Previous studies have reported that nanoclay Laponite can promote the osteogenic differentiation of BMSCs, and Laponite hydrogel composites can be used to facilitate the repair of bone defects. In order to realize the biomedical application of Laponite, the study of the osteogenesis process of Laponite became essential.This study aimed to elucidate the proportion of Laponite in hydrogels that can exert optimal osteogenic efficacy and its potential mechanisms. Various proportions of Laponite in hydrogel composites were prepared using a simple molding method and the proportion of Laponite in a hydrogel that could optimally promote osteogenesis and bone repair was investigated in vitro and in vivo. Transcriptome sequencing was performed to identify and verify the potential signaling pathways. We found that Laponite decreased the water content of the hydrogel composites but increased their mechanical strength and was gradually released as the hydrogels degraded. Additionally, when the proportion of Laponite in the hydrogel composite was 2%, BMSCs exerted a stronger osteogenic differentiation potential in vitro, and rat femoral condyles with critical bone defects were optimally repaired without the production of fibrous capsule. Transcriptome sequencing revealed that the MAPK signaling pathway was more prominent than other pathways, and MAPK-Erk pathway activation was the most significant. When the Erk pathway was blocked, the bone-enhancing effect of Laponite was substantially reduced. This study demonstrated the appropriate proportion of Laponite in hydrogel to optimally promote osteogenesis and examined the major signaling pathways, which could provide corresponding strategies for Laponite application in biomedical engineering.

Residual powder on the surface and within the pores of Gyroid-structured porous 316L stainless steel implants fabricated via powder bed fusion-laser beam (PBF-LB) impairs biocompatibility and increases implant failure risk. This study introduces a reverse high-voltage anodic oxidation (AO) technique to address this issue effectively. By leveraging high-voltage AO, non-ordered, large-diameter, deep, and weakly bonded honeycomb structures are generated, facilitating the removal of residual powder. Subsequently, low-frequency ultrasound is applied to further disrupt these structures for deeper powder removal and the creation of stable micro-nanoscale surface patterns. Mechanical testing revealed that polished 316L-AU-50 samples maintained compressive properties, exhibiting higher plateau stress and energy absorption, which provided superior bone protection. Moreover, These modifications significantly enhance bioactivity by creating ripple-like, fish-scale, and dendritic textures on the pore walls, which promote cell adhesion, proliferation, and differentiation. This study demonstrates that reverse high-voltage AO, combined with ultrasonic disruption, is a promising approach for removing residual powder, preserving mechanical integrity, and enhancing bioactivity, offering significant potential for clinical applications of porous 316L stainless steel implants.

Vat photopolymerization (VPP) enables the fabrication of hydroxyapatite (HAp) with high resolution, complex geometry and interconnected porous structures. However, the inherent property characterization of the VPP-printed HAp as a comparative benchmark for peer studies is still lacking. This study systematically analyzed the performance of VPP-printed HAp with a 55 vol% solid loading, focusing on printability, fabrication quality, mechanical performance limits, reliability, and biological response. The optimized HAp slurry presented high polymerization reactivity and efficient, precise photocuring performance at 17 mJ/cm2. With a high density of 98.98 % and compacted grain boundaries, the bending strength of the HAp reached 127 MPa, surpassing the highest reported value for 3D-printing HAp by 23.3 %. In vitro studies demonstrated that the VPP-printed HAp promoted osteoblast proliferation and osteogenic differentiation. The HAp fabricated via VPP with efficient printability, controllable fabrication accuracy (within 1 %) and quality, good mechanical performance and osteogenic activity showcased its promising potential in implant fabrication for bone tissue repair.

ABSTRACTBackgroundHigh tibial osteotomy (HTO) is a surgical procedure for treating certain knee conditions. Proper execution of HTO can preserve joint function and delay or avoid the need for total knee replacement. This study compared different 3D printing techniques (fused deposition modeling, selective laser sintering, and direct metal laser sintering) and a navigation system for their suitability in assisting HTO surgeries.MethodsTibial saw‐bones were used as models, and surgical guides and the navigation system were employed during the procedures. Six parameters (planning time, manufacturing time, delivery time, material cost, operation time, and accuracy) were evaluated. One‐way analysis of variance (ANOVA) and t‐test were used for the analysis.ResultsThe results showed that the metal surgical guides had the highest accuracy (angle differences mean, 2.4°) and operation time (mean 9.75 min), followed by plastic guides, classic guides, and the navigation system. The differences in accuracy were attributed to factors like rigidity, melting point, and errors during incisions.ConclusionsThe study recommended metal surgical guides as the best option for assisting HTO due to their accuracy and operation time. And the results have implications for orthopedic surgeons performing HTO surgeries, as they can use this information to improve postoperative outcomes, such as mechanical axis alignment and quality of life for HTO patients.

BackgroundThis study introduced an Augmented Reality (AR) navigation system to address limitations in conventional high tibial osteotomy (HTO). The objective was to enhance precision and efficiency in HTO procedures, overcoming challenges such as inconsistent postoperative alignment and potential neurovascular damage.MethodsThe AR-MR (Mixed Reality) navigation system, comprising HoloLens, Unity Engine, and Vuforia software, was employed for pre-clinical trials using tibial sawbone models. CT images generated 3D anatomical models, projected via HoloLens, allowing surgeons to interact through intuitive hand gestures. The critical procedure of target tracking, essential for aligning virtual and real objects, was facilitated by Vuforia's feature detection algorithm.ResultsIn trials, the AR-MR system demonstrated significant reductions in both preoperative planning and intraoperative times compared to conventional navigation and metal 3D-printed surgical guides. The AR system, while exhibiting lower accuracy, exhibited efficiency, making it a promising option for HTO procedures. The preoperative planning time for the AR system was notably shorter (4 min) compared to conventional navigation (30.5 min) and metal guides (75.5 min). Intraoperative time for AR lasted 8.5 min, considerably faster than that of conventional navigation (31.5 min) and metal guides (10.5 min).ConclusionsThe AR navigation system presents a transformative approach to HTO, offering a trade-off between accuracy and efficiency. Ongoing improvements, such as the incorporation of two-stage registration and pointing devices, could further enhance precision. While the system may be less accurate, its efficiency renders it a potential breakthrough in orthopedic surgery, particularly for reducing unnecessary harm and streamlining surgical procedures.

Background: Distal humerus fractures are a challenge to treat, and the current standard of care, open reduction internal fixation with a double -plate, has a high rate of complications. We proposed a novel internal fixation configuration, lateral intramedullary nail and medial plate (LINMP) and verified its rigidity through biomechanical tests and finite element analysis. Methods: The study involved biomechanical testing of 30 synthetic humerus models to compare 2 different fixation systems for an AO 13C-2.3 type fracture. The orthogonal double -plate (ODP) group and the LINMP group were compared through biomechanical testing to measure stiffness and failure load fewer than 3 working conditions. Based on the results, we optimized the intramedullary nail by eliminating the holes at the distal end of the nail and incorporating a 2 -hole external locking plate. The Finite element analysis was also conducted to further compare the modified LINMP configuration with the previous 2 fixation configurations. Results: In biomechanical tests, the ODP group exhibited lower stiffness under bending and compression forces compared to the LINMP group, but higher stiffness and failure loads under torsion force. In finite element analysis, the modified LINMP reduces the maximum stress of the fixation structure without significantly reducing the stiffness under bending stress and axial compression conditions. In torsion stress conditions, the modified LINMP enhances both the maximum stress and the stiffness, although it remains marginally inferior to the ODP structure. Conclusion: Our study demonstrates that the innovative LINMP presents comparable or slightly superior concerning bending and axial loading compared to orthogonal double -plate osteosynthesis for distal humeral intra-articular fractures, which might become a minimally invasive option for these fractures. Level of evidence: Basic Science Study; Biomechanics and Computer Modeling (c) 2023 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Background: Extracellular matrix metabolism dysregulation in nucleus pulposus (NP) cells represents a crucial pathophysiological feature of intervertebral disc degeneration (IDD). Our study elucidates the role and mechanism of Testis expressed 11 (TEX11, also called ZIP4) extracellular matrix degradation in the NP. Materials and methods: Interleukin-1 beta (IL-1 beta) and H2O2 were used to treat NP cells to establish an IDD cell model. Normal NP tissues and NP tissues from IDD patients were harvested. ZIP4 mRNA and protein profiles in NP cells and tissues were examined. Enzyme-linked immunosorbent assay (ELISA) confirmed the profiles of TNF-alpha, IL-6, MDA, and SOD in NP cells. The alterations of reactive oxygen species (ROS), lactate dehydrogenase (LDH), COX2, iNOS, MMP-3, MMP-13, collagen II, aggrecan, FoxO3a, histone deacetylase 4 (HDAC4), Sirt1 and NF-kappa B levels in NP cells were determined using different assays. Results: The ZIP4 profile increased in the NP tissues of IDD patients and IL-1 beta- or H2O2-treated NP cells. ZIP4 upregulation bolstered inflammation and oxidative stress in NP cells undergoing IL-1 beta treatment and exacerbated their extracellular matrix degradation, whereas ZIP4 knockdown produced the opposite outcome. Mechanistically, ZIP4 upregulated HDAC4 and enhanced NF-kappa B phosphorylation while repressing Sirt1 and FoxO3a phosphorylation levels. HDAC4 knockdown or Sirt1 promotion attenuated the effects mediated by ZIP4 overexpression in NP cells. Conclusions: ZIP4 upregulation aggravates the extracellular matrix (ECM) degradation of NP cells by mediating inflammation and oxidative stress through the HDAC4-FoxO3a axis.

To construct a three-dimensional statistical shape model of the pelvis and investigate its three-dimensional morphological changes. We collected CT data from 201 Chinese individuals and used deep learning to reconstruct three-dimensional models of the pelvis automatically. Through three-dimensional model registration, dense correspondence mesh mapping, and the use of statistical shape modeling (SSM) and principal component (PC) analysis methods, we extracted models of variations (MoVs) of pelvic shape changes and statistically compared the shape MoVs between males and females. We analyzed the top 10 principal components of shape variations, which accounted for 86.1% of the total variability. Among them, PC1, PC2, and PC4 showed significant differences between genders (p-values of 0.000, 0.000, and 0.010), accounting for a total variability of 60.1%. PC8 and PC10 demonstrated pelvic asymmetry, accounting for a total variability of 3.8%. We constructed a three-dimensional statistical shape model of the pelvis in Chinese individuals, deepening our understanding of anatomical variations in pelvic morphology. This model can also be further applied in anatomy education and implant design.

Ionic liquids (ILs) have emerged as versatile tools for interfacial engineering in perovskite photovoltaics. Their multifaceted application targets defect mitigation at SnO2-perovskite interfaces, finely tuning energy level alignment, and enhancing charge transport, meanwhile suppressing non-radiative recombination. However, the diverse chemical structures of ILs present challenges in selecting suitable candidates for effective interfacial modification. This study adopted a systematic approach, manipulating IL chemical structures. Three ILs with distinct anions are introduced to modify perovskite/SnO2 interfaces to elevate the photovoltaic capabilities of perovskite devices. Specifically, ILs with different anions exhibited varied chemical interactions, leading to notable passivation effects, as confirmed by Density Functional Theory (DFT) calculation. A detailed analysis is also conducted on the relationship between the ILs' structure and regulation of energy level arrangement, work function, perovskite crystallization, interface stress, charge transfer, and device performance. By optimizing IL chemical structures and exploiting their multifunctional interface modification properties, the champion device achieved a PCE of 24.52% with attentional long-term stability. The study establishes a holistic link between IL structures and device performance, thereby promoting wider application of ILs in perovskite-based technologies.

Fractures of the talar neck and body are associated with spine fractures and scoliosis deformity, which affect cosmetic appearance and cause difficulty in ambulation. The implant design for talus surgery is thriving as a functional alternative in case of severe talar destruction, focusing on segmentation and reconstruction of the talus’s shape. However, manual segmentation of the talus is time-consuming and subjective. In this study we exploited the automatic segmentation framework to efficiently train a deep learning-based model to accurately segment the talus based on computed tomography imaging. We developed three model configurations with nnU-Net and investigated their Dice similarity coefficients (DSC) and 95% Hausdorff distances (HD95) for talus segmentation on a CT image dataset. The three configurations performed well (DSC > 0.95, HD95 < 0.6). When tested on the same samples, one of the configurations was more efficient while ensuring higher accuracy. We propose to focus on talus anatomic variations with increasing age based on this framework and apply it to clinical trials at the next stage.

[This corrects the article DOI: 10.1016/j.bioactmat.2021.07.030.].

[This corrects the article DOI: 10.2147/IJN.S428429.].

Background: Ultrasound is widely used for image-guided therapy (IGT) in many surgical fields, thanks to its various advantages, such as portability, lack of radiation and real-time imaging. This article presents the first attempt to utilize multiple deep learning algorithms in distal humeral cartilage segmentation for dynamic, volumetric ultrasound images employed in minimally invasive surgery. Methods: The dataset, consisting 5,321 ultrasound images were collected from 12 healthy volunteers. These images were randomly split into training and validation sets in an 8:2 ratio. Based on deep learning algorithms, 9 semantic segmentation networks were developed and trained using our dataset at Southern University of Science and Technology Hospital in September 2022. The performance of the networks was evaluated based on their segmenting accuracy and processing efficiency. Furthermore, these networks were implemented in an IGT system to assess their feasibility in 3-dimentional imaging precision. Results: In 2D segmentation, Medical Transformer (MedT) showed the highest accuracy result with a Dice score of 89.4%, however, the efficiency in processing images was relatively lower at 2.6 frames per second (FPS). In 3D imaging, the average root mean square (RMS) between ultrasound (US)-generated models based on the networks and magnetic resonance imaging (MRI)-generated models was no more than 1.12 mm. Conclusions: The findings of this study indicate the technological feasibility of a novel method for real-time visualization of distal humeral cartilage. The increased precision of ultrasound calibration and segmentation are both important approaches to improve the accuracy of 3D imaging.

Given afferent functions, sensory nerves have recently been found to exert efferent effects and directly alter organ physiology. Additionally, several studies have highlighted the indirect but crucial role of sensory nerves in the regulation of the physiological function of osteoclasts. Nonetheless, evidence regarding the direct sensory nerve efferent influence on osteoclasts is lacking. In the current study, we found that high levels of efferent signals were transported directly from the sensory nerves into osteoclasts. Furthermore, sensory hypersensitivity significantly increased osteoclastic bone resorption, and sensory neurons (SNs) directly promoted osteoclastogenesis in an in vitro coculture system. Moreover, we screened a novel neuropeptide, Cyp40, using an isobaric tag for relative and absolute quantitation (iTRAQ). We observed that Cyp40 is the efferent signal from sensory nerves, and it plays a critical role in osteoclastogenesis via the aryl hydrocarbon receptor (AhR)-Ras/Raf-p-Erk-NFATc1 pathway. These findings revealed a novel mechanism regarding the influence of sensory nerves on bone regulation, i.e., a direct promoting effect on osteoclastogenesis by the secretion of Cyp40. Therefore, inhibiting Cyp40 could serve as a strategy to improve bone quality in osteoporosis and promote bone repair after bone injury.

Objective:To review targeted muscle reinnervation (TMR) surgery for the construction of intelligent prosthetic human-machine interface, thus providing a new clinical intervention paradigm for the functional reconstruction of residual limbs in amputees.Methods:Extensively consulted relevant literature domestically and abroad and systematically expounded the surgical requirements of intelligent prosthetics, TMR operation plan, target population, prognosis, as well as the development and future of TMR.Results:TMR facilitates intuitive control of intelligent prostheses in amputees by reconstructing the "brain-spinal cord-peripheral nerve-skeletal muscle" neurotransmission pathway and increasing the surface electromyographic signals required for pattern recognition. TMR surgery for different purposes is suitable for different target populations.Conclusion:TMR surgery has been certified abroad as a transformative technology for improving prosthetic manipulation, and is expected to become a new clinical paradigm for 2 million amputees in China.

Groove patterns are widely used in material surface modifications. However, the independent role of ditches/ridges in regulating fibrosis of soft tissues is not well-understood, especially the lack of linkage evidence in vitro and in vivo. Herein, two kinds of combinational microgroove chips with the gradient ditch/ridge width were fabricated by photolithography technology, termed R and G groups, respectively. In group R, the ridge width was 1, 5, 10, and 30 μm, with a ditch width of 30 μm; in group G, the groove width was 5, 10, 20, and 30 μm, and the ridge width was 5 μm. The effect of microgrooves on the morphology, proliferation, and expression of fibrous markers of stem cells was systematically investigated in vitro. Moreover, thicknesses of fibrous capsules were evaluated after chips were implanted into the muscular pouches of rats for 5 months. The results show that microgrooves have almost no effect on cell proliferation but significantly modulate the morphology of cells and focal adhesions (FAs) in vitro, as well as fibrosis differentiation. In particular, the differentiation of stem cells is attenuated after the intracellular force caused by stress fibers and FAs is interfered by drugs, such as rotenone and blebbistatin. Histological analysis shows that patterns of high intracellular force can apparently stimulate soft tissue fibrosis in vivo. This study not only reveals the specific rules and mechanisms of ditch/ridge regulating stem cell behaviors but also offers insight into tailoring implant surface patterns to induce controlled soft tissue fibrosis.

Calcaneus is the most susceptible tarsal bone to fractures, presenting the most challenging treatment for associated tissue damage. Intra-articular calcaneal fractures present substantial challenges for patients and surgeons due to their association with both immediate and delayed complications. The purposes of this study were to establish a method for three dimensional morphological measurements of the normal calcaneus, we develop a statistical shape model (SSM) of the calcaneus that incorporates CT scans to enable a comprehensive assessment of its three-dimensional morphology. Though surface-based registration and point-wise correspondence analysis, the left and right calcaneus bones were compared with a variety of shape analysis. The compactness and parallel analysis test on the statistical shape model yielded 7 prominent shape modes of variations (MoVs), which accounted for approximately 89% of the total 3D variations in the population of shapes. Among these modes, two captured discriminating features from both the left and right calcaneus bones (p value < 0.05). Visual inspection confirmed that these two shape modes represented abnormalities in the anterior and anteromedial parts of the calcaneus, highlighting them as the primary bony risk factors in ankle injuries. In conclusion, our study utilizing a Statistical Shape Model (SSM) has identified significant shape variations (MoVs) of the calcaneus bone which correlate significantly with the left and right sides of the body. The results of our study also demonstrate the potential utility of the SSM as a tool for providing guidance in surgical planning and treatment of calcaneus pathologies.

Introduction:Bone defects in diabetes mellitus (DM) remain a major challenge for clinical treatment. Fluctuating glucose levels in DM patients lead to excessive production of reactive oxygen species (ROS), which disrupt bone repair homeostasis. Bone filler materials have been widely used in the clinical treatment of DM-related bone defects, but overall they lack efficacy in improving the bone microenvironment and inducing osteogenesis. We utilized a gelatine methacrylate (GelMA) hydrogel with excellent biological properties in combination with molybdenum (Mo)-based polyoxometalate nanoclusters (POM) to scavenge ROS and promote osteoblast proliferation and osteogenic differentiation through the slow-release effect of POM, providing a feasible strategy for the application of biologically useful bone fillers in bone regeneration.Methods:We synthesized an injectable hydrogel by gelatine methacrylate (GelMA) and POM. The antioxidant capacity and biological properties of the synthesized GelMA/POM hydrogel were tested.Results:In vitro, studies showed that hydrogels can inhibit excessive reactive oxygen species (ROS) and reduce oxidative stress in cells through the beneficial effects of pH-sensitive POM. Osteogenic differentiation assays showed that GelMA/POM had good osteogenic properties with upregulated expression of osteogenic genes (BMP2, RUNX2, Osterix, ALP). Furthermore, RNA-sequencing revealed that activation of the PI3K/Akt signalling pathway in MC3T3-E1 cells with GelMA/POM may be a potential mechanism to promote osteogenesis. In an in vivo study, radiological and histological analyses showed enhanced bone regeneration in diabetic mice, after the application of GelMA/POM.Conclusion:In summary, GelMA/POM hydrogels can enhance bone regeneration by directly scavenging ROS and activating the PI3K/Akt signalling pathway.

Introduction and importance: We used induced membrane combined with tissue-engineered bone (TEB) to repair the 14-cm juvenile ulnar defect formed after osteomyelitis debridement. The TEB was completely transformed into autologous bone after 4-year follow-up.Case presentation: A 13-year-old male was hospitalized because of right ulna chronic osteomyelitis. After focal debridement, the total length of ular defect was 14 cm. Anti-infective bone cement was filled in the bone defect area. B-Tricalcium phosphate (B-TCP) was used as TEB scaffold. Autologous iliac bone marrow stromal cells (BMSCs) were cultured in vitro and were planted on B-TCP scaffold to form TEB 3 weeks later. 47 months after implantation of TEB, the repaired ulna had continuous and smooth bone cortex, completely ossification of TEB, completely recanalization of medullary cavity. The upper limb function DASH score was 35.Clinical discussion: Masquelet put forward the concept of "induced membrane" and applied this technique on bone defects treatment formed after debridement of osteomyelitis. B-Tricalcium phosphate (B-TCP) is artificial bone materials commonly used in clinical. In this case, the seed cells used were autologous BMSCs and the culture medium was autologous serum. Cytokines promoting cell growth and differentiation were not used.Conclusion: The results of this case showed that TEB combined with induced membrane could repair ulna segmental bone defects as long as 14 cm in adolescents. This technique gives one alternative method to repair juvenile bone defects caused by osteomyelities of trauma. More clinical cases are needed to verify the effectiveness of this technique in the next.

断指再植是通过显微外科技术吻合血管对完全或不完全离断指体再血管化的过程，其中也包括对离断指体的骨、肌腱及神经组织等的修复。自上世纪60年代首例断指再植取得成功以来 [1]，随着显微外科技术的不断普及，再植已成为手指离断伤的最佳术式；从1972年在广州举办的全国断肢（指）再植经验交流会到1995年在哈尔滨召开的全国断指再植专题研讨会，实现断指再植成活率从约30%到90%以上的飞跃式突破 [2,3,4]。而且在半个多世纪的发展过程中，各种特殊情况下的断指再植成功不断报道，如国内开展的多指多节段离断再植 [5]、指尖离断再植 [6]、幼儿断指再植 [7]、异位再植 [8]、寄养再植 [9]等高难度断指再植手术。然而对上述特殊类型断指命名及界定不明确，分类方法和依据也不统一；国内外文献缺乏具有广泛共识的"特殊类型断指"定义 [10,11,12,13,14,15,16]。这就使得一方面不同文献报道断指再植成活率间缺乏可比性，另一方面，也不利于同质性相近的"特殊类型断指"再植经验进行系统性总结和交流。因此，有必要对特殊类型断指的涵义加以明确，这既是满足临床诊疗规范化的需求，也是推进学术交流规范化的需要。