Assessing the Stiffness of Spinal Fusion in Animal Models

The clinical goal of spinal fusion is to reduce motion and the associated pain. Therefore, measuring motion under loading is critical. The purpose of this study was to validate four-point bending as a means to mechanically evaluate simulated fusions in dog and rabbit spines. We hypothesized that this method would be more sensitive than manual palpation and would be able to distinguish unilateral vs bilateral fusion. Spines from four mixed breed dogs and four New Zealand white rabbits were used to simulate posterolateral fusion with polymethyl methacrylate as the fusion mass. We performed manual palpation and nondestructive mechanical testing in four-point bending in four planes of motion: flexion, extension, and right and left bending. This testing protocol was used for each specimen in three fusion modes: intact, unilateral, and bilateral fusion. Under manual palpation, all intact spines were rated as not fused, and all unilateral and bilateral simulated fusions were rated as fused. In four-point bending, dog spines were significantly stiffer after unilateral fusion compared with intact in all directions. Additionally, rabbit spines were stiffer in flexion and left bending after unilateral fusion. All specimens exhibited significant differences between intact and bilateral fusion except the rabbit in extension. For unilateral vs bilateral fusion, significant differences were present for right bending in the dog model and for flexion in the rabbit. Unilateral fusion can provide enough stability to constitute a fused grade by manual palpation but may not provide structural stiffness comparable to bilateral fusion.     

前路半椎体切除截骨后路矫形固定治疗严重先天性脊柱侧凸

目的探讨分期前路半椎体切除截骨后路矫形手术治疗严重先天性脊柱侧凸的临床疗效。方法严重先天性脊柱侧凸14例,男4例,女10例;年龄8～13岁,平均11.2岁。其中形成缺陷2例,分节缺陷6例,混合型6例。半椎体位于T53例,T2、T8、T10、T11、L1、L4各1例。胸弯12例,胸腰弯2例。术前冠状面Cobb角63°～95°,平均72.1°。胸椎后凸减小或前凸8例,胸腰段后凸4例。一期采用前路半椎体切除、多节段椎体间楔形截骨及分节不全松解;二期采用后路椎弓根钉棒系统三维矫形固定。前后路手术均植骨,平均截骨5.5个节段。结果一期前路术后冠状面Cobb角48°～60°,平均51.5°;矫正率19.6%～37.8%,平均28.6%。二期术后冠状面Cobb角5°～45°,平均30.5°;矫正率52.6%～87.5%,平均62.5%。8例存在胸椎后凸减小或前凸的患者均恢复生理性后凸,4例胸腰段后凸患者3例达到矢状面矫正。全部病例随访8～30个月,平均12.1个月。无断钉、断棒及明显的矫正度丢失,植骨融合良好。发生并发症2例,椎弓根钉帽松动1例,T1神经根激惹1例。结论一期前路半椎体切除、多节段椎体间楔形截骨、分节不全松解,二期后路矫形固定及前后路植骨治疗先天性脊柱侧凸能够达到较满意的矫形效果,适合于8～12岁的青春期前患者。     

Fracture of the thoracic spine with paralysis and esophageal perforation

A 17-year-old young man presented with a highly unstable fracture dislocation of the third and fourth thoracic vertebrae with neurological deficit, in which the fractured spine had perforated the thoracic esophagus. Open reduction and internal fixation of the spinal fractures in combination with aggressive treatment of the mediastinitis caused by esophageal perforation, consisting of two re-thoracotomies, was performed. Two years after the accident, the patient had recovered well. The neurological deficit had recovered, and there were no difficulties with swallowing.     

The lumbar and lumbosacral facet-syndrome. Diagnostic measures,surgical treatment and results in 119 patients

Summary The authors present their diagnostic and therapeutic protocol as well as the surgical outcome in a series of 119 patients with the lumbar facet syndrome.By use of different surgical techniques such as translaminar screw fixation (n=56), Louis plate fixation (n=36), Cotrel-Dubousset instrumentation (n=11) and soft system stabilization according to Graf (n=14) excellent, good, satisfactory, moderate and poor results were obtained in 78 (67%), 20 (17%), 14 (12%), 4 (3%), and 1 (1%) instances, respectively.     

Anterior lumbar fusion using a hybrid interbody graft

Summary This is a radiographic report of 40 patients (20 men, 20 women) who underwent anterior lumbar interbody fusions (73 levels) utilizing a “hybrid” interbody graft composed of femoral cortical allograft (FCA) bone and iliac crest cancellous autograft bone. The average age at surgery was 38 years (range 17–64 years), and follow-up averaged 1.4 years (range 1.0–2.4 years). Nineteen of the patients had undergone previous lumbar surgery. Thirty-two patients (63 levels) underwent anterior fusion combined with some type of posterior fixation, and eight patients (10 levels) had no posterior fixation. Types of posterior fixation included: for 20 patients (36 levels) Steffee variable screw placement fixation, for 10 patients (23 levels) translaminar facet screws (TFS), for 1 patient (3 levels) Knodt rods and for 1 patient (1 level) facet screws. Based on the persistence of lucent lines at the graft-host interface, three patients (one level each) were felt to have non-unions at their latest follow-ups at 1.4, 1.5 and 2.0 years, respectively. Two of these patients had no posterior fixation, and the other had TFS fixation. The overall fusion rate was 96% (70 of 73 levels). The fusion rate for all levels treated with posterior fixation was 98% compared with 75% for those without fixation. Intervertebral disc heights (IVDH) were measured on all films and corrected for magnification with computer assistance. On average, the IVDH was increased postoperatively but returned to preoperative values at follow-up. IVDH loss was independent of the type of instrumentation used. No complications arose from the use of the hybrid graft. Incorporation of the allograft portion of the graft is slow and was felt to be complete in only 7 of the 73 levels at follow-up. We conclude that the hybrid interbody graft technique is a safe and reliable method for performing anterior lumbar interbody fusions and should be combined with some type of posterior fixation. Long-term follow-up will be required to assess the behaviour of the allograft until incorporation is complete.     

重建钛板枢椎椎弓根螺钉及颗粒状植骨枕颈融合术

目的 探讨重建钛板螺钉及颗粒状自体松质骨植骨在枕颈融合中的应用。方法 2002年4月～2005年1月，选择枕颈区不稳定患者19例，年龄31～67岁；病程3个月～2年。其中枕寰枢椎复合畸形8例，陈旧性寰枢椎骨折脱位8例，类风湿性关节炎所致寰椎前脱位2例，枢椎齿状突肿瘤1例。JOA脊髓功能评分平均9．8分。使用重建钛板和枢椎椎弓根螺钉固定枕颈部，同时枕骨与枢椎后弓间颗粒状自体松质骨植骨。结果 术中、术后无并发症发生，切口Ⅰ期愈合。19例均获随访6个月～2年8个月，平均16个月，均获得了骨性融合。无神经血管损伤，无断钉、断板及内固定松脱。JOA脊髓功能评分平均达14．4分。结论 重建钛板枢椎椎弓根螺钉固定可靠，置入方便，自体颗粒状松质骨具有较高的融合率，在枕颈融合中效果满意。     

Value of polydirectional tomography in the assessment of the postoperative spine after anterior decompression and vertebral body autografting

With the growing number of orthopedic reconstructive spinal procedures, the use of bone grafting has steadily increased in the past decade. An understanding of the biology of bone grafting is essential for both the clinician and radiologist. Despite the advent of computed tomography and magnetic resonance imaging, conventional polydirectional tomography remains an important tool in the evaluation of vertebral body autografts. Trispiral or hypocycloidal tomography plays a valuable role in the assessment of bone graft fusion and possible complications, especially in the presence of metallic fixation devices. We present our imaging experience derived from 375 patients with cervical, thoracic, or lumbar anterior spinal fusion. True graft complications occurred in 27 patients (7%) and consisted of fracture (4%), malpositioning (3%), and infection (<1%).     

凋亡相关蛋白Apr-2的克隆、测序及初步表达

目的: 从HL-60细胞凋亡模型中克隆凋亡相关蛋白Apr-2编码区基因,并对其进行表达,为进一步研究Apr-2的结构功能及多克隆抗体的制备奠定基础.方法: 建立HL-60细胞凋亡模型,提取HL-60凋亡细胞总RNA,以RT-PCR方法获取Apr-2 cDNA编码区全序列,将其与PGEM-T Easy载体连接,转化E.coli DH5α,构建重组克隆载体PGEM-TEasy/apr-2,测序正确后,将目的片段亚克隆入PGEX-4T-2原核表达载体,并转化大肠杆菌, IPTG诱导重组蛋白质表达,分析蛋白质在细菌中的表达分布,进行凝胶自动扫描分析. 结果:序列分析表明,与GenBank中已登录的Apr-2 cDNA编码区序列比较,完全一致.表达的融合蛋白占菌体总蛋白质的40%以上,主要以包涵体的形式存在. 结论:成功的获得了细胞凋亡模型HL-60中Apr-2 cDNA编码区的克隆及其融合蛋白表达产物.     

经关节突入路椎间融合椎弓根固定治疗峡部裂性腰椎滑脱

目的 评价经关节突入路手术治疗峡部裂性腰椎滑脱的应用价值。方法 2000年 9月 ~2003年 5月我院手术治疗峡部裂性腰椎滑脱患者 83例,随访患者 81例,年龄(55. 25±19. 21)岁,随访时间 (1. 68±0. 93)年。按照不同的手术入路方法分为两组,Ⅰ组经关节突入路,椎间融合椎弓根固定;Ⅱ组经椎板切除入路,椎间融合椎弓根固定。按各组术中的临床出血量、手术时间、术前和术后JOA评分等数据经SPSS11. 5统计软件处理数据。结果　术后采用Stauffer Coventry下腰椎术后疗效评定标准:临床优良率分别为 87%与 75%;术后神经功能改善率分别为 87. 81%与62. 88%。术后均无螺钉松动、断裂或者滑脱加重等并发症,有 3例假关节形成。结论　在峡部裂性腰椎滑脱的患者的手术治疗中,经关节突入路椎间融合椎弓根固定技术具有良好的临床效果。