Effect of inclination and anteversion angles on kinematics and contact mechanics of dual mobility hip implants

BackgroundSteep inclination and excessive anteversion angles of acetabular cups could result in adverse edge-loading. This, in turn, increases contact pressure and impingement risk for traditional artificial hip joints. However, the influence of high inclination and anteversion angles on both the kinematics and contact mechanics of dual mobility hip implants has rarely been examined.MethodsThis study focuses on investigating both the kinematics and contact mechanics of a dual mobility hip implant under different inclination and anteversion angles using a dynamic explicit finite element method developed in a previous study.FindingsThe results showed that an inclination angle of both the back shell and liner ranging from 30° to 70° had little influence on the maximum contact pressure and the accumulated sliding distance of inner and outer surfaces of the liner under normal walking gait. The same results were obtained for an anteversion angle of the liner varying between −20° and +20°. However, when the anteversion angle of the liner was beyond this range, the contact between the femoral neck and the inner rim of the liner occurred. Consequently, this caused a relative rotation at the outer articulation.InterpretationsThis suggests that both inclination and modest anteversion angles have little influence on the kinematics and contact mechanics of dual mobility hip implants. However, too excessive anteversion angle could result in a rotation for this kind of hip implant at both articulations.     

Association of weight-adjusted-waist index with all-cause and cardiovascular mortality in China: A prospective cohort study

Background and aimsAs a new simple anthropometric index, the weight-adjusted-waist index (WWI) appears to be superior to body mass index (BMI) and waist circumference (WC) in assessing both muscle and fat mass. We aimed to explore the association of WWI with all-cause and cardiovascular mortality in southern China.Methods and resultsA total of 12,447 participants (mean age, 59.0 ± 13.3 years; 40.6% men) in Jiangxi Province from the China Hypertension Survey study were included. WWI was defined as WC divided by the square root of weight. The outcome was all-cause and cardiovascular mortality. During a median follow-up of 5.6 years, 838 all-cause deaths occurred, with 390 cardiovascular deaths. Overall, there was a nonlinear positive relationship of WWI with all-cause and cardiovascular mortality. Accordingly, compared with participants in quartiles 1–3 (<11.2 cm/√kg), a significant higher risk of all-cause mortality (HR: 1.36, 95% CI: 1.17, 1.58) and cardiovascular mortality (HR: 1.43, 95% CI: 1.15, 1.77) were found in quartile 4 (≥11.2 cm/√kg). Further adjustment for BMI and WC did not substantially alter the results. No significant interactions were found in any of the subgroups (sex, age, area, physical activity, current smoking, current alcohol drinking, hypertension, and stroke).ConclusionHigher WWI levels (≥11.2 cm/√kg) were associated with increased the risk of all-cause and cardiovascular mortality in southern China. These findings, if confirmed by further studies, suggested that WWI may serve as a simple and effective anthropometric index in clinical practice.     

Laparoscopic versus open pancreatoduodenectomy: an individual participant data meta-analysis of randomized controlled trials

BackgroundRandomized trials have compared laparoscopic pancreatoduodenectomy (LPD) to open pancreatoduodenectomy (OPD) with conflicting results. An IPDMA may give more insight into the differences between LPD and OPD, and could identify high-risk subgroups.MethodsA systematic literature search was performed in the Pubmed, Embase, and the Cochrane library databases (October 2019). Out of 1410 studies, three randomized trials were identified. Primary outcome was major complications (Clavien-Dindo grade ≥ III). Subgroup analyses were performed for high-risk subgroups including patients with BMI of ≥25 kg/m2, pancreatic duct <3 mm, age ≥70 years, and malignancy.ResultsData from 224 patients were collected. After LPD, major complications occurred in 33/114 (29%) patients compared to 34/110 (31%) patients after OPD (adjusted odds ratio (OR) 0.62; 95% confidence interval (CI) 0.3–1.4, P = 0.257). No differences were seen for major complications and 90-day mortality LPD 8 (7%) vs OPD 4 (4%) (adjusted OR 0.2; 95% CI 0.02–1.3, P = 0.080). With LPD, operative time was longer (420 vs 318 min, p < 0.001) and hospital stay was shorter (mean difference ?6.97 days). Outcomes remained stable in the high-risk subgroups.ConclusionLPD did not reduce the rate of major postoperative complications as compared to OPD. LPD increased operative time and shortened hospital stay with 7 days.     

遥控骨水泥推注装置在经皮球囊扩张椎体后凸成形术中的应用

目的探讨遥控骨水泥推注装置在经皮球囊扩张椎体后凸成形术（PKP）中的作用与临床效果。方法回顾分析自2010—07—2012—03收治的骨质疏松性椎体压缩骨折75例．在PKP中应用遥控骨水泥推注装置可匀速推注骨水泥,防止骨水泥渗漏,同时明显减少手术医生在X线下的暴露时间。结果75例术后经6～12个月随防（平均10个月）,所有患者术后腰背痛视觉模拟评分（VAS）均较术前明显改善（P〈O．01）。未使用遥控骨水泥推注装置时手术医生在X线下暴露30～50次,接受约1000mSvX线射线,使用遥控骨水泥推注装置后术者在X线下暴露lO～15次,接受约300mSvX线射线,明显缩短术者在X线下的暴露时间。手术过程未发生骨水泥渗漏、脊髓损伤。结论PKP治疗骨质疏松性椎体压缩骨折具有创伤小、恢复快的优点,配合使用遥控骨水泥推注装置可使骨水泥匀速缓慢推注,有效防止骨水泥渗漏．明显减少手术医生在X线下的暴露时间．有较高的临床应用价值。     

维生素D缺乏性佝偻病患儿破骨细胞活性的研究

目的 探讨维生素D缺乏性佝偻病患儿破骨细胞功能状态,了解其与性别和年龄的关系。方法 选取符合维生素D缺乏性佝偻病诊断标准患儿有68例列入佝偻病组,健康婴幼儿66例列入对照组,检测血清25-(OH)D、抗酒石酸酸性磷酸酶5b(tartrate-resistant acid phosphatase isoform 5b,TRACP5b)、I型胶原交联羧基端肽(carboxyterminal cross-linking telopeptide,CTX),对所得结果采用SPSS 20.0软件进行数据分析处理。结果 维生素D缺乏性佝偻病组较对照组血清25-(OH)D、TRACP5b、CTX水平均低,有显著统计学差异,两组血清25-(OH)D水平婴儿较幼儿均低,两组血清TRACP5b、CTX水平婴儿较幼儿均高,差异有显著统计学意义。两组血清25-(OH)D、TRACP5b、CTX水平男女之间差异均无统计学意义。维生素D缺乏性佝偻病组血清TRACP5b、CTX与25-(OH)D水平呈负相关关系,血清TRACP5b与CTX水平呈正相关关系。结论 维生素D缺乏性佝偻病患儿破骨细胞活性明显活跃。婴儿破骨细胞活性较幼儿明显活跃,同年龄组不同性别之间破骨细胞活性无明显差异。TRACP5b和CTX是评价骨吸收的良好指标。破骨细胞分子标志物可作为维生素D缺乏性佝偻病的评价指标。     

青少年特发性脊柱侧凸腰主弯患者腰椎-骨盆的生物力学分析

文题释义： 青少年特发性脊柱侧凸：为脊柱三维平面上的畸形,会导致青少年脊柱结构发生明显的改变,结构的改变会导致椎骨及椎间盘应力发生相应的改变,且腰椎、骨盆在人体中的力学作用极为重要,青少年时期为人体脊柱生长发育的高峰期,脊柱结构及应力的改变在该时期的进展尤为明显。 背景：青少年特发性脊柱侧凸导致脊柱结构和应力发生改变,腰椎在脊柱中承受的载荷最大,骨盆也起着传导重力的作用,故青少年特发性脊柱侧凸腰主弯患者腰椎骨盆的生物力学分析尤为重要。 目的：建立青少年特发性脊柱侧凸腰主弯腰椎-骨盆三维数字化模型并进行有限元分析。 方法：根据1例13岁女性特发性脊柱侧凸腰主弯患者的腰椎-骨盆CT薄层数据,应用Mimics 15.0软件重建三维数字化模型,以Pro/E 5.0软件建立初步几何模型并导入Hypermesh 13.0进行网格划分,最终通过Abaqus 6.14软件对该模型进行有限元分析。分析有限元模型在6种载荷条件下的位移、应力变化及该模型各椎体及椎间盘的应力变化。患者家属对试验方案知情同意,且得到医院伦理委员会批准。 结果与结论：①建立了青少年特发性脊柱侧凸腰主弯患者的腰椎-骨盆的三维有限元模型;②模型在6种载荷条件下,L₁椎体上部在左、右侧屈时位移变化最大,骶骨下端在前屈时位移最大;③椎间盘右缘在右侧屈运动条件下所受应力最大;前屈位时,腰椎间盘所受应力为前缘最大,左缘所受应力最小;后伸位时后缘所受应力最大,而右缘所受应力最小;侧屈位及旋转位时,右缘所受应力最大,前缘所受应力最小;④L₅在6种运动中应力均最大,其中应力集中于上下关节突及椎弓根,尤其以右侧最为集中;⑤提示青少年特发性脊柱侧凸不同载荷会引起椎体或椎间盘不同位置受力及位移有相应变化,研究结果对脊柱侧凸的治疗和预防具有重要意义。 ORCID: 0000-0001-5810-6674(张聪) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

12-15岁青少年腰椎椎弓根螺钉置入最佳选择的形态学分析

文题释义：椎弓根螺钉：椎弓根置钉是目前脊柱内固定的常用方法,椎弓根形态学参数决定置钉成功率,对于发育中的青少年脊柱疾患,椎弓根螺钉同样发挥重大作用。  三维重建测量：利用三维重建软件对人体组织结构进行3D重建,可清晰完整、更加直观地表现人体组织特点,得到的测量数据更准确,可以更好的服务于临床。 背景：关于成人胸腰段椎弓根形态的研究已经发表了大量文献,但对青少年椎弓根形态的了解较少,尤其是在亚洲人群中。青少年脊柱疾患日益增多且精确的形态学研究较少。 目的：研究内蒙古地区12-15岁青少年腰椎的解剖结构,为椎弓根螺钉置入提供详细资料,确定安全合适的螺钉大小,并为螺钉尺寸设计提供数据参考。 方法：收集内蒙古地区65例12-15岁青少年正常胸腰CT资料,根据年龄分2组,12-13岁31例,14-15岁34例。将连续扫描的胸腰椎断层影像原始数据以DICOM格式导入Mimics 21.0分析与测量,指标包括椎弓根宽、椎弓根高、椎管横径、椎管纵径、椎弓根长、椎弓根外偏角、椎弓根最大外偏角、椎弓根头倾角及椎弓根面积。 结果与结论：①2组L₁-L₄ 椎弓根宽小于椎弓根高,L₅椎弓根宽与椎弓根高相似,椎弓根宽决定螺钉直径,男性大于女性;②12-13岁,螺钉长L₁-L₅均为40-45 mm;14-15岁,螺钉长L₁-L₄为40-45 mm,L₅为45-50 mm;③2组规律相同,椎管横径均大于椎管纵径,椎管横径、椎管纵径之间差异有显著性意义(P < 0.05),男女之间差异无显著性意义;④椎弓根外偏角：12-13岁L₁-L₂变化不大,L₂-L₅逐渐增大;14-15岁L₁-L₅逐渐增大,2组均男性大于女性;⑤椎弓根最大外偏角：2组规律相同,L₁-L₅逐渐增大,随年龄增长而减小,左右侧与性别间差异均无显著性意义,不同年龄间差异有显著性意义(P < 0.05);⑥椎弓根头倾角： 12-13岁为3°-8°,14-15岁为0°-5°;随年龄增长而减小,L₃-L₄男女之间差异有显著性意义(P < 0.05);⑦椎弓根面积：2组规律相同,L₁-L₅逐渐增大,L₄-L₅有一个明显的变化趋势;⑧根据椎弓根参数分析可得出正常青少年腰椎各节段置入螺钉的适合尺寸,帮助临床医师掌握腰椎解剖结构,提高置钉准确性。 ORCID: 0000-0001-5877-8358(许阳阳) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

前交叉韧带重建手术并发症诊断及处理的研究进展

随着医学诊疗水平的提高,因为前交叉韧带断裂而接受重建手术的患者数量在逐年增加,如何避免前交叉韧带重建术并发症的发生是运动医学领域目前关注的热点问题。目前的研究结果显示,手术中移植物的获取、骨道钻取、移植物的固定等操作以及术后的恢复过程均可能出现并发症,而术后我们更多关注关节活动度、物理治疗的进程以及恢复运动能力的情况等。因此,正确认识前交叉韧带重建手术的并发症,可以最大程度地降低前交叉韧带重建手术不良事件的发生,获得最佳的手术效果。     

大鼠视神经损伤视网膜内P38丝裂原活化蛋白激酶活性的表达

目的:动态观察视神经损伤后视网膜中P38丝裂原活化蛋白激酶(MAPK)活性的表达变化和早期细胞凋亡情况。方法:制作大鼠视神经钳夹伤模型后设立对照组、假手术组和视神经夹伤组,应用免疫组化方法及流式细胞仪分别检测视神经损伤后1,6,12,24h;15,30d共6个时间点3组大鼠视网膜中磷酸化(活化)P38MAPK的表达和早期细胞凋亡率,同时对视网膜形态学改变进行观察。结果:视神经损伤诱导视网膜神经节细胞(RGC)严重丧失,损伤后1~15dRGC快速减少,15d后缓慢减少。在正常对照组、假手术组磷酸化P38MAPK表达阴性,视神经损伤后P38MAPK活性的表达于6h检测到表达,逐渐增加至24h阳性表达达高峰,15d表达下降,30d消失,具有统计学意义(P<0.01)。视神经损伤后早期细胞凋亡率逐渐上升,24h达最高8.9%,随后下降。结论:视神经不完全损伤刺激了大鼠视网膜中P38MAPK的活性表达,与早期细胞凋亡率变化相似。P38MAPK通路与视神经损伤诱导的大鼠视网膜RGC凋亡密切相关。