Activatable fluorescent probes for imaging and diagnosis of rheumatoid arthritis

Rheumatoid arthritis(RA)is a systemic autoimmune disease that is primarily manifested as synovitis and polyarticular opacity and typically leads to serious joint damage and irreversible disability,thus adversely affecting locomotion ability and life quality.Consequently,good prognosis heavily relies on the early diagnosis and effective therapeutic monitoring of RA.Activatable fluorescent probes play vital roles in the detection and imaging of biomarkers for disease diagnosis and in vivo imaging.Herein,we review the fluorescent probes developed for the detection and imaging of RA biomarkers,namely reactive oxygen/nitrogen species(hypochlorous acid,peroxynitrite,hydroxyl radical,nitroxyl),pH,and cysteine,and address the related challenges and prospects to inspire the design of novel fluorescent probes and the improvement of their performance in RA studies.

数字化骨科技术在骨科临床教学中的应用

骨科临床教学是骨科学生培养的关键过程。传统的教学方法和媒介存在诸多不足,而迅速发展的数字化骨科技术结合了计算机、图像处理、3D打印等多种新型医学处理技术,具有形象化、可视化、可重复性和可操作性等优点,在骨科临床教学中展现出广阔的应用前景。

三维有限元技术联合PBL教学在骨科研究生临床教学中的应用

目的评价三维有限元技术联合基于问题的学习(problem-based learning,PBL)教学模式在骨科研究生临床教学实践中的应用效果。方法选取2019年9月至2020年12月在中日友好医院骨科基地进行住院医师规范培训的42名硕士研究生,随机分为A、B、C三组,对同一课程内容采用不同方式进行教学。A组为三维有限元技术联合PBL教学,B组为PBL教学,C组为传统教学,通过考试及自评式问卷评估教学效果。结果 A组学生成绩优良率显著高于B组(78.57%vs. 35.71%)、C组(78.57%vs. 21.43%),A组学生对授课的满意度、知识的掌握度以及课程感兴趣度亦显著高于B、C两组,差异均具有统计学意义(P <0.05)。结论三维有限元技术联合PBL教学模式能显著提升学生学习成绩,改善教学质量,具有较好的教学效果。

自噬相关信号转导通路在骨代谢中的作用

自噬是组织衰老退变的有效保护机制,在细胞增殖、分化和成熟过程中发挥重要作用。参与骨代谢的主要细胞包括成骨细胞和破骨细胞,它们共同在骨骼发育和维持中起着至关重要的作用。研究发现,在成骨细胞中主要通过去乙酰化酶1及丝裂原激活蛋白激酶8/forkhead box O3来调节自噬水平的高低,在破骨细胞中主要通过Bcl-2相互作用卷曲蛋白1、p62/sequestosome 1、哺乳动物雷帕霉素靶蛋白及缺氧诱导因子-1α来调节自噬水平的高低。本文就骨代谢中自噬相关信号转导通路在成骨细胞和破骨细胞自噬中的作用作一综述。

Corticosteroid-induced Osteonecrosis of the Femoral Head:Detection,Diagnosis,and Treatment in Earlier Stages

Objective： This review aimed to provide a current recommendation to multidisciplinary physicians for early detection, diagnosis, and treatment of corticosteroid-induced osteonecrosis of the femoral head （ONFH） based on a comprehensive analysis of the clinical literature. Data Sources： For the purpose of collecting potentially eligible articles, we searched for articles in the PubMed, Cochrane Library, Embase, and CNKI databases up to February 2017, using the following key words： ＆quot;corticosteroid＆quot;, ＆quot;osteonecrosis of the femoral head＆quot;,＆quot;risk factors＆quot;, ＆quot;diagnosis＆quot;, ＆quot;prognosis＆quot;, and ＆quot;treatment＆quot;. Study Selection： Articles on relationships between corticosteroid and ONFH were selected for this review. Articles on the diagnosis, prognosis, and intervention of earlier-stage ONFH were also reviewed. Results： The incidence of corticosteroid-induced ONFH was associated with high doses of corticosteroids, and underlying diseases in certain predisposed individuals mainly occurred in the first 3 months of corticosteroid prescription. The enhanced awareness and minimized exposure to the established risk factors and earlier definitive diagnosis are essential for the success of joint preservation. When following up patients with ONFH, treatment should be started if necessary. Surgical treatment yielded better results than conservative therapy in earlier-stage ONFH. The ideal purpose of earlier intervention and treatment is permanent preservation of the femoral head without physical restrictions in daily living. Conclusions： Clinicians should enhance their precaution awareness of corticosteroid-induced ONFH. For high-risk patients, regular follow-up is very important in the 1st year after high-dose prescription of corticosteroids. Patients with suspected ONFH should be referred to orthopedists for diagnosis and treatment in its earlier stage to preserve the joint.

Pericollapse Stage of Osteonecrosis of the Femoral Head： A Last Chance for Joint Preservation

Objective： To propose a new definition of the pericollapse stage of osteonecrosis of the femoral head （ONFH） and review its significance in disease diagnosis and treatment selection. Data Sources： A search for eligible studies was conducted in three electronic databases including PubMed, Cochrane Library, and Embase up to August 10, 2018, using the following keywords： ＂osteonecrosis＂, ＂prognosis＂, and ＂treatment＂. Study Selection： Investigations appraising the clinical signs, symptoms, and imaging manifestations in different stages of ONFH were included. Articles evaluating the prognosis of various joint-preserving procedures were also reviewed. Results： The pericollapse stage refers to a continuous period in the development of ONFH from the occurrence of subchondral fracture to early collapse （〈2 mm）, possessing specific imaging features that mainly consist of bone marrow edema and joint effusion on magnetic resonance imaging （MR1）, crescent signs on X-ray films, and clinical manifestations such as the sudden worsening of hip pain. Accumulating evidence has indicated that these findings may be secondary to the changes after subchondral fractures. Of note. computed tomography provides more information for identifying possible subchondral fractures than does MRI and serves as the most sensitive tool for grading the pericollapse lesion stage. The pericollapse stage may indicate a high possibility of progressive disease but also demonstrates satisfactory long- and medium-term outcomes fbr joint-preserving techniques. In tact, if the articular surface subsides more than 2 mm, total hip arthroplasty is preferable. Conclusions： The pericollapse stage with distinct clinical and imaging characteristics provides a last good opportunity for the use of joint-preserving techniques. It is necessary to separate the pericollapse stage as an independent state in evaluating the natural progression of ONFH and selecting an appropriate treatment regimen.

Effects of Lower Limb Alignment and Tibial Component Inclination on the Biomechanics of Lateral Compartment in Unicompartmental Knee Arthroplasty

Background： Lateral compartmental osteoarthritis （LCOA）, a major complication after medial mobile-bearing unicompartmental knee arthroplasty （UKA）, is highly associated with the increased stress of the lateral compartment. This study aimed to analyze the effects on the stress and load distribution of the lateral compartment induced by lower limb alignment and coronal inclination of the tibial component in UKA through a finite element analysis. Methods： Eight three-dimensional models were constructed based on a validated model for analyzing the biomechanical effects of implantation parameters on the lateral compartment after medial Oxford UKA： postoperative lower limb alignment of 3° valgus, neutral and 3° varus, and the inclination of tibial components placed in 4°, 2° valgus, square, and 2° and 4° varus. The contact stress of femoral and tibial cartilage and load distribution were calculated for all models. Results： In the 3° valgus lower limb alignment model, the contact stress of femoral （3.38 MPa） and tibial （3.50 MPa） cartilage as well as load percentage （45.78%） was highest compared to any other model, and was increased by 36.75%, 47.70%, and 27.63%, respectively when compared to 3° varus. In the condition of a neutral position, the outcome was comparable for the different tibial tray inclination models. The inclination did not greatly affect the lateral compartmental stress and load distribution. Conclusions： This study suggested that slightly varus （undercorrection） lower limb alignment might be a way to prevent LCOAin medial mobile-bearing UKA. However, the inclination （4° varus to 4° valgus） of the tibial component in the coronal plane would not be a risk factor for LCOA in neutral position.

Four Methods for Calculating Blood-loss after Total Knee Arthroplasty

Background： Currently, various calculation methods for evaluating blood-loss in patients with total knee arthroplasty （TKA） are applied in clinical practice. However, different methods may yield different results. The purpose of this study was to determine the most reliable method for calculating blood-loss after primary TKA. Methods： We compared blood-loss in 245 patients who underwent primary unilateral TKA from February 2010 to August 2011. We calculated blood-loss using four methods： Gross equation, hemoglobin （Hb） balance, the Orthopedic Surgery Transfusion Hemoglobin European Overview （OSTHEO） formula, and Hb-dilution. We determined Pearson＇s correlation coefficients for the four methods. Results： There were large differences in the calculated blood-loss obtained by the four methods. In descending order of combined correlation coefficient based on calculated blood-loss, the methods were Hb-balance, OSTHEO formula, Hb-dilution, and Gross equation. Conclusions： The Hb-balance method may be the most reliable method of estimating blood-loss after TKA.

Significance of Lateral Pillar in Osteonecrosis of Femoral Head:A Finite Element Analysis

Background： The lateral pillar of the femoral head is an important site for disease development such as osteonecrosis of the femoral head. The femoral head consists of medial, central, and lateral pillars. This study aimed to determine the biomechanical effects of early osteonecrosis in pillars of the femoral head via a finite element （FE） analysis. Methods： A three-dimensional FE model of the intact hip joint was constructed from the image data of a healthy control. Further, a set of six early osteonecrosis models was developed based on the three-pillar classification. The von Mises stress and surface displacements were calculated for all models. Results： The peak values of von Mises stress in the cortical and cancellous bones of normal model were 6.41 MPa and 0.49 MPa, respectively. In models with necrotic lesions in the cortical and cancellous bones, the von Mises stress and displacement of lateral pillar showed significant variability： the stress of cortical bone decreased from 6.41 MPa to 1.51 MPa （76.0% reduction）, while cancellous bone showed an increase from 0.49 MPa to 1.28 MPa （159.0% increase）; surface displacements of cortical and cancellous bones increased from 52.4 μm and 52.1 μm to 67.9 μm （29.5%） and 61.9 μm （18.8%）, respectively. In addition, osteonecrosis affected not only pillars but also adjacent structures in terms of the von Mises stress and surface displacement levels. Conclusions： This study suggested that the early-stage necrosis in the femoral head could increase the risk of collapse, especially in lateral pillar. On the other hand, the cortical part of lateral pillar was found to be the main biomechanical support of femoral head.

Focused extra-corporeal shockwave treatment during early stage of osteonecrosis of femoral head

In recent years,increasing evidence has demonstrated that extra-corporeal shockwave therapy (ESWT) can offer an effective and non-invasive method for the treatment of musculoskeletal disorders,such as shoulder tendinopathies,lateral epicondylopathy of the elbow,greater trochanteric pain syndrome,patellar tendinopathy,Achilles tendinopathy,plantar fasciitis,and bone disorders.[1,2]As a safe,cheap,and non-invasive therapeutic method,ESWT has played a promising role in orthopedic medicine.[3-5] Inspired by this,several researchers have attempted to investigate its use for treating osteonecrosis of the femoral head.ESWT deserves being recommended as the optimal choice for osteonecrosis of the femoral head (ONFH).