计算骨丧失量经椎弓根打压植骨治疗胸腰椎压缩性骨折的生物力学研究

[目的]探讨用计算骨丧失量的方法经椎弓根打压植骨(transpedicular impacted grafting,TPIG)治疗胸腰椎压缩性骨折的生物力学性能。[方法]将6具成人新鲜尸体胸腰椎标本,模拟正常组、压缩性骨折损伤组、单纯计算骨丧失量TPIG和单纯经椎弓根植骨组(transpedicular grafting,TPG)、计算骨丧失量TPIG+椎弓根固定和TPG+椎弓根固定组,行生物力学实验应力分析,比较各组的椎体和椎间盘的强度、刚度和稳定性以及扭转生物力学性能。[结果](1)计算骨丧失量TPIG+椎弓根固定组的椎体和椎间盘的强度、刚度和稳定性高于TPG+椎弓根固定组,具有显著性差异(P0.05);(2)单纯计算骨丧失量TPIG组的强度和刚度高于单纯TPG组,并具有显著性差异(P0.05);(3)从扭转生物力学试验中也同样得到了相似的结论。[结论]计算骨丧失量TPIG+椎弓根固定治疗胸腰椎压缩性骨折具有优越的生物力学性能,适合于临床应用。     

胸腰椎体压缩性骨折三维有限元模型的建立和分析

[目的]建立胸腰椎体压缩性骨折三维有限元模型,探索胸腰段椎体压缩性骨折三维有限元模型的建模方法和有限元方法在胸腰段椎体压缩性骨折临床治疗中的应用前景。[方法]在正常胸腰椎三维非线性有限元模型的基础上结合临床胸腰椎压缩性骨折实际病例,运用有限元软件,建立胸腰椎椎体骨折压缩1/3、1/2有限元模型,进行有限元分析,测量并比较正常胸腰椎模型及胸腰椎椎体骨折压缩1/3、1/2模型在屈、伸、侧屈、旋转等工况下的活动度(ROM)。[结果]胸腰椎压缩性骨折有限元模型外观逼真,几何相似性好,各个工况下的活动度较正常胸腰椎模型明显增大,并且随着椎体压缩程度的增加,活动度相应增大,尤其是前屈分别增加了1.13°(椎体骨折压缩1/3)、2.14°(椎体骨折压缩1/2);后伸增加了0.66°(椎体骨折压缩1/3)、0.94°(椎体骨折压缩1/2)。[结论]胸腰段椎体压缩性骨折三维有限元模型能够较好的模拟胸腰椎压缩性骨折实际病例,可用于临床对胸腰椎压缩性骨折患者的生物力学分析,其结果可以指导制定胸腰椎压缩性骨折的治疗策略。     

三种伤椎置钉固定胸腰椎爆裂骨折的疗效对比

[目的]探讨后路不同内固定方式治疗胸腰椎爆裂性骨折的临床疗效。[方法]2009年2月~2015年7月对116例胸腰椎爆裂性骨折患者行后路复位固定手术治疗,按手术方式将患者分为三组,38例采用伤椎椎弓根内置短螺钉(伤椎短钉组),38例采用伤椎椎弓根内置长螺钉(伤椎长钉组),40例后路短节段椎弓根钉内固定伤椎不置螺钉(伤椎无钉组)。[结果]随访9~36个月,平均15.8个月。三组手术前后伤椎前缘高度比、脊柱后凸Cobb角、伤椎椎管矢状径和横截面积比较均有明显改善,差异有统计学意义(P<0.01)。术后神经功能状态较术前有显著改善,差异有统计学意义(P<0.05)。伤椎短钉组、伤椎无钉组在术后矫正率、术后椎管面积改善率,优于伤椎长钉组,组间比较差异有统计学意义(P<0.05)。伤椎短钉组和伤椎长钉组的远期矫正丢失率和内固定失效率均低于伤椎无钉组(P<0.05)。三组间神经功能恢复比较差异无统计学意义(P>0.05)。术后疼痛评分伤椎短钉组优于伤椎长钉组和伤椎无钉组(P<0.05)。术后并发症三组无显著差别。[结论]在后路内固定中增加经伤椎椎弓根内置短螺钉内固定是治疗胸腰椎爆裂性骨折的更有效手段。     

经皮椎体成形术治疗骨质疏松性胸腰椎压缩性骨折

[目的]观察经皮椎体成形术（PVP）治疗疼痛性高龄骨质疏松性胸腰椎压缩骨折的临床疗效。[方法]在C臂X线透视监控下，以骨水泥（PMMA）为充填材料，经单侧或双侧椎弓根穿刺行PVP治疗6例、脊柱后凸成行术治疗2例。[结果]术中无骨水泥渗漏，术后患者疼痛明显缓解或消失，无1例出现严重并发症。[结论]PVP治疗疼痛性高龄骨质疏松性胸腰椎压缩性骨折是安全、有效、经济的。     

经后路伤椎单节段椎弓根螺钉固定治疗胸腰段骨折的体会

[目的]探讨后路单节段椎弓根螺钉内固定治疗胸腰椎骨折的临床疗效。[方法]自2009年2月²011年3月行后路单节段椎弓根螺钉内固定治疗胸腰椎骨折21例,男12例,女9例,年龄232011年3月行后路单节段椎弓根螺钉内固定治疗胸腰椎骨折21例,男12例,女9例,年龄23⁶4岁,平均34岁,观察骨折椎的椎弓根螺钉位置及手术前后伤椎复位高度和后凸Cobb角。[结果]术后CT示伤椎椎弓根螺钉均在正常骨性结构内,术后无脊髓损伤、感染等并发症发生。伤椎椎体前缘高度百分比从术前平均(54.75±0.06)%恢复至术后平均(92.35±0.12)%,(P<0.05);骨折椎后凸Cobb角从术前平均(25.13±2.67)°恢复至(4.83±1.43)°(P<0.05)。患者VAS评分改善明显(P<0.05)。所有骨折全部获得骨性愈合,骨折椎体高度无明显丢失,无钉棒弯曲、松动或断裂。[结论]后路单节段椎弓根螺钉内固定对于胸腰段骨折治疗有效。只要手术适应证选择正确,后路单节段椎弓根螺钉内固定可用于治疗胸腰段骨折。     

椎板减压与非椎板减压椎弓根螺钉间接复位治疗胸腰椎爆裂性骨折的疗效分析

[目的]探讨利用椎弓根螺钉复位椎板减压与非减压2种方法治疗胸腰椎爆裂性骨折的临床疗效.[方法]采用后路椎弓根螺钉内固定治疗胸腰椎爆裂性骨折126例.[结果]将已随访的96例病人中选择54例随机分为两组:椎板减压组(A)27例,非椎板减压组(B)27例,病例随访时间9个月～11年.A组:术中出血平均800 ml,手术时间平均180 min.非减压组:术中出血平均350 ml,手术时间平均115 min.[结论]两组病例在伤椎高度的恢复、Cobb角恢复无统计学差异(P>0.05);非椎板减压组术中出血、手术时间有明显的差异(P<0.05);故非椎板减压椎弓根螺钉间接复位治疗胸腰椎爆裂性骨折,对于一定的病人群体,不失为一种值得推广的手术方法.     

伤椎置钉与跨节段椎弓根螺钉内固定术治疗胸腰椎骨折的比较研究

[目的]探讨后路伤椎置钉内固定术治疗胸腰椎骨折的临床效果.[方法]回顾性分析本院2005年1月-2007年12月42例(A组) 伤椎置钉内固定治疗胸腰椎单一椎体骨折患者的临床资料,随机选择同期跨节段椎弓根螺钉内固定40例(B组)作为对照.术后随访6～36个月,平均15.8个月.[结果]A组在术后矫正率、术后椎管面积改善值、远期丢失率、内固定失效率方面明显优于B组(P< 0.05),具有统计学意义.[结论]胸腰椎爆裂性骨折应用伤椎置钉椎弓根螺钉内固定可以增强内固定系统的牢固性,并有利于矫正后凸畸形和维持矫正效果.     

后路椎弓根钉内固定联合椎间融合治疗胸腰椎骨折脱位疗效观察

[目的]观察后路椎弓根钉内固定联合椎间融合治疗胸腰椎骨折脱位的疗效,探讨其临床应用价值。[方法]选择本院于2010年3月~2012年3月收治的胸腰椎骨折脱位患者90例作为研究对象,按照配对分组法分为两组,每组45例,对照组给予短节段椎弓根螺钉内固定治疗,观察组给予后路椎弓根钉内固定联合椎间融合治疗,比较两组疗效。[结果]观察组总有效率44例(97.8%),显著高于对照组38例(84.4%),χ2=4.939,P0.05。术后36个月,观察组椎体前缘高度比值、椎体后缘高度比值均大于对照组,且Cobb角小于对照组,P0.05。观察组神经功能恢复情况显著优于对照组,P0.05。术后并发症发生率比较两组差异无统计学意义。[结论]后路椎弓根钉内固定联合椎间融合治疗胸腰椎骨折脱位疗效较佳,椎体稳定性更佳,神经功能恢复情况优。具有重要的临床应用价值。     

单、双侧人路PKP对胸腰椎压缩性骨折疼痛感、脊柱功能的影响及安全性分析

正近年来,经皮球囊扩张椎体后凸成形术(percutaneous kyphoplasty,PKP)已成为治疗胸腰椎压缩性骨折的有效手段,其具有快速止痛、矫正畸形效果明显、早期恢复椎体高度等优势~([2-3])。本研究特将92例胸腰椎压缩性骨折患者通过分组进行对照试验,以探讨单、双侧入路PKP治疗胸腰椎压缩性骨折的疗效及安全性,现报道如下。     

小切口直视置入普通椎弓根螺钉治疗胸腰椎压缩性骨折

[目的]探讨小切口直视置入普通椎弓根螺钉治疗胸腰椎压缩性骨折的可行性、安全性及有效性。[方法]2013年5月~2015年5月对37例单节段胸腰椎压缩性骨折患者在全麻下行小切口直视置入普通椎弓根螺钉治疗(小切口组)。其中男性26例,女性11例,年龄29~51岁,平均41.27岁。记录切口长度、手术时间、术中出血量、术后VAS评分、伤椎前缘高度压缩率及伤椎矢状面Cobb角,并与同期37例经皮椎弓根螺钉手术患者(经皮组)进行比较。[结果]小切口组与经皮组相比,平均切口长度、术中出血量、术后VAS评分差异均无统计学意义(P>0.05);但小切口组手术时间较经皮组明显缩短,差异有统计学意义(0.92±0.71)h vs(1.47±0.92)h,t=3.187,P=0.002],两组患者术中及术后均未出现严重并发症。随访时间13~15个月,平均13.92个月。小切口组平均术后伤椎前缘高度压缩率明显小于经皮组,两组间差异有统计学意义[(6.54±2.23)%vs(12.72±4.53)%,t=7.453,P<0.001],小切口组平均术后伤椎矢状面Cobb角明显小于经皮组,两组间差异有统计学意义[(2.61±1.08)°vs(6.37±2.31)°,t=9.111,P<0.001]。[结论]小切口直视置入普通椎弓根螺钉治疗胸腰椎压缩性骨折能够明显减小医源性创伤,其对人体组织的损伤与经皮椎弓根螺钉固定技术大致相同,但其操作更方便、骨折复位效果更好和医疗费用更低。     

"Free" and "exchangeable" or "trapped" and "non-exchangeable" water in cartilage

We repeated some of our own previous experiments, as well as some of Torzilli's recent experiments (11) on which he bases his conclusions relating to a nonexchangeable "trapped water" in cartilage. We are unable to confirm Torzilli's findings. We observed partition coefficients for 3H.HO very close to unity. That both the extrafibrillar and most of the intrafibrillar water is freely exchangeable and behaves as available water towards small solutes has been independently shown (3) for other collagenous tissues. All the different permutations of partition experiments have yielded results that are fully consistent with our original picture of the very major fraction of cartilage water being free.     

Spatiotemporal analysis of auditory "what" and "where" working memory

Goal-directed attention to sound identity (what) and sound location (where) has been associated with increased neural activity in ventral and dorsal brain regions, respectively. In order to ascertain when such segregation occurs, we measured event-related potentials during an n-back (n = 1, 2) working memory task for sound identity or location, where stimuli selected randomly from 3 semantic categories (human, animal, music) were presented at 3 possible virtual locations. Accuracy and reaction times were comparable in both "what" and "where" tasks, albeit worse for the 2-back than for the 1-back condition. The partial least squares analysis of scalp-recorded and source waveform data revealed domain-specific activity beginning at about 200-ms poststimulus onset, which was best expressed as changes in source activity near Heschl's gyrus, and in central medial, occipital medial, right frontal and right parietal cortex. The effect of working memory load emerged at about 400-ms poststimulus and was expressed maximally over frontocentral scalp region and in sources located in the right temporal, frontal and parietal cortices. The results show that for identical sounds, top-down effects on processing "what" and "where" information is observable at about 200 ms after sound onset and involves a widely distributed neural network.     

"Gas off" or "vaporizer off"

Editor—It is a common misconception that turning off thevaporizer while leaving the fresh gas flow (FGF) on, during     

"Empty wall" and "vertical strut" signs of ACL insufficiency

We report our observation on the "empty wall" and "vertical strut" signs of anterior cruciate ligament (ACL) insufficiency. ACL tears most commonly occur in the midsubstance; arthroscopic evaluation of patients with these tears often reveals minimal evidence of previous ACL tissue along the intercondylar wall, thus giving the appearance of an "empty wall." In proximal ACL tears, the long remnant of ACL tissue may adhere to adjacent PCL tissue. Arthroscopically, one may see this vertically oriented strut of tissue, which to the casual arthroscopist may mimic a normal-appearing ACL except for orientation and tension. In addition, the "empty wall" sign will be noted because the lateral intercondylar wall becomes easily visible following ACL injury. In two separate prospective studies of 84 such patients, the combined incidence of the empty wall sign was 82%, and the incidence of the vertical strut sign was 50%. These findings should be sought for meticulously at the time of arthroscopic evaluation. The vertical strut should not be misinterpreted as an aberrantly oriented ACL or partial ACL tear.