To explore the effect of hydrogen sulfide (H 2 S) drug-loaded nanoparticles (H 2 S-NPs) on the mTOR/STAT3 signaling pathway in rats and its mechanism on repair of spinal cord injury (SCI), a new H 2 S-NP (G 16 MPG-ADT) was prepared and synthesized. The rats were selected as the research objects to explore the mechanism of SCI repair. The G 16 MPG-ADT NPs were evaluated by average particle size (APS), dispersion coefficient (DC), drug loading content (DLC), drug loading efficacy (DLE), in vitro release (IV-R), and acute toxicity (AT). It was found that G 16 MPG-ADT nanoparticles had a uniform particle size distribution with a unimodal distribution, with an average particle size of 186.5 nm and a dispersion coefficient of 0.129; within the concentration range of 8~56 μ g/L, there was a good linear relationship with the peak area; and the release rate of the nanoparticles within 16 h~32 h was higher than 50%. G 16 MPG-ADT NP injection treatment was performed on rats with SCI. Western blotting (WB) and immunofluorescence staining were adopted to analyze the expression levels of mammalian target of rapamycin (mTOR) and signal transducers and activators of transcription (STAT3) protein and the growth of neurites. It was found that G 16 MPG-ADT can increase mTOR and STAT3 protein levels and promote nerve growth after SCI. Finally, the Basso, Beattie and Bresnahan locomotor rating (BBB) score was to evaluate the recovery effect of rats after treatment. It was found that the recovery effect was excellent after G 16 MPG-ADT treatment. In summary, G 16 MPG-ADT has a good effect on SCI repair in rats and can be promoted in the clinic.
Abstract Background Recent studies have shown that bone marrow stromal cell-derived exosomes (BMSC-Exos) can be used for tissue repair. However, whether the BMSC-Exos can promote tendon-bone healing after anterior cruciate ligament reconstruction (ACLR) is still unclear. In this study, we observed in vivo and in vitro the effect of rat BMSC-Exos on tendon-bone healing after ACLR and its possible mechanism. Methods Highly expressed miRNAs in rat BMSC-Exos were selected by bioinformatics and verified in vitro . The effect of overexpressed miRNA in BMSC-Exos on M2 macrophage polarization was observed. A rat model of ACLR was established. The experimental components were divided into three groups: the control group, the BMSC-Exos group, and the BMSC-Exos with miR-23a-3p overexpression (BMSC-Exos mimic) group. Biomechanical tests, micro-CT, and histological staining were performed for analysis. Results Bioinformatics analysis showed that miR-23a-3p was highly expressed in rat BMSC-Exos and could target interferon regulatory factor 1 (IRF1, a crucial regulator in M1 macrophage polarization). In vitro, compared with the control group or the BMSC-Exos group, the BMSC-Exos mimic more significantly promoted the polarization of macrophages from M1 to M2. In vivo, at 2 weeks, the number of M2 macrophages in the early local stage of ACLR was significantly increased in the BMSC-Exos mimic group; at 4 and 8 weeks, compared with the control group or the BMSC-Exos group, the bone tunnels of the tibia and femur sides of the rats in the BMSC-Exos mimic group were significantly smaller, the interface between the graft and the bone was narrowed, the bone volume/total volume ratio (BV/TV) increased, the collagen type II alpha 1 level increased, and the mechanical strength increased. Conclusions BMSC-Exos promoted M1 macrophage to M2 macrophage polarization via miR-23a-3p, reduced the early inflammatory reaction at the tendon-bone interface, and promoted early healing after ACLR.
Abstract Background Systemic vancomycin administration pre-operatively for the infection prophylaxis of spinal implant surgery remains unsatisfactory. This study aimed to explore the efficacy and dosage of local use of vancomycin powder (VP) in preventing surgical site infections after spinal implant surgery in a rat model. Methods Systemic vancomycin (SV; intraperitoneal injection, 88 mg/kg) or intraoperative intra-wound VP (VP0.5: 44 mg/kg, VP1.0: 88 mg/kg, VP2.0: 176 mg/kg) was applied after spinal implant surgery and methicillin-resistant S. aureus (MRSA; ATCC BAA-1026) inoculation in rats. General status, blood inflammatory biomarkers, microbiological and histopathological evaluation were performed during 2 weeks post-surgery. Results No post-surgical deaths, wound complications and obvious signs of vancomycin adverse effects were observed. Bacterial counts, blood and tissue inflammation were reduced in the VP groups compared with the SV group. VP2.0 group showed better outcomes in weight gain and tissue inflammation than the VP0.5 and VP1.0 group. Microbial counts indicated that no bacteria survived in the VP2.0 group, whereas MRSA was detected in VP0.5 and VP1.0 groups. Conclusions Intra-wound VP may be more effective than systemic administration in preventing infection caused by MRSA (ATCC BAA-1026) after spinal implant surgery in a rat model.
Abstract Objectives: This study aimed to explore adenoid regrowth after transoral power-assisted adenoidectomy down to the pharyngobasilar fascial surface. Methods: Transoral adenoidectomy down to the pharyngobasilar fascia surface was performed on 39 patients under endoscopic guidance, using a power-assisted system. The operation time, amount of blood loss and iatrogenic injury, presence of complications, and success and regrowth rates were recorded to assess the feasibility, safety and effectiveness of our surgical technique. Results: In this adenoidectomy procedure, the pharyngobasilar fascia was left intact. The estimated blood loss was 5–50 ml (mean 15 ml), and the success rate was 97.3 per cent. Early complications occurred in 2.3 per cent of patients, while no long-term complications occurred in the cohort. No regrowth was found in the follow-up assessments, which were performed for 18–36 months after surgery. Conclusion: Adenoid regrowth was rare after adenoidectomy down to the pharyngobasilar fascial surface. The pharyngobasilar fascia can therefore be considered a surgical boundary for adenoidectomy.
Objective
To establish a three-dimensional finite element model of pelvic anteroposterior compression (APC) for analysis of mechanisms for related ligamentous damages.
Methods
A finite element model and a laboratory mechanical model of APC were established using the same pelvic specimens. In a finite element model of normal pelvic bones and ligaments, after the right pelvis was fixated the pubic symphysis (PS) was sectioned. Next, a manual external mobile force was gradually applied to the left hemipelvis to make the PS diastasis 10, 20, 30, 40, 60, 80 and 100 mm apart. The mechanical experiment revealed the anterior sacroiliac ligament (ASIL) was ruptured when the PS diastasis reached 28 mm. After the strain value of ASIL was calculated through the finite element model, it was applied to the other pelvic ligaments. The displacement in front of the sacroiliac joint (SIJ), stress, strain and extent of injury and disruption of sacrotuberous/sacrospinous ligaments (STL/SSL) with a corresponding PS diastasis were observed and recorded.
Results
ASIL failed at the point when the PS diastasis was 28 mm and the displacement in front of SIJ was 7.41±1.14 mm. The strain and maximum principal stress of ASIL calculated in the finite element model were 259.5% and 543.24 MPa respectively. The maximum principal stress value of SSL was 35.00 MPa at the point of failure when the PS diastasis and the displacement in front of SIJ were 51 mm and 15.23±2.88 mm, respectively. When the PS diastasis and the displacement in front of SIJ were 100 mm and 7.5 mm respectively, the maximum principal stress value of STL was 16.17 MPa but the strained ligament was not ruptured. When the pelvis was rotated externally step by step, the ASIL failure was followed by the rupture of SSL but not necessarily by the STL failure.
Conclusion
As the finite element pelvic bone-ligament model established in this study can effectively simulate the mechanisms for APC injury, it can be used to evaluate different extents of pelvic ligamentous injury, providing a basis for the biomechanical study of pelvic bones and ligaments.
Key words:
Pelvis; Ligaments; Wound and injuries; Biomechanics; Finite element analysis
Objective Most both‐column acetabular fractures are combined with posterior wall fragments. However, the morphology of this posterior wall is varied, and how to fix this posterior wall remains a controversial topic. To investigate the morphological characteristics of posterior wall fragments of both‐column acetabular fractures and select corresponding fixation methods. Methods Data from 352 patients with acetabular fractures admitted to the level one trauma centre in our hospital between January 2006 and December 2022 were collected. The morphology of posterior wall fragments was observed and analyzed in 83 cases of both‐column acetabular fractures and classified according to the consistency of posterior wall morphology. A fracture map of the posterior wall was created on a normal template according to the three morphological types of posterior wall fragments. Finally, the high‐incidence area of the posterior wall fracture was projected onto the iliac fossa and the medial side of the posterior column to guide the fixation of the posterior wall fragment using the anterior intrapelvic approach. Results Fractures were divided into four types: I, large posterior wall fragment which was high in the ilium bone (34 cases, 41.0%); II, posterior wall fragment in the acetabular parietal region (18 cases, 21.7%); III, posterior wall marginal fracture (10 cases, 12.0%); and IV, non‐combined posterior wall fracture (21 cases, 25.3%). The most common morphologies of the posterior wall fragments of the first two types were mapped and projected onto the anterior iliac inner plate and medial side of the posterior column, where the corresponding area could be used to guide the insertion of the internal fixation. Conclusion Both‐column acetabular fractures combined with posterior wall fractures can be divided into four types according to the morphology of the posterior wall fragment. Understanding the corresponding three‐dimensional morphology and projection position of different types of these fragments can help surgeons determine the position and orientation of internal fixation of posterior wall fractures.
Objectives: To study the anatomy of the dorsal metacarpal arteries and their branches, to understand the positions and shapes of the arteries and their branches, and to observe the capillary network formed on the lateral and the dorsal sides of the finger under a microscope. Based on this anatomy, a finger fascia pedicled skin artery branch flap was designed to repair fingertip wounds. Methods: A total of 5 fresh adult cadaveric hand specimens were infused with red latex. The anatomy of the dorsal finger intrinsic arteries of the 40 fingers (excluding the thumbs) were observed under a microscope, and a capillary network was formed on the lateral and the dorsal sides of the fingers. Then, 10 cases of finger soft tissue defects were repaired using an anatomy-based design finger fascia pedicled skin artery branch flap. Results: The anatomical observations indicated that the intrinsic artery on each side of the finger sends four thicker cutaneous branches toward to the dorsal side, wherein the descending branch of the upper cutaneous branch coincides with the ascending branch of the next cutaneous branch to form a lateral vascular chain. A fascia flap pedicled (>0.5 cm) skin artery branch flap was used to repair the patients’ finger injuries (8 males and 2 females, aged 21 to 52 years). The wound surface ranges were about 2.8 cm × 1.9, and the flap ranges were about 3 cm × 2.1 cm. During the 5-12 months of follow-up, all the flaps survived well. Conclusion: The bilateral finger arteries emit a number of macroscopically identifiable capillary branches and form a capillary network using anastomosis between the cutaneous branches. The finger fascia pedicled skin artery branches flap, not <0.5 cm wide, contains the capillary branch of the dorsal finger artery as the flap for the blood supply. The flap can cover various types of distal finger wounds.
Abstract Background Venous thromboembolism (VTE) is a potentially fatal complication after arthroplasty. Numerous prophylactic strategies and studies to reduce VTEs have focused on the duration of the hospital stay and on few extramural hospitals. This study aimed to investigate extramural hospital management of VTE after total hip/knee arthroplasty (THA/TKA) in China with a novel survey tool. Methods A total of 180 patients undergoing arthroplasty, including 68 THA patients and 112 TKA patients, were enrolled in this study. All patients received anticoagulant treatment management. A survey querying VTE management and adherence, such as therapy information, understanding of anticoagulation, satisfaction with the ability of medical staff, and satisfaction with health care costs, was administered by a questionnaire (TKA/THA Patients’ Experience with Anticoagulation in the Post-discharge Period) for quality improvement. Results The average age of the patients was 65.27 ± 13.62 years. All patients knew their follow-up times. 85 % of them were suggested that re-examine at the next 14 days, and the others at the next 28 days. All patients continued to visit the orthopaedic clinic after discharge without choosing other types of outpatient services, such as an anticoagulant clinic or home visit with a nurse/pharmacist or remote evaluation by telephone. A total of 96.6 % of all patients used new oral anticoagulants, and the most common treatment duration was 2–4 weeks (93.3 %). 48 % informed their physicians that they were taking anticoagulation medications when they visited ophthalmology, dentistry, dermatology, and other departments. The overall rate of satisfaction with anticoagulation management was 81.67 %, and 6.67 % of patients were not unsatisfied with their medical expenses. Patient compliance decreased with increasing follow-up time. Continuous follow-ups after discharge significantly improved patient compliance. Conclusions These results elucidate how we can improve the quality of anticoagulation. Continuous follow-up appointments for 30 days after discharge, especially for individuals over 65 years old, significantly improved patient satisfaction and reduced the incidence of VTE and medical costs.
Abstract Background: The optimal treatment of Pauwels type III femoral neck fracture in young patients remains a worldwide challenge in orthopedic surgery. Methods: Finite element models of four internal fixations were developed to treat Pauwels type III Femoral neck fracture: a: the traditional inverted triangular cannulated screw model, b: the F-technique cannulated screw model, c: the modified F-technique cannulated screw model using a fully threaded screw instead of a partially threaded distally, d: the dynamic hip screw coupled with anti-rotational screw model. Under the same conditions, finite element analyses were carried out to compare the displacement and von Mises stress distribution of four internal fixations and femurs, the maximum crack distances of the fracture surfaces, Z axis displacements of four models as well as the stress distribution in the subtrochanteric region. Results: The modified F-technique configuration resulted in a more stable fixation as compared to the other three approaches, with respect to the maximum displacement and stress peaks of femur and internal fixations, the maximum crack distances of the fracture surfaces, Z axis displacements of four configurations as well as the stress distribution in the subtrochanteric region. Conclusions: Our results suggested that modified F-technique configuration show a better performance in resisting shearing and rotational forces in treating Pauwels type III femoral neck fractures compared to those using traditional inverted triangular, the F-technique configuration or dynamic hip screw coupled with anti-rotational screw, providing a new choice for the treatment of femoral neck fractures.
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