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.     

多孔陶瓷板固定床生物反应器设计及模拟

设计了一种结构新型的多孔陶瓷固定床生物反应器，与传统的固定床相比，该反应器具有氧传递性能好，能够均匀接种等优点，通过模拟，考察了反应器内的流体流动和气液传递性质，计算证明反应器的供氧能力能够满足链霉菌发酵过程对氧的需求。     

复方山绿茶缓释袋泡剂的研究

用网状多孔性纤维包念材料制备的复方山绿茶缓袋泡剂，具有速释和缓释作用，在１－８ｈ内按埝级方式释药。Ｔ０．５为１．３ｈ，Ｔｄ为３．２ｈ，１－８ｈ的平均释药速率７２．３５ｍｇ／ｈ。与传统的半生药型袋泡剂比较，具有栽药量高，使用方便，性质稳定，疗效确切的优点。     

齿槽裂植骨整复畸形鼻

目的:探讨齿槽裂及鼻底进行天然多孔骨(Bio-OssCollagen材料)移植整复畸形鼻的可行性和临床疗效。方法:对12例齿槽裂及鼻底行Bio-OssCollagen材料植入整复手术。结果:随访9￣12月外形恢复良好,唇部和鼻底丰满,鼻翼提升,X线片示齿槽裂及鼻底植入Bio-OssCollagen材料基本被自体骨取代。结论:用Bio-OssCollagen材料代替自体骨植入齿槽裂及鼻底整复畸形鼻,均效果良好。     

天然生物材料构建组织工程支架的研究进展

细胞培养支架材料是组织工程的重要研究内容之一.本文综述近年来几种典型天然生物材料构建组织工程支架的研究进展,并详细介绍了适用于天然生物材料制备组织工程支架的致孔方法.     

Fluid Flow through Filtering Appendages of Insects

Many organisms use structures composed of arrays of cylindersto capture particulate food or molecules form the water or airaround them. The performance of such filters depends on thevelocity of fluid movement through them; hence, mathematicalmodels of flow through fibrous structures can provide insightsabout the functional morphology of biological filters. In thispaper, the authors address the case of feather-like biologicalfilters of finite width and assess several possible models forfluid motion through them by comparing model predictions withobservational data. Two examples of insect appendages are considered:the cephalic fans of black fly aquatic larvae that capture particulatefood and the antennae of adult male moths that catch sex-attractantmolecules released by female moths. The results suggest thatflow through such structures can be much slower than ambientcurrents, that the finest hairs in the structure are the morphologicalfeatures with the greatest effect on leakiness, and that thevelocity of movement (or of ambient flow), as well as the morphologyof such filters, can be critical in determining their performance.     

紫外线对两种聚四氟乙烯电荷储存稳定性的影响

利用在室温下的栅控恒压电晕充电后经不同强度紫外线辐照的表面电位测量,研究了紫外线对聚四氟乙烯(polytetrafluoroethylene,PTFE)多孔膜、聚四氟乙烯非多孔膜驻极体电荷储存稳定性的影响,探讨了两种聚四氟乙烯驻极体医疗产品使用紫外消毒方法的可行性.结果:(1)在常温条件下,紫外线辐照对两种聚四氟乙烯驻极体的电荷储存稳定性的影响不大;(2)聚四氟乙烯多孔膜驻极体的电荷储存能力随环境湿度的提高而略有下降;(3)聚四氟乙烯医用驻极体产品可采用紫外消毒法消毒.     

In vitro corrosion study of porous metal fibre coatings for bone ingrowth

As a first part of a biocompatibility testing programme, in vitro corrosion tests were carried out on porous stainless steel AISI 316L and titanium compacts made of 100 microns thick fibres. The present porous metal structures are used as coatings on permanent orthopaedic implants; with osseous tissue invading the pores, the implant becomes securely anchored to the surrounding bone. The results show that no inadvertent reactions occur with porous titanium. It can probably be used with no greater risk of localized electrochemical attack than the parent bulk material.     

纳米锶磷灰石纤维多孔钛复合材料的生物安全性研究

目的评价新型生物材料纳米锶磷灰石纤维多孔钛复合材料的生物安全性。方法对纳米锶磷灰石纤维多孔钛复合材料的生物安全性进行体外评价,分别进行以下实验:急性全身毒性实验;血液相容性评价(溶血试验);热原试验;皮内刺激实验。结果纳米锶磷灰石纤维多孔钛复合材料对生物体无毒性、无致热原性、无刺激性,不引起溶血反应。结论纳米锶磷灰石纤维多孔钛复合材料具有良好的生物安全性,有望作为新型骨植入生物材料应用于临床。     

Temporary strecker stent for management of acute dissection in popliteal and crural arteries

Stent placement is a widely used bail-out treatment for dissection of peripheral arteries. Below the level of the superficial femoral artery permanent stenting is complicated by a high incidence of subacute thrombosis and restenosis. We present two cases of arterial occlusion due to acute iatrogenic dissection of the popliteal and distal fibular arteries. Successful treatment was achieved with a new bail-out procedure. Strecker stents were implanted to seal off the dissection flap. Stents were retrieved easily after 24 hr using a myocardial biopsy forceps. After stent retrieval the temporarily stented segments were patent and showed a larger lumen compared with segments treated by balloon dilatation alone. Temporary stenting is a simple and safe procedure and offers the advantage of tacking up dissection membranes and preventing recoil. Persistent presence of a metallic implant as a source of continued injury and stimulus for intimal proliferation is avoided.