Contemporary bone loss options: Rebuild,reinforce, and augment

Bone loss is commonly encountered during revision total knee arthroplasty (TKA). Small defects can be adequately managed with cement filling (with or without screws), modular prosthetic augments, and morselized allograft. For larger defects, cancellous impaction grafting and structural allografts have traditionally been utilized. More recently, highly porous tantalum cones and titanium sleeves have been designed to achieve axial and rotational stability in the metaphysis and subsequent biologic fixation. Sleeves are linked to one type of prosthesis, whereas cones are unlinked and can be used with any implant design. Multiple studies have demonstrated excellent survivorship and radiographic osseointegration at mid-term follow-up. This article provides a review of contemporary methods of bone loss management with a focus on highly porous metals and an emphasis on the authors’ preferred method for managing the severe bone loss in revision TKA.     

Polyethylene in knee arthroplasty: A review

Polyethylene (PE) has been used extensively in knee arthroplasty since the mid 20th century. Progress in material manufacturing and processing has led to newer polyethylenes over last few decades with different material properties. It has been established that PE wear in knee arthroplasty causes particle induced osteolysis which is the main reason for late failure and requires revision surgery. Although there are various causes of wear, the properties of PE have long been a matter of investigation as a contributory factor. The advent of newer highly cross linked PE has been shown to improve wear rates in hip arthroplasty but the benefits have not been shown to be of the same degree in knee arthroplasty. The laboratory and clinical studies so far are limited and slightly conflicting in their conclusions. The risks of using highly cross linked PE in knee arthroplasty include tibial post fracture, disruption of locking mechanism, liner fracture which can lead to increased wear and osteolysis. The current evidence suggests that highly cross linked polyethylenes should be used with caution and only considered in younger active patients. The results of a recently completed randomized trial to compare the conventional with high molecular weight PE in knee arthroplasty are awaited.     

Adsorption of Human Recombinant Erythropoietin on Dialysis Membranes In Vitro

Abstract: The adsorptive characteristics of 5 dialysis membranes for recombinant human erythropoietin (EPO) were studied in vitro in a closed circuit system. For 120 min, EPO added with bovine serum was significantly adsorbed by polymethylmetacrylate (PMMA) and polyacry–lonitrile (PAN) membranes but not by Cuprophan, ethylene vinyl alcohol (EVAL), or polysulfone (PS) membranes. In addition the EPO adsorptive rate, as well as that of β₂–microglobulin (β₂–MG), was greater with a PMMA membrane than with a PAN membrane. EPO was not detected in the ultrafiltrate at 15 min with 5 membranes. These results indicate that EPO was eliminated by membrane adsorption only with some dialysis membranes.     

起搏器高度依赖性患者起搏器置换方法与疗效探讨

目的 :探讨起搏器高度依赖性患者起搏器置换方法与疗效。　方法 :对 8例起搏器高度依赖性患者 ,在起搏器与电极的接口松解前 ,应用在体起搏器间断接触法 ,使自身逸搏心律得已恢复 ,然后再行松解接口以及必要的起搏参数测试。　结果 :起搏器离体次数为 3～ 7(5± 2 )次 ,最长逸搏间期为 3.38～ 6 .2 0 (4.5 1± 1.11)s,自身逸搏心率为 30～ 4 3(38± 5 )次 /min ,均顺利完成起搏器置换。　结论 :在体起搏器间断接触法切实可行 ,能够明显提高起搏器高度依赖性患者起搏器置换的安全性     

腹腔镜高选择性迷走神经切断术联合Nissen胃底折叠术:效果如何?——腹腔镜Nissen迷走神经切断术治疗胃食管返流

背景：Nissen胃底折叠术（Nissen fundoplication，NF）已不是治疗胃食管返流性疾病（gastroesophageal reflux disease，GERD）的唯一、有效的方法。对于能降低胃酸的手术方式来讲，如高选择性迷走神经切断术（highly selective vagotomy，HSV），也不仅仅是一种辅助治疗方法。对高选择性迷走神经切断术联合Nissen胃底折叠术（Nissen fundoplication with highly selective vagotomy，NFHSV）治疗GERD的作用目前尚无完整的评价。方法：2003年6月～2005年6月8例女性病人接受NFHSV，8例均有6个月GERD病史，经药物治疗症状无缓解，有餐前痛、消化性溃疡或严重的胃炎。平均随访时间12个月，术前、术后进行烧心严重程度评分测定（heart burn severity score，HSS）。结果：平均手术时间110min，无手术并发症。1例术后须用质子泵抑制剂，术后经戒烟5个月后停药。8例术后症状和烧心严重程度评分测定有明显改善。结论：NFHSV是有效的联合手术方式，尚需要进一步的研究证实这一联合术式的完全有效性和安全性。     

英文医学科技论文写作中词的选择与搭配

作者结合实际工作经验简要论述了英文医学科技论文写作中词的选择与搭配的问题,并就如何提高英文写作水平提出了几点建议。     

高敏受者肾移植术前行血浆置换的临床探讨

目的 :探讨高敏受者肾移植术前行血浆置换 (PE)的效果。方法 :12例高敏受者在肾移植术前进行PE治疗 ,37例高敏受者未行PE治疗 ,观察两组肾移植病人排斥反应发生率的差异。结果 :PE组置换前PRA值71.0 %± 19.1% ,置换后 34.3%± 17.9% ,两者有显著性差异 (P <0 .0 1)。术后发生超排 2例 ,急性排斥 2例 ;未行PE组发生超排 2例 ,急性排斥 8例 ,两组间超排和急性排斥的发生率均无显著性差异。结论 :PE对预防超排和降低急性排斥的发生率均无明显作用。PE治疗的主要适应症为PRA大于 80 %的受者 ,能快速降低PRA值 ,有助于HLA抗体特异性分析和HLA配型。     

在线考试系统设计

作为评价网络学习效果的一个环节，网上考试越来越被人们接受和认同。文章介绍了在线考试系统的功能和结构，并对该考试系统中所用到的关键技术进行了详细的介绍，包括系统的通用性和安全性、题库的建设和管理、随机组卷算法等。     

英语医学科技论文中冠词的使用

从语法角度归纳了医学科技论文中冠词的使用规律,以期减少英语医学科技论文中冠词的衍缺现象。