Basic Science Evidence Research Articles

Overwrapping Bivalved Casts: Does the Material Matter?

Circumferential integrity of bivalved casts (cut twice longitudinally) can be restored by overwrapping with different materials. This study compared the mechanical properties of solid casts and bivalved casts overwrapped with semirigid fiberglass (SF), elastic bandages (EB), and rigid fiberglass (RF) using an overwrapped-bivalved cast-bone fracture (OBCBF) model. This study used an MTS Bionix Servohydraulic system to test properties of OBCBF models in 4 conditions: intact Control made of RF (not bivalved or overwrapped), a Rigid overwrapped model made of a Control bivalved and overwrapped with RF, a Semirigid overwrapped model made of a Control bivalved and overwrapped with SF, and an Elastic model made of a Control bivalved and overwrapped with EB. Constructs were tested in 4-point bending. Force-displacement curves (FDC) were generated to calculate load-at-critical-failure (LCF, angulation > 10 degrees = 6.6mm vertical deformation) and stiffness. Five controls and 30 OBCBF models with 3 overwrapped cast types were tested, with each overwrapped cast type tested with 2 orientations of the initial cast bivalve axis, yielding 7 conditions (Control, Rigid 0 degrees, Rigid 90 degrees, Semirigid 0 degrees, Semirigid 90 degrees, Elastic 0 degrees, Elastic 90 degrees). Mean LCF was: Rigid 90 degrees > Rigid 0 degrees > Control > Semirigid 0 degrees > Semirigid 90 degrees > Elastic 90 degrees > Elastic 0 degrees ( P <0.0001). Mean stiffness was: Rigid 0 degrees > Rigid 90 degrees > Control > Semirigid 90 degrees > Semirigid 0 degrees > Elastic 0 degrees > Elastic 90 degrees ( P <0.0001). Multiple comparisons indicated no significant difference between LCF and stiffness for Semirigid 0 degrees/90 degrees casts compared with Controls. Mechanical properties of overwrapped bivalved casts change depending on the materials used to overwrap, with higher LCF and stiffness when overwrapping with RF > SF > EB; however, mean comparisons indicate that rigid bivalved casts overwrapped with SF did not have significantly different mean stiffness and LCF from controls and other cast models. This study compares the bending properties of a bivalved cast-construct overwrapped with different materials, providing basic science evidence for orthopaedic surgeons who have several choices of materials to overwrap bivalved casts.

Discovery of Coumarins from Zanthoxylum dimorphophyllum var. spinifoliumas and Their Potential against Rheumatoid Arthritis.

In the present study, a series of coumarins, including eight undescribed bis-isoprenylated ones Spinifoliumin A-H, were isolated and identified from the aerial parts of Zanthoxylum dimorphophyllum var. spinifolium (ZDS), a plant revered in traditional Chinese medicine, particularly for treating rheumatoid arthritis (RA). The structures of the compounds were elucidated using 1D and 2D NMR spectroscopy, complemented by ECD, [Rh2(OCOCF3)4]-induced ECD, Mo2(OAc)4 induced ECD, IR, and HR-ESI-MS mass spectrometry. A network pharmacology approach allowed for predicting their anti-RA mechanisms and identifying the MAPK and PI3K-Akt signaling pathways, with EGFR as a critical gene target. A CCK-8 method was used to evaluate the inhibition activities on HFLS-RA cells of these compounds. The results demonstrated that Spinifoliumin A, B, and D-H are effective at preventing the abnormal proliferation of LPS-induced HFLS-RA cells. The results showed that compounds Spinifoliumin A, D, and G can significantly suppress the levels of IL-1β, IL-6, and TNF-α. Moreover, molecular docking methods were utilized to confirm the high affinity between Spinifoliumin A, D, and G and EGFR, SRC, and JUN, which were consistent with the results of network pharmacology. This study provides basic scientific evidence to support ZDS's traditional use and potential clinical application.

A gender and size specific evaluation of Grammont-type inlay versus lateralizing onlay stem designs in achieving lateralization and distalization in reverse shoulder arthroplasty

IntroductionIn reverse shoulder arthroplasty (RSA) new designs enable greater amounts of lateralization to prevent instability and scapular notching and increase range of motion, however, excessive lateralization leads to stress upon the acromion that can result in scapular spine fatigue fractures. Aim of this study was to gender- and size-specifically assess the influence of glenosphere size and different humeral designs on lateralization, distalization, and bony impingement-free range of motion (ROM) in patients undergoing RSA.MethodsComputed tomography scans from 30 osteoarthritic patients (f:15, m:15) and 20 cuff tear arthropathy patients (f:10, m:10) were used to virtually simulate RSA implantation. The efficacy of an inlay Grammont-type system vs. an onlay lateralizing system combined with different glenosphere sizes (36 mm vs. 42 mm) in achieving ROM, lateralization, and distalization was evaluated. Moreover, gender and patient’s constitution were correlated to humeral size by radiologically measuring the best-fit circle of the humeral head.ResultsA different amount of relative lateralization was achieved in both genders using large glenospheres and onlay designs. Latter yielded a higher ROM in all planes for men and women with a 42 mm glenosphere; with the 36 mm glenosphere, an increased ROM was observed only in men. The 155° inlay design led to joint medialization only in men, whereas all designs led to lateralization in women. When adjusting the absolute amount of lateralization to humerus’ size (or patient’s height), regardless of implant type, women received greater relative lateralization using 36 mm glenosphere (inlay: 1%; onlay 12%) than men with 42 mm glenosphere (inlay: -3%; onlay: 8%).ConclusionThe relative lateralization achieved using onlay design is much higher in women than men. Small glenospheres yield greater relative lateralization in women compared to large glenospheres in men. Humeral lateralization using onlay designs should be used cautiously in women, as they lead to great relative lateralization increasing stress onto the acromion.Level of evidenceBasic Science Study, Computer Modeling.

Modular baseplate augmentation: a simple and effective method for addressing eccentric glenoid wear

BackgroundAugmented baseplates can be effective at addressing eccentric glenoid wear in reverse total shoulder arthroplasty (rTSA). However, these implants often come in a limited number of predetermined shapes that require additional reaming to ensure adequate glenoid seating. This typically involves complex instrumentation and can have a negative impact on implant stability. Modular baseplate augmentation based on intra-operative measurements may allow for more precise defect filling while preserving glenoid bone. The purpose of this investigation was to assess the stability of a novel ringed baseplate with modular augmentation in comparison to non-augmented standard and ringed baseplate designs. MethodsIn this biomechanical study, baseplate micromotion was tested for three constructs according to American Society for Testing and Materials (ASTM) guidelines. The constructs included a non-augmented curved baseplate, a non-augmented ringed baseplate and ringed baseplate with an 8 mm locking modular augmentation peg. The non-augmented constructs were mounted flush onto polyurethane (PU) foam blocks, while the augmented baseplate was mounted on a PU block with a simulated defect. Baseplate displacement was measured prior to and after 100,000 cycles of cyclic loading. ResultsPrior to cyclic loading, the non-augmented and augmented ringed baseplates both demonstrated significantly less micromotion than the non-augmented curved baseplate design (81.1 μm vs 97.2 μm vs 152.7 μm; p=0.009). After cyclic loading, both ringed constructs continued to have significantly less micromotion compared to the curved design (105.5 μm vs 103.2 μm vs 136.6 μm; p<0.001). The micromotion for both ringed constructs remained below the minimum threshold required for bony ingrowth (150 μm) at all time points. ConclusionIn the setting of a simulated glenoid defect, locked modular augmentation of a ringed baseplate does not result in increased baseplate micromotion when compared to full contact, non-augmented baseplates. This design offers a simple method for tailored baseplate augmentation that can match specific variations in glenoid anatomy, limiting the need for excessive reaming and ultimately optimizing the environment for long term implant stability. Level of EvidenceBasic Science Study; Biomechanics

A unique tribological inverted bearing solution for reverse shoulder arthroplasty: Vitamin E and ceramic (unique inverse pairings in rTSR)

Background Reverse total shoulder arthroplasty has gained popularity for various shoulder conditions and has evolved over time to accommodate for material changes and design philosophy including inverse materials. The tribological behaviour of shoulder arthroplasty has been extensively studied in relation to biological osteolysis which is a notable concern regarding component loosening. Methods This study aims to assess the wear performance of a vitamin E-stabilised glenosphere or conventional ultra-high-molecular-weight polyethylene glenosphere whilst paired with ceramic or cobalt–chrome–molybdenum inlay in a shoulder joint wear simulator. A cumulative total of five million cycles was utilised with gravimetric and visual analysis of wear. Results Gravimetric wear was observed to be the lowest when a vitamin E-stabilised glenosphere was paired with a ceramic inlay – demonstrating the greatest wear resistance. Conclusion Our results demonstrate that the combination of vitamin E-stabilised polyethylene glenosphere and ceramic inlay has improved wear resistance properties in load simulations when compared to other bearing surface combinations. This supports the use of the novel inverse combination in clinical practice to attain longer-term survivorship in reverse total shoulder replacements. Level of evidence Basic Science Study; Tribology

Toma de decisiones para el manejo ambulatorio de la bronquiolitis según fisioterapeutas docentes de la Universidad del Gran Rosario

IntroductionClinical practice guidelines recommend against performing respiratory physiotherapy in children with bronchiolitis. It is unknown which interventions physiotherapists use in routine practice, and what factors influence their decisions. The aim was to characterize decision-making in outpatient management of bronchiolitis according to teaching physiotherapists from the University of Gran Rosario. Material and methodsA Delphi technique-based survey was conducted with physiotherapy teachers in 2 stages. The first stage involved a questionnaire with open-ended questions. The second stage was developed from the results of the first, consisting of closed-ended questions. A majority criterion was established among physiotherapists≥60%. ResultsA considerable variability was observed in the interventions considered for the management of bronchiolitis. Over 60% of professionals expressed full agreement that their interventions are based on their knowledge of basic sciences, scientific evidence, clinical evaluation, and academic training. Also, over 60% stated full agreement that the application of interventions depends on clinical aspects of the child, their socioeconomic context, and their family's commitment to treatment. ConclusionsThe clinical intervention process as informed by physiotherapists differs from clinical practice guidelines recommendations. Multiple factors seem to condition, according to the statements of consulted physiotherapists, decision-making in the outpatient management of bronchiolitis.

Biomechanical evaluation of the modified lasso technique

BackgroundThe Terrible Triad of the elbow is a constellation of elbow dislocation, radial head fracture and coronoid process fracture. A common type of coronoid fracture documented with this triad is type II Regan-Morrey coronoid fractures. The preferred fixation method for this fracture type is the lasso technique, medial-lateral tunnel orientation being the traditional approach. Considering elbow anatomy, we saw an opportunity to potentially improve fixation by altering the suture lasso tunnel orientation to a proximal-distal orientation. HypothesisTwo tunnels in the proximal-distal direction would result in greater biomechanical stability as compared to the traditional lasso technique. Material and methodsA type 2 Regan-Morrey fracture was created in 12 fresh frozen cadaveric elbows at 50% of the coronoid height using an oscillating saw. The humero-ulnar joint was placed in 0 degrees flexion then loaded at a rate of 10mm/min to failure. ResultsThe control technique (medio-lateral tunnels) showed failure load of 150±81N that was not significantly different (p=0.825) than the 134±116N measured for the modified technique (distal-proximal tunnels). The portion of the load-displacement curve used to calculate stiffness was linear (R^2=0.94±0.04) with determination coefficients that did not differ between the two groups (p=0.351). For stiffness, we measured 17±13N/mm and 14±12N/mm respectively for control and modified techniques that did not result in a significant difference (p=0.674). ConclusionIn this attempt to improve the shortcomings of the lasso technique, we found that changing from medio-lateral to proximal-distal drilling directions did not result in an appreciable biomechanical benefit. Level of evidenceBasic science study; Biomechanics.

Toxic Effects of Local Anesthetics on Rat Fibroblasts: An In-Vitro Study

BackgroundInfusion catheters facilitate a controlled infusion of local anesthetic (LA) for pain control after surgery. However, their potential effects on healing fibroblasts are unspecified. MethodsRat synovial fibroblasts were cultured in 12-well plates. Dilutions were prepared in a solution containing reduced-serum media and 0.9% sodium chloride in 1:1 concentration. Each well was treated with 500μl of the appropriate LA dilution or normal saline for 15- or 30-minutes. LA dilutions included: 0.5% ropivacaine HCl, 0.2% ropivacaine HCl, 1% lidocaine HCl and epinephrine 1:100,000, 1% lidocaine HCl, 0.5% bupivacaine HCl and epinephrine 1:200,000, and 0.5% bupivacaine HCl. This was replicated three times. Dilution of each LA whereby 50% of the cells were unviable (Lethal dose 50 [LD50]) was analyzed. ResultsLD50 was reached for lidocaine and bupivacaine, but not ropivacaine. Lidocaine 1% with epinephrine is toxic at 30-minutes at 1/4 and 1/2 sample dilutions. Bupivacaine 0.5% was found to be toxic at 30-minutes at 1/2 sample dilution. Bupivacaine 0.5% with epinephrine was found to be toxic at 15- and 30-minutes at 1/4 sample dilution. Lidocaine 1% was found to be toxic at 15- and 30-minutes at 1/2 sample dilution. Ropivacaine 0.2% and 0.5% remained below LD50 at all time-points and concentrations, with 0.2% demonstrating the least cell death. ConclusionsThough pain pumps are generally efficacious, LAs may inhibit fibroblasts, including perineural fibroblast and endoneurial fibroblast-like cells, which may contribute to persistent nerve deficits, delayed neurogenic pain, and negatively impact healing. Should a continuous infusion be used, our data supports ropivacaine 0.2%. Level of EvidenceBasic Science Study; Animal model

Toxicological evaluation of Sargassum plagiophyllum extract in male mice

Purpose: To provide valid scientific evidence for the safety of Sargassum plagiophyllum extract in an animal model.&#x0D; Methods: Sargassum plagiophyllum extract (SPE) was obtained via water extraction using an autoclave at 121°C for 20 min. The SPE was administered to 4 groups of adult male mice via gavage once a day for 21 days. The treatment groups received different doses of SPE, i.e., 100, 500, 1000, and 2000 mg/kg. Control mice were given distilled water. Body weight, and feed and water intakes were recorded. The toxicity of SPE was assessed by determining blood, biochemical, and histopathological indices.&#x0D; Results: Intake of SPE for 21 days did not produce any impact on body mass, feed intake and water intake, even at 2000 mg/kg. Hematological parameters were also unaffected. Biochemical analysis of blood/serum revealed normal levels of blood urea nitrogen (BUN), creatinine, alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) in all treatment groups, when compared to control group. Moreover, histopathological studies confirmed healthy conditions of the liver, kidney, colon, and other organs in all treatment groups.&#x0D; Conclusion: These results from a mouse model provide basic scientific evidence of the safety of consuming Sargassum plagiophyllum extract, even at high doses thus expanding its potential use as a medication for improving health.

A arte de endurecer sem perder a ternura: o uso de tecnologias por obstetrizes na atenção ao parto domiciliar planejado

Abstract Introduction: Given the intense medicalization of childbirth and the hegemony of a technocratic model, there is a growing need for professional midwives to promote safe pregnancy and childbirth with minimal interventions. Objective: This study aims to identify the technologies present in the toolbox of certified midwives graduated from University of São Paulo. Methodology: It consists of a descriptive-exploratory study, with a qualitative approach. Semi-structured interviews were carried out virtually with five midwives from August 2020 to May 2021. The material was analyzed using dialogical maps. Results: A very heterogeneous range of technologies was identified, which included soft, soft-hard, and hard technologies. Soft technologies include affection, effective communication (knowing how to speak, knowing how to listen), and bonding. Soft-hard technologies include basic disciplines, scientific evidence, experience, and intuition. Finally, hard technologies include human-made instruments, in addition to the use of the materiality of the body. Conclusions: Midwives tend to use hard technologies when they are unable to achieve the desired effect with the soft technologies they had available, while also using their interrelational resources throughout the entire process. Furthermore, to employ such technological resources, professionals use different kinds of knowledge, without hierarchizing them.

Diversity of soil seed bank and influencing factors in the nascent wetland of the Yellow River Delta.

Soil seed bank is the growth and reproduction source of vegetation community, playing an important role in vegetation establishment, succession and renewal, biodiversity maintenance. This study has selected the nascent wetland in the Yellow River Delta (YRD) formed in 1996 as study area and investigated the diversity and key influencing factors of soil seed bank diversity. The study results show that: (1) The soil seed bank in the study area has a simple structure, containing relatively few species. A total of five plant species, which belong to four families and five genera, were found in this bank, with Phragmites australis and Suaeda salsa being the dominant plants. (2) All species are herbs without woody species. One herb is annual herb and the others are perennial herbs. (3) From the sea to the river, the changes rules of the overall density and diversity of the seed bank are not obvious. (4) The dispersal distance from salt and freshwater has a significant influence on the density of the soil seed bank but has no significant influence on the diversity. Meanwhile, the soil salt content has a significant negative influence on the diversity of seed banks. (5) Aboveground vegetation did not closely relationship with diversity of soil seed bank. All above results can provide basic data and scientific evidence for the conservation of vegetation communities in the nascent wetlands and vegetation restoration in the degraded wetlands in the YRD.

Biomechanical comparison of tension band suture fixation and tension band wiring in olecranon fractures

PurposeTraditional tension band wire fixation (TBWF) of olecranon fractures is associated with high revision rates due to implant-related complications. The purpose of the study was to compare the strength of fixation in olecranon fractures between TBWF and an all-suture based technique. MethodsA transverse fracture was created in 20 paired fresh-frozen human cadaveric elbows. Fractures were randomly (alternating right-left) assigned for fixation with either tension band suture fixation (TBSF) or TBWF. The elbow was fixed in 90° of flexion and underwent cycling loading by pulling the triceps tendon to 300 N for 200 cycles. Fracture displacement was optically recorded using digital image correlation (DIC). Finally, load-to-failure was assessed by a monotonic pull to 1000 N and failure mechanism was recorded. ResultsTwo specimens in the TBSF group were excluded from the cycling loading analysis due to technical difficulties with the DIC. After cyclic loading, median (min-max) fracture displacement was 0.28 mm (0.10–0.44) in the TBSF group and 0.18 mm (0.00–1.48) in the TBWF group (p = 0.315). No difference was found between the two groups in the repeated measures analysis of variance (p = 0.329). In the load-to-failure test, 6/10 specimens failed in the TBSF group (median load-to-failure 791 N) vs. 8/10 in the TBWF group (median load-to-failure 747 N). The TBSF constructs failed due to fracture of the dorsal cortex, suture breakage or triceps failure. The TBWF constructs failed due to breakage of the wire. ConclusionThere was no difference in fixation strength between the TBWF and TBSF constructs. Our findings suggest TBSF to be a feasible alternative to TBWF and we hypothesize that a non-metallic implant may have fewer implant-related complications. Level of evidenceBasic science study

Role of opioid and β-adrenergic receptors in bladder underactivity induced by prolonged pudendal nerve stimulation in cats.

To determine the role of opioid and β-adrenergic receptors in bladder underactivity induced by prolonged pudendal nerve stimulation (PNS). In α-chloralose anesthetized cats, 30-min PNS was applied repeatedly for 3-9 times to induce poststimulation or persistent bladder underactivity. Then, naloxone (opioid receptor antagonist, 1 mg/kg, IV) or propranolol (β-adrenergic receptor antagonist, 3 mg/kg, IV) was given to reverse the bladder underactivity. After the drug treatment, an additional 30-min PNS was applied to counteract the drug effect. Repeated cystometrograms were performed by slowly (1-2 mL/min) infusing the bladder with saline via a urethral catheter to determine the bladder underactivity and the treatment effects. Prolonged (2-4.5 h) PNS induced bladder underactivity evident as a large bladder capacity (169 ± 49% of control) and a reduced amplitude of bladder contraction (59 ± 17% of control). Naloxone fully reversed the bladder underactivity by reducing bladder capacity to 113 ± 58% and increasing the amplitude of bladder contraction to 104 ± 34%. After administration of naloxone an additional 30-min PNS temporarily increased the bladder capacity to the underactive bladder level (193 ± 74%) without changing the amplitude of the bladder contraction. Propranolol had no effect on bladder underactivity. A tonic enkephalinergic inhibitory mechanism in the CNS plays a critical role in the bladder underactivity induced by prolonged PNS, while the peripheral β-adrenergic receptor mechanism in the detrusor is not involved. This study provides basic science evidence consistent with the clinical observation that comorbid opioid usage may contribute to voiding dysfunction in patients with Fowler's syndrome.

A novel miRNA mimic attenuates organ injury after hepatic ischemia/reperfusion.

Extracellular cold-inducible RNA-binding protein (eCIRP) is a novel mediator of inflammation and tissue injury. It has been shown that miRNA 130b-3p acts as an endogenous inhibitor of eCIRP. Because RNA mimics are unstable after in vivo administration, we have chemically engineered miRNA 130b-3p mimic (named PS-OMe miR130) to improve its stability by protection from nuclease activity. We hypothesize that PS-OMe miR130 reduces eCIRP-mediated injury and inflammation in a murine model of hepatic ischemia/reperfusion (I/R), a model of sterile inflammation. Adult male mice underwent 70% hepatic ischemia for 60 minutes and 24-hour reperfusion. At the start of reperfusion, mice were treated intravenously with vehicle (phosphate-buffered saline) or PS-OMe miR130. Blood and liver tissue were collected after 24 hours for biochemical analysis. Apoptosis in the liver tissue was determined by transferase dUTP nick-end labeling assay. After hepatic I/R, organ injury markers including aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase significantly decreased after PS-OMe miR130 treatment. Furthermore, histological analysis of liver sections demonstrated significantly less injury in PS-OMe miR130 treatment mice versus vehicle mice. In addition, tumor necrosis factor α mRNA, interleukin-1β mRNA, and neutrophil infiltration (myeloperoxidase activity and granulocyte receptor 1 immunohistochemistry) were significantly attenuated after PS-OMe miR130 treatment. Finally, apoptosis significantly decreased in liver tissue after treatment. PS-OMe miR130 decreases eCIRP-mediated injury and inflammation in a murine model of hepatic I/R.

Bench-to-bedside: Feasibility of nano-engineered and drug-delivery biomaterials for bone-anchored implants and periodontal applications.

Nanotechnology and drug-release biomaterials have been thoroughly explored in the last few years aiming to develop specialized clinical treatments. However, it is rare to find biomaterials associated with drug delivery properties in the current dental market for application in oral bone- and periodontal-related procedures. The gap between basic scientific evidence and translation to a commercial product remains wide. Several challenges have been reported regarding the clinical translation of biomaterials with drug-delivery systems (BDDS) and nanofeatures. Therefore, processes for BDDS development, application in preclinical models, drug delivery doses, sterilization processes, storage protocols and approval requirements were explored in this review, associated with tentative solutions for these issues. The diversity of techniques and compounds/molecules applied to develop BDDS demands a case-by-case approach to manufacturing and validating a commercial biomaterial. Promising outcomes such as accelerated tissue healing and higher antibacterial response have been shown through basic and preclinical studies using BDDS and nano-engineered biomaterials; however, the adequate process for sterilization, storage, cost-effectiveness and possible cytotoxic effects remains unclear for multifunctional biomaterials incorporated with different chemical compounds; then BDDSs are rarely translated into products. The future benefits of BDDS and nano-engineered biomaterials have been reported suggesting personalized clinical treatment and a promising reduction in the use of systemic antibiotics. Finally, the launch of these specialized biomaterials with solid data and controlled traceability onto the market will generate strong specificity for healthcare treatments.

Biomechanical comparison of Tibial-sided supplemental fixation techniques in Bone-Patellar Tendon-Bone anterior cruciate ligament reconstruction

PurposeThe purpose of this study was to compare the biomechanical properties of a commercially available suture anchor and a screw post for supplemental tibial fixation of a bone-patellar tendon-bone (BTB) graft at time zero. We hypothesized that supplemental fixation using a suture anchor would demonstrate similar biomechanical performance in comparison with a screw post. MethodsSixteen fresh frozen, healthy human cadaveric knees underwent BTB autograft harvest, placement, and primary tibial-sided interference screw fixation using a standardized technique performed by a single surgeon. Specimens were randomly assigned to one of two tibial-sided supplemental fixation groups (suture anchor or screw post), yielding eight specimens in each group. Each specimen was affixed to a custom loading apparatus, with the tibial tunnel aligned in a vertical position that allowed for parallel “worst-case scenario” loading and eliminated loading variation due to tibial tunnel angle. Grafts were pretensioned to 30 N and biomechanical performance was compared with respect to cyclical loading between 50–250 N for 500 cycles at 0.5 Hz and pull-to-failure loading at 60 mm/min. ResultsThe suture anchor and screw post supplemental constructs demonstrated similar performance with respect to all biomechanical parameters assessed, including yield strength (294.0 N [IQR 267.2–304.2 N] versus 332.1 N [IQR 313.8–350.4 N]; P = 0.079) and ultimate strength (330.1 N [IQR 306.9–418.7 N] versus 374.7 N [IQR 362.0–387.3 N]; P = 0.3798). However, of the eight original specimens in each group, one suture anchor specimen (12.5%) and six metallic screw post specimens (75%) failed during cyclical testing and were unable to undergo displacement and load to failure testing. ConclusionThis study provides preliminary evidence that supplemental tibial-sided fixation of a BTB ACL graft with a suture anchor has similar loading characteristics or load-to-failure strength when compared to supplemental fixation with a screw post construct. Study designLaboratory Controlled Study. Level of evidenceBasic Science Study.

东方白鹳在山东省适宜栖息地的分布预测

PDF HTML阅读 XML下载 导出引用 引用提醒 东方白鹳在山东省适宜栖息地的分布预测 DOI: 10.5846/stxb202009052308 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 云南省基础研究计划项目(20210AT070040,2019FD0070) Prediction of the suitable habitat distribution of Oriental White Stork in Shandong Province Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:东方白鹳(Ciconia boyciana) 隶属鹳形目(Ciconiiformes)鹳科(Cioniidae)鹳属(Ciconia),被IUCN濒危物种红色名录列为濒危(EN),主要繁殖于俄罗斯远东地区与中国东北三江平原,在长江中下游鄱阳湖等沿海内陆湖泊越冬。山东省从2003年开始有东方白鹳繁殖记录,黄河三角洲为该物种在山东省的主要繁殖地。以在黄河三角洲自然保护区收集到的位点数据、物种分布数据库(GBIF)提取的位点数据和山东省环境气候因子为基础数据,基于最大熵(Maxent)模型和地理信息系统(ArcGIS)技术平台,预测东方白鹳在山东省的潜在适生区。结果表明在该物种在黄河三角洲及附近地区存在较集中的高适宜区,庙岛群岛和微山湖地区存在少量高适宜区,高适宜区总面积为1359.27km2;北至河北边界,南至微山县,沿黄河支流至西到达聊城市、菏泽市,存在1893.82km2较适宜区和3955.63km2低适宜区。潜在适宜生境总和为7208.72km2,占比为研究区域的0.89%。新出现的较为集中的较适宜区在微山湖周围地区,此地目前并无该物种出现的记录。通过对环境因子分析得知,东方白鹳选择适宜栖息地时更倾向于选择的植被类型是灌丛和草甸,土地利用类型是沼泽地、滩涂与河渠,远离道路,显著影响东方白鹳选择适宜区的气候因子是最暖季度降雨量和最干月份降雨量。研究旨在探究何种环境因子影响东方白鹳对适宜栖息地的选择,为该物种的栖息地管理和保护区建立提供科学依据,进而促进该物种种群和栖息地保护。 Abstract:The Oriental White Stork (Ciconia boyciana) belongs to the Ciconiiformes Stork family (Cioniidae) and the Stork genus (Ciconia). It is an endangered (EN) species on the International Union for Conservation of Nature (IUCN) Red List and is the national first-level protected wildlife. They mainly breed in the Far East of Russia and the Sanjiang Plain in Northeast China and overwinter in coastal inland lakes such as Poyang Lake in the middle and lower reaches of the Yangtze River. Shandong Province has recorded the reproduction of the Oriental White Stork since 2003. The Yellow River Delta is the main breeding ground for this species in Shandong Province. The purpose of this study is to explore what environmental factors affect the selection of suitable habitats for the Oriental White Stork. This article uses the site data collected in the Yellow River Delta Nature Reserve, the site data extracted from the Species Distribution Database (GBIF) and the environmental and climate factors of Shandong Province as the basic data, based on the Maximum Entropy (Maxent) model and geographic information system (ArcGIS), and predicts the potential suitable area of the Oriental White Stork in Shandong Province. The results show that the most suitable habitat for the species is concentrated in the Yellow River Delta and nearby areas. From the border of Hebei in the north of Shandong Province to Weishan County in the south, along the tributaries of the Yellow River to the west to Liaocheng City and Heze City, there are 3955.63 km2 low suitable areas and 1893.82 km2 more suitable area. The total potential suitable habitat is 7208.72 km2, of which the most suitable area is 1359.27 km2, accounting for 0.89% of the study area. The newly emerged more concentrated and more suitable patches are in the area around Weishan Lake, where there is currently no record of this species. Through the analysis of environmental factors, it is known that the vegetation types that the Oriental White Stork prefers to choose when choosing suitable habitats are shrubs and meadows, and the land use types are swamps, tidal flats and canals far away from roads. The climatic factors that significantly affect the Oriental White Stork's selection of suitable areas are the warmest quarter rainfall and the driest month rainfall. The results provide basic scientific evidence for the habitat management and establishment of the protected areas for this species, and promote the protection of the species' population and habitat. 参考文献 相似文献 引证文献

Computer-assisted analysis of functional internal rotation after reverse total shoulder arthroplasty: implications for component choice and orientation

PurposeFunctional internal rotation (IR) is a combination of extension and IR. It is clinically often limited after reverse total shoulder arthroplasty (RTSA) either due to loss of extension or IR in extension. It was the purpose of this study to determine the ideal in-vitro combination of glenoid and humeral components to achieve impingement-free functional IR.MethodsRTSA components were virtually implanted into a normal scapula (previously established with a statistical shape model) and into a corresponding humerus using a computer planning program (CASPA). Baseline glenoid configuration consisted of a 28 mm baseplate placed flush with the posteroinferior glenoid rim, a baseplate inclination angle of 96° (relative to the supraspinatus fossa) and a 36 mm standard glenosphere. Baseline humeral configuration consisted of a 12 mm humeral stem, a metaphysis with a neck shaft angle (NSA) of 155° (+ 6 mm medial offset), anatomic torsion of -20° and a symmetric PE inlay (36mmx0mm). Additional configurations with different humeral torsion (-20°, + 10°), NSA (135°, 145°, 155°), baseplate position, diameter, lateralization and inclination were tested. Glenohumeral extension of 5, 10, 20, and 40° was performed first, followed by IR of 20, 40, and 60° with the arm in extension of 40°—the value previously identified as necessary for satisfactory clinical functional IR. The different component combinations were taken through simulated ROM and the impingement volume (mm3) was recorded. Furthermore, the occurrence of impingement was read out in 5° motion increments.ResultsIn all cases where impingement occurred, it occurred between the PE inlay and the posterior glenoid rim. Only in 11 of 36 combinations full functional IR was possible without impingement. Anterosuperior baseplate positioning showed the highest impingement volume with every combination of NSA and torsion. A posteroinferiorly positioned 26 mm baseplate resulting in an additional 2 mm of inferior overhang as well as 6 mm baseplate lateralization offered the best impingement-free functional IR (5/6 combinations without impingement). Low impingement potential resulted from a combination of NSA 135° and + 10° torsion (4/6 combinations without impingement), followed by NSA 135° and -20° torsion (3/6 combinations without impingement) regardless of glenoid setup.ConclusionThe largest impingement-free functional IRs resulted from combining a posteroinferior baseplate position, a greater inferior glenosphere overhang, 90° of baseplate inclination angle, 6 mm glenosphere lateralization with respect to baseline setup, a lower NSA and antetorsion of the humeral component. Surgeons can employ and combine these implant configurations to achieve and improve functional IR when planning and performing RTSA.Level of evidenceBasic Science Study, Biomechanics.

Application of Amniotic Membrane Allograft in the Treatment of Foot and Ankle Pathologies: A Review of the Basic Science and Clinical Evidence

Application of Amniotic Membrane Allograft in the Treatment of Foot and Ankle Pathologies: A Review of the Basic Science and Clinical Evidence

Semi-automated 3-dimensional analysis of the normal foot and ankle using weight bearing CT – A report of normal values and bony relationships

BackgroundFoot and ankle deformities have translational and rotational components in multiple planes, at multiple levels. Semi-automatic segmentation is a relatively new technology, which when used with weight-bearing CT (WBCT), can build an accurate model of the foot and calculate the orientation and relationships of bones under physiological load. However, few papers report reference values using these techniques. We report normative values for key bony relationships based on semi-automated analysis of WBCT. MethodsThis was a single-centre, retrospective analysis of 100 feet without deformity from 55 adult patients undergoing WBCT as part of routine clinical activity (mean age 40.5 ± 17.3 years). Imaging was analysed using Bonelogic 2.1 (DISIOR, Finland). Semi-automatic segmentation was used to compute the various bony axes in 3-dimensional space. Selected coronal, axial and sagittal plane relationships were then calculated for bones of the hindfoot, midfoot and forefoot. ResultsData is presented on axial and sagittal plane relationships between the metatarsals in the forefoot, and the metatarsals and cuneiforms in the midfoot. In the hindfoot, the calcaneal pitch, talar-first-metatarsal angles, talonavicular coverage angles and Saltzman angles are reported. Coronal plane axes and their relationships are reported at multiple levels from hindfoot to forefoot. Results are presented as mean values with standard deviations and 95% confidence intervals. ConclusionsWe present an observational analysis of the normal values from non-deformed feet. We highlight the major relationships in the axial, sagittal and coronal planes as obtained by semi-automated analysis of WBCT. This data may serve as a reference for future research. Level of evidenceBasic science study