Comparison of 3 Different Surgical Techniques for Rotator Cuff Repair in a Rabbit Model: Direct Suture, Inlay Suture, and Polyether Ether Ketone (PEEK) Suture Anchor.

BACKGROUND: Rotator cuff tears have been repaired using the transosseous method for decades. The direct suture (DS) technique has been widely used for rotator cuff tears; however, the retear rate is relatively high. Suture anchors are now used frequently for rotator cuff repair (RCR) in accordance with recent developments in materials. However, polyether ether ketone (PEEK) may still cause complications such as the formation of cysts and osteophytes. Some studies have developed the inlay suture (IS) technique for RCR. PURPOSE/HYPOTHESIS: To compare how 3 different surgical techniques-namely, the DS, IS, and PEEK suture anchor (PSA)-affect tendon-bone healing after RCR. We hypothesized that the IS technique would lead to better tendon-to-bone healing and that the repaired structure would be similar to the normal enthesis. STUDY DESIGN: Controlled laboratory study. METHODS: Acute infraspinatus tendon tears were created in 36 six-month-old male rabbits, which were divided into 3 groups based on the technique used for RCR: DS, IS, and PSA. Animals were euthanized at 6 and 12 weeks postoperatively and underwent a histological assessment and imaging. The expression of related proteins was demonstrated by immunohistochemistry and immunofluorescence staining. Mechanical properties were evaluated by biomechanical testing. RESULTS: At 12 weeks, regeneration of the enthesis was observed in the 3 groups. However, the DS group showed a lower type I collagen content than the PSA and IS groups, which was similar to the results for scleraxis. The DS group displayed a significantly inferior type II collagen expression and proteoglycan deposition after safranin O/fast green and sirius red staining. With regard to runt-related transcription factor 2 and alkaline phosphatase, the IS group showed upregulated expression levels compared with the other 2 groups. CONCLUSION: Compared with the DS technique, the PSA and IS techniques contributed to the improved maturation of tendons and fibrocartilage regeneration, while the IS technique particularly promoted osteogenesis at the enthesis. CLINICAL RELEVANCE: The IS and PSA techniques may be more beneficial for tendon-bone healing after RCR.

Identification of difficult laryngoscopy using an optimized hybrid architecture.

BACKGROUND: Identification of difficult laryngoscopy is a frequent demand in cervical spondylosis clinical surgery. This work aims to develop a hybrid architecture for identifying difficult laryngoscopy based on new indexes. METHODS: Initially, two new indexes for identifying difficult laryngoscopy are proposed, and their efficacy for predicting difficult laryngoscopy is compared to that of two conventional indexes. Second, a hybrid adaptive architecture with convolutional layers, spatial extraction, and a vision transformer is proposed for predicting difficult laryngoscopy. The proposed adaptive hybrid architecture is then optimized by determining the optimal location for extracting spatial information. RESULTS: The test accuracy of four indexes using simple model is 0.8320. The test accuracy of optimized hybrid architecture using four indexes is 0.8482. CONCLUSION: The newly proposed two indexes, the angle between the lower margins of the second and sixth cervical spines and the vertical direction, are validated to be effective for recognizing difficult laryngoscopy. In addition, the optimized hybrid architecture employing four indexes demonstrates improved efficacy in detecting difficult laryngoscopy. TRIAL REGISTRATION: Ethics permission for this research was obtained from the Medical Scientific Research Ethics Committee of Peking University Third Hospital (IRB00006761-2015021) on 30 March 2015. A well-informed agreement has been received from all participants. Patients were enrolled in this research at the Chinese Clinical Trial Registry ( http://www.chictr.org.cn , identifier: ChiCTR-ROC-16008598) on 6 June 2016.

Ultrasound-Controlled Delivery of Growth Factor-Loaded Cerasomes Combined with Polycaprolactone Scaffolds Seeded with Bone Marrow Mesenchymal Stem Cells for Biomimetic Tendon-to-Bone Interface Engineering.

Rotator cuff tear (RCT) is a prevalent shoulder injury that poses challenges for achieving continuous and functional regeneration of the tendon-to-bone interface (TBI). In this study, we controlled the delivery of growth factors (GFs) from liposomal nanohybrid cerasomes by ultrasound and implanted three-dimensional printed polycaprolactone (PCL) scaffolds modified with polydopamine loaded with bone marrow mesenchymal stem cells (BMSCs) to repair tears of the infraspinatus tendon in a lapine model. Direct suturing (control, CTL) was used as a control. The PCL/BMSC/cerasome (PBC) devices are sutured with the enthesis of the infraspinatus tendon. The cerasomes and PCL scaffolds are highly stable with excellent biocompatibility. The roles of GFs BMP2, TGFß1, and FGF2 in tissue-specific differentiation are validated. Compared with the CTL group, the PBC group had significantly greater proteoglycan deposition (P = 0.0218), collagen volume fraction (P = 0.0078), and proportions of collagen I (P = 0.0085) and collagen III (P = 0.0048). Biotin-labeled in situ hybridization revealed a high rate of survival for transplanted BMSCs. Collagen type co-staining at the TBI is consistent with multiple collagen regeneration. Our studies demonstrate the validity of biomimetic scaffolds of TBI with BMSC-seeded PCL scaffolds and GF-loaded cerasomes to enhance the treatment outcomes for RCTs.

Preoperative radiological indicators for prediction of difficult laryngoscopy in patients with atlantoaxial dislocation.

Background: Difficult airway remains a great challenge in patients with atlantoaxial dislocation (AAD). Preoperative evaluation and reliable prediction are required to facilitate the airway management. We aimed to screen out reliable radiological indicators for prediction of difficult laryngoscopy in patients with AAD. Methods: A retrospective nested case-control study within a single center longitudinal AAD cohort was conducted to investigate the radiological indicators. All the patients with difficult laryngoscopy from 2010 to 2021 were enrolled as the difficult laryngoscopy group. Others in the cohort without difficult laryngoscopy were randomly selected as the non-difficult laryngoscopy group by individually matching with the same gender, same surgery year, and similar age (±5 years) at a ratio of 6:1. Radiological data on preoperative lateral X-ray images between the two groups were compared. Bivariate logistic regression model was applied to screen out the independent predictive indicators and calculate the odds ratios of indicators associated with difficult laryngoscopy. Receiver operating characteristic curve and area under the curve (AUC) were used to describe the discrimination ability of indicators. Results: A total of 154 patients were finally analyzed in this study. Twenty-two patients with difficult laryngoscopy and matched with 132 controls. Four radiological parameters showed significant difference between the two groups. Among which, ΔC1C2D (the difference of the distance between atlas and axis in the neutral and extension position), owned the largest AUC. Conclusions: ΔC1C2D could be a valuable radiologic predictor for difficult laryngoscopy in patients with AAD.

Comparative analysis of popular predictors for difficult laryngoscopy using hybrid intelligent detection methods.

Difficult laryngoscopy is associated with airway injury, and asphyxia. There are no guidelines or gold standards for detecting difficult laryngoscopy. There are many opinions on which predictors to use to detect difficult laryngoscopy exposure, and no comprehensively unified comparative analysis has been conducted. The efficacy and accuracy of deep learning (DL)-based models and machine learning (ML)-based models for predicting difficult laryngoscopy need to be evaluated and compared, under the circumstance that the flourishing of deep neural networks (DNN) has increasingly left ML less concentrated and uncreative. For the first time, the performance of difficult laryngoscopy prediction for a dataset of 671 patients, under single index and integrated multiple indicators was consistently verified under seven ML-based models and four DL-based approaches. The top dog was a simple traditional machine learning model, Naïve Bayes, outperforming DL-based models, the best test accuracy is 86.6%, the F1 score is 0.908, and the average precision score is 0.837. Three radiological variables of difficult laryngoscopy were all valuable separately and combinedly and the ranking was presented. There is no significant difference in performance among the three radiological indicators individually (83.06% vs. 83.20% vs. 83.33%) and comprehensively (83.74%), suggesting that anesthesiologists can flexibly choose appropriate measurement indicators according to the actual situation to predict difficult laryngoscopy. Adaptive spatial interaction was imposed to the model to boost the performance of difficult laryngoscopy prediction with preoperative cervical spine X-ray.

Observation of In-Plane Quantum Griffiths Singularity in Two-Dimensional Crystalline Superconductors.

Quantum Griffiths singularity (QGS) reveals the profound influence of quenched disorder on the quantum phase transitions, characterized by the divergence of the dynamical critical exponent at the boundary of the vortex glasslike phase, named as quantum Griffiths phase. However, in the absence of vortices, whether the QGS can exist under a parallel magnetic field remains a puzzle. Here, we study the magnetic field induced superconductor-metal transition in ultrathin crystalline PdTe_{2} films grown by molecular beam epitaxy. Remarkably, the QGS emerges under both perpendicular and parallel magnetic field in four-monolayer PdTe_{2} films. The direct activated scaling analysis with a new irrelevant correction has been proposed, providing important evidence of QGS. With increasing film thickness to six monolayers, the QGS disappears under perpendicular field but persists under parallel field, and this discordance may originate from the differences in microscopic processes. Our work demonstrates the universality of parallel field induced QGS and can stimulate further investigations on novel quantum phase transitions under parallel magnetic field.

Anterior neck soft tissue thickness for airway evaluation measured by MRI in patients with cervical spondylosis: prospective cohort study.

OBJECTIVES: Anterior neck soft tissue thickness, usually measured by ultrasound, is increasingly being investigated to predict difficult laryngoscopy, but the results have not been validated. Considering the conflicting measurement data, different measuring body positions and lack of a standard ultrasound procedure, we used MRI to verify the efficacy of these popular ultrasonographic parameters. DESIGN: Prospective cohort study. SETTING: A tertiary hospital in Beijing, China. METHODS: We enrolled 315 adult patients who underwent cervical spinal surgery in Peking University Third Hospital from April to October 2016. We analysed MRI data to predict difficult laryngoscopy. Cormack-Lehane scales were assessed during intubation, and patients with a class III or IV view were assigned to the difficult laryngoscopy group. RESULTS: Univariate analysis showed that male sex (p<0.01), older age (p=0.03) and body weight (p=0.02) were associated with difficult laryngoscopy. MRI data consisted of five common ultrasonographic variables used to predict difficult laryngoscopy, but none was a valuable predictor: skin to hyoid (p=0.18), skin to midpoint of epiglottis (p=0.72), skin to thyroid cartilage at the level of the vocal cords (p=0.10), skin to vocal cords (p=0.44) or skin to anterior to the trachea at the level of suprasternal notch (p=0.92). Adjusted by sex, age and body weight, none of the five MRI indicators had predictive value (p>0.05). CONCLUSION: The five most commonly studied ultrasonographic indicators of anterior soft tissue thickness appeared unreliable to predict difficult laryngoscopy in patients with cervical spondylosis. Further study is needed to validate the most valuable indicator to predict difficult laryngoscopy. TRIAL REGISTRATION NUMBER: ChiCTRROC-16008598; Pre-results.