大鼠室旁核内催产素免疫阳性细胞树突棘样结构在脱水状态下的改变

树突棘，室旁核，催产素，脱水，免疫组化，大鼠下丘脑内催产素大细胞神经分泌细胞与水盐代谢的调节有关，并伴有细胞形态的改变如细胞体积的增大及细胞膜与细胞膜间接触的增加和多突触的形成等。本文用免疫组化法发现在脱水状态下室旁核的催产素免疫阳性神经元上树突棘样结构有所增加。光镜观察并计算室旁核前大细胞亚核、内侧大细胞亚核及后大细胞亚核中含树突棘样结构的催产素神经元百分数变化，显示正常大鼠室旁核神经元树突棘样结构多位于树突干上，少数在胞体上。前大细胞亚核含树突棘样结构的细胞百分数为２１．２７％，内侧大细胞亚核为３０．２２％，后大细胞亚核为２０．２２％。轻度脱水大鼠室旁核含树突棘样结构细胞百分数显著增加（前大细胞亚核：２８．６５％，Ｐ＜０．０５；内侧大细胞亚核：３５．５３％，Ｐ＞０．０５；后大细胞亚核：３４．７８％，Ｐ＜０．０１）。细胞上树突棘样结构数也增加，其体积略为增大。重度脱水大鼠室旁核中树突棘样结构细胞百分数增加较小，仅后大细胞亚核内有显著变化（２７．１３％，Ｐ＜０．０５）。不同程度脱水组之间无显著变化。结果说明脱水可引起神经元膜结构的改变。树突棘样结构数变化是否与新突触的形成有直接关系？尚待进一步证实。     

生物活性锶羟基磷灰石骨水泥应用于椎体后凸成形术的生物力学研究

目的探讨单侧和双侧球囊扩张注射生物活性锶羟基磷灰石骨水泥（SrHAC）行椎体后凸成形术对骨折椎体模型的高度和生物力学性能的修复能力。方法从2具新鲜冰冻人脊柱标本中分离14个椎体（T8～L5），随机分为单侧组（单侧球囊扩张注射SrHAC）和双侧组（双侧球囊扩张注射SrHAC），每组7个椎体。测量各椎体的骨密度、原始高度后，对各椎体标本施加轴向压力负载，测出各椎体的原始强度和原始刚度，并建立椎体压缩骨折模型。测量椎体骨折后的刚度。在c型臂x线机下手术，术中控制球囊扩张的体积均为3．00mL，术后测量各椎体的高度、强度和刚度。用单因素方差分析比较两组椎体的骨密度、原始刚度和原始强度。用配对t检验比较两组椎体的高度和生物力学性能在手术前、后的改变，其中椎体中线两侧高度差在手术前、后的改变用单因素方差分析。结果两组椎体的骨密度、原始强度和刚度之间差异无统计学意义（P〈0．05）。骨折后，椎体的前缘、中线和后缘高度均减少，刚度较原始刚度降低。单侧组平均注入3．07mLSrHAC，双侧组平均注入5．82mLSrHAC。术后椎体各部位的高度均有所增加，但未能恢复到原始高度水平。术后两组椎体中线两侧的高度及两组椎体强化后的强度差异均无统计学意义（P〉0．05）。两组椎体强化后的刚度均有一定程度的修复，双侧组较单侧组刚度修复效果好。结论单侧或双侧注射SrHAC行球囊扩张椎体后凸成形术均能修复骨折椎体模型的高度和生物力学性能。     

X线引导下经皮通用脊柱系统内固定治疗胸腰椎骨折

目的探讨X线引导下经皮通用脊柱系统(USS)内固定治疗胸腰椎骨折的可行性.方法 2002年10月～2004年5月对无须减压胸腰椎骨折8例采用后路经皮USS椎弓根螺钉植入,在椎旁肌深层置入固定棒行伤椎复位固定.结果手术时间120～240 min,平均140 min.术中出血量20～90 ml,平均40 ml.后凸Cobb's角术前(21.5±4.3)°、术后(2.7±1.5)°(t=17.541,P=0.001),椎体塌陷术前18.5%±4.1%、术后2.4%±1.0%(t=16.504,P=0.001).术后3周佩戴腰围支具下床,复查Frankel分级,C级恢复至D级2例,D级恢复至E级1例,保持D级1例,保持E级4例.结论经皮USS内固定治疗无须减压的胸腰椎骨折创伤小,恢复快,但技术难度高,X线暴露时间长.     

螺旋CT三维重建脊柱的临床意义和应用前景

目的：探讨螺旋CT扫描和三维重建在脊柱病变中的临床应用价值。方法：对12例脊柱疾病患者进行螺旋CT扫描和三维重建。结果：腰椎间盘突出症和椎管狭窄症3例，脊柱骨折5例，侧弯畸形2例，肿瘤2例，均得到正确诊治。结论：螺旋CT扫描及三维重建技术可广泛应用于脊柱病变的诊断，能直观显示脊柱病变部位的形态。     

术中射频消融后病灶刮除治疗脊柱转移瘤

目的:探讨术中射频消融(RFA)后再行病灶刮除术治疗脊柱转移瘤的可行性及疗效.方法:2004年～2006年,对11例脊柱转移瘤患者术中实施RFA后再行病灶刮除术,将FRA前后病灶标本进行光镜和电镜病理检查,随访患者疼痛缓解情况及肿瘤复发情况.结果:术中未出现脊髓和神经根损伤,RFA后瘤组织固缩,刮除顺利,出血量350～3800ml,平均1024.5ml.全部病例得到6个月以上随访,平均9.8个月,全部患者生存期超过6个月,VAS评分术前平均5.8分,术后6个月时平均1.9分.1例出现局部肿瘤复发.RFA前的标本光、电镜检查均未见肿瘤组织坏死.RFA后光镜检查3例无明显坏死,9例肿瘤细胞完全坏死:电镜检查10例肿瘤细胞完全坏死,1例肿瘤细胞部分坏死,1例无明显坏死.结论:术中RFA后再行病灶刮除治疗脊柱转移瘤安全可行,有利于肿瘤的刮除,减少局部复发的风险.     

Classification of thoracic and lumbar spine fractures: problems of reproducibility

Reproducibility of fracture classification systems in general has been a matter of controversy. The reproducibility of spinal fracture classifications has not been sufficiently studied. We studied the inter-observer and intra-observer reproducibility of the Magerl (AO) classification using radiograms, CTs and MRIs of 53 patients. We compared this classification with the older and simpler Denis classification. Five observers classified the fractures, first using the radiograms and CTs and, 6 weeks later, with radiograms and MRIs. Three of the observers repeated the readings after 3 months. Three observers also classified the fractures according to Denis. Agreement was measured using Cohen's kappa test. The type (A, B, C) classification of the AO system was fairly reproducible with CTs. With MRI this was only moderate. Group subclassification of the types yielded higher kappa values, corresponding to substantial agreement. The agreement was, in general, better with the Denis classification, but the variance was higher due to the difficulty of finding proper categories for some injury patterns. Although the AO classification allows proper registration of all kinds of injury, the reproducibility, especially at the type level, is problematic. Use of MRI and better definition of the distinctive properties of the three different types may enhance the reproducibility of the scheme.     

Fusion and failure following anterior cervical plating with dynamic or rigid plates: 6-months results of a multi-centric, prospective, randomized, controlled study

Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is settling. Recent biomechanical studies showed that dynamic anterior plates provide a better graft loading possibly leading to accelerated spinal fusion with a lower incidence of implant complications. This, however, was investigated in vitro and does not necessarily mean to be the case in vivo, as well. Thus, the two major aspects of this study were to compare the speed of bone fusion and the rate of implant complications using either rigid- or dynamic plates. The study design is prospective, randomized, controlled, and multi-centric, having been approved by respective ethic committees of all participating sites. One hundred and thirty-two patients were included in this study and randomly assigned to one of the two groups, both undergoing routine level-1- or level-2 anterior cervical discectomy with autograft fusion receiving either a dynamic plate with screws being locked in ap - position (ABC, Aesculap, Germany), or a rigid plate (CSLP, Synthes, Switzerland). Segmental mobility and implant complications were compared after 3- and 6 months, respectively. All measurements were performed by an independent radiologist. Mobility results after 6 months were available for 77 patients (43 ABC/34 CSLP). Mean segmental mobility for the ABC group was 1.7 mm at the time of discharge, 1.4 mm after 3 months, and 0.8 mm after 6 months. For the CSLP- group the measurements were 1.0, 1.8, and 1.7 mm, respectively. The differences of mean segmental mobility were statistically significant between both groups after 6 months (P = 0.02). Four patients of the CSLP-group demonstrated surgical hardware complications, whereas no implant complications were observed within the ABC-group (P = 0.0375). Dynamic plate designs provided a faster fusion of the cervical spine compared with rigid plate designs after prior spinal surgery. Moreover, the rate of implant complications was lower within the group of patients receiving a dynamic plate. These interim results refer to a follow-up period of 6 months after prior spinal surgery. Further investigations will be performed 2 years postoperatively.     

Disc replacement using Pro-Disc C versus fusion: a prospective randomised and controlled radiographic and clinical study

Anterior cervical discectomy and fusion (ACDF) may be considered to be the gold standard for treatment of symptomatic degenerative disc disease within the cervical spine. However, fusion of the segment may result in progressive degeneration of the adjacent segments. Therefore, dynamic stabilization procedures have been introduced. Among these, artificial disc replacement by disc prosthesis seems to be promising. However, to be so, segmental motion must be preserved. This, again, is very difficult to judge and has not yet been proven. The aim of the current study was to first analyse the segmental motion following artificial disc replacement using a disc prosthesis. A second aim was to compare both segmental motion as well as clinical result to the current gold standard (ACDF). This is a prospective controlled study. Twenty-five patients with cervical disc herniation were enrolled and assigned to either study group (receiving a disc prosthesis) or control group (receiving ACDF, using a cage with bone graft and an anterior plate.) Radiostereometric analysis was used to quantify intervertebral motion immediately as well as 3, 6, 12 and 24 weeks postoperatively. Further, clinical results were judged using visual analogue scale and neuro-examination. Cervical spine segmental motion decreased over time in the presence of disc prosthesis or ACDF. However, the loss of segmental motion is significantly higher in the ACDF group, when looked at 3, 6, 12 and 24 weeks after surgery. We observed significant pain reduction in neck and arm postoperatively, without significant difference between both groups (P > 0.05). Cervical spine disc prosthesis preserves cervical spine segmental motion within the first 6 months after surgery. The clinical results are the same when compared to the early results following ACDF.     

Evolution of Vertebroplasty: A Biomechanical Perspective

This paper is a collection of computational, finite element studies on vertebroplasty performed in our laboratory, which attempts to provide new biomechanical evidence and a fresh perspective into how the procedure can be implemented more effectively toward the goal of preventing osteoporosis-related fractures. The percutaneous application of a bone cement to vertebral defects associated with osteoporotic vertebral compression fracture has proven clinical successful in alleviating back pain. When the biomechanical efficacy of the procedure was examined, however, vertebroplasty was found to be limited in its ability to provide sufficient augmentation to prevent further fractures without risking complications arising from cement extravasations. The procedure may instead be more efficient biomechanically as a prophylactic treatment, to mechanically reinforce osteoporotic vertebrae at risk for fracture. Patient selection for such intervention may be reliably achieved with the more accurate fracture risk assessments based on vertebral strength, predicted using geometrically detailed, specimen-specific finite element models, rather than on bone density alone. Optimal cement volume, placement, and material properties were also recommended. The future of vertebroplasty involving biodegradable augmentation material laced with osteogenic agents that upon release will stimulate new bone growth and increase bone mass was proposed.     

脊柱融合的基因治疗

稳定的脊柱融合与相邻椎骨的融合有关，经典的脊柱融合手术采用剥离椎骨，自体髂骨植骨融合术，虽然应用自体髂骨植骨被认为是植骨融合的金标准，但是它常伴有并发症出现，基因治疗被认为是促进脊柱关节固定融合的新途径，研究表明在动物模型中应用腺病毒，脂质体搭载人骨形成蛋白（hBMP)基因族能促进脊柱融合，有关在动物模型中通过基因转染促进脊柱融合的研究，本文对此作简要介绍，弄清楚骨形成中基因的表达和开发出新的基因转染载体是目前研究的重点，相信在不远的将来，基因治疗脊柱融合能在临床中得到应用。