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Background: With orthopedic surgery increasing year on year, the main challenges in bone drilling are thermal damage, mechanical damage, and drill skid. The need for new orthopedic drills that improve the quality of surgery is becoming more and more urgent., Methods: Here, we report the skidding mechanism of drills at a wide range of inclination angle and propose two crescent drills (CDTI and CDTII). The anti-skid performance and drilling damage of the crescent drills were analyzed for the first time. Inclined bone drilling experiments were carried out with crescent drills and twist drills and real-time drilling forces and temperatures were collected., Results: The crescent drills are significantly better than the twist drill in terms of anti-skid, reducing skidding forces, thrust forces and temperature. The highest temperature is generated close to the upper surface of the workpiece rather than at the hole exit. Finally, the longer crescent edge with a small and negative polar angle increases the rake angle of the cutting edge and reduces thrust forces but increases skidding force and temperature. This study can promote the development of high-quality orthopedic surgery and the development of new bone drilling tools., Conclusion: The crescent drills did not skid and caused little drilling damage. In comparison, the CDTI performs better in reducing the skidding force, while the CDTII performs better in reducing the thrust force., (© 2024. The Author(s).)

Background: Traditional open surgery for bone tumours sometimes has as a consequence an excessive removal of healthy bone tissue because of the limitations of rigid surgical instruments, increasing infection risk and recovery time., Methods: We propose a remote robot with a 4.5-mm diameter bendable end-effector, offering four degrees of freedom for accessing the inside of the bone and performing tumour debridement. The preclinical studies evaluated the effectiveness, clinical scenario, and usability across 12 total surgeries-six phantom surgeries and six bovine bone surgeries. Evaluation criteria included skin incision size, bone window size, surgical time, removal rate, and conversion to open surgery., Results: Preclinical studies demonstrated that the robotic approach requires significantly smaller incision size and procedure times than traditional open curettage., Conclusion: This study validated the performance of the proposed system by assessing its preclinical effectiveness and optimising surgical methods using human phantom and bovine bone tumour models., (© 2024 John Wiley & Sons Ltd.)

When treating orthopaedic damage or illness and accidental fracture, bone grafting remains the gold standard of treatment. In cases where this approach does not seem achievable, bone tissue engineering can offer scaffolding as a substitute. Defective and fractured bone tissue is extracted and substituted with porous scaffold structures to aid in the process of tissue regeneration. 3D bioprinting has demonstrated enormous promise in recent years for producing scaffold structures with the necessary capabilities. In order to create composite biomaterial inks for 3D bioprinting, three different materials were combined such as silk fibroin, bone particles, and synthetic biopolymer poly (ε-caprolactone) (PCL). These biomaterials were used to fabricate the two composites scaffolds such as: silk fibroin + bovine bone (SFB) and silk fibroin + bovine bone + Polycaprolactone (SFBP). The biomechanical, structural, and biological elements of the manufactured composite scaffolds were characterized in order to determine their suitability as a possible biomaterial for the production of bone tissue. The in vitro bioactivity of the two composite scaffolds was assessed in the simulated body fluids, and the swelling and degradation characteristics of the two developed scaffolds were analyzed separately over time. The results showed that the mechanical durability of the composite scaffolds was enhanced by the bovine bone particles, up to a specific concentration in the silk fibroin matrix. Furthermore, the incorporation of bone particles improved the bioactive composite scaffolds' capacity to generate hydroxyapatite in vitro. The combined findings show that the two 3D printed bio-composites scaffolds have the required mechanical strength and may be applied to regeneration of bone tissue and restoration, since they resemble the characteristics of native bone., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Autologous bone dust can be filled in bone defects to promote effective bone healing but typically it is lost when using suction during surgery. The aim of this study was to develop a novel bone collector that can be used to collect bone chips/dust of varying sizes without changing current surgical procedures., Research Design and Methods: This collector was designed to connect to a surgical continuous suction system and comprised a plate filter with a 3 mm hole and featured a taper filter with a mesh size of 0.27 mm for the separation and collection of both coarse and fine bone chips/dust. The bone collector was manufactured using nylon 3D printing and plastic injection with biocompatible materials., Results: The bone collector functional test revealed high bone chip collection efficiency (93%) with automatic size separation function. Low (3.42%) filtration errors showed that most of the water can be drained smoothly from the bone collector. In clinical usability testing, bone collectors can provide functions demonstrated in in vivo spinal fusion and femoral fracture surgeries with different bone grafting size requirements., Conclusions: The novel bone collector has been validated as a viable and effective surgical device, offering surgeons an additional option to enhance patient outcomes.

Implants have always been within the interest of both clinicians and material scientists due to their places in reconstructive and prosthetics surgery. Excessive bone loss or resorption in some patients makes it difficult to design and manufacture the implants that bear the necessary loads to carry the final prosthetics. With this study; we tried to determine the minimum material thickness of the subperiosteal implants that can withstand the physiological forces. We have created a digital average bone structure based on actual patient data and designed different subperiosteal implants with 1, 1.5, and 2mm material thicknesses (M1, M2, M3) for this digital model. The designed implant models are subjected to 250 Newtons (N) of force, and the implant and bone are tested for the stress they are exposed to, the pressure they transmit to, and their mechanical strength with Finite Element Analysis with the physical parameters boot for the implant material and human bone. Results show us that under specific design parameters and thicknesses, the 1mm thickness design failed due to exceeding the yield stress limit of 415MPa with a 495,44MPa value. The thinnest implant showed plastic deformation and transmitted excessive forces, which may cause bone resorption due to residual stress. We determined that thinner subperiosteal implants down to 1.5mm that have the necessary material parameters for function and tissue support can be designed and manufactured with current technologies., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Purpose: Bone biopsies are currently conducted under computed tomography (CT) guidance using a battery-powered drill to obtain tissue samples for diagnosis of suspicious bone lesions. However, this procedure is suboptimal as images produced under CT lack soft tissue discrimination and involve ionizing radiation. Therefore, our team developed an MRI-safe pneumatic drill to translate this clinical workflow into the MR environment, which can improve target visualization and eliminate radiation exposure. We compare drill times and quality of samples between the 2 drills using animal bones., Methods: Five porcine spare rib bones were obtained from a butcher shop. Each bone was drilled twice using the Arrow OnControl battery-powered drill and twice using our pneumatically actuated drill. For this study, we used an 11-gauge bone biopsy needle set with an internal core capturing thread. A stopwatch recorded the overall time of drilling for each specimen obtained., Results: All 20 samples collected contained a high-quality inner core and cortex. The total average time for drilling with the pneumatic drill was 8.5 s (+ / - 2.5 s) and 7.1 s (+ / - 1.4 s) with the standard battery-powered drill., Conclusion: Both drills worked well and were able to obtain comparable specimens. The pneumatic drill took slightly longer, 1.39 s on average, but this extra time would not be significant in clinical practice. We plan to use the pneumatic drill to enable MRI-safe bone biopsy for musculoskeletal lesions. Biopsy under MRI would provide excellent lesion visualization with no ionizing radiation., (© 2023. CARS.)

Preparation of the femoral proximal medullary cavity by reaming is essential for intramedullary nail osteosynthesis and hip revision arthroplasty. The use of reamers sometimes exerts high torsional forces on the bone. Design and direction of rotation of the reamer are potential influencing factors. The aim of this biomechanical study is to evaluate the best combination of a right- or left-cutting reamer with a clockwise- or counterclockwise-rotating insert in terms of preparation and safety. Right- and left-cutting reamers with conical design were each introduced into five synthetic femurs in both clockwise and counterclockwise rotation with constant feed force. A specially constructed test system was used for this series of tests, with which the respective intramedullary channel were reamed step by step. This was then used to determine the required torque. In addition, the feed rate measurement was analyzed using a modified digital caliper. The feed rates of the reamers with rotation in the same direction as the cutting direction were significantly increased compared to rotation in the opposite cutting direction (CCRLC vs. CCRRC 76.8 ± 9.0 mm/s vs. 25.2 ± 8.3 mm/s and CRRC vs. CRLC 54.3 ± 12.3 mm/s vs. 19.3 ± 0.6 mm/s; p < 0.01). In contrast, the mean torque during the reaming process was identical in all four groups. When preparing the proximal femoral medullary cavity, especially in cases with fragile bone structure, the available reamers should be introduced in opposite rotation to the cutting direction to achieve a more controllable feed of the reamer. Left-cutting reamers represent an alternative, using them in the usual clockwise-rotating technique to reduce the risk of complications during reaming., (© 2024. The Author(s).)

Plant-derived cellulose biomaterials have been employed in various tissue engineering applications. In vivo studies have shown the remarkable biocompatibility of scaffolds made of cellulose derived from natural sources. Additionally, these scaffolds possess structural characteristics that are relevant for multiple tissues, and they promote the invasion and proliferation of mammalian cells. Recent research using decellularized apple hypanthium tissue has demonstrated the similarity of its pore size to that of trabecular bone as well as its ability to effectively support osteogenic differentiation. The present study further examined the potential of apple-derived cellulose scaffolds for bone tissue engineering (BTE) applications and evaluated their in vitro and in vivo mechanical properties. MC3T3-E1 preosteoblasts were seeded in apple-derived cellulose scaffolds that were then assessed for their osteogenic potential and mechanical properties. Alkaline phosphatase and alizarin red S staining confirmed osteogenic differentiation in scaffolds cultured in differentiation medium. Histological examination demonstrated widespread cell invasion and mineralization across the scaffolds. Scanning electron microscopy (SEM) revealed mineral aggregates on the surface of the scaffolds, and energy-dispersive spectroscopy (EDS) confirmed the presence of phosphate and calcium elements. However, despite a significant increase in the Young's modulus following cell differentiation, it remained lower than that of healthy bone tissue. In vivo studies showed cell infiltration and deposition of extracellular matrix within the decellularized apple-derived scaffolds after 8 weeks of implantation in rat calvaria. In addition, the force required to remove the scaffolds from the bone defect was similar to the previously reported fracture load of native calvarial bone. Overall, this study confirms that apple-derived cellulose is a promising candidate for BTE applications. However, the dissimilarity between its mechanical properties and those of healthy bone tissue may restrict its application to low load-bearing scenarios. Additional structural re-engineering and optimization may be necessary to enhance the mechanical properties of apple-derived cellulose scaffolds for load-bearing applications.

Bone defects or bone discontinuities caused by trauma, infection, tumours and other diseases have led to an increasing demand for bone grafts and biomaterials. Autologous bone grafts, bone grafts with vascular tips, anastomosed vascular bone grafts and autologous bone marrow components are all commonly used in clinical practice, while oversized bone defects require the use of bone tissue engineering-related biomaterials to repair bone defects and promote bone regeneration. Currently, inorganic components such as polysaccharides and bioceramics, as well as a variety of bioactive proteins, metal ions and stem cells can be loaded into hydrogels or 3D printed scaffold materials to achieve better therapeutic results. In this review, we provide an overview of the types of materials, applications, potential mechanisms and current developments in the repair of bone defects., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The fibrocartilaginous enthesis is a highly specialised tissue interface that ensures a smooth mechanical transfer between tendon or ligament and bone through a fibrocartilage area. This tissue is prone to injury and often does not heal, even after surgical intervention. Enthesis augmentation approaches are challenging due to the complexity of the tissue that is characterised by the coexistence of a range of cellular and extracellular components, architectural features and mechanical properties within only hundreds of micrometres. Herein, we discuss enthesis repair and regeneration strategies, with particular focus on elegant interfacial and functionalised scaffold-based designs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The number of patients with bone defects caused by trauma, bone tumors, and osteoporosis has increased considerably. The repair of irregular, recurring, and large bone defects poses a great challenge to clinicians. Bone tissue engineering is emerging as an appropriate strategy to replace autologous bone grafting in the repair of critically sized bone defects. However, the suitability of bone tissue engineering scaffolds in terms of structure, mechanics, degradation, and the microenvironment is inadequate. Three-dimensional (3D) printing is an advanced additive-manufacturing technology widely used for bone repair. 3D printing constructs personalized structurally adapted scaffolds based on 3D models reconstructed from CT images. The contradiction between the mechanics and degradation is resolved by altering the stacking structure. The local microenvironment of the implant is improved by designing an internal pore structure and a spatiotemporal factor release system. Therefore, there has been a boom in the 3D printing of personalized bone repair scaffolds. In this review, successful research on the preparation of highly bioadaptive bone tissue engineering scaffolds using 3D printing is presented. The mechanisms of structural, mechanical, degradation, and microenvironmental adaptations of bone prostheses and their interactions were elucidated to provide a feasible strategy for constructing highly bioadaptive bone tissue engineering scaffolds.

Background: The rising incidence and complexity of revision knee arthroplasty has led to an increase in the use of metaphyseal reconstruction systems. One of the most widely used systems are metaphyseal sleeves as they have demonstrated excellent long-term survival. However, there is concern about the possible difficulty of extracting a sleeve if it were necessary, as no known procedures have yet been validated., Methods: We examined the outcomes of removing 23 well-integrated metaphyseal sleeves using the same systematized technique., Results: All sleeves were extracted without any intraoperative complications. Four subjects required an osteotomy to complete the extraction, while 62% of the sample were found to have an AORI IIB defect. All cases were successfully reconstructed with a new metaphyseal fixation, implanting a new sleeve in 38% of subjects compared with cones in the remaining 62%., Conclusions: The technique described here produced successful, reproducible outcomes for the removal of integrated metaphyseal sleeves with minimal bone loss and no intraoperative complications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Short stems were introduced into total hip arthroplasty (THA) to preserve bone stock, to transmit more load to the proximal femur, and to enable minimal invasive approaches. This study is the first long-term study (with a follow-up of 10 years) of the survival as well as the clinical and radiographic outcomes of the Fitmore hip stem, a short curved uncemented stem., Methods: In total, 123 Fitmore hip stems were prospectively evaluated. At the final 10-year follow-up, 80 Fitmore stems (78 patients: 30 female, 48 male) were eligible for evaluation. Clinical parameters were thigh pain, EQ-5D, Harris Hip Score (HHS) and Oxford Hip Score. Radiographic parameters were cortical hypertrophy (CH), bone condensation, cortical thinning, radiolucency, reactive lines, calcar rounding, calcar resorption, subsidence and varus/valgus position., Results: After 10 years, there was a survival rate of 99% (1 revision because of aseptic stem loosening). HHS had improved from 59 to 94 and Oxford Hip Score from 22 to 43. CH rate after 1 year was 69% and after 10 years 74%. In the first year, radiolucency was found in 58% and in 17.5% after 10 years. Subsidence after 1 year was 1.6 ± 1.6 mm and 5.0 ± 3.1 mm after 10 years., Conclusions: The Fitmore hip stem showed a survival rate of 99% as well as good clinical and radiographic outcomes in the long-term follow-up of 10 years., (© 2023. The Author(s).)

The biggest challenge during periodontal regeneration in the anterior region is the prevention of soft tissue recession. Minimally invasive surgeries, particularly papilla preservation techniques and soft tissue augmentation, may significantly reduce such postoperative soft tissue recession. This article presents the vestibular incision subperiosteal tunnel access (VISTA) approach for periodontal regeneration in the anterior region. A subperiosteal tunnel prepared from a single vertical vestibular incision adjacent to the defect is used for debridement, application of enamel matrix derivative, defect grafting with corticocancellous tuberosity bone, and insertion of the connective tissue graft. Evaluation of six cases with up to 6 years of follow-up showed improvements in all clinical parameters. The probing pocket depth improved from 8.2 ± 0.75 mm initially to 2.7 ± 0.52 mm at follow-up, clinical attachment level improved from 8.5 ± 0.83 mm initially to 2.7 ± 0.52 mm at follow-up, and midfacial gingival recession of 1 mm at two sites was corrected. The papillae were stable at all sites, with an average distance of 4.8 mm from the incisal edge to the papilla tip. This technique seems to be a promising approach for achieving both esthetic and functional goals of periodontal regenerative surgery. However, experience in performing microsurgeries and harvesting tuberosity tissues may be a limitation.

The aim of the research was to study the framework ability of the fibrous non-woven PCL matrices we've created during the restoration of bone tissue.There were performed some spectroscopic, histological and immunohistochemical, radiological and clinical analyses of the effectiveness of microfibrous non-woven PCL polycaprolactone matrices developed by us, in the work. The obtained results of morphological studies of bone tissue in the experiment of the implantation of a fibrous matrix indicated an increase in reparative osteogenesis in the form of an increase in osteoid areas up to 34.38% (p<0.05) at an early period. The analysis of clinical data showed the effectiveness of the frame developed by us, which was confirmed by the absence of pronounced compaction of bone tissue in group III, in contrast to group II, where, on the contrary, the use of granulate based on hydroxyapatite and tricalcium phosphate has led to a significant increase in density indices of 974.53+19.74 HU p<0.05, which did not exceed 36.8% of indices of the group III 615.17+24.53 HU p<0.05.The matrix material developed by us is not only a means of delivering some other substances and materials into the damaged area, but also serves as a kind of framework for the restoration of bone tissue.

Background: In specific clinical scenarios characterized by poor tissue conditions surrounding a wound, achieving stable flap fixation with standard sutures can be challenging. The anchoring flap suture technique, which is commonly used for soft tissue-to-bone attachment in cases of injury, may be an alternative and effective approach., Case Report: This report describes the successful application of the anchoring flap suture technique to repair a wound with exposed bone in a 39-year-old female patient. She presented with a 7% TBSA wound of the left trunk following hip disarticulation. After 4 operations, a wound with exposed iliac bone remained. Given the compromised condition of the tissues surrounding the exposed bone, the authors opted to anchor a local flap directly to the exposed bone. Steady flap fixation was achieved using the anchoring flap suture method, resulting in complete healing of that wound. Remarkably, no short- or long-term complications associated with the flap were observed. Three months after hospital discharge, the patient regained mobility, walking on 1 leg with the assistance of a 4-legged walker., Conclusion: The anchoring flap suture technique seems to be a reliable and effective treatment option, particularly in cases in which inadequate soft tissue precludes the use of traditional flap fixation using standard sutures.

Porous scaffold (PorS) implants, particularly those that mimic the structural features of natural cancellous bone (NCanB), are increasingly essential for the treatment of large-area bone defects. However, the mechanical properties of NCanB-based bionic bone scaffold (BioS) and its performance as a bone repair material have not been fully explored. This study investigates the effect of bionic structure parameters on the mechanical properties and bone reconstruction performance of BioS. Using laser powder bed fusion (L-PBF) technology, different BioS with various structural parameters were created and evaluated using Micro-CT, compression testing, Finite Element (FE) Simulation, and computational fluid dynamics (CFD), and compared to commonly used clinical PorS. Assess the capacity of the BioS scaffold to support and enhance bone reconstruction following implantation through the evaluation of its mechanical properties, permeability, and fluid shear stress (FSS). BioS-85-90 and BioS-80-50 showed suitable mechanical properties, performed well in FE simulation of implantation, demonstrated outstanding abilities for osteoinductive ingrowth and bone tissue differentiation, and proved to be reliable materials for the reconstruction of bone defects. Therefore, BioS shows significant potential for clinical application as a bone reconstruction material, providing a solid foundation for the integration of tissue engineering and bionic design., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Zhihui Zhang reports financial support was provided by National Natural Science Foundation of China. Xiebin Wang reports financial support was provided by Natural Science Foundation of Shandong Province. Qing Han reports financial support was provided by National Natural Science Foundation of China. Zhihui Zhang reports financial support was provided by Jilin Scientific and Technological Development Program., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Current tendon/ligament reconstructions integrate via scar tissue rather than proper bone-tendon interface regeneration, which affects graft longevity, changes in bone tunnel size, and functional outcomes. The purpose of this study was to develop a functional demineralized bone matrix (DBM) + fibrocartilage extracellular matrix (FCECM) composite scaffold, characterize its physicochemical properties, and evaluate its efficacy in repairing tendon-bone interface in a rabbit tendon reconstruction model. Solubilized FCECM was loaded and crosslinked on to DBM scaffolds via gamma-irradiation to create DBM + FCECM scaffolds. The resulting scaffold showed interconnected pores coated with FCECM and protein cargo similar to FCECM. The addition of FCECM modified the physicochemical properties of the DBM scaffold, including microstructure, biochemical composition, mechanical strength, thermodynamic properties, and degradation period. The DBM + FCECM scaffold was biocompatible for mesenchymal stem cells (MSCs) and resulted in elevation of fibrochondrogenic gene markers compared to DBM scaffolds in vitro. In vivo implantation of DBM + FCECM scaffold resulted in neofibrocartilage formation, better pullout strength, and less bone tunnel widening compared to DBM only group in a rabbit tendon reconstruction model. In conclusion, the FCECM augmented DBM scaffold repairs the tendon-bone interface with osseous-fibrocartilage tissue, which may be utilized to improve current tendon reconstruction surgeries., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

In recent years, hydrogels have been widely used in the biomedical field as materials with excellent bionic structures and biological properties. Among them, the excellent comprehensive properties of natural polymer hydrogels represented by sodium alginate have attracted the great attention of researchers. At the same time, by physically blending sodium alginate with other materials, the problems of poor cell adhesion and mechanical properties of sodium alginate hydrogels were directly improved without chemical modification of sodium alginate. The composite blending of multiple materials can also improve the functionality of sodium alginate hydrogels, and the prepared composite hydrogel also has a larger application field. In addition, based on the adjustable viscosity of sodium alginate-based hydrogels, sodium alginate-based hydrogels can be loaded with cells to prepare biological ink, and the scaffold can be printed out by 3D printing technology for the repair of bone defects. This paper first summarizes the improvement of the properties of sodium alginate and other materials after physical blending. Then, it summarizes the application progress of sodium alginate-based hydrogel scaffolds for bone tissue repair based on 3D printing technology in recent years. Moreover, we provide relevant opinions and comments to provide a theoretical basis for follow-up research., Competing Interests: Declaration of competing interest The authors report no conflicts of interest, financial or otherwise, in this work., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Bone tissue plays a crucial role in protecting internal organs and providing structural support and locomotion of the body. Treatment of hard tissue defects and medical conditions due to physical injuries, genetic disorders, aging, metabolic syndromes, and infections is more often a complex and drawn out process. Presently, dealing with hard-tissue-based clinical problems is still mostly conducted via surgical interventions. However, advances in nanotechnology over the last decades have led to shifting trends in clinical practice toward noninvasive and microinvasive methods. In this review article, recent advances in the development of nanoscale platforms for bone tissue engineering have been reviewed and critically discussed to provide a comprehensive understanding of the advantages and disadvantages of noninvasive and microinvasive methods for treating medical conditions related to hard tissue regeneration and repair.

The goal of this in vitro study was to evaluate and propose a new strategy for osseodensification technique using a drill counterclockwise to densification of bone of low density. Synthetic bone blocks of two different low densities (type III and IV) were used for the tests. The conventional drilling group (CD group) used Turbo-drill in a clockwise direction, and the osseodensification group (OD group) applied Turbo-drill in a counterclockwise direction. The applied tests were: (i) measurement of the temperature variation (ΔT) and (ii) measurement of the torque during the osteotomies, comparing the new strategy with the conventional drilling. Both groups were tested without (condition c1) and with (condition c2) irrigation, generating four subgroups: CDc1, CDc2, ODc1, and ODc2. Twenty osteotomies were made for each subgroup with a thermocouple positioned intra-bone (1 mm distant from the osteotomy) to measure the temperature produced. Other 20 samples/group were used to measure the torque value during each osteotomy in both synthetic bone density blocks. The mean of the ΔT during the osteotomies in type III bone was: 6.8 ± 1.26 °C for the CDc1 group, 9.5 ± 1.84 °C for the ODc1, 1.5 ± 1.35 °C for the CDc2, and 4.5 ± 1.43 °C for ODc2. Whereas, in the type IV bone, the ΔT was: 5.2 ± 1.30 °C for the CDc1 group, 7.0 ± 1.99 °C for the ODc1, 0.9 ± 1.05 °C for the CDc2, and 2.7 ± 1.30 °C for ODc2. The maximum torque during the osteotomies was: 8.8 ± 0.97 Ncm for CD samples and 11.6 ± 1.08 Ncm for OD samples in the type III bone; and 5.9 ± 0.99 Ncm for CD samples and 9.6 ± 1.29 Ncm for OD samples in the type IV bone. Statistical differences between the groups were detected in tests and conditions analyzed (p < 0.05). Using the drill counterclockwise for osseodensification in low-density bone generated a significantly greater torque of a drill than in CD and temperature variation during osteotomies. However, the temperature range displayed by the OD group was below critical levels that can cause damage to bone tissue., (© 2023. The Author(s).)

An increasing number of publications over the past ten years have focused on the development of chitosan-based cross-linked scaffolds to regenerate bone tissue. The design of biomaterials for bone tissue engineering applications relies heavily on the ideals set forth by a polytherapy approach called the "Diamond Concept". This methodology takes into consideration the mechanical environment, scaffold properties, osteogenic and angiogenic potential of cells, and benefits of osteoinductive mediator encapsulation. The following review presents a comprehensive summarization of recent trends in chitosan-based cross-linked scaffold development within the scope of the Diamond Concept, particularly for nonload-bearing bone repair. A standardized methodology for material characterization, along with assessment of in vitro and in vivo potential for bone regeneration, is presented based on approaches in the literature, and future directions of the field are discussed.

Aim: To evaluate and compare the effectiveness of nanocrystalline hydroxyapatite (NcHA) with advanced platelet-rich fibrin (A-PRF) and hydroxyapatite-reinforced beta tricalcium phosphate (HA + β-TCP) with A-PRF in the treatment of human infrabony defects clinically and radiographically using cone-beam computed tomography (CBCT)., Materials and Methods: There were a total of 28 defects, with 14 defects in the test and control groups, respectively. There were total 28 patients were involved in the study. The test group (group A) was treated with NHA and A-PRF, while the control group (group B) was treated with HA + β-TCP and A-PRF. Bone defect fill was the primary result of the investigation. Periodontal pocket depth (PPD), R-CAL, papillary bleeding index (PBI), and PI were the secondary outcome. Clinical and radiographic measurements were recorded at baseline and 6 months postoperatively., Results: No significant difference was observed between the two groups in terms of PPD reduction (4.64 ± 0.74 mm vs 4.07 ± 0.99 mm), clinical attachment loss (CAL) gain (4.64 ± 0.74 mm vs 3.92 ± 0.99 mm) and radiographic defect depth reduction (2.41 ± 0.32 mm vs 2.40 ± 0.27 mm) for test and control groups, respectively., Conclusion: At 6-month post-surgery, both treatment modalities demonstrated statistically significant improvements with regard to CAL gains, PPD reduction, and reduction in radiographic defect depth., Clinical Relevance: The NcHA and HA + β-TCP with A-PRF is a novel material used in the treatment of infrabony defect for periodontal regeneration. The NcHA and HA + β-TCP with A-PRF need to consider biomaterials for bone defect fill.

Bone screws must be appropriately tightened to achieve optimal patient outcomes. If over-torqued, the threads formed in the bone may break, compromising the strength of the fixation; and, if under-torqued, the screw may loosen over time, compromising the stability. Previous work has proposed a model-based system to automatically determine the optimal insertion torque. This system consists of a reverse-modelling step to determine strength, and a forward modelling step to determine maximum torque. These have previously been tested in isolation, however future work must test the combined system. To do so, the data must be segmented and pre-processed. This was done based on specific features of the recorded data. The methodology was tested on 50 screw-insertion data sets across 5 different materials. With the parameters used, all data sets were correctly segmented. This will form a basis for the further processing of the data and validating the combined systemClinical relevance: The system for torque limit determination must be tested in its entirety to properly asses its performance. This paper discusses some of the steps required to pre-process the data to make this assessment. If successful, this system may improve patient outcomes in orthopaedic surgery.

This classic discusses the original publication 'Arthroscopic double-bundle anterior cruciate ligament reconstruction (ACL): An anatomical approach', the first detailed description of the surgical technique popularised by Dr Freddie Fu. The technique, in which the anteromedial and posterolateral bundles of the ACL are reconstructed individually using two grafts with independent bone tunnels, was designed to more closely recreate the function of the native ACL by more closely reproducing the functional anatomy. This reconstruction was biomechanically superior to single-bundle reconstruction, particularly with regards to rotational control, leading to great interest from ACL surgeons around the world. Clinical superiority was more difficult to demonstrate; however, and the technical difficulty of the procedure has limited its use. Nevertheless, the pursuit of improved patient outcomes through attention to functional anatomical detail continues. 'Recreating the functional anatomy of the intact ACL remains the cornerstone of ACL reconstruction'., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

The proximal tibia and distal femur are intimately linked with the biomechanics of the knee and they are to be considered in total knee arthroplasty (TKA). The aim of the present study was to evaluate the proximal tibial torsion (PTT) in relation to surgical epicondylar axis (SEA) in a healthy cohort and a pathological cohort affected by knee osteoarthritis (OA). We retrospectively analyzed computed tomography of OA knee of 59 patients before they underwent TKA and nonarthritic knee of 39 patients as control. Posterior condylar angle (PCAn), femoral tibial torsion (SEA-proximal tibial condyle [PTC] and SEA-PTT), PTT (PTC-PTT and posterior condylar axes [PCAx]-PTC), and distance between tibial tuberosity and the trochlear groove (TT-TG) were measured. No differences were found for gender, age, TT-TG, and PCAn angles. Statistically significant differences were found for all the other angles considered. Significant correlation was found between tibial torsion and SEA-PTT angles, between PCAx-PTC and SEA-PTC, between SEA-PTT and SEA-PTC, and between PCAx-PTC and SEA-PTT. All measures, except TT-TG and PCAn angles, showed high validity (area under the curve [AUC] > 75%) in associating with OA, with SEA-PTT displaying the highest validity with an AUC of 94.38%. This is the first study to find significant differences in terms of proximal tibia geometry and anatomy between nonarthritic and OA knees. From our results, we reported that OA group was characterized by a greater internal rotation of tibia with respect to SEAs compared with control group. Since the design of the study cannot evaluate a cause-effect relationship, further studies need to be performed to assess the potential implications of these anatomic differences for knee OA and arthroplasty surgeries., Competing Interests: None declared., (Thieme. All rights reserved.)

Bone cutting is a common and important procedure in surgery. As a type of orthopedic instrument, ultrasonic orthopedic scalpels (UOSs) have been widely used due to their safety and convenience. Therefore, it is very important to have a deep understanding of the cutting process and the bone removal behavior of a UOS, to improve cutter design and complement the basic theory of the bone-cutting mechanism. However, few studies have focused on the characteristics of ultrasonic cutting. In this work, based on bone structure, the bone-cutting processes of a UOS were defined and the bone removal behavior in ultrasonic bone cutting was studied. In this study, it was believed that a direction of ultrasonic vibration different from that of the lamellar arrangement and collagen fibers would lead to different cutting characteristics. Based on this, the cutting modes were divided into four typical types. After examining and analyzing the crack propagation and chip formation of compact bone for the four cutting modes, the removal behaviors of ultrasonic bone cutting were defined. At the same time, the surface morphology indicated that there were significant differences in the surface damage for different cutting modes, which supported the idea that the bone removal behaviors were different for different modes. In addition, the force signals were analyzed and the results showed that there were differences in the cutting forces for different cutting modes. The static and dynamic components of the cutting forces were also analyzed. The study demonstrated the correlation between bone removal and the microscopic and submicroscopic structure of bone in ultrasonic cutting. These conclusions provided guidelines for analyzing bone tissue injuries caused by UOSs, improving the surgical process of bone cutting, optimizing the design of orthopedic instruments, and further complementing the basic theory of bone cutting., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Bone drilling is a universal procedure in orthopaedics for fracture fixation, installing implants, or reconstructive surgery. Surgical drills are subjected to wear caused by their repeated use, thermal fatigue, irrigation with saline solution, and sterilization process. Wear of the cutting edges of a drill bit (worn drill) is detrimental for bone tissues and can seriously affect its performance. The aim of this study is to move closer to minimally invasive surgical procedures in bones by investigating the effect of wear of surgical drill bits on their performance. The surface quality of the drill was found to influence the bone temperature, the axial force, the torque and the extent of biological damage around the drilling region. Worn drill produced heat above the threshold level related to thermal necrosis at a depth equal to the wall thickness of an adult human bone. Statistical analysis showed that a sharp drill bit, in combination with a medium drilling speed and drilling at shallow depth, was favourable for safe drilling in bone. This study also suggests the further research on establishing a relationship between surface integrity of a surgical drill bit and irreversible damage that it can induce in delicate tissues of bone using different drill sizes as well as drilling parameters and conditions., (© 2023. The Author(s).)

Background: Improved survival of cancer patients leads to more skeletal metastatic lesions that need local therapies for tumor control and pain relief. Not all tumors are radiosensitive and alternative therapies are direly needed. Microwave ablation (MWA) is a technique for minimally invasive local tumor control by physical ablation. In soft tissue local temperature ablation is more common, but studies on bone tissue are limited. To ensure safe and effective treatment, studies on local tumor ablation in bone are needed., Method: Microwave ablation was performed on sheep bone, for both in- and ex-vivo settings. Both a slow-cooking MWA protocol (gradually increasing wattage in the first two minutes of ablation) and a fast-cooking protocol (no warm-up period) were used. Heat distribution through the bone during ablation was determined by measuring temperature at 10- and 15mm from the ablation probe (= needle). Ablation size after procedure was measured using nitro-BT staining., Results: In-vivo ablations led to up to six times larger halos than ex-vivo with the same settings. Within both ex- and in-vivo experiments, no differences in halo size or temperature were found for different wattage levels (65W vs 80W). Compared to a fast cooking protocol, a two-minute slow cooking protocol led to increased temperatures and larger halos. Temperatures at 10- and 15mm distance from the needle no longer increased after six minutes. Halo sizes kept increasing over time without an evident plateau., Conclusion: Microwave ablation is technically effective for creating cell death in (sheep) long bone. It is recommended to start ablations with a slow-cooking period, gradually increasing the surrounding tissue temperature in two minutes from 40 to 90°C. Ex-vivo results cannot simply be translated to in-vivo., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Nijland et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose: To verify the efficacy and safety of calcined cattle bone grafting material in filling alveolar bone defect after tooth extraction., Methods: A randomized, bind, parallel, positive-control multicenter clinical trial was conducted. A total of 280 subjects were randomly assigned to either the experimental group (calcined cattle bone group) or control group (Bio-Oss group) equally. The main efficacy indicator was the imaging changes 24 weeks after material implantation. Secondary efficacy indicators were wound healing, rejection, bone metabolism, post-filling symptoms and signs of bone infection. The safety of material was assessed by the incidence of adverse events and serious adverse events. SAS 8.2 software package was used for statistical analysis., Results: A total of 280 cases were included, of them 267 cases completed the study while 13 cases fell off. The effective rate of FAS(PPS) was 90.58%(97.46%) in the experimental group and 87.05% (95.04%) in the control group. The difference of effective rate between the experimental group and control group (95%CI) was 3.53% (-3.88%, 10.94%) of FAS, 2.42% (-2.38%, 7.22%) of PPS, and there was no significant difference between the two groups. The incision healing of the two groups was good, and the incidence of rejection, bone infection signs, post-filling symptoms and bone metabolic changes was very low. The incidence of adverse events was similar in the two groups, and no serious adverse events related to the study materials occurred., Conclusions: The efficacy of calcined cattle bone grafting material in filling alveolar bone defect after tooth extraction is not inferior to that of Bio-Oss, and it is safe and effective for alveolar bone defect repair.

Background: BASHTI is an implant-less anterior cruciate ligament (ACL) reconstruction technique, which resolves the problems caused by implants such as interference screws. This study aims to investigate the effect of the drill bit and tendon's diameter on the Core Bone Engaged Length (CBEL) and the fixation strength. CBEL is the length of core bone which has a full engagement with both tunnel and graft at the same time., Methods: 60 in-vitro tests were conducted for 6, 7, 8, and 9 mm tendon sizes with a 10 mm bone tunnel. In this study bovine tendons and dummy bone blocks were used to model the fixation. Drill bits were used to extract the core bone for securing the auto-graft. A three-stage tensile test including a force-controlled cyclical preloading of 10-50 N with a frequency of 0.1 Hz for 10 cycles, followed by the main force-controlled cyclical loading of 50-200 N with a frequency of 0.5 Hz for 150 cycles, and immediately a displacement-controlled single cycle pull-out load with a rate of 20 mm/min were carried out to discover the fixation strength of each sample., Results: The 6 mm group had the greatest CBEL. However, all cases in this group failed in loadings below 200 N, which is the minimum required strength after ACL reconstruction. The fixation strength of cases with more than 200 N fixation strength for 7, 8, and 9 mm tendon diameters were 275 ± 42, 330 ± 110, and 348 ± 93 N, respectively, showing insignificant difference between groups (P-value = 0.45). Nevertheless, CBELs for these groups were 16.6 ± 3.4, 9.6 ± 2.4, and 11.7 ± 3.8 mm, respectively, implying a significant increase in CBEL in the 7 mm group than that for 8 and 9 mm groups (P-value = 0.002 and 0.049, respectively)., Conclusion: Results showed that CBEL could assess the quality of BASHTI technique. However, CBEL was an inverse function of tendon compression, so it was not an independent parameter to determine BASHTI strength. Also, the CBEL of 7 mm group which fulfilled the 200 N threshold was higher than that of 8 and 9 mm groups, so its healing process speed may be higher, which is recommended for a future study in this field., (© 2023. The Author(s).)

Background: Surgical treatment of patients with osteoarthritis of the hip and persisting symptoms under conservative therapy has become increasingly important against the background of an aging population., Objectives: What are the physiological reactions in the interface between cementless implants and bone?, Methods: The literature is reviewed, expert opinions and animal models are analyzed and discussed., Results: Surface coating of implants with hydroxyapatite or titanium can have positive effects on osteointegration. Additional local application of mediators might be beneficial for osteointegration in the future., Conclusion: Early peri-implant bone healing directly after implantation and late remodeling of the bone-implant interface are essential for secondary implant stability., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Bone tissue engineering (BTE) is constantly seeking novel treatments to address bone injuries in all their varieties. It is necessary to find new ways to create structures that perfectly emulate the native tissue. Self-healing hydrogels have been a breakthrough in this regard, as they are able to reconstitute their links after they have been partially broken. Among the most outstanding biomaterials when it comes to developing these hydrogels for BTE, those polymers of natural origin (e.g., gelatin, alginate) stand out, although synthetics such as PEG or nanomaterials like laponite are also key for this purpose. Self-healing hydrogels have proven to be efficient in healing bone, but have also played a key role as delivery-platforms for drugs or other biological agents. Moreover, some researchers have identified novel uses for these gels as bone fixators or implant coatings. Here, we review the progress of self-healing hydrogels, which hold great promise in the field of tissue engineering., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

The purpose of this study is to propose a quantitative assessment scheme to help with surgical bone drilling training. This pilot study gathered and compared motion and force data from expert surgeons (n = 3) and novice residents (n = 6). The experiment used three-dimensional printed bone simulants of young bone (YB) and osteoporotic bone (OB), and drilling overshoot, time, and force were measured. There was no statistically significant difference in overshoot between the two groups (p = 0.217 for YB and 0.215 for OB). The results, however, show that the experts took less time (mean = 4.01 s) than the novices (mean = 9.98 s), with a statistical difference (p = 0.003 for YB and 0.0001 for OB). In addition, the expert group performed more consistently than the novices. The force analysis further revealed that experts used a higher force to drill the first cortical section and a noticeably lower force in the second cortex to control the overshoot (approximate reduction of 5.5 N). Finally, when drilling time and overshoot distance were combined, the motion data distinguished the skill gap between expert and novice drilling; the force data provided insight into the drilling mechanism and performance outcomes. This study lays the groundwork for a data-driven training scheme to prepare novice residents for clinical practice., (© 2022 Orthopaedic Research Society. Published by Wiley Periodicals LLC.)

Purpose: Short stems are increasingly used in total hip arthroplasty (THA) because of advantages in bone and soft tissue preservation and reconstruction of hip geometry. Digital templating is essential in determining the correct offset option and stem size in THA. However, the preoperative template sizes might be intraoperatively overruled., Patients and Methods: We evaluated the effect of intraoperative overruling of the preoperatively templated offset option of a short curved stem on hip offset, leg length, implant positioning, and femoral canal fill index. The overruling was performed in case of intraoperative instability, telescoping, or both. A series of 1052 consecutive THAs with a cementless short curved stem and press-fit cup was retrospectively screened. One hundred patients with unilateral THA and a contralateral native and morphologically healthy hip as a reference met the inclusion criteria. Measurements were carried out on preoperative and 3 months anterior-posterior postoperative radiographs. Patients were divided according to the overruling by offset option or stem size., Results: Hip offset was increased in all groups, but only with significant increase if an offset option + 1 was used intraoperatively (p = 0.025). LLD was restored without significance in all groups (p = 0.323; p = 0.157)., Conclusion: Intraoperative overruling of the preoperative digital template in cementless short stem total hip arthroplasty results in an increase of hip offset compared to a contralateral healthy hip. However, the increase is marginal and clearly under 5 mm compared to the contralateral healthy hip., (© 2022. The Author(s).)

The initial fixation of cementless tibial trays after total knee arthroplasty is critical to ensure bony ingrowth and long-term fixation. Various fixed-bearing implant designs that utilize different fixation features, surface coatings, and bony preparations to facilitate this initial stability are currently used clinically. However, the role of tibiofemoral conformity and the effect of different tray fixation features on initial stability are still unclear. This study assessed the implant stability of two TKA designs during a series of simulated daily activities including experimental testing and corresponding computational models. Tray-bone interface micromotions and the porous area ideal for bone ingrowth were investigated computationally and compared between the two designs. The isolated effect of femoral-insert conformity and fixation features on the micromotion was examined separately by virtually exchanging design features. The peak interface micromotions predicted were at least 47% different for the two designs, which was a combined result of different femoral-insert conformity (contributed 79% of the micromotion difference) and fixation features (21%). A more posterior femoral-insert contact due to lower tibiofemoral conformity in a force-controlled simulation significantly increased the micromotion and reduced the surface area ideal for bone ingrowth. The maximum difference in peak micromotions caused by only changing the fixation features was up to 33%. Overall, the moment arm from the insert articular contact point to the anterolateral tray perimeter was the primary factor correlated to peak and average micromotion. Our results indicated that tray-bone micromotion could be minimized by centralizing the load transfer and optimizing the fixation features., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Paul Rullkoetter reports financial support was provided by DePuy Synthes., (Copyright © 2022. Published by Elsevier Ltd.)

This study's objective was to identify a difference in maximum temperature change during forward versus oscillating drilling of cadaveric bone. Paired femurs were dissected from the soft tissue of five cadavers. Each cadaver had one femur assigned to forward and the other to oscillation. The first drill hole was 2.5 cm distal to the lesser trochanter and the remaining 10 holes were evenly spaced 2 cm apart. A System 7 drill and 3.5 mm drill bit were attached to an Instron 5500R to provide a progressive force of 50 Newtons per minute for each drill hole. A thermal camera recorded each drilling. A new drill bit was used for each femur. Fifty bicortical drillings were analyzed in each group. The average time to complete forward drilling (45.0 seconds) was shorter compared to oscillation (55.5 s, p < 0.001). The average force required for forward drilling (27.7 N) was lower than for oscillation (44.3N, p < 0.001). The maximum change in temperature during the drilling process was similar (oscillating 100.2° F vs. forward 100.7° F, p = 0.871). The maximum change in temperature at the near cortex was lower for oscillation (78.1°F) compared to forward drilling (89.1°F, p = 0.011), while the maximum change at the far cortex was lower for forward drilling (89.3°F) compared to oscillation (95.8°F, p = 0.115) but not significantly. Overall, there is no difference in the thermal output between techniques. Oscillation may be beneficial in proximity to vital structures or to navigate narrow bony corridors, but it requires additional time and force. (Journal of Surgical Orthopaedic Advances 31(4):233-236, 2022).

Bone drilling is frequently used during orthopaedic surgeries to treat the fractured part of the bone. A major concern for surgeons is the increase in temperature during real-time orthopaedic bone drilling. The temperature elevation at the bone-tool interface may cause permanent death of regenerative soft tissues and cause thermal osteonecrosis. A robust predictive machine-learning model is suggested in this in-vitro research for monitoring temperature rise during surgery. The objective of the present work is to introduce different machine learning algorithms for predicting temperature elevations in rotary ultrasonic bone drilling. Different machine-learning models were compared with the standard response surface methodology. The performance and accuracy of different predictive models were compared at different error metrics. It was witnessed that support vector machines performed the best for predicting the change in temperature in comparison to other predictive models. Moreover, the error metrics for statistical response surface methodology analysis were comparatively higher than the machine learning algorithms. By using machine learning models, it is possible to predict temperature rise during bone drilling., Competing Interests: Declaration of Competing Interest None declared, (Copyright © 2022. Published by Elsevier Ltd.)

The long-term success of a dental implant is related to the material and design of the implant, and bone density. Conventional implants cause stress-shielding due to a mismatch between the implant and bone stiffness. Functionally graded porous materials and designs are a great choice for the design of implants to control the local stiffness at a certain location to meet the biomechanical requirements. The purpose of this study is to analyze five designs of axial and radial functionally graded materials (FGM) implants besides the conventional implant and conical and cylindrical shapes that were simulated with five different bone densities. The results showed that strain in bone increased with a decrease in cancellous bone density. The shape of the implant did not play an important role in strain/stress distribution. Conventional implants showed optimal strain (1000-2240 με) in low-density (0.7-0.8 g/cm 3 ) bone, however, FGM implants produced optimal strain (990-1280 με) in the high-density bone (0.9-1 g/cm 3 ) as compared to conventional implants. The proposed designs of FGM implants have the potential to address the complications of conventional implants in high-density bone., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In the process of repairing fractures in the bone region with orthopedic injuries, the application of supporting and strengthening the bone tissue with screws, wires, rods, and plates is a widely preferred internal fixation method. In this treatment process, it is necessary to drill the bone tissue to fix the screws. Due to the heat generated in the drilling process, mechanical and thermal damage occurs in the bone tissue. In this study, it is focused that the effect of different cutting conditions on the temperature distribution and necrosis zones in the drilling of human cortical bone. In this context, by selecting variable drill geometry (diameter, point angle, and helix angle) and variable cutting parameters (cutting speed and feed rate), temperature distribution and necrosis zones were investigated with finite element analyses and analytical calculations. When the findings were evaluated, it was understood that drill diameter and cutting speed did not have a significant effect on temperatures and necrosis zone at low cutting speeds. At high cutting speeds, it was observed that the feed rate and drill point angle had an indeterminate effect on the temperatures. The lowest temperature values were obtained at cutting speed of 750 rpm and a feed rate of 0.1 mm/rev for low cutting speeds, and cutting speed of 1500 rpm, helix angle of 10° and drill bit diameter of 2 mm for high cutting speeds. The narrowest necrosis zones were obtained at cutting speed of 250 rpm and feed rate of 0.1 mm/rev for both drill diameters. As a result, the effects of different drill geometry and cutting parameters were determined in order to obtain low temperature distribution and narrow necrosis zone in cortical bone drilling., (© 2022 John Wiley & Sons Ltd.)

Purpose: To investigate the impact of implantoplasty (IP) with or without regenerative procedures on treatment outcomes of peri-implantitis., Materials and Methods: Electronic and manual literature searches were conducted for clinical trials published up to October 2020 that evaluated clinical outcomes (at least 6-month follow-up) after peri-implantitis treatment involving IP. The implant survival rate and clinical parameters (eg, probing depth [PD], bleeding on probing [BOP], marginal bone loss [MBL], clinical attachment level [CAL], and mucosal recession [REC]) at baseline and follow-ups were extracted from original articles for qualitative analyses. Risk ratio and weighted mean difference with 95% CI were calculated using a random-effects model., Results: Out of 322 studies, 17 (9 randomized controlled trials, 4 controlled clinical trials, and 4 case series) were included in the present study. The regeneration group presented a 97% (95% CI: 0.95 to 1.00) implant survival rate, and the nonregeneration group showed a 94% (95% CI: 0.90 to 0.98) survival rate. Both groups revealed similar outcomes in PD and BOP reductions and soft tissue REC. However, the regeneration group had more favorable results in MBL., Conclusion: Data from this study suggested that applying implantoplasty during a regeneration or nonregeneration surgical approach resulted in a high implant survival rate and peri-implantitis resolution. Although no differences were found in the majority of clinical parameters in both groups, the regenerative approach resulted in more radiographic bone fill than the nonregenerative treatment.

As bone grafts become more commonly needed by patients and as donors become scarcer, acellularized bone grafts (ABGs) are becoming more popular for restorative purposes. While autogeneic grafts are reliable as a gold standard, allogeneic and xenogeneic ABGs have been shown to be of particular interest due to the limited availability of autogeneic resources and reduced patient well-being in long-term surgeries. Because of the complete similarity of their structures with native bone, excellent mechanical properties, high biocompatibility, and similarities of biological behaviors (osteoinductive and osteoconductive) with local bones, successful outcomes of allogeneic and xenogeneic ABGs in both in vitro and in vivo research have raised hopes of repairing patients' bone injuries in clinical applications. However, clinical trials have been delayed due to a lack of standardized protocols pertaining to acellularization, cell seeding, maintenance, and diversity of ABG evaluation criteria. This study sought to uncover these factors by exploring the bone structures, ossification properties of ABGs, sources, benefits, and challenges of acellularization approaches (physical, chemical, and enzymatic), cell loading, and type of cells used and effects of each of the above items on the regenerative technologies. To gain a perspective on the repair and commercialization of products before implementing new research activities, this study describes the differences between ABGs created by various techniques and methods applied to them. With a comprehensive understanding of ABG behavior, future research focused on treating bone defects could provide a better way to combine the treatment approaches needed to treat bone defects.

In medical surgery, bone drilling is an inevitable procedure. The thermal necrosis in the drilling process can affect post-operative recovery. In this study, the method of drill bit precooling is proposed in bone drilling with robot assisted system. The influence of process parameters on the drilling temperature were investigated and analyzed. The results showed that the method of drill bit precooling could reduce the drilling temperature. The drill bit starting temperature and the feed rate were more important parameters on the drilling temperature compared with rotational speed and cooling length of the drill bit. The quadratic regression model obtained from response surface experiments can predicted the drilling temperature correctly under the range of process parameters in this study. The optimal parameter combination is rotational speed = 1610 rpm, feed rate = 0.5 mm/s, the starting temperature of drill bit = 8°C, and the cooling length = 34.8 mm. The results provide an effective method to reduce thermal necrosis of bone cells in drilling.

Mechanical and thermal damage to the bone tissue during drilling process is inevitable and directly affects the postoperative recovery. According to clinical practices and present academic investigations, this study tries to reduce bone damage by experimental investigation of bone drilling by Kirschner wire considering the drilling force and temperature factors. Finite element method has been applied to modelling of the drilling process. Then, grouped experiments have been carried out using bovine femoral bone and analyzed based on the orthogonal experimental method. The influence of key parameters such as Kirschner wire bevel angle, feed speed and rotational speed on the microscopic bone chip size, drilling force, drilling temperature and hole inlet burr was analyzed to conduct comprehensive analysis and optimizations. It is certain that the chips size is closely related to drilling force and drilling temperature. The low drilling temperature does not mean that the damage area is small. The drilling process should be completed quickly at high feed rates. The lower rotational speed, Kirschner wire bevel angle, and higher feed rate help reduce the thermal damage area of the bone drill, effectively reduce the drilling force and hole entrance burrs., (Copyright © 2022. Published by Elsevier Ltd.)

This systematic review was planned to assess the clinical outcomes of transport distraction osteogenesis (TDO) compared with autogenous grafts for reconstruction of the ramus condyle unit (RCU). We searched Medline, Embase, Cochrane Library, Clinicaltrial.gov, and the references of included trials. The primary outcome was maximal incisal opening (MIO). Of the 148 studies retrieved, five were included (TDO = 49, autogenous grafts =123). The mean difference in MIO between TDO and autogenous graft RCU reconstruction, based on the random-effects model was 1.28 mm (95% CI 0.167 to 2.403) in favour of TDO. Re-ankyosis was observed in four cases in the costochondral graft group and none in the TDO group. Reconstruction of the RCU using TDO is comparable to autogenous grafts after the release of TMJ ankylosis, though the evidence is weak considering the small number of trials, high risk of bias, and absence of long-term results., (Copyright © 2021 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

The mechanical drilling process is a typical step in treating bone fractures to fix broken parts with screws and plates. Drilling generates a significant amount of heat and elevates the temperature of the bone, which can cause thermal osteonecrosis and damage to the surrounding bone tissue and nerves. Thermal inertia between heat flux and temperature gradient in nonhomogeneous interior structural medium-like biological tissues is arguable. Therefore, this paper proposes an analytical model of heat propagation in bone drilling for orthopedic surgery based on the hyperbolic Pennes bioheat transfer equation (HPBTE). Drilling experiments in bovine cortical bone samples were also carried out using an infrared thermography approach to confirm the proposed analytical model. Around the drilled hole surface, thermal necrosis is spread out from 1 to 10 mm. Increased feed rate reduces necrosis penetration distance and increases intense bone necrosis. The HPBTE includes thermal relaxation time effect and internal convective function of tissue perfusion rate. As these factors are not considered in the parabolic heat transfer equation (PHTE), the results show that the HPBTE is more accurate in predicting temperature and thermal osteonecrosis than the PHTE. As a result, proposed analytical model is a handy tool for calculating temperature to avoid thermal damage while improving process efficiency. Furthermore, it has the capability of controlling the manual or robotic drilling procedure for minimally invasive operations.

Undue heat production in surgical bone drilling leads to osteonecrosis and can be an important cause of failure of osteosynthesis, impaired healing, and loosening of implants following orthopedic surgery. The present work aims to minimize heat production below the critical temperature for thermal osteonecrosis (i.e., 47°C) and obviate thermal bone damage due to drilling. A total of 20 samples from the shaft of the human femur were obtained at autopsies and drilling was performed at room temperature by an operation theater (OT) compatible rotary ultrasonic bone drilling (RUBD) machine. K-type thermocouples were used to measure the temperature rise during drilling and the physical changes of the bone samples were observed by infrared gama camera. Light microscopic and transmission electron microscopic studies were performed to evaluate the bone cell damage. The maximum temperature recorded in RUBD (40.6 ± 1.3°C) was much below the critical temperature for thermal osteonecrosis (p < .05) at the rotational speed of 2000 rpm. Light microscopic and ultrastructural studies also revealed that there was no appreciable damage to the bone cells. Conventional bone drilling (CD) on the other hand recorded much higher temperature (66.6 ± 3.2°C), tissue burn and bone cell necrosis. Hence, RUBD machine has a potentiality for its use in orthopedic surgery and may provide better results., (© 2021 Wiley Periodicals LLC.)