Objective To review the research progress regarding the over-the-top technique for anterior cruciate ligament (ACL) reconstruction. MethodsThe relevant literature on ACL reconstruction using the over-the-top technique was analyzed for its evolution, clinical application, advantages, and limitations. Results Over-the-top technique for ACL reconstruction is a combined intra- and extra-articular technique. Because it avoids drilling the femoral tunnel, its advantages are mainly highlighted in the protection of the femur. Therefore, it is widely used in children and adolescents with epiphyseal occlusion and in patients with revision reconstruction. In addition, significant improvements in postoperative joint stability, functional scores, and return to exercise rates are found in long-term follow-up studies of patients with primary ACL reconstruction and combined anterolateral tenodesis. However, the technique also has some limitations, such as poor stability of knee flexion after operation, high requirement for graft length, and easy impact of graft in the intercondylar fossa. Conclusion The current research results show the effectiveness and safety of the over-the-top technique for primary and revision ACL reconstruction, with the advantages of wide application, simple operation, and quick recovery; however, more researches are needed to further optimize the selection of grafts and femoral condyle management problems, and to clarify the long-term effectiveness.
ObjectiveTo investigate the influence of lateral posterior tibial slope (LPTS) on tibial tunnel expansion after anatomical single-bundle anterior cruciate ligament (ACL) reconstruction and the effect of tibial tunnel expansion on knee joint function.MethodsA clinical data of 52 patients with ACL rupture, who underwent arthroscopic anatomical single-bundle reconstruction between November 2018 and December 2019, was retrospectively analyzed. There were 32 males and 20 females with an average age of 34.3 years (range, 14-64 years). There were 22 cases of left knee and 30 cases of right knee. The time from injury to operation ranged from 7 to 30 days, with an average of 15.9 days. The knee function was evaluated by International Knee Documentation Committee (IKDC) score and Lysholm score before operation and at 3 and 6 months after operation. At 3 and 6 months after operation, the LPTS and the width of exit, middle segment, entrance, and 2 cm from the exit of the articular surface of the tibial tunnel were measured based on MRI. The expansion of tibial tunnel was calculated and graded (degrees 0-3). According to LPTS, the patients were divided into group A (<6.0°), group B (6°-12°), and group C (>12°), and the difference in the expansion of tibial tunnel between groups was compared.ResultsAll the 52 patients were followed up 6-12 months (mean, 7.1 months). The IKDC and Lysholm scores at 3 and 6 months after operation were significantly different from those before operation (P<0.05); and the difference of knee scores between 3 and 6 months after operation was significant (P<0.05). The tibial tunnel expanded after operation, and the relative expansion at the exit and the middle segment showed significant difference between 3 months and 6 months after operation (P<0.05). The expansion degree of tibial tunnel was rated as degree 0 in 5 cases, degree 1 in 28 cases, degree 2 in 16 cases, and degree 3 in 3 cases at 3 months after operation, and degree 0 in 5 cases, degree 1 in 20 cases, degree 2 in 25 cases, and degree 3 in 2 cases at 6 months after operation. There was no significant difference in IKDC and Lysholm scores between patients with different expansion degrees of tibial tunnels (P>0.05). The LPTS of 52 patients ranged from –0.8° to 18.7° (mean, 10.6°); there were 7 cases in group A, 24 cases in group B, and 21 cases in group C. There was no significant difference in age, gender, preoperative IKDC and Lysholm scores, and initial width of tibial tunnel between groups (P>0.05). There was no significant difference in the relative expansion of tibial tunnel at exit and middle segment between groups at 3 months after operation (P>0.05), and there was significant difference at 6 months after operation (P<0.05).ConclusionAfter anatomical single-bundle reconstruction of ACL, the tibial tunnel would expand to some extent in a short time. LPTS had a significant effect on tibial tunnel expansion, and the larger the angle was, the more obvious the expansion of the proximal tibial tunnel was. However, early knee function is not affected by tibial tunnel expansion.
Objective To observe the effect of dynamic mechanical loading on the proliferation, differentiation, and specific gene expression of MC3T3-E1 cells that on three-dimensional (3D) biomimetic composite scaffolds prepared by low temperature 3D printing technology combined with freeze-drying. Methods The silk fibroin, collagen type Ⅰ, and nano-hydroxyapatite (HA) were mixed at a mass ratio of 3∶9∶2 and were used to prepare the 3D biomimetic composite scaffolds via low temperature 3D printing technology combined with freeze-drying. General morphology of 3D biomimetic composite scaffold was observed. Micro-CT was used to observe the pore size and porosity of the scaffolds, and the water swelling rate, stress, strain, and elastic modulus were measured. Then, the MC3T3-E1 cells were seeded on the 3D biomimetic composite scaffolds and the cell-scaffold composites were randomly divided into 2 groups. The experimental group was subjected to dynamic mechanical loading (3 500 με, 1 Hz, 15 minutes per day); the control group was not subjected to loading treatment. After 7 days and 14 days, the cell-scaffold composites of 2 groups were harvested to observe the growth of cells on the scaffolds by HE staining and scanning electron microscope. And the gene and protein expressions of collagen type Ⅰ, BMP-2, and osteocalcin (OCN) were measured by real-time fluorescent quantitative PCR and Western blot. Results The 3D biomimetic composite scaffold was a white cubic grid. Micro-CT detection showed the pore network structure in the scaffold material with good pore connectivity. The diameters of large pore and micro-aperture were (506.37±18.63) μm and (62.14±17.35) μm, respectively. The porosity was 97.70%±1.37%, and the water absorption swelling rate was 1 341.97%±64.41%. Mechanical tests showed that the compression displacement of the scaffold was (0.376±0.004) mm, the compressive stress was (0.016±0.002) MPa, and the elastic modulus was (162.418±18.754) kPa when the scaffold was compressed to 10%. At 7 days and 14 days, HE staining and scanning electron microscope observation showed that the cells grew inside the scaffold, mainly distributed around the scaffold pore wall. The cells in experimental group were more than control group, and the cells morphology changed from shuttle to flat. There was no significant difference in the cell counting between 2 groups at 14 days after 200-fold microscopy (t=–2.024, P=0.080), but significant differences were found between 2 groups at different time points under different magnifications (P<0.05). Real-time fluorescent quantitative PCR showed that the mRNA relative expressions of collagen type Ⅰ and OCN in experimental group were significantly higher than those in control group at 7 and 14 days (P<0.05). However, the mRNA relative expression of BMP-2 showing no significant difference between 2 groups (P>0.05). The protein relative expressions of collagen type Ⅰ, BMP-2, and OCN in experimental group were significantly higher than those in control group at 7 and 14 days (P<0.05). Conclusion After dynamic mechanical loading, the expressions of BMP-2, collagen type Ⅰ, and OCN in MC3T3-E1 cells inoculated into 3D biomimetic composite scaffolds are significantly up-regulated, indicating that appropriate mechanical loads favor osteoblast differentiation of MC3T3-E1 cells.
In this study, we aim to investigat the effect of microgravity on osteoblast differentiation in osteoblast-like cells (MC3T3-E1). In addition, we explored the response mechanism of nuclear factor-kappa B (NF-κB) signaling pathway to " zero-g” in MC3T3-E1 cells under the simulated microgravity conditions. MC3T3-E1 were cultured in conventional (CON) and simulated microgravity (SMG), respectively. Then, the expression of the related osteoblastic genes and the specific molecules in NF-κB signaling pathway were measured. The results showed that the mRNA and protein levels of alkaline phosphatase (ALP), osteocalcin (OCN) and type Ⅰ collagen (CoL-Ⅰ) were dramatically decreased under the simulated microgravity. Meanwhile, the NF-κB inhibitor α (IκB-α) protein level was decreased and the expressions of phosphorylation of IκB-α (p-IκB-α), p65 and phosphorylation of p65 (p-p65) were significantly up-regulated in SMG group. In addition, the IL-6 content in SMG group was increased compared to CON. These results indicated that simulated microgravity could activate the NF-κB pathway to regulate MC3T3-E1 cells differentiation.
ObjectiveTo compare the effects of different airway management strategies on outcomes of patients with out-of-hospital cardiac arrest (OHCA).MethodsWe searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and WanFang Data for relevant studies comparing the influence of different airway management strategies on outcomes of OHCA patients. The deadline was up to 31st May, 2019. Grading of Recommendations Assessment, Development and Evaluation system 3.6 was used for quality assessment, and RevMan 5.3 software was used for meta-analysis. Odds ratio (OR) and 95% confidence interval (CI) were used to conduct the comparison. Results A total of 20 studies were finally enrolled, including 880 567 OHCA patients. Compared with supraglottic airway (SGA), bag-valve mask (BVM) improved the rate of survival to discharge of OHCA patients [OR=1.45, 95%CI (1.01, 2.08), P=0.04], while the rate of return of spontaneous circulation (ROSC) was not improved (P>0.05); in the subgroup analysis, BVM and SGA had similar effect on the rate of ROSC and the rate of survival to discharge in Asian countries (P>0.05), while BVM performed better than SGA in the two rates in European and American countries. BVM and endotracheal intubation (ETI) had similar effect on the two rates (P>0.05). In Asian countries, ETI performed better than BVM in the rate of ROSC [OR=0.63, 95%CI (0.49, 0.81), P=0.000 3], and there was no statistically significant difference in the rate of survival to discharge between ETI and BVM (P>0.05); while in European andAmerican countries, BVM performed better than ETI in the rate of survival to discharge [OR=3.10, 95%CI (2.69, 3.56), P<0.000 01], and there was no statistically significant difference in the rate of ROSC between ETI and BVM (P>0.05). Compared with SGA, ETI improved the rate of ROSC [OR=0.68, 95%CI (0.62, 0.76), P<0.000 01] and the rate of survival to discharge [OR=0.89, 95%CI (0.81, 0.98), P=0.02]. In Asian countries, ETI performed better than SGA in the two rates (P<0.05); while in European and American countries and New Zealand, ETI performed better than SGA in the rate of ROSC (P<0.05), but there was no statistically significant difference in the rate of survival to discharge (P>0.05). Conclusions Different airway management strategies have differente effects on OHCA patients. The optimal airway management strategy when rescuing OHCA patients might be selected based on local emergency medical service system conditions.
Objective To explore factors affecting the shunt safety of patients in emergency intensive care unit (EICU), construct a shunt safety evaluation model, and evaluate its prediction effectiveness, so as to provide a theoretical basis for the decision-making of shunt safety in EICU. Methods The demographic data, vital signs, laboratory examinations and other indicators of patients transferred to the general ward from the EICU of West China Hospital of Sichuan University from 0:00 on August 1, 2019 to 23:59 on May 31, 2021 were collected and analyzed. The short-term poor prognosis after being transferred out of the EICU was regarded as the end-point event. Of the patients, 70% were randomly selected as the model construction cohort, and 30% were the model validation cohort. In the model construction cohort, multivariate logistic regression analysis was used to screen the influencing factors affecting shunt safety, and the shunt safety evaluation model of patients in EICU was constructed. In the validation cohort, receiver operating characteristic curve was used to evaluate the effectiveness of the model in evaluating the shunt safety of patients in EICU. Results A total of 582 patients were included, of whom 59 patients (10.1%) had a poor short-term prognosis. Multivariate logistic regression analysis showed that the patients’ respiratory rate when leaving the EICU [odds ratio (OR)=0.863, 95% confidence interval (CI) (0.794, 0.938), P=0.001], Glasgow Coma Scale scores [OR=1.575, 95%CI (1.348, 1.841), P<0.001], albumin [OR=1.137, 95%CI (1.008, 1.282), P=0.036], prothrombin time [OR=0.956, 95%CI (0.914, 1.000), P=0.048] were the influencing factors of shunt safety. Based on the above indicators, a shunt safety evaluation model for patients in EICU was created. The area under the curve for the shunt safety assessment model to predict poor short-term prognosis was 0.815, the best cut-off value was 4 points, the sensitivity was 93.3%, and the specificity was 61.5%. Conclusions The patients’ respiratory rate when leaving EICU, Glasgow Coma Scale scores, albumin and prothrombin time are factors affecting the shunt safety for patients in EICU. The shunt safety assessment model can better predict the short-term poor prognosis of patients transferred from EICU to general ward.
The small molecule nutrients and cell growth factors required for the normal metabolism of chondrocyte mainly transport into the cartilage through free diffusion. However, the specific mass transfer law in the cartilage remains to be studied. In this study, using small molecule rhodamine B as tracer, the mass transfer models of cartilage were built under different pathways including surface pathway, lateral pathway and composite pathway. Sections of cartilage at different mass transfer times were observed by using laser confocal microscopy and the transport law of small molecules within different layers of cartilage was studied. The results showed that rhodamine B diffused into the whole cartilage layer through surface pathway within 2 h. The fluorescence intensity in the whole cartilage layer increased with the increase of mass transfer time. Compared to mass transfer of 2 h, the mean fluorescence intensity in the superficial, middle, and deep layers of cartilage increased by 1.83, 1.95, and 3.64 times, respectively, after 24 h of mass transfer. Under lateral path condition, rhodamine B was transported along the cartilage width, and the molecular transport distance increased with increasing mass transfer time. It is noted that rhodamine B could be transported to 2 mm away from cartilage side after 24 h of mass transfer. The effect of mass transfer under the composite path was better than those under the surface path and the lateral path, and especially the mass transfer in the deep layer of cartilage was improved. This study may provide a reference for the treatment and repair of cartilage injury.
American Heart Association (AHA) updated the advanced cardiovascular life support use of antiarrhythmic drugs during and immediately after cardiac arrest in the AHA guidelines for cardiopulmonary resuscitation and emergency cardiovascular care in November 2018. Based on the latest progress of relative evidence-based clinical evidence and 2015 AHA guidelines for cardiopulmonary resuscitation and cardiovascular emergency cardiovascular care. This update gave recommends on the use of antiarrhythmic drugs during resuscitation from adult shock-refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) cardiac arrest and immediately after restoration of spontaneous circulation following shock-refractory VF/pVT cardiac arrest, respectively. This review aims to interpret this update by reviewing the literature and comparing the recommends in this update with other guidelines.
Objective To evaluate the clinical diagnostic value of MRI at 90°at 90° flexed knee position for meniscal Ramp lesions. Methods A total of 228 patients with knee pain as the main complaint who were admitted between September 2021 and September 2023 were selected as the research subjects, of which 51 patients met the selection criteria and were enrolled in the study. There were 31 males and 20 females with an average age of 38.6 years (range, 15-67 years). Body mass index was 17.2-28.7kg/m2 (mean, 23.9 kg/m2). There were 25 cases of left knee and 36 cases of right knee. The time from injury to admission was 0.1-14.3 weeks (mean, 2.1 weeks). Preoperative MRI at fully extended (knee extension position) and 90° flexed knee positions (knee flexion position) were performed to determine the presence of irregular signs at the posterior edge of the medial meniscus, and complete fluid filling between the posterior horn of the medial meniscus (PHMM) and the capsule margin (i.e. PHMM fluid high signal). Findings obtained under arthroscopy served as the gold standard to analyze the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of MRI at knee extension and flexion positions for the two specific signs of Ramp lesions. Results Twenty-one patients (41%) were diagnosed with Ramp lesions by using arthroscopy, including 1 case of Thaunat type Ⅰ, 2 cases of type Ⅱ, 6 cases of type Ⅲ, 7 cases of type Ⅳ, and 5 cases of type Ⅴ. The positive rates of irregular signs at the posterior edge of the medial meniscus on MRI at knee extension and knee flexion positions were significantly different from the diagnosis of Ramp injury under arthroscopy (P<0.05). The sensitivity, specificity, accuracy, PPV, and NPV of MRI in the diagnosis of irregular signs were 76.1%, 60.0%, 66.7%, 57.1%, and 78.3% respectively at knee extension position, and 85.7%, 73.3%, 78.4%, 69.2%, and 88.0% respectively at knee flexion position. The positive rates of PHMM fluid high signal on MRI at knee extension and knee flexion positions were significantly different from the diagnosis of Ramp injury under arthroscopy (P<0.05). The sensitivity, specificity, accuracy, PPV, and NPV of MRI in diagnosing PHMM fluid high signal were 38.1%, 100%, 74.5%,100%, and 69.8% respectively at knee extension position, and 85.7%, 100%, 94.1%, 100%, and 90.9% respectively at knee flexion position. ConclusionMRI at 90° flexed knee position improves the diagnostic performance of the detection of medial meniscal Ramp lesions compared with MRI at fully extended position.