The relationship between tibiofemoral geometry and musculoskeletal function during normal activity

BackgroundThe effect of tibiofemoral geometry on musculoskeletal function is important to movement biomechanics.Research questionWe hypothesised that tibiofemoral geometry determines tibiofemoral motion and musculoskeletal function. We then aimed at 1) modelling tibiofemoral motion during normal activity as a function of tibiofemoral geometry in healthy adults; and 2) quantifying the effect of tibiofemoral geometry on musculoskeletal function.MethodsWe used motion data for six activity types and CT images of the knee from 12 healthy adults. Geometrical variation of the tibia and femoral articular surfaces were measured in the CT images. The geometry-based tibiofemoral motion was calculated by fitting a parallel mechanism to geometrical variation in the cohort. Matched musculoskeletal models embedding the geometry-based tibiofemoral joint motion and a common generic tibiofemoral motion of reference were generated and used to calculate joint angles, net joint moments, muscle and joint forces for the six activities analysed. The tibiofemoral model was validated against bi-planar fluoroscopy measurements for walking for all the six planes of motion. The effect of tibiofemoral geometry on musculoskeletal function was the difference between the geometry-based model and the model of reference.ResultsThe geometry-based tibiofemoral motion described the pattern and the variation during walking for all six motion components, except the pattern of anterior tibial translation. Tibiofemoral geometry had moderate effect on cohort-averages of musculoskeletal function (R² = 0.60–1), although its effect was high in specific instances of the model, outputs and activities analysed, reaching 2.94 BW for the ankle reaction force during stair descent. In conclusion, tibiofemoral geometry is a major determinant of tibiofemoral motion during walking.SignificanceGeometrical variations of the tibiofemoral joint are important for studying musculoskeletal function during normal activity in specific individuals but not for studying cohort averages of musculoskeletal function. This finding expands current knowledge of movement biomechanics.     

lncRNA RP11-86H7.1在川崎病诊断中的临床意义

目的：探讨lncRNA RP11-86H7.1在川崎病（KD）患者血清中的表达及其与临床病理特征及预后的关系。方法：筛选KD特异相关的循环lncRNA，分KD治疗前患儿组、KD治疗后患儿组、普通发热患儿组及健康儿童组，采用qPCR检测各组血清lncRNA RP11-86H7.1相对表达。分析血清lncRNA RP11-86H7.1相对表达与KD临床病理特征间关系；绘制ROC曲线，分析血清lncRNA RP11-86H7.1表达水平对KD的诊断效能。结果：KD急性患儿组血清lncRNA RP11-86H7.1相对表达量高于各对照组（P＜0.05）；年龄和性别比例与低表达组比较差异无统计学意义（P＞0.05）；qPCR发现lncRNA RP11-86H7.1在KD急性期患儿血清中表达水平明显高于KD恢复期、健康儿童及发热儿童组，差异均有统计学意义（P＜0.05）。结论：血清lncRNA RP11-86H7.1在KD患者中表达上调，其可作为KD早期诊断和评估预后的潜在的生物标志物。     

非酒精性脂肪性肝炎诊断研究进展

非酒精性脂肪性肝病是一种慢性非传染性疾病。近年来其患病率和发病率不断增高,发病年龄也出现低年龄化趋势,该疾病已取代慢性乙型肝炎成为第一大慢性肝脏疾病。重点综述非酒精性脂肪性肝病中的非酒精性脂肪性肝炎的诊断研究进展,介绍非酒精性脂肪性肝炎的临床病史、病理学诊断、非侵入方法诊断,为临床诊断提供参考。     

Does Dosage or Duration of Concurrent Oral Corticosteroid Influence Elevated Risk of Postoperative Complications After Total Joint Arthroplasty?

BackgroundThis report seeks to clarify whether the dosage and duration of preoperative concurrent corticosteroid use influence postoperative complications after primary total joint arthroplasty (TJA).MethodsThis retrospective single institutional study enrolled 1128 primary TJA cases, including 905 total hip arthroplasties and 223 total knee arthroplasties at a minimum 6 months of follow-up. Mean follow-up period was 51.9 ± 34.1 months (range 6-146). Of all joints, 120 joints (10.6%) were associated with chronic concurrent oral corticosteroid use. Multivariate analysis was performed to identify whether chronic concurrent oral corticosteroid use elevated the risk of postoperative complications including surgical site infection/periprosthetic joint infection, delayed wound healing, periprosthetic fracture, and implant loosening. For chronic concurrent oral corticosteroid user, we determined whether the dosage and duration of preoperative concurrent corticosteroid use influenced postoperative complications and have an effective threshold for postoperative complications using receiver operating characteristic curve analysis.ResultsThe multivariate analysis revealed that American Society of Anesthesiologist Physical Status 3 was an independent risk factor for postoperative complications, while concurrent oral corticosteroid use was not an independent risk factor. When we compared joints with (n = 13) and without (n = 107) postoperative complications in chronic concurrent oral corticosteroid user, there was no statistical difference in the dosage (P = .97) and duration (P = .69) between the 2 groups. Area under the curve values for the oral corticosteroid dosages and duration were 0.482 and 0.549, respectively.ConclusionThis study revealed that neither dosage nor duration of concurrent oral corticosteroid use was predictive of postoperative complications after TJA. American Society of Anesthesiologist Physical Status 3 is a major factor in postoperative complications after TJA.     

Disability,kinesiophobia, perceived stress,and pain are not associated with trunk muscle strength or aerobic capacity in chronic nonspecific low back pain

ObjectivesTo investigate to which extent disability, psychological and pain-related factors are associated with the outcomes of an isometric trunk muscle strength test and a cardiopulmonary exercise test in persons with chronic nonspecific low back pain (CNSLBP).DesignCross-sectional study.SettingREVAL Rehabilitation Research Center (Hasselt, Belgium).ParticipantsPersons with CNSLBP.Main outcome measuresQuestionnaires concerning disability, patient specific functioning, kinesiophobia, perceived stress, pain intensity, and central sensitization were recorded. Outcomes of an isometric trunk strength test (maximum back and abdominal torque) and cardiopulmonary exercise test (VO₂max) were assessed. Multivariate linear regression models determined factors explaining outcome variance.ResultsData of 101 persons (39 males, mean age: 44.2y (SD = 9.6)) was assessed. Neither disability, nor psychological, nor pain-related factors were associated with the assessments. Variance in back muscle strength (R² = 0.44, F = p < 0.01), abdominal muscle strength (R² = 0.68, F = p < 0.01), and aerobic capacity (R² = 0.76, F = p < 0.01) could only be explained through the included demographics covariates (age, gender, weight).ConclusionThis study highlighted the lack of biopsychosocial factors in explaining variance in outcomes of abdominal and back strength, and aerobic capacity in persons with CNSLBP with characteristics as depicted in the current sample. This information supports the valid interpretation of the outcomes of these assessments.     

Validity of various portable devices to measure sit-to-stand velocity and power in older adults

BackgroundMovement velocity and power in a single STS are related to functional performance in older adults. Identifying accessible tools that provide valid measures of STS velocity/power would allow practitioners to evaluate physical function in clinical settings where time, space and finances are limited.Research questionDoes a linear position transducer (LPT), iPhone application (App), and inertial measurement unit (IMU) obtain valid measurements of velocity and power during a single STS compared with 3D motion capture?MethodsTwenty-seven community-dwelling older adults aged ≥60 years completed a single STS test with mean velocity and power simultaneously measured with 3D motion capture, an LPT, IMU and App. Acceptable validity was established if the Pearson correlation coefficient (r) was very high (≥0.7) and bias as a standardised effect size (ES) was small (<0.6). The relationship between STS velocity/power and 30s chair STS performance was also evaluated.ResultsMeasures of STS velocity obtained by the LPT (r = 0.94, ES = −0.21) and App (r = 0.89, ES = −0.19) were very highly valid when compared to 3D motion capture, and were very strongly related to 30s STS performance (r ≥0.74). The LPT (r = 0.87, ES = 0.13) and App (r = 0.74, ES = −0.12) also showed very high correlations and negligible bias for measuring STS power. Data collected by the IMU failed to meet our pre-determined threshold of acceptable validity for STS velocity (r = 0.72, ES = 1.00) or power (r = 0.61, ES = 0.34).SignificanceThe LPT and iPhone App, but not the IMU, are valid tools for measuring STS velocity and power in community-dwelling older adults. Clinicians can use STS velocity obtained by either the LPT or App as a simple and valid proxy for functional status, which could help identify patients at high-risk of incident disability.     

超声造影联合血清CEA、CA72-4对卵巢良恶性肿瘤鉴别诊断的价值

目的:探讨超声造影联合血清癌胚抗原（CEA）、糖类抗原72-4（CA72-4）对卵巢良恶性肿瘤鉴别诊断的价值。方法:选取2017年1月至2018年6月本院肿瘤科收治的128例卵巢肿瘤患者进行研究，进行超声造影和血清CEA、CA72-4水平检测，观察超声造影、CEA、CA72-4及联合检测对卵巢良恶性肿瘤鉴别诊断的价值。结果:在良性肿瘤组中超声造影符合率为72.92%，恶性肿瘤组中超声造影符合率为75.00%，两组比较差异无统计学意义（P>0.05）；恶性肿瘤组患者血清CEA、CA72-4水平高于良性肿瘤组，两组比较差异有统计学意义（P<0.05）；恶性肿瘤组超声造影、CA72-4检测阳性率均高于良性肿瘤组（P<0.05），两组血清CEA检测阳性率比较差异无统计学意义（P>0.05），三者联合检测阳性率高于单项指标检测（P<0.05）；通过ROC曲线分析显示，CEA的AUC为0.644，诊断灵敏度为31.25%，特异性为82.29%，CA72-4的AUC为0.702，诊断灵敏度为40.63%，特异性为79.17%，二者联合检测的AUC为0.785，诊断敏感性为56.25%，特异性为73.96%；三项指标单独检测，超声造影检测的灵敏度、阳性预测率、阴性预测率、诊断准确度及误诊率最高，CEA检测的特异性、漏诊率最高，三者联合检测的灵敏度、特异性、阳性预测率、阴性预测率、诊断准确度最高，漏诊率、误诊率最低。结论:超声造影联合血清CEA、CA72-4检测较单独检测诊断效能高，对卵巢良恶性肿瘤鉴别诊断有较高参考价值。