硅胶和聚甲基丙烯酸甲酯人工晶状体对晶状体后囊混浊影响的系统评价

目的评价白内障摘除联合人工晶状体术后植入硅胶(silicone)与聚甲基丙烯酸甲酯(polymethylmethacrylate,PMMA)人工晶状体对晶状体后囊混浊(posterior capsule opacification, PCO)影响的差异.方法计算机检索MEDLINE(1966～2003)、EMBASE(1980～2003)、Cochrane图书馆临床对照试验资料库(2003年第1期)和中国生物医学文献光盘数据库(1979～2003),收集有关比较PMMA和Silicone两种材料的人工晶状体植入对PCO形成影响的随机对照试验(RCT),由两位研究者独立进行质量评价、资料提取,并进行交叉核对.采用RevMan 4.2进行Meta分析.结果共纳入9篇RCT,672只眼.老年性白内障亚组的Meta分析结果显示,在PCO程度[SMD合并=-0.92, 95%CI (-1.19,-0.64)]和Nd:YAG激光后囊切开率[OR合并=0.35, 95%CI (0.22,0.57)]方面,Silicone组明显低于PMMA组,其差异有统计学意义;在术后视力方面,其差异无统计学意义[OR合并=1.22, 95%CI (0.43,3.50)].葡萄膜炎并发白内障亚组的Meta分析结果显示,在术后视力方面,PMMA组较Silicone组为好,其差异有统计学意义[OR合并=0.38, 95%CI (0.15,0.91)];在PCO程度[SMD=0.23, 95%CI (-0.59, 1.05)]和Nd:YAG激光后囊切开率[OR合并=1.82, 95%CI (0.47,6.95)]方面,其差异无统计学意义.结论现有资料表明,在降低PCO方面,老年性白内障患者选用Silicone优于PMMA;由于纳入研究少,葡萄膜炎并发白内障患者选用何种材料人工晶状体较好,尚不能得出肯定结论.     

重度骨质疏松腰椎中椎弓根螺钉稳定性与骨水泥注射剂量的相关性

目的 :比较重度骨质疏松腰椎中不同剂量骨水泥强化椎弓根螺钉的稳定性,分析螺钉稳定性与骨水泥剂量间的相关关系及初步探索注射PMMA的合适剂量。方法:18个新鲜腰椎标本来自4具新鲜尸体(男性1名和女性3名,平均年龄65±9岁),测量各椎体的骨密度(bone mineral density,BMD)后将18个腰椎标本的36侧椎弓根随机分为6个实验组(A~F组)。相同方法制备钉道后,从A组到F组中,依次向钉道内注入0ml、1.0ml、1.5ml、2.0ml、2.5ml、3.0ml PMMA后拧入普通椎弓根螺钉。待骨水泥硬化后进行X线检查观察螺钉周围骨水泥的分布情况,随后进行轴向拔出实验并测量最大轴向拔出力(the maximum axial pullout strength,Fmax)。采用单因素方差分析和LSD检验比较各组中的BMD和Fmax的差异。Fmax和PMMA剂量之间进行相关性分析。结果:所有腰椎的BMD均小于0.6g/cm2,T值均小于-3.5,根据WHO的标准均诊断为重度骨质疏松椎体,各组中BMD之间的差异无统计学意义(P=0.799)。A组中,螺钉周围未见任何PMMA;B~F组中,PMMA相对均匀地分布于螺钉周围的骨质中。所有腰椎中螺钉位置良好,均未见明显PMMA渗漏。A~F组的Fmax分别为358.50±86.00N、442.67±96.02N、532.00±103.18N、740.67±120.90N、841.50±133.42N和1111.50±158.57N。与A组相比,B~F组的Fmax的提高程度分别为23.48%、48.40%、106.60%、134.73%和210.04%。A组和B组之间,B组和C组之间,E组和F组之间Fmax的差异均不具有统计学意义(P=0.230,P=0.203,P=0.152),其余各组间的差异均具有统计学意义(P0.05)。Fmax与PMMA剂量之间存在显著的正相关关系(Pearson相关系数r=0.877,P0.05)。结论 :PMMA可以提高重度骨质疏松腰椎中椎弓根螺钉的稳定性,螺钉稳定性与PMMA剂量成显著的正相关关系。在一定范围内,注射PMMA和增加PMMA的剂量并不能显著增加螺钉的稳定性。生物力学研究表明,重度骨质疏松腰椎中提高螺钉稳定性时注射PMMA的合适剂量是3ml。     

Use of polymethylmethacrylate to treat pigmented villonodular synovitis in the posterior compartment of the knee

Pigmented villonodular synovitis (PVNS) is a benign process that mainly affects the knee joint. There are two types of PVNS, a localised and a diffuse form. Although adjuvant therapies are possible, the treatment consists of arthroscopic or open synovectomy of the affected area. The most common complication is local recurrence. We report the case of a patient with PVNS and osteolysis of the femoral condyle, treated with anterior arthroscopic synovectomy and posterior approach for the treatment of the femoral condyle erosion. The bone erosion was treated with polymethylmethacrylate (PMMA) cement. There are no publications indexed in our knowledge that explain the treatment of PVNS associated with bone erosion by PMMA. Nine years after the procedure, the patient is leading a fully active life with no evidence of active disease.     

Percutaneous augmentation of the superior pubic ramus with polymethyl methacrylate: treatment of acute traumatic and chronic insufficiency fractures

The injection of polymethylmethacrylate (PMMA) is a minimally invasive image-guided procedure that is typically used to treat vertebral body fractures due to osteoporosis or neoplastic involvement. The injection of PMMA into various other locations including the sacrum, acetabulum, pedicles, femur and tibia has been reported previously, and these procedures have, overall, been highly effective at alleviating pain and discomfort. Although the injection of PMMA into the vertebral body is a very common procedure that has been performed for over 2 decades for the percutaneous treatment of vertebral body fractures, the percutaneous injection of PMMA has not been reported in the English literature as treatment for superior pubic ramus fractures. We report the percutaneous treatment of an acute superior pubic ramus fracture and of a chronic insufficiency fracture of the superior pubic ramus using a parasymphyseal approach to access the region of injury.     

椎体成形术在治疗脊椎骨质疏松压缩性骨折中的应用

目的 评价经皮椎体内注入骨水泥(聚甲基丙烯酸甲酯)治疗脊椎骨质疏松压缩性骨折的临床价值。方法 自2001年8月起，对16例19个椎体的骨质疏松压缩性骨折的患者使用经皮椎体内注射骨水泥，行椎体成形术。结果术后1～2d所有患者的疼痛消失或明显减轻，3d内均下床活动：随访1～7个月(平均4．6个月)，无疼痛复发。术中、术后无严重并发症：结论经皮椎体内注入骨水泥治疗脊椎骨质疏松压缩性骨折是一种简单、安全、有效的新方法。     

骨质疏松尸体腰椎中膨胀式椎弓根螺钉与骨水泥强化椎弓根螺钉固定稳定性的比较研究

【摘要】 目的：比较骨质疏松尸体腰椎膨胀式椎弓根螺钉（expansive pedicle screw,EPS）固定与骨水泥强化椎弓根螺钉（polymethylmethacrylate-augmented pedicle screw,PMMA-PS）固定的稳定性。方法：16个腰椎标本取自4具新鲜尸体的脊柱（L1~L4）。年龄51~78岁,平均63岁,其中女性3具,男性1具。所有标本经X线检查排除畸形、骨折等病变,其中1个腰椎因严重畸形被剔除。测量各椎体的骨密度值（bone mineral density,BMD）后,将15个椎体随机分为3组。采用相同方法制备钉道,普通椎弓根螺钉（CPS）组直接置入CPS;PMMA-PS组先向钉道内注入PMMA,再置入CPS;EPS组直接置入EPS。置钉后24h,对标本进行X线检查和CT扫描,观察螺钉位置及骨水泥分布情况;然后将椎体固定于MTS 858上,沿椎弓根螺钉的长轴方向以10mm/min的加载速度进行拔出实验,测量螺钉的最大轴向拔出力（the maximum pullout strength,Fmax）和能量吸收值（energy absorbed value,EAV）。结果：所有腰椎的BMD均小于0.8g/cm2,T值为-3.5~-2.5,均为骨质疏松椎体,3组之间BMD的差异无统计学意义（P>0.05）。X线检查和CT重建显示各组螺钉位置均良好,PMMA-PS组中未见PMMA渗漏现象;CPS组螺钉被周围的骨质直接包绕;PMMA-PS组螺钉被PMMA所包裹,PMMA存在于螺钉周围的骨质中,在椎体内形成了“纺锤样”结构;EPS组螺钉的前端在椎体内明显膨胀,形成了“爪状”结构。CPS组、PMMA-PS组和EPS组的Fmax分别为751.50±251.37N、1521.70±513.27N和1175.20±396.51N,PMMA-PS组和EPS组均显著高于CPS组（P<0.001,P=0.026）,而PMMA-PS组和EPS组之间的差异无统计学意义（P=0.064）。CPS组、PMMA-PS组和EPS组的EAV分别为1.47±0.51J、3.09±0.93J和2.46±0.69J,PMMA-PS组和EPS组均显著高于CPS组（P<0.001,P=0.005）,而PMMA-PS组和EPS组之间的差异无统计学意义（P=0.067）。结论：EPS可显著提高骨质疏松腰椎内椎弓根螺钉的稳定性,达到了与传统PMMA强化椎弓根螺钉接近的固定强度,具有良好的临床应用前景。     

经椎弓根截骨联合头尾骨水泥强化椎弓根螺钉固定治疗陈旧性骨质疏松椎体压缩骨折伴后凸畸形

目的观察后路短缩截骨联合椎弓根螺钉头尾侧骨水泥强化固定治疗骨质疏松椎体压缩骨折继发的陈旧性胸腰椎后凸畸形的临床疗效。方法选择2010年1月～2016年6月以来本院采用后路截骨矫形手术治疗骨质疏松椎体压缩骨折继发陈旧性胸腰椎后凸畸形患者12例。其中,男2例,女10例;年龄59～72岁,平均66.3岁。采用后路经后凸顶点短缩截骨闭合矫形术。观察手术前后的后凸Cobb角、腰椎前凸角(lumbar lordosis,LL)、脊柱矢状位平衡(sagittal vertical axis,SVA)改善距离的变化。通过独立人员严格随访,记录术前及末次随访JOA评分、VAS评分和Oswestry功能障碍评分(ODI),记录手术前后的Frankel分级系统分级情况。结果手术前后凸角度平均38.9°±6.2°,腰椎前凸角平均35.9°±5.8°,脊柱SVA平均(62.4±11.1)mm。随访时间平均29个月,末次随访后凸角度平均11.7°±5.7°,平均改善率69.92%;腰椎前凸角平均25.7°±10.5°,平均改善率28.41%;脊柱SVA平均(14.6±10.5)mm,平均改善率81.25%。术前12例神经损害患者Frankel分级为10例D级、2例C级,术后提高至10例E级、2例D级。腰痛VAS评分由术前平均7.8分降至术后平均2.1分、JOA评分由术前平均为13.6分增加到术后21.2分、ODI评分由术前平均为54.8%降至术后的30.1%,相比术前差异具有统计学意义(P0.05)。结论后路截骨联合椎弓根螺钉头尾侧骨水泥强化固定治疗陈旧性骨质疏松椎体压缩骨折继发胸腰椎后凸畸形,明显改善后凸畸形,能有效恢复脊柱矢状位平衡,神经功能明显改善。     

三种充填材料应用于经皮椎体成形术的动物实验研究

目的探讨PMMA、CPC和rhBMP-2/CPC三种充填材料在骨质疏松症山羊模型上行经皮椎体成形术(PVP)的材料特点并观察其影像学表现.方法 6～7岁健康雌性山羊14只,使用双能X线骨密度仪(DEXA)行骨密度(BMD)测量,然后随机分为三组:Ⅰ组为正常对照组(n=2);Ⅱ组为假手术组(n=2);Ⅲ组为双侧卵巢切除术(OVX)组(n=10).Ⅱ、Ⅲ组术后4个月,所有动物再行BMD测量,然后各组分别处死2只动物,取腰椎椎体松质骨行组织学检查,证实骨质疏松(OVX)组达到OP大动物模型标准.Ⅲ组,在C形臂X光机监视下,每只山羊的L2～L6,随机选取2节椎体在分离麻醉下分别行PVP,分别充填PMMA、CPC和rhBMP-2/CPC,保证每只山羊两节穿刺椎体的充填材料各不相同.结果 8只山羊16个椎体的PVP均成功,三种材料的充填量无显著差异(P＞0.05);PMMA推注阻力较大,可操作时间短;CPC和rhBMP-2/CPC推注阻力较小,可操作时间长;术后第二天CT扫描示充填材料不规则分布椎体内,有5个椎体出现渗漏,渗漏率31.3%.结论 OVX山羊是研究PVP的良好动物模型;在推注阻力和可操作时间上,CPC和rhBMP-2/CPC优于PMMA.     

Pullout Strength after Expandable Polymethylmethacrylate Transpedicular Screw Augmentation for Pedicle Screw Loosening

Objective

Pedicle screw fixation for spine arthrodesis is a useful procedure for the treatment of spinal disorders. However, instrument failure often occurs, and pedicle screw loosening is the initial step of a range of complications. The authors recently used a modified transpedicular polymethylmethacrylate (PMMA) screw augmentation technique to overcome pedicle screw loosening. Here, they report on the laboratory testing of pedicle screws inserted using this modified technique.

Methods

To evaluate pullout strengths three cadaveric spinal columns were used. Three pedicle screw insertion methods were utilized to compare pullout strength; the three methods used were; control (C), traditional transpedicular PMMA augmentation technique (T), and the modified transpedicular augmentation technique (M). After control screws had been pulled out, loosening with instrument was made. Screw augmentations were executed and screw pullout strength was rechecked.

Results

Pedicle screws augmented using the modified technique for pedicle screw loosening had higher pullout strengths than the control (1106.2±458.0 N vs. 741.2±269.5 N; p=0.001). Traditional transpedicular augmentation achieved a mean pullout strength similar to that of the control group (657.5±172.3 N vs. 724.5±234.4 N; p=0.537). The modified technique had higher strength than the traditional PMMA augmentation technique (1070.8±358.6 N vs. 652.2±185.5 N; p=0.023).

Conclusion

The modified PMMA transpedicular screw augmentation technique is a straightforward, effective surgical procedure for treating pedicle screw loosening, and exhibits greater pullout strength than traditional PMMA transpedicular augmentation. However, long-term clinical evaluation is required.     

新型多孔聚甲基丙烯酸甲酯与磷酸钙骨水泥复合材料的实验研究

目的：制备并研究新型多孔聚甲基丙烯酸甲酯/磷酸钙骨水泥的聚合温度、材料成分、机械特性、孔隙率等临床应用相关特性,为进一步开发理想骨水泥修复材料提供理论依据。方法：在传统聚甲基丙烯酸甲酯骨水泥制备的基础上,以羧甲基纤维素钠和α-磷酸三钙作为成孔剂和骨引导剂,制备不同组分的多孔聚甲基烯酸甲酯/磷酸钙骨水泥,用热电偶、x射线衍射仪、体式显微镜、显微CT和MTS材料试验系统分别评价合成产物的最高聚合温度、材料成分、孔隙率、孔径大小、机械特性等特征。结果：具有骨引导性的α-磷酸三钙能成功载入多孔聚甲基烯酸甲酯支架中,生成的产物具有安全的聚合温度。不同含量的羧甲基纤维素钠会影响支架中孔径的大小,但不会影响孔隙率（P=0.102）。虽然α-磷酸三钙的载入会降低孔隙率（P〈0.001）,但所有产物之间的抗压强度和弹性模量无显著性差异（P=0.724,P=0.601）。结论：多孔聚甲基丙烯酸甲酯支架能与α-磷酸三钙成功复合成具有适宜机械性能的生物材料,这为开发理想骨水泥修复材料提供了新的思路。