Experimental analysis of femoral head intraosseous vascular anastomosis in the treatment of porcine subcapital femoral neck fractures.

Introduction: Femoral neck fractures are challenging injuries associated with a compromised blood supply to the femoral head, leading to a high risk of avascular necrosis and poor clinical outcomes. This study aimed to investigate the efficacy of femoral head intraosseous vascular anastomosis in the treatment of porcine sub-capital femoral neck fractures. Methods: Ten Landrace pigs were used as experimental animal models. The femoral head was completely removed after femoral neck sub-cephalic fracture. It was fixed on the medial side of the knee joint, and the blood supply to the femoral head was reconstructed by anastomosing the femoral head vessels. One week later, blood flow in the femoral head was observed by borehole, digital subtraction angiography examination, and hematoxylin and eosin staining. Further, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling tests were performed to detect pathological changes in the femoral head. Results: After one-week, digital subtraction angiography of the femoral head revealed a blood circulation rate of 70 %, and the blood seepage rate of the borehole was 80 %. Hematoxylin and eosin staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling test results showed that necrosis of bone marrow cells in the experimental group was significantly improved compared to that in the control group. Discussion: This study highlights the potential benefits of femoral head intraosseous vascular anastomosis in the treatment of porcine sub-capital femoral neck fractures. Further research and clinical trials are warranted to validate these findings and to explore the translational potential of this technique in human patients.

Method for reconstructing femoral head blood supply by anastomosing the intraosseous artery.

Background: The reconstruction of femoral head blood supply is crucial in the management of avascular necrosis and related conditions. This study presents a method for reconstructing the femoral head blood supply by anastomosing the intraosseous artery. Methods: The femoral heads of six male Landrace swine were surgically exposed, and subcranial fractures of the femoral neck were intentionally created. Under microscopic guidance, the trophoblastic foramen of the posterior supporting artery was identified. Subsequently, a triangular bone window was carefully crafted to expose the intraosseous artery. Following the fixation of the femoral head, an anastomosis was performed between the intraosseous artery and the posterior inferior supporting artery located at the distal end of the fracture. The assessment of femoral head blood supply was conducted using Kirschner's pinhole and angiography techniques. Results: The anastomotic intraosseous artery exhibited a vibrant red color, indicating adequate blood perfusion, and demonstrated pulsatile flow. Observation through pinholes in the surface of the femoral head revealed continuous blood flow. Angiography further confirmed the successful circulation, as the contrast agent entered the inferior retinacular artery branch originating from the deep femoral artery. The contrast agent then proceeded to enter the femoral head through the retinacular artery, reaching the anastomosis site of the intraosseous artery. Notably, the angiography also revealed the presence of visible internal branches, highlighting the establishment of a functional vascular network. Discussion: The method of reconstructing the blood supply to the femoral head through anastomosis of the intraosseous artery enables utilization of the existing blood supply system within the femoral head. This study is just a preliminary study of this innovative technique that has the potential to prevent and/or treat femoral head necrosis following a femoral neck fracture. By restoring adequate blood flow to the affected area, this approach holds promise in preserving the viability and functionality of the femoral head, ultimately improving patient outcomes.

Anatomical characterization of the intraosseous arteries of the porcine tibia.

Introduction: Tibial fractures have a high rate of post-fracture complications. Blood supply is recognized as a positive factor in tibial fracture healing. However, it's difficult to assess blood supply damage after tibial fracture because of the lack of understanding of the tibial intraosseous arteries. This study aimed to delineate and anatomically characterize porcine tibial intraosseous arteries, as a model for the human system. Methods: Twenty right calf specimens with popliteal vessels were prepared from ordinary Landrace pigs. Epoxy resin was perfused into the vasculature from the popliteal artery. After 24 h, casts of the intraosseous arteries of the tibia were exposed through acid and alkali corrosion. The distribution and anatomy of the exposed intraosseous arteries were observed and measured under a microscope, and the data were statistically analyzed. Results: Sixteen complete specimens were obtained. The medullary artery bifurcated into the main ascending and descending branches, which each split into two upward primary branches that further divided into 1-3 secondary branches. Among all specimens, 56 ascending and 42 descending secondary branches, which were all ≥0.3 mm in diameter. Furthermore, the horizontal plane was divided into three zones-safety, buffer, and danger zones-according to the probability of the presence of intraosseous artery. Discussion: The cast perfusion and corrosion approach was successfully applied for anatomical characterization of the intraosseous arteries of the porcine tibia. These observations provide a theoretical basis for understanding the tibial vasculature in humans and will facilitate the establishment of novel "safe corridor" in the tibia for the protection of the blood supply during surgery.

Significant Zero Thermal Expansion Via Enhanced Magnetoelastic Coupling in Kagome Magnets.

Zero-thermal-expansion (ZTE) alloys, as dimensionally stable materials, are urgently required in many fields, particularly in highly advanced modern industries. In this study, high-performance ZTE with a negligible coefficient of thermal expansion av as small as 2.4 ppm K-1 in a broad temperature range of 85-245 K is discovered in Hf0.85 Ta0.15 Fe2 C0.01 magnet. It is demonstrated that the addition of trace interstitial atom C into Ta-substituted Hf0.85 Ta0.15 Fe2 exhibits significant capability to tune the normal positive thermal expansion into high-performance ZTE via enhanced magnetoelastic coupling in stabilized ferromagnetic structure. Moreover, direct observation of the magnetic transition between ferromagnetic and triangular antiferromagnetic states via Lorentz transmission electron microscopy, along with corresponding theoretical calculations, further uncovers the manipulation mechanism of ZTE and negative thermal expansion. A convenient and effective method to optimize thermal expansion and achieve ZTE with interstitial C addition may result in broadened applications based on the strong correlation between the magnetic properties and crystal structure.

A Method to Visualize and Quantify the Intraosseous Arteries of the Femoral Head by Vascular Corrosion Casting.

OBJECTIVE: To describe a method to display the three-dimensional distribution of intraosseous arteries in the femoral head by vascular corrosion casting. METHODS: An experimental study was done to expose the intraosseous arteries of the femoral head by a microperfusion corrosion method between January 2021 and May 2021. Specimens were 23 swine femoral heads (12 female specimens and 11 male specimens, where age of swine ranged from 8 to 12 months, and the weight was approximately 150 kg). The femoral heads were microperfused with the vascular casting resin through retinacular arteries, and the bone of the femoral head was dissolved with 50% sodium hydroxide and 10% hydrochloric acid and rinsed under the microscope until the vessel casts were completely exposed. The distribution and anastomosis of the arteries in the femoral head were observed under direct vision and microscopy. The diameter of the artery in the femoral head was measured at 0.5 cm after its entry into the bone of the femoral head with a microscale under the microscope. The number of internal arteries with diameter ≥0.05 mm was counted. The number and diameter of the main trunk of the epiphyseal arteries in the femoral head between male and female swine were compared. RESULTS: The vascular casting specimen of the swine femoral head was successfully produced by using epoxy resin as a casting agent, and the three-dimensional intraosseous vascular structures were clearly visible. The number of epiphyseal arteries in male and female swine was 8.55 ± 2.15 and 8.83 ± 2.15 (t = -0.31, p = 0.38), respectively. The diameters of the superior epiphyseal arteries in male and female swine were 0.35 ± 0.09 and 0.31 ± 0.08 mm (t = 1.03, p = 0.16), the diameters of the inferior epiphyseal arteries were 0.47 ± 0.05 and 0.49 ± 0.09 mm (t = -0.57, p = 0.29), and the diameters of the anterior epiphyseal arteries were 0.34 ± 0.08 and 0.33 ± 0.13 mm (t = 0.32, p = 0.37). There was no significant difference in the number and diameter of the main trunk of intraosseous arteries between male and female swine (p > 0.05). The main trunk of intraosseous arteries formed an anastomosis in the center of the femoral head. Among 23 swine femoral head samples, three types of intraosseous anastomosis were observed, including 13 (57%) posterior superior-posterior inferior, seven (30%) posterior inferior-anterior, and three (13%) uniform intraosseous anastomosis. CONCLUSION: The microperfusion corrosion method can produce the vascular casting specimen of swine femoral head revealing the three-dimensional structure of the intraosseous artery, which clearly shows the origin, course and branches, and diameter, as well as the anastomosis, of nutrient arteries in the femoral head. This method provides a simple and rapid technique for quantifying and visualizing intraosseous arteries.

Effect of glucocorticoids infiltration on CRSwNP after endoscopic sinus surgery and the curative efficacy of nasal ventilation function and mucociliary clearance.

OBJECTIVES: This study investigated and analyzed the effects of glucocorticoid infiltration on chronic rhino-sinusitis with nasal polyps (CRSwNP) after endoscopic sinus surgery (ESS) and its curative efficacy on nasal ventilation function and mucociliary clearance (MCC). METHODS: 126 CRSwNP patients admitted to the hospital from March 2018 to May 2020 were enrolled and randomly divided into observation group (n=65) and control group (n=61) based on random number table. The control group received ESS, and the observation group was given glucocorticoids treatment after ESS. The changes of nasal ventilation function, MCC and quality of life between the two groups of patients before and after treatment were compared. RESULTS: The overall effective rate of clinical therapy was critically higher in observation group than in control group (P<0.05). In addition, NMCA and NCV in observation group were critically higher than those in control group (P<0.05), and nasal airway resistance (NAR) in observation group was notably lower than that in control group (P<0.05). In addition, the Saccharin removal time in observation group after treatment was remarkably lower than that in control group (P<0.05), while the speed and rate of MCC were critically higher than those in control group (P<0.05). Finally, the scores of each dimension of WHOQOL-100 scale in two groups of subjects after treatment were critically higher than those before treatment (P<0.05), and the scores in observation group were notably higher than those in control group (P<0.05). CONCLUSION: The treatment of glucocorticoid infiltration on CRSwNP after ESS can effectively improve the curative effect. It improves the patient's function of nasal ventilation and MCC, thus beneficial to promoting the sufferers' living quality and is worthy of clinical promotion.

Biomechanical evaluation of calcium phosphate-based nanocomposite versus polymethylmethacrylate cement for percutaneous kyphoplasty.

BACKGROUND CONTEXT: Polymethylmethacrylate (PMMA) is the most commonly used filling material when performing percutaneous kyphoplasty (PKP) for the treatment of osteoporotic vertebral compression fractures. However, there are some inherent and unavoidable drawbacks with the clinical use of PMMA. PMMA bone cement tends to leak during injection, which can lead to injury of the spinal nerves and spinal cord. Moreover, the mechanical strength of PMMA-augmented vertebral bodies is extraordinary and this high level of mechanical strength might predispose to adjacent vertebral fractures. A novel biodegradable calcium phosphate-based nanocomposite (CPN) for PKP augmentation has recently been developed to potentially avoid these issues. PURPOSE: By comparison with PMMA, the leakage characteristics, biomechanical properties, and dispersion of CPN were evaluated when used for PKP. STUDY DESIGN: Biomechanical evaluation and studies on the dispersion and anti-leakage properties of CPN and PMMA cements were performed and compared using cadaveric vertebral fracture model, sheep vertebral fracture model, and simulated rigid foam model. METHODS: Sheep vertebral bodies were decalcified by ethylenediaminetetraacetic acid disodium salt (EDTA-Na2) to simulate osteoporosis in vitro. After compression to create wedge-shaped fractures using a self-designed fracture creation tool, human cadaveric vertebrae and decalcified sheep vertebrae were augmented by PKP. In addition, three L5 vertebral bodies from human cadavers were used in a contrast vertebroplasty (VP) augmentation experiment. Occurrence of cement leakage was observed and compared between CPN and PMMA during the process of vertebral augmentation. Open-cell rigid foam model (Sawbones#1522-507) was used to create a simulated leakage model for the evaluation of the leakage characteristics of CPN and PMMA with different viscosities. The augmentation effects of CPN and PMMA were evaluated in human cadaveric and decalcified sheep vertebral models and then compared to the results from solid rigid foam model (Sawbones#1522-23). The dispersion abilities of CPN and PMMA were evaluated via three methods as follows. The dispersion volume and dispersion ratio were calculated by three-dimensional reconstruction using human vertebral body CT scans; the ratio of cement area to injection volume was calculated from three-dimensional sections of micro-CT scans of a sheep vertebra; and the micro-CT images of cement dispersion in open-cell rigid foam model (Sawbones#1522-507) were compared between CPN and PMMA. This study was funded by the National Natural Science Foundation of China (No. 81622032, 190,000 dollars and No. 51672184, 90,600 dollars), Principal Project of Natural Science Research of Jiangsu Higher Education Institutions (No. 17KJA180011, 22,000 dollars), and Jiangsu Innovation and Entrepreneurship Program (146,000 dollars). RESULTS: There was no significant difference in vertebral height between CPN and PMMA during PKP augmentation and both cements restored the vertebral height after augmentation. In PKP augmentation experiment, posterior wall cement leakage occurred in 75% of human vertebrae augmented with PMMA; however, no leakage occurred in human vertebrae augmented with CPN. Anterior leakage occurred in all vertebrae augmented by PMMA, while in only 75% of vertebra augmented by CPN. Furthermore, CPN and PMMA had completely different leakage patterns in the simulated rigid foam model whether administered at the same injection speed or under the same injection force, suggesting that CPN has anti-leakage characteristics. The augmentation in human cadaveric vertebrae was lower with CPN compared to PMMA (1,668±816 N vs. 2,212±813 N, p=.459, respectively), but this difference was not significant. The augmentation force in sheep vertebral bodies reached 1,393±433 N when augmented with PMMA, but 1,108±284 N when augmented with CPN. The dispersion of CPN was better, and the dispersion volume and ratio were greater, with CPN than with PMMA. Imaging of the open-cell rigid foam model showed completely different dispersion modes for CPN and PMMA. After injection, the PMMA cement formed a contracted clump in the open-cell rigid foam model. However, the CPN cement extended many antennae outward, appearing to spread to the surrounding area. The surface areas of the CPN cement blocks with different liquid-to-solid ratios were significantly larger than the surface area of the PMMA cement in the open-cell rigid foam model (p<.05). CONCLUSIONS: CPN has anti-leakage properties, which might be related to its high viscosity and viscoplasticity. CPN had a slightly lower augmentation force than PMMA when used in cadaveric vertebrae, decalcified sheep vertebrae, and in the standard rigid foam model. However, CPN diffused more easily into cancellous bone than did PMMA and encapsulated bone tissue during the dispersion process. The excellent dispersion of CPN generated better interdigitation with cancellous bone, which may be why the augmentation effect of CPN is similar to that of PMMA. CLINICAL SIGNIFICANCE: Biodegradable CPN is a potential alternative to PMMA cement in PKP surgery, in which CPN is likely to reduce the cement leakage during the surgery and avoid the post-surgery complications caused by excessive strengths and nondegradability of PMMA cement.