompatibility, and bone induction potential. To further improve their performance with extra functions such as antibacterial activity, various kinds of metal ion-doped HA-based materials have been proposed and synthesized. This paper offered a comprehensive review of metal ion-doped HA-based materials for bone defect restoration based on the introduction of the physicochemical characteristics of HA followed by the synthesis methods, properties, and applications of different kinds of metal ion (Ag+, Zn2+, Mg2+, Sr2+, Sm3+, and Ce3+)-doped HA-based materials. In addition, the underlying challenges for bone defect restoration using these materials and potential solutions were discussed. [ABSTRACT FROM AUTHOR]

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

Bones play an important role in maintaining exercise and protecting organs. Bone defect, as a common orthopedic disease in clinics, can cause tremendous damage with long treatment cycles. Therefore, the treatment of bone defect remains as one of the main challenges in clinical practice. Today, with increased incidence of bone disease in the aging population, demand for bone repair material is high. At present, the method of clinical treatment for bone defects including non-invasive therapy and invasive therapy. Surgical treatment is the most effective way to treat bone defects, such as using bone grafts, Masquelet technique, Ilizarov technique etc. In recent years, the rapid development of tissue engineering technology provides a new treatment strategy for bone repair. This review paper introduces the current situation and challenges of clinical treatment of bone defect repair in detail. The advantages and disadvantages of bone tissue engineering scaffolds are comprehensively discussed from the aspect of material, preparation technology, and function of bone tissue engineering scaffolds. This paper also summarizes the 3D printing technology based on computer technology, aiming at designing personalized artificial scaffolds that can accurately fit bone defects. [ABSTRACT FROM AUTHOR]

Background: The induced membrane technique (IMT) is a two-step procedure used for reconstructing segmental bone defects in the limbs. The osteogenic mechanism after bone grafting using IMT remains unclear, and efforts to modify the original techniques are limited to the investigative phase. Therefore, reviewing existing knowledge and identifying hotspots and new trends in IMT is critical. Methods: We retrieved reviews and articles associated with IMT published between 2004 and 2023 from the Web of Science Core Collection (WoSCC). The keywords included induced membrane technique, guided bone regeneration, bone defect reconstruction, bone graft, stem cells, Masquelet technique, management of bone defects, and scaffold. HistCite, VOSviewer, CiteSpace, and R-bibliometrics were used for scientometric analysis. Results: A total of 1019 publications from 374 academic journals with 33,995 co-cited references by 2,331 institutions from 65 countries or regions were included. China (n = 235) and the United States (n = 215) were the most productive countries, with Shanghai Jiao Tong University producing the most number of publications (n = 18). Journal Injury [co-citations = 1774; impact factor (IF) 2022 = 2.5] published the most manuscripts, while Masquelet AC and Giannoudis PV published literature with a significant influence on IMT, showing more co-citations (n = 727; n = 355). Two preface hotspots of IMT focused on investigating the microscopic mechanism (such as the membrane supporting graft-to-bone union and the role of inflammatory cells) and developing new techniques to improve IMT (such as bone tissue engineering and new drugs). Conclusion: This study comprehensively reviewed the literature about IMT published in the last 20 years using qualitative and quantitative methods, providing valuable information for researchers investigating IMT. [ABSTRACT FROM AUTHOR]

The repair of bone defects has been the focus of research at home and abroad in recent years. Gelatin methacryloyl (GelMA) hydrogels, with their good biocompatibility, low cost, photo-cross-linking structure, and easily adjustable physicochemical property, have been widely used in bone regeneration. GelMA hydrogels can overcome issues such as inadequate mechanical property, poor bioactivity, and uncontrolled degradation through various strategies. This paper presents a systematic review of recent advances in GelMA hydrogels in the field of bone defect repair, covering the preparation of GelMA hydrogels and the effect of reaction conditions on the property, the loading and controlled release of GelMA hydrogels (drugs, cells, growth factors, exosomes), material hybridization (organic nanomaterials, inorganic nanomaterials, organic and inorganic hybrid materials) of GelMA hydrogels, structural modulation (electrostatic spinning, microspheres, 3D printing), as well as the mechanism of osteogenic activity (vascular, neural, immunomodulation) in bone defects. Finally, we summarized this article and looked forward to the prospects and challenges of GelMA hydrogel in repairing bone defects. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Modern Medicine & Health is the property of Journal of Modern Medicine & Health and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The treatment of bone defects has always been a major problem in orthopedics. Due to the limited regenerative capacity of bone, large-scale bone defects often cannot be healed by themselves. Icariin (ICA) has an obvious effect on bone formation. ICA contained in Icariin is a flavonoid compound and an active compound, which has dual activities of promoting bone formation and inhibiting bone absorption. Icariin can also be delivered locally through a variety of biological materials to promote bone defect repair, showing a good bone induction potential. It has been found that ICA mainly repairs bone defects by promoting bone formation, cartilage formation, angiogenesis, and by inhibiting bone resorption and anti-inflammatory effects. In this paper, ICA repair of bone defect and its mechanism of action are summarized in order to provide some reference for the follow-up research. [ABSTRACT FROM AUTHOR]

Background: This paper aimed to propose a modified technique of bone transport. An annular frame combined with a retrograde tibiotalocalcaneal arthrodesis nail was used in this novel technique for treating large distal tibial periarticular osteomyelitis and associated defects. Methods: Our team conducted a retrospective research. Forty-three patients with large distal tibial periarticular bone loss were involved in this study. Sixteen patients were treated using the modified hybrid transport technique (MHT group) while 27 were subjected to traditional bone transport (BT group). The mean bone loss was 7.8 ± 2.4 cm in the MHT group and 7.6 ± 2.6 cm in the BT group. The external fixation index, time in transport frame, self-rating anxiety scale, bone healing results and postoperative complications were recorded. Results: The mean time in frame for the MHT group was 3.6 ± 1.5 months, while that of the BT group was 10.3 ± 2.7 months (p < 0.05). The mean external fixation index of MHT group was 0.46 ± 0.08 months/cm versus 1.38 ± 0.24 months/cm of the BT group (p < 0.05). There was no statistical difference for the bone healing results between the MHT and BT groups (p = 0.856). The self-rating anxiety scale and total complication incidence of the MHT group were significantly lower than that of BT patients (p < 0.05). Conclusion: Compared to the traditional BT technique, our modified hybrid transport technique showed better clinical outcomes for treating large distal tibial periarticular bone loss, including less time in transport frame, lower external fixation index and complication incidence. Therefore, this modified technique should be further promoted and developed. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bone tissue engineering is a promising approach that uses seed-cell-scaffold drug delivery systems to reconstruct bone defects caused by trauma, tumors, or other diseases (e.g., periodontitis). Metformin, a widely used medication for type II diabetes, has the ability to enhance osteogenesis and angiogenesis by promoting cell migration and differentiation. Metformin promotes osteogenic differentiation, mineralization, and bone defect regeneration via activation of the AMP-activated kinase (AMPK) signaling pathway. Bone tissue engineering depends highly on vascular networks for adequate oxygen and nutrition supply. Metformin also enhances vascular differentiation via the AMPK/mechanistic target of the rapamycin kinase (mTOR)/NLR family pyrin domain containing the 3 (NLRP3) inflammasome signaling axis. This is the first review article on the effects of metformin on stem cells and bone tissue engineering. In this paper, we review the cutting-edge research on the effects of metformin on bone tissue engineering. This includes metformin delivery via tissue engineering scaffolds, metformin-induced enhancement of various types of stem cells, and metformin-induced promotion of osteogenesis, angiogenesis, and its regulatory pathways. In addition, the dental, craniofacial, and orthopedic applications of metformin in bone repair and regeneration are also discussed. [ABSTRACT FROM AUTHOR]

Objective: To prepare a bone repair material with certain mechanical strength and biological activity, this paper used calcium sulfate hemihydrate (CSH) powder compounded with calcium hydroxide (Ca(OH)2) powder to prepare a bone repair scaffold material for physicochemical property characterization and testing. Methods: The physical and chemical properties and characterization of the dried and cured bone repair materials were determined by Fourier infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy; Universal material testing machine to determine the mechanical and mechanical strength of composite materials. Results: XRD showed that the structure of the composite material phase at 5% concentration was calcium sulfate hemihydrate and calcium hydroxide after hydration. The FT-IR and XRD analyses were consistent. Scanning electron microscopy (SEM) results showed that calcium hydroxide was uniformly dispersed in the hemihydrate calcium sulfate material. 0%, 1%, 5%, and 10% specimen groups had compressive strengths of 3.86±3.1, 5.27±1.28, 8.22±0.96, and 14.4±3.28 MPa. 10% addition of calcium hydroxide significantly improved the mechanical strength of the composites, but also reduced the the porosity of the material. Conclusion: With the addition of calcium hydroxide, the CSH-Ca(OH)2 composite was improved in terms of mechanical material and is expected to be a new type of bone repair material. [ABSTRACT FROM AUTHOR]

Background:There are numerous animal models available to study bone healing as well as test strategies to accelerate bone formation. Sheep are commonly used for evaluation of long bone fractures due to similar dimensions and weight bearing environments compared to patients. Large critical-size defects can be created in sheep to facilitate the study of implantable materials, osteogenic proteins, and stem cell treatments. Studies have been published using plates to stabilize large critical size defects in femoral, tibial, and metatarsal defects. External fixators have also been used to stabilize tibial defects in sheep.Methods: The purpose of the current paper is to detail the surgical technique for creation of a 42 mm mid-diaphyseal femoral defect stabilization with an intramedullary device in sheep. Additional surgical details are provided for dynamization, reverse dynamization, and device removal.Conclusion: The article provides multiple technical tips applicable to this and other ovine osteotomy models and concludes with a discussion comparing the use of each stabilization technique in clinically significant large critical-size bone defects. [ABSTRACT FROM AUTHOR]

To share our experience of establishing a bone bank in Pakistan, and the clinical use of these indigenously produced bone grafts. We retrospectively reviewed our experience of the procurement, processing, and storage of bone grafts at a bone bank in Karachi, Pakistan, the first bone bank to be established in a public sector hospital in Pakistan. The bone bank was established at Sindh Institute of Urology and Transplantation (SIUT), Karachi, in collaboration with Department of Orthopaedic Surgery, Dow University of Health Sciences/Civil Hospital, Karachi (CHK) in May, 2015. Since then, a large number of bone grafts from the tissue bank have been used for various orthopedic procedures. This paper describes the problems and challenges faced in establishing and running a tissue bank in a Muslim and a developing country and the progress of the bone bank over the first 4 years. A total of 93 bone grafts were retrieved and preserved in the bone bank over the 4-year period. Among these, 56 (60.2%) bones were retrieved from male donors and 37 (39.8%) from females. The mean age of all donors was 55.9 ± 15.34 years (range: 16–90 years). All bone donors were living patients. No c bones were obtained from deceased donors. Types of bone grafts included: femoral heads, 68; head with neck of femur, 19; radius and ulna, 1; lower femur, knee joint, lower leg and foot bones, 4; and skull bone, 1. All grafts were subjected to aerobic and anaerobic bacterial cultures, as well as fungal cultures. Microbiological contamination was observed in 18/93 (19.35%). All culture positive bones were discarded. Bone grafts issued from the bank and transplanted were 51/93 (54.8%) in all. Bone grafts were used in a variety of tumor and non-tumor orthopaedic procedures in CHK. Nine bone grafts were donated to the other hospitals to be used for revision total hip replacement and tumor surgeries. There were no service charges. Two patients (3.92%) developed infections postoperatively, one superficial and one deep. No other complications were noted. This is the preliminary report on the establishment and functioning of a bone bank in a public sector hospital in Pakistan. The favorable outcome has inculcated confidence in orthopedic surgeons for greater use of bone allografts for a variety of indications in this country. [ABSTRACT FROM AUTHOR]

The reconstruction of long-bone segmental defects remains challenging, with the three common methods of treatment being bone transport, vascularized bone transfer, and the induced membrane technique (IMT). Because of its simplicity, replicability, and reliability, usage of IMT has spread all over the world in the last decade, with more than 300 papers published in the PubMed literature database on this subject so far. Most of the clinical studies have reported high rates of bone union, yet some also include more controversial results with frequent complications and revision surgeries. At the same time, various experimental research efforts have been designed to understand and improve the biological properties of the induced membrane. This literature review aims to provide an overview of IMT clinical results in terms of bone union and complications and to compare them with those of other reconstructive procedures. In light of our findings, we then propose an original classification scheme of IMT failures distinguishing between preventable and nonpreventable failures. [ABSTRACT FROM AUTHOR]

Adequate bone tissue is a prerequisite for oral implant administration. The common causes of bone defect are periodontal disease, trauma, cyst or tumor removal and related systemic diseases. With the development of oral implant surgery, advances in bone augmentation techniques have become a significant topic in the field of oral implantology. In this paper, the application progress of this topic is reviewed. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the improvement in medical level, the clinical demand for bone repair materials is gradually increasing, and the requirements are also getting more and mora. OBJECTIVE: To review the related research progress in the field of bone repair materials in recent years, to analyze the advantages and disadvantages of different materials, and to guide future development in this research field. METHODS: A computer-based online search of CNKI, Wanfang, PubMed, Web of Science databases was perfonned to retrieve papers published during 1950-2019 with the search tenns '"tissue engineering, bone repair material, bone defect, natural bone material, bone graft replacement material, traditional Chinese medicine" in Chinese and English. A total of over 900 papers were retrieved, and 68 of them were included in the final analysis. RESULTS AND CONCLUSION: In recent year, with the flourish development of bone tissue engineering, the research of bone tissue repair materials is in the ascendant. In addition to optimizing natural bone, a variety of bone graft substitute materials have been developed, for example, natural macromolecule materials, synthetic macromolecule materials, biomedical ceramics materials, biomedical metal materials, etc., but these materials have different properties. Although there are many bone repair materials at present, the ideal bone repair materials are few. Therefore, bone tissue repair and bone remodeling is still one of the urgent orthopedic problems to be solved in the clinic. In addition, the traditional Chinese medicine for bone repair, such as pyritum combined with modem bone repair materials, can effectively avoid some of the drawbacks of the current bone repair materials, thereby effectively treating bone defect diseases. This deserves in-depth investigation in the field of bone repair. [ABSTRACT FROM AUTHOR]

BACKGROUND: Since non-coding RNAs maintain bone homeostasis through various pathways, applications of non-coding RNAs as bioactive molecules in bone tissue engineering for bone defect repair has become an increasing area of interest. OBJECTIVE: To introduce non-coding RNAs as bioactive molecules in bone tissue engineering. METHODS: A computer-based online search of Web of Science, PubMed, SpringerLink databases was performed by the first author between December 2018 and March 2019 using the search terms "bone tissue engineering, ncRNA (miRNA, siRNA or lncRNA), scaffold, drug delivery system" to retrieve papers published during 2004-2019. A total of 1754 papers were preliminarily retrieved, and 95 of them were eligible for final analysis. RESULTS AND CONCLUSION: Because non-coding RNAs play a key role in osteogenic differentiation, they can be used as important bioactive factors for bone tissue engineering. At present, bone tissue engineering repair methods based on non-coding RNA bioactive factors have become a research hotspot in bone defect repair. There are two major application strategies: (1) The non-coding RNA transcription within the seed cells is purposefully altered and combines with the bone tissue-engineered scaffold to promote bone defect repair. (2) a specifically designed bone engineered scaffold can controllably and purposefully alter the expression of non-coding RNA in the seed cells, which promotes bone defect repair. In addition, the function of more and more non-coding RNAs has been identified in the process of bone regeneration. This shows good application prospects of non-coding RNAs. [ABSTRACT FROM AUTHOR]

Background: Early detection of peri-implant bone defects can improve long-term durability of dental implants. By the advances in cone-beam computed tomography (CBCT) scanners and introduction of new algorithms, it is important to find the most efficient protocol for detection of bone defects. This study aimed to assess the efficacy of metal artifact reduction (MAR) and advanced noise reduction (ANR) algorithms for detection of peri-implant bone defects. Materials and methods: In this in vitro study, 40 titanium implants were placed in 7 sheep mandibles. Crestal, apical, and Full defects (n = 10 from each type) were created around the implants, and 10 implants were also placed as controls. CBCT scans were obtained in four modes: with MAR, with ANR, with both MAR and ANR, and without any filter. Totally, 28 scans were obtained and evaluated by a radiologist and a maxillofacial surgeon. The observers recorded their observations in a checklist, and data were analyzed by SPSS version 21 using the kappa coefficient of agreement, sensitivity and specificity values, area under the receiver operating characteristic (ROC) curve (AUC), intraclass correlation coefficient, t-test and paired t-test (P < 0.05). Results: The inter-observer agreement was high for detection of all defects in all modes except with ANR. No significant difference was found in AUC and diagnostic accuracy of different scan modes (P > 0.05). The most common diagnostic error was related to misdiagnosis of control group with full defect with ANR filter, such that the existing bone was not detected. Defect depth was averagely over-estimated while defect length was under-estimated. Correct diagnosis of defects had the highest frequency when both filters were on. Conclusion: The diagnostic accuracy and sensitivity for detection of different defect types were not significantly different in different scan modes but activation of ANR filter significantly decreased the specificity and positive predictive value compared with no use of filter. [ABSTRACT FROM AUTHOR]

Osteoporotic fractures are characterized by abnormal inflammation, deterioration of the bone microenvironment, weakened mechanical properties, and difficulties in osteogenic differentiation. The chronic inflammatory state characterized by aging macrophages leads to delayed or non‐healing of the fracture or even the formation of bone defects. The current bottleneck in clinical treatment is to achieve strong fixation of the comminuted bone fragments and effective regulation of the complex microenvironment of aging macrophages. Inspired by cement and gravel in concrete infrastructure, a biomimetic bone glue with poly(lactic‐co‐glycolic acid) microspheres is developed and levodopa/oxidized chitosan hydrogel stabilized on an organic‐inorganic framework of nanohydroxyapatite, named DOPM. DOPM is characterized via morphological and mechanical characterization techniques, in vitro experiments with bone marrow mesenchymal stromal cells, and in vivo experiments with an aged SD rat model exhibiting osteoporotic bone defects. DOPM exhibited excellent adhesion properties, good biocompatibility, and significant osteogenic differentiation. Transcriptomic analysis revealed that DOPM improved the inflammatory microenvironment by inhibiting the NF‐κB signaling pathway and promoting aging macrophage polarization toward M2 macrophages, thus significantly accelerating bone defect repair and regeneration. This biomimetic bone glue, which enhances osteointegration and reestablishes the homeostasis of aging macrophages, has potential applications in the treatment of osteoporotic bone defects. [ABSTRACT FROM AUTHOR]

Background: Bone defects and nonunion following initial treatment remain significant clinical challenges. The Ilizarov method constitutes a fundamental approach for addressing bone defects, and its integration with adjunctive techniques, such as the accordion maneuver, antibiotic spacers, or internal fixation, has become increasingly widespread. Despite this, limited research exists on the clinical outcomes specifically related to the use of the Ilizarov method combined with the accordion technique for treating long bone defects in the lower limbs. Objective: This study seeks to systematically review the application of the Ilizarov method in combination with the accordion technique for addressing long bone deficiencies in the lower limbs. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review was performed in alignment with the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), involving searches of Medline, Embase, Web of Science, and the Cochrane Library, with the search process concluding on August 20, 2024. The study population consisted of patients with bone defects who underwent treatment using the Ilizarov method in conjunction with the accordion technique. The methodological quality of the included studies was evaluated using the MINORS (Methodological Index for Non-Randomized Studies) scoring system. This study recorded and analyzed the participant count for each study that met the inclusion criteria, along with the number of patients who achieved bone healing, the bone and functional outcomes, and complications such as pin infections, pain, and refracture. Results: Drawing from eight studies involving 80 patients with bone defects treated through the Ilizarov method combined with the accordion technique, this systematic review evaluated the method's impact on bone regeneration. Of these patients, 24% presented with femoral defects, while 76% had tibial defects. The mean patient age was 32.8 years, with an average follow-up of 25.2 months. The accordion technique involved daily distraction and compression adjustments ranging from 0.25 to 1 mm, typically in more than two cycles, effectively promoting bone healing. The bone healing rate was high, with the majority of patients rated as having excellent or good functional recovery, according to standards such as ASAMI and Paley. Common complications included superficial pin tract infections (33.75%) and deep pin tract infections (6.25%), both of which were generally manageable with routine treatment. The accordion technique showed promising results in shortening healing time and enhancing the quality of bone healing. Conclusion: This systematic review demonstrates that despite variations in parameter settings across studies, the Ilizarov method combined with the accordion technique consistently shows strong efficacy and safety in promoting bone regeneration and functional recovery. While some complications may arise, they are generally well-managed with standard care. This approach represents a reliable option for complex bone reconstruction, with future research needed to optimize parameters and further enhance clinical outcomes. [ABSTRACT FROM AUTHOR]

Aim: Studying in rabbit model, the bone behavior during the process of osseointegration of dental implants mimicking vitamin deficiency D3. Materials and Methods: Six rabbits received implants in the area of the removed lower first incisor after creating a condition of vitamin D3 deficiency. Afterwards, the examinations were carried out on days 3, 5, 7, 30, and 90 when all animals were removed from the experiment. At that time, a bone block was collected within the installed dental implant, with the intact area and the area of the adjacent tooth. The samples were examined by histomorphometry analysis. Results: In rabbits with vitamin D3 deficiency, dental implants could be osseointegrated by the regeneration of the bone tissues after surgeries. However, a decrease in the number of cells involved in the construction of bone tissue—osteocytes—was recorded in the regenerated bone (40% ± 7%) as compared with the native bone immediately after implantation, before the bone remodeling processes. Conclusions: The study's results on the rabbit model in vivo confirmed the relationship between vitamin D3 and the process of osseointegration. This in vivo experiment can be the basis for future clinical study. [ABSTRACT FROM AUTHOR]

Treatment of bone defects resulting after tumor surgeries, accidents, or non-unions is an actual problem linked to morbidity and the necessity of a second surgery and often requires a critical healthcare cost. Although the surgical technique has changed in a modern way, the treatment outcome is still influenced by patient age, localization of the bone defect, associated comorbidities, the surgeon approach, and systemic disorders. Three-dimensional magnesium-based scaffolds are considered an important step because they can have precise bone defect geometry, high porosity grade, anatomical pore shape, and mechanical properties close to the human bone. In addition, magnesium has been proven in in vitro and in vivo studies to influence bone regeneration and new blood vessel formation positively. In this review paper, we describe the magnesium alloy’s effect on bone regenerative processes, starting with a short description of magnesium’s role in the bone healing process, host immune response modulation, and finishing with the primary biological mechanism of magnesium ions in angiogenesis and osteogenesis by presenting a detailed analysis based on a literature review. A strategy that must be followed when a patient-adapted scaffold dedicated to bone tissue engineering is proposed and the main fabrication technologies are combined, in some cases with artificial intelligence for Mg alloy scaffolds, are presented with examples. We emphasized the microstructure, mechanical properties, corrosion behavior, and biocompatibility of each study and made a basis for the researchers who want to start to apply the regenerative potential of magnesium-based scaffolds in clinical practice. Challenges, future directions, and special potential clinical applications such as osteosarcoma and persistent infection treatment are present at the end of our review paper.

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The repair of critical-size bone defect remains a challenge for orthopedic surgeons. With the advent of an aging society and their accompanying chronic diseases, it is becoming more difficult to treat bone defects, especially large segmental bone defects that are caused by trauma, tumors, infections, and congenital malformations. New materials and technologies need to be developed to address these conditions. 3D bioprinting is a novel technology that bridges the biomaterial and living cells and is an important method in tissue engineering projects. 3D bioprinting has the advantages of replacing or repairing damaged tissue and organs. The progress in material science and 3D printing devices make 3D bioprinting a technology which can be used to create various scaffolds with a large range of advanced material and cell types. However, in regard to the widespread use of bioprinting, biosafety, immunogenicity and rising costs are rising to be concerned. This article reviews the developments and applications of 3D bioprinting and highlights newly applied techniques and materials and the recent achievements in the orthopedic field. This paper also briefly reviews the difference between the methods of 3D bioprinting. The challenges are also elaborated with the aim to research materials, manufacture scaffolds, promote vascularization and maintain cell viability. [ABSTRACT FROM AUTHOR]

Several progresses have been introduced in the field of bone regenerative medicine. A new term tissue engineering (TE) was created. In TE, a highly porous artificial extracellular matrix or scaffold is required to accommodate cells and guide their growth in three dimensions. The design of scaffolds with desirable internal and external structure represents a challenge for TE. In this paper, we introduce a new method known as automated scaffold design (ASD) for designing a 3D scaffold with a minimum mismatches for its geometrical parameters. The method makes use of k-means clustering algorithm to separate the different tissues and hence decodes the defected bone portions. The segmented portions of different slices are registered to construct the 3D volume for the data. It also uses an isosurface rendering technique for 3D visualization of the scaffold and bones. It provides the ability to visualize the transplanted as well as the normal bone portions. The proposed system proves good performance in both the segmentation results and visualizations aspects. [ABSTRACT FROM AUTHOR]

Background. The problem of management of bone tissue defects remains one of the tasks that a surgeon faces during primary total knee arthroplasty (TKA). Since the number of TKA is increasing every year, modern scientific research aimed at solving the problem of bone defect replacement remains important. The aim of the study was to evaluate the effectiveness of various methods of bone defects management in primary TKA based on the analysis of literature. Materials and Methods. We conducted a search of articles in PubMed, eLIBRARY, Scopus from 2005 to 2020. Results. On the whole our search led to 1217 papers. Finally 19 articles that met inclusion criteria were included in this review. Each of the methods of bone defect replacement has its advantages and disadvantages. The results of the studies show that the he defect size is not a key factor for choosing the method, since with relatively identical defect parameters, different plastic options were used with a satisfactory clinical outcome. The endoprosthesis component should be fixed in at least two zones in every chosen method. In young patients with good bone quality preference in chosen methods should be given to bone grafts, which allow to preserve the bone stock. Based on the papers analysis, we have proposed the algorithm for method choosing for each clinical case. Conclusion. Each surgeon chooses a method for replacing bone defects based on their own preferences and such criteria as the equipment of the operating room, the surgical team experience, the quality of the patients bone and the defect size.

Introduction: Total knee arthroplasty revision (TKAr) is increasing of relevance in orthopaedic surgeon daily practice and will become more and more relevant in the future. The aim of this study is to summarize indications, complications, clinical and radiological mid-term results of metaphyseal sleeves in management of bone defects in TKAr.Methods: A systematic review of English literature was performed on Medline. Retrospective or prospective studies with 2 years of follow-up (FU) were included. The PRISMA 2009 flowchart and checklist were considered to edit the review. Rates of intraoperative fractures, aseptic loosening, periprosthetic joint infection (PJI), reoperations and re-revisions were extrapolated by the papers.Results: 13 articles with a level of evidence of IV were included in the systematic review. 1079 TKAr (1554 sleeves) with a mean FU of 4.0 ± 1.1 years were analysed. The studies showed good clinical and functional outcomes. Sleeves allowed a stable metaphyseal fixation and osseointegration with an implant and sleeves aseptic survival rate of 97.7 and 99.2%, respectively. The incidence of PJI was 2.7 ± 2.4%. The estimated rate of reoperations and re-revisions were 14.2 ± 9.2 and 7.1 ± 4.8%, respectively.Conclusion: Metaphyseal sleeves represent a viable option in management of types IIb and III AORI bone defects in TKAr. Further high-quality log-term studies would better clarify complications, clinical and radiological results of this promising technique in total knee arthroplasty revision. [ABSTRACT FROM AUTHOR]