ARTHROSCOPIC REMOVAL OF ACRYLIC CEMENT FROM UNREDUCED HIP PROSTHESIS

A case is reported in which entrapped polymethylmethacrylate following traumatic dislocation of a total hip replacement prevented complete reduction. A combined arthroscopic and fluoroscopic technique was used to remove the entrapped polymethylmethacrylate. Manipulation of the total hip prosthesis was done after removal of polymethylmethacrylate to minimize mechanical abrasion. This technique allows direct visual assessment of the articulating surfaces as well as the mechanical stability of the prosthesis. The morbidity related to the procedure is minimal and a short rehabilitation period is the major advantage.     

椎体成形术中注射聚甲基丙烯酸酯和锶羟磷灰石的比较

【目的】比较采用两种填充物聚甲基丙烯酸酯(polymethylmethacrylate,PMMA)和锶羟磷灰石(strontium-contained hydroxyapatitecement,SrHAC)行经皮椎体成形术(percutaneous vertebroplasty,PVP)的临床应用结果。【方法】选择单椎体骨折患者49例,其中男19例,女30例,随机分成2组,PMMA组26例,SrHAC组23例,对填充物注入量、术中患者血压、心率、血氧饱和度及术后填充物渗漏、疼痛改善、临床效果、影像学征象等指标进行评价分析。【结果】PMMA组平均注入量为(2.82±0.39)mL,SrHAC组平均注入量为(3.75±0.52)mL,两组比较差异有统计学意义(P<0.01)。SrHAC组注入填充物时血压、心率、血氧饱和度稳定。PMMA组视觉模拟量表(visual analogue pain scale,VAS)评分由术前平均的(7.0±0.8)分下降至末次随访时的(1.7±0.4)分;SrHAC组术前平均为(7.2±1.0)分,末次随访降为(1.8±0.5)分。两组组内比较手术前后差异均有统计学意义(P<0.01)。术后临床效果SC法评价,优良率:PMMA组为84.6%、SrHAC组为82.6%,两组比较差异无统计学意义(P>0.05)。末次随访时椎体均无继续塌陷征象。随访达1年以上的SrHAC组见填充物开始降解。【结论】应用两种填充剂行PVP均为治疗骨质疏松性椎体压缩性骨折的有效办法。     

Decontamination Strategies for Creutzfeldt-Jakob Disease Agent

Abstract

A polymethylmethacrylate technique that permits processing of enucleated eye globes with intact bone and tissue is described. The process includes decalcification in 5% formic acid, 22 hr dehydration in ascending alcohols, and 4hr clearing with xylenes to facilitate sectioning.

The combination of established techniques, decalcification agent, and plastic embedment decreases artifact and damage to ocular tissue and avoids lengthy celloidin procedures. (The J Histotechnol 15:311, 1992)     

Effects of Vancomycin,Cefazolin and Test Conditions on the Wear Behavior of Bone Cement

Antibiotic cement has been recommended in the treatment of prosthetic infections. The purpose of this study was to investigate the mechanical behavioral changes in cement loaded with two antibiotics, vancomycin and cefazolin, in dry and liquid medium. Six groups and four study conditions were established according to the doses of antibiotic used and the ageing (immersion in phosphate buffered saline) of the samples. Properties evaluated were friction coefficient and wear. Samples in dry medium showed higher wears than in liquid. Antibiotic selection did not influence wear properties tested in dry conditions, however, in liquid medium, there were higher frictional coefficients and wear for cefazolin loaded cement after one week and for vancomycin and cefazolin after one month. The results suggest that antibiotic cements behave differently in liquid and that the molecular characteristics of antibiotics are essential for determining this influence.     

不同偶联剂用量对纳米SiO2增强聚甲基丙烯酸甲酯力学性能的影响

目的：研究硅烷偶联剂和钛酸酯偶联剂用量对纳米SiO2增强聚甲基丙烯酸甲酯（PMMA）力学性能的影响。方法分别使用质量分数为1%、2%、3%、4%、5%的硅烷偶联剂和钛酸酯偶联剂对纳米SiO2进行表面改性,将处理后的纳米SiO2按3%添加量与PMMA混合后制作标准模件,未经处理的为对照组,进行三点弯曲实验、硬度及摩擦磨耗测试。结果硅烷偶联剂和钛酸酯偶联剂的最佳用量为2%和3%。结论在一定质量分数范围内2种偶联剂改性的纳米SiO2均能提高树脂基托的机械强度,针对本实验所用的偶联剂及方法,硅烷偶联剂的最佳用量为2%;钛酸酯偶联剂的最佳用量为3%。     

Implantation of a Keratoprosthesis of Novel Design in Rabbits

Purpose To evaluate a keratoprosthesis, implanted by penetrating keratoplasty, in rabbits.Methods We implanted our keratoprosthesis (optics and flange portions of polymethylmethacrylate and a polyurethane skirt with micropores) into 14 eyes of 14 rabbits. In four eyes, we evaluated histologically the junction between the keratoprosthesis and host cornea. Long-term keratoprosthesis survival was evaluated in ten eyes by slit-lamp biomicroscopy.Results The histological study showed good approximation of the keratoprosthesis to the host cornea in the junction area, with overlying superficial corneal stroma on the skirt, keratocyte and collagen fiber ingrowth into the micropores, and partial migration of epithelial cells onto the skirt. However, in the long-term survival study, eight out of ten eyes developed acute suture-related inflammation, considered to be from bacterial infection, requiring enucleation 30 ± 18 weeks after implantation. The remaining two eyes have survived for 70 and 76 weeks.Conclusions Our keratoprosthesis was well tolerated in the short term. However, further modifications are necessary to avoid corneal infection. Jpn J Ophthalmol 2004;48:448–453 © Japanese Ophthalmological Society 2004     

光动力抗微生物化学疗法修复骨髓炎模型兔的实验

背景:光动力抗微生物化学疗法具有广谱抗菌、起效快和无耐药的特点,目前已被广泛应用于浅表局限性感染的治疗。目的:了解光动力抗微生物化学疗法治疗骨髓炎的效果。方法:取新西兰大白兔(中国人民解放军军事医学科学院实验动物中心提供)36只,建立左侧胫骨骨髓炎模型,造模28 d后随机分3组处理:空白组胫骨开窗清创后不做任何处理;对照组胫骨开窗清创后在感染胫骨骨髓腔内填入万古霉素聚甲基丙烯酸甲酯骨水泥;实验组胫骨开窗清创后对感染胫骨骨髓腔进行光动力抗微生物化学治疗。术后4,8,12周,分别进行大体观察、影像学检查及细菌培养。实验已通过武警后勤学院附属医院伦理委员会批准[(2015)-0002]。结果与结论:①大体皮肤外观:空白组可见脓性分泌物,实验组与对照组脓性分泌物消失,皮肤愈合良好;②X射线检查:随着时间的延长,空白组骨髓炎逐渐加重,实验组及对照组治疗后骨质破坏逐渐减少,骨质缺损逐渐愈合,实验组与对照组术后不同时间点的表现无差异;③细菌培养:随着时间的延长,空白组细菌阳性率无明显变化,实验组及对照细菌组阳性率逐渐下降,且实验组与对照组术后不同时间点的细菌阳性率比较差异无显著性意义(P>0.05);④结果表明:光动力抗微生物化学疗法作为一种新型的治疗骨髓炎方法,可有效控制感染,为骨髓炎临床治疗积累了实验依据。     

犬急性骨水泥肺栓塞的实验研究

目的通过股静脉注入骨水泥建立犬急性肺栓塞模型,探讨一定剂量范围内不同量骨水泥肺栓塞引起的生理病理变化间的差异。方法 18只成年家犬随机分成A、B、C 3组,每组6只,麻醉后行胸部CT平扫,穿刺右股静脉、左股动脉并置入血管鞘,经静脉鞘注入聚甲基丙烯酸甲酯(PMMA)A组0.5 ml,B组1 ml,C组2 ml。于注入PMMA前和注入后即刻、30 min及1 h分别检测血气分析、平均肺动脉压;于注入PMMA前、后5 min行肺动脉造影。术后1h行胸部CT平扫+增强。术后2 h将犬处死,开胸解剖观察大体形态后,沿肺动脉分支方向随机取肺组织3块进行病理学检查。结果 18只实验犬经股静脉注入PMMA操作均成功,经CT及病理证实均成功建立急性骨水泥肺栓塞模型。各组实验犬动脉血氧分压、二氧化碳分压在骨水泥注入前后差异均无统计学意义(P>0.05)。仅C组骨水泥注入后即刻平均肺动脉压为(24.12±1.74)mmHg,注入后30 min为(23.84±1.25)mmHg,注入后1 h为(24.17±1.63)mmHg,均较注射前的(16.47±0.55)mmHg差异有统计学意义(P<0.05)。A组、B组平均肺动脉压在骨水泥注入前后差异均无统计学意义(P>0.05)。各组实验犬术后胸部CT平扫均可见两肺高密度影,下肺多见,C组尤为明显。部分实验犬平扫见条索状阴影及肺不张征象。C组部分实验犬胸部增强CT可见肺动脉小分支内部分充盈缺损。肺动脉造影仅C组部分实验犬出现肺内部分细小血管减少,血管纹理稀疏,未见肺动脉主干及分支的充盈缺损。病理学检查均发现肺动脉分支存在骨水泥栓子,未见继发血栓形成。结论≤2 ml的骨水泥致急性肺栓塞的严重程度与注入骨水泥剂量没有相关性。在心肺功能正常情况下,≤2 ml的急性骨水泥肺栓塞不会引起明显的呼吸功能障碍。