可动型人工椎体的研究进展

目前使用人工椎体植入物在治疗脊柱肿瘤、感染、骨折等疾病已经取得了较好的疗效。然而,融合型人工椎体会导致邻近椎间关节退变,丧失原有的生理曲度及活动度。可动型人工椎体可以一定程度恢复脊柱正常的生理运动,减少脊柱生物力学改变,以减少并发症的发生。可动型人工椎体的设计是在获得可靠稳定性的基础上增加可动装置,其原理大可分为球窩关节和弹性形变,但可动型人工椎体的整体设计还需进一步完善。传统机械加工方法难以加工复杂的假体,其生产的假体与病灶契合率低,而新兴的3D打印技术可以实现假体个性化改进,但其速率慢,成本高等情况有待改善。可动型人工椎体制作的材料大体可分为金属、陶瓷、生物材料、高分子材料等。金属材料以钛合金为主流,应用广泛,但其弹性模量与人骨还有差距,与骨融合尚不理想;陶瓷材料种类丰富,但存在耐磨性差,易碎等特点;生物材料包括自体骨、异体骨等,其来源有限,操作复杂;高分子材料和生物可降解材料种类丰富,理想性能优异,但还需进一步研究其性质与应用。可动型人工椎体仍需提升和发展,临床实验数据仍不足,远期疗效还有待进一步观察研究,本文对可动型人工椎体的发展、优点、设计、加工、材料等方面展开综述,为可动型人工椎体的优化设计、加工处理与临床应用等提供有益参考。     

生物陶瓷人工椎体系统重建椎体缺损的研究

目的检测由脊柱前路解剖型固定钢板,生物陶瓷与骨水泥等组成的生物陶瓷人工椎体系统临床应用的可行性。方法选健康2～4岁山羊14只,平均体重28．6kg,经氯胺酮诱导,气管插管,安氟醚吸入麻醉后,取右下腹腹膜外斜切口,前路切除L4椎体后,应用钛合金解剖型固定钢板、骨水泥、磁性生物陶瓷组成的“生物陶瓷人工椎体”植入体内。结果一般情况：所有试验动物均成活,术后8h即可恢复站立,行走（不使用任何外固定支架）;24h后恢复正常行走,进食。术后6个月,腹部彩色B超检查未见血拴形成,腹部大血管血供正常。定期X线检查,肉眼大体标本观察,光境观察,扫描电镜（SEM）观察,材料与骨实现“生物愈合”。结论“生物陶瓷人工椎体系统”是一个制约性固定结构,类似于“钢筋骨水泥”,稳定性极强,能够保证生物材料与椎骨的“生物愈合”,形成“生物固定”,减少了长期固定“松动”发生的可能,整个系统操作简单,使用安全。具有极大的临床使用价值。     

新型3D打印个体化人工椎体在脊柱重建中的初步研究

目的探讨新型3D打印个体化人工椎体在脊柱重建中的优势,并对其重建效果进行临床评估。方法收集2017年1月至2018年12月行全椎体切除术后采用3D打印个体化人工椎体行脊柱重建的15例肿瘤患者的临床资料,其中男8例,女7例;年龄(39.5±13.4)岁(范围:20~57岁)。原发肿瘤12例,转移肿瘤3例。依据肿瘤位置及周围软组织侵及范围,采取单纯后路或前后路联合手术方式行全椎体切除,并进行3D打印人工椎体重建。分析手术时间、术中出血量、术后人工椎体稳定情况、与相邻椎体骨长入情况,手术前后神经功能改变情况、疼痛视觉模拟评分(visual analogue scale,VAS),局部控制情况及患者生存情况。结果本组15例的手术时间(412.0±166.1)min(范围:135~740 min);术中出血量(4140.0±3809.3)ml(范围:100~14000 ml);术后随访(23.2±7.0)个月(范围:12~35个月)。术前VAS评分(4.7±1.1)分,术后7 d(1.6±0.6)分,末次随访时(1.0±0.5)分,术后7 d及末次随访较术前的差异均有统计学意义(P<0.001)。术后7 d术前Frankel分级C级的3例逐渐恢复到D级,余12例D级和E级无变化,差异无统计学意义(Z=-1.732,P=0.083);术后末次随访时Frankel分级较术后7 d无明显变化。影像学表现:术后3个月时人工椎体与临近椎体已有初步的骨愈合;术后12个月时人工椎体和邻近椎体有大量骨连接形成,形成骨整合;术后24个月时可见人工椎体与邻近椎体骨整合更加确实。在随访期内人工椎体无松动移位,内固定无断裂失效。术中1例出现胸膜破裂,术后1例发生脑脊液漏,1例出现L5神经根麻痹,积极对症处理后均痊愈。1例血管内皮细胞瘤和1例上皮样血管肉瘤,分别于术后33个月和35个月死亡,1例软骨肉瘤术后16个月局部复发,服用安罗替尼治疗,肿瘤无进展,余12例无肿瘤复发及远处转移。结论利用3D打印个体化人工椎体对脊柱肿瘤切除后重建,有利于精确恢复脊柱连续性,提供更好的界面匹配,利于骨的长入,同时人工椎体植入后即刻及远期稳定性良好,可满足脊柱重建的需要。     

人工椎体的发展与应用

人工椎体在治疗脊柱肿瘤、结核、骨折等疾病方面取得了较好的效果。目前人工椎体种类繁多、各有利弊,总体分为融合型与可动型2类,融合型根据高度能否调节及自稳性强弱分为支撑固定型、可调固定型、自固定型3三类,自固定型又因轴套螺纹旋转结构有高度能否调节之分;可动型因球窝关节或镂空结构等可动装置的存在代替了椎间盘的功能,一定程度上保留了脊柱的活动度。人工椎体的制作材料目前包括金属、陶瓷、生物材料及高分子复合材料等多种材料,金属以钛合金为主导,至今已发展至第3代,但仍存在表面生物活性不佳等缺陷;陶瓷以羟基磷灰石复合材料、磁性生物陶瓷、多晶氧化铝陶瓷等为代表,但是存在着加工复杂、力学性能参差不齐等缺陷;生物材料主要以异种骨为主,其结构与性能与人体骨最为接近,但是存在韧性低、制作复杂等缺陷;高分子复合材料因生物学特性总体分为生物降解型与非降解型,分别以聚乙交酯与聚乙烯为代表,各有利弊。假体的设计及制作材料虽取得了较大进步,但尚难以完全满足脊柱内置物的苛刻要求,有待进一步优化。3D打印技术使假体复杂结构的加工以及个体化定制成为可能,具有广阔的发展前景,但制作周期长、成本高等缺陷有待克服。虽然人工椎体在治疗脊柱疾病方面疗效显著,但不乏假体松动、移位的报道,加之评价标准不统一,随访时间短,其确切疗效有待进一步观察。     

人工椎体置换行脊柱重建术

目的 :分析人工椎体行脊柱重建术的手术方法选择和临床效果。方法 :1997年 8月～ 2 0 0 2年 12月 ,应用人工椎体行颈、胸、腰、骶椎椎体重建术 3 1例。观察患者神经症状恢复及椎节高度、椎间角、人工椎体植入位置变化等。结果 :平均随访 16个月 ,所有患者疼痛缓解或消失 ,2 4例神经功能较术前改善。术后早期椎节高度较术前平均增加 3mm ,术后 3个月椎节有不同程度塌陷 ;术后椎间角较术前平均减少 6 6°。人工椎体在椎体中部者 14例 ,中部偏后 4例 ,中部偏前 1例 ,其余 12例 (3 9% )人工椎体在椎体侧方或倾斜放置。无人工椎体脱落或滑出。结论 :人工椎体置换可满意恢复椎节高度及生理曲度 ,有效重建脊柱稳定性 ,但应尽量避免其斜放或偏向一侧放置。人工椎体是否附加内固定取决于病变的部位、切除范围、患者的年龄、职业、人工椎体种类等。     

Prospective multicenter study with a new implant for thoracolumbar vertebral body replacement

BACKGROUND: There are several therapeutic strategies for restoring the anterior column of the vertebral body after trauma, tumor and infection. We present a multicenter study with a new distractable titanium implant for vertebral body replacement. METHODS: Prospective documentation was collected of the first 126 patients treated with Synex during the 1st year of the clinical course. There was an evaluation of surgical indication, classification, localisation of the lesion, operative details, complications, and clinical course. RESULTS: A total of 70 men and 56 women (average age 46.9 years) underwent surgery for vertebral fracture, correction of posttraumatic kyphosis, infection, vertebral tumor and metastasis, and other diseases such as ankylosing spondylitis. Synex was used in open and minimally invasive surgery. In almost every case, an additional anteriorly or posteriorly stabilizing implant was used. Anterior fusion was performed with cement in tumors and autologous bone in fractures. Mono- and multisegmental lesions in the thoracic and lumbar spine were treated. CONCLUSIONS: The Synex implant is very easy to manage and is suitable for many indications such as vertebral fracture, correction of posttraumatic kyphosis, infection, vertebral tumor/metastasis, and other diseases. The vertebral body replacement can be used for defects of different sizes with the option of in situ distraction. No cases of implant failure, dislocation, or other implant-related complication have been observed. As a consequence of this prospective series, an additional implant size has been added, and the distraction device (spreading forceps) has been modified for more powerful spreading.     

可调式中空钛合金人工椎体的生物力学评价

目的 测试并评价可调式中空肽合金人工椎体的生物力学性能。方法 27具小牛胸腰椎标本随机分为对照组(IS)、髂骨植骨组(IBG)及人工椎体组(AVB)3组，测试屈曲、伸展、侧屈及扭转状态下的载荷—应变、载荷—位移关系变化以及最大载荷时的应力强度及刚度。IBG组、AVB组分别附加前路钢板及后路椎弓根螺钉进行第2次、第3次测试，各组间进行比较，并进行统计学处理。结果 髂骨植骨组不同状态下应变及位移均大于原始标本，人工椎体组小于原始标本，且差异具显著性(P＜0．05)；附加内固定后应变及位移均较不附加内固定者减小(P＜0．05)，且人工椎体组附加内固定后分别小于髂骨植骨组(P＜0．05)。人工椎体附加或不附加内固定时的应力强度及轴向刚度均大于或接近原始标本，而单纯髂骨植骨组伸展及侧屈状态下，以及附加前路或后路固定后的侧屈状态下的应力强度低于原始标本；轴向压缩刚度亦小于原始标本，附加前路钢板后有所提高，但只有附加后路椎弓根螺钉后才与原始标本相当。人工椎体组的扭转强度大于髂骨组，扭转刚度与原始标本接近。而髂骨植骨组即使附加内固定后的扭转刚度亦远小于原始标本。结论 单纯人工椎体替代基本可满足生物力学性能要求，附加前路或后路固定后，可满足包括扭转性能在内的生物力学要求；单纯髂骨植骨后不满提供足够的生物力学稳定性、必须辅加内固定，同时应注意术后保护。     

人工腰椎间盘植入后椎体应力分布的比较研究

目的 通过三维有限元的方法研究正常腰椎间盘、髓核摘除术后腰椎间盘、人工腰椎间盘3组椎体的应力分布,探讨人工腰椎间盘植入对椎体应力分布的影响。方法 利用有限元软件MSC．MARK,建立正常腰椎间盘、髓核摘除、人工腰椎间盘及L4-5运动节段的三维模型,然后模拟腰椎节段的运动,进行椎体应力分布的比较研究。结果 人工腰椎间盘植入后在各种运动状态下椎体松质骨的应力水平显著低于正常腰椎间盘及髓核摘除术后腰椎间盘,且应力呈均布状态,但髓核摘除后椎体松质骨的应力水平较正常腰椎间盘组有所提高,并且在不同运动状态下应力的分布状态有所不同,前屈时,应力集中于椎体松质骨的前部,后伸时集中于椎体松质骨的后部,右侧弯时集中于椎体松质骨的右侧,压缩、旋转时,应力较为均布。结论 从人工腰椎间盘植入对椎体的生物力学影响来看,用人工腰椎间盘置换术重建椎间盘的功能是合理的。     

多孔隙3D打印人工椎体在脊柱结核重建手术中的应用

目的：观察3D打印人工椎体应用于脊柱结核椎体重建的临床结果。方法：2018年5月～2021年6月,我科连续住院手术治疗36例脊柱结核患者,其中10例采用病灶清除、3D打印人工椎体重建,包括3例定制假体,7例非定制假体;男性4例,女性6例;年龄26～73岁,中位年龄59岁。颈椎1例,胸椎4例,胸腰段2例,腰椎1例,腰骶段2例。累及3个相邻椎体2例,2个相邻椎体8例。所有患者术前接受2周正规抗结核药物化疗,根据椎体病灶大小规划手术切除范围,个体化设计假体与骨的接触面和固定模式。术后继续口服抗结核药物治疗12～18个月,每月复查血沉、血常规、肝肾功能,定期随访手术部位影像片、VAS疼痛评分、Frankel神经功能、假体融合情况、日常活动功能等。结果：平均随访20.1±9.1个月（12～45个月）,手术节段角度术前为-24°～24°,末次随访时为-8°～32°,后凸改善0～32°。术前VAS评分6.4±2.6分,末次随访时为2.0±1.8分;末次随访Frankel脊髓功能分级：8例改善1级或以上,2例维持稳定;除1例耐药结核外,所有假体位置稳定,无假体松动、下沉和移位。假体融合情况Bridwe...     

可调式中空人工椎体的研制与临床应用

目的自行研制可调式中空人工椎体,并将其应用于治疗脊椎肿瘤和椎体爆裂性骨折患者。方法采用无磁性的医用钛金属加工制成可调式中空人工椎体,其长度可调节,中空部分可植骨,周壁上孔隙可使植骨与周围骨组织融合,上下端带刺,可插至断端骨质内固定。椎体切除减压后置入人工椎体,撑开固定治疗椎体肿瘤和爆裂性骨折 23例。术后定期进行 X线检查,观察手术椎节的稳定性和融合情况。结果随访 6个月～ 4年,平均 1.2年。脊髓功能障碍按 Frankel分级评价,术后平均提高 1.2级,神经根引起的疼痛迅速缓解。 X线平片定期观察,结果显示人工椎体稳定、椎间高度恢复良好。结论可调式中空人工椎体可撑开施术椎节,恢复前柱高度,并提供即刻稳定,适用于脊柱椎节广泛切除的病例。     

纳米羟基磷灰石/聚酰胺复合人工椎板预防脊柱后路术后椎管内瘢痕粘连的实验研究

目的：探讨纳米羟基磷灰百／聚酰胺（nano-hydmxyapatite／polyamide-66，n-HA／PA66）复合人工椎板在防止脊柱后路术后椎管内瘢痕粘连，重建脊柱后部结构完整性的价值。方法：22只1岁龄雄性家犬行L5椎板切除，实验组13只行复合人丁椎板植入，另9只作空白对照。术后4、8、16、24周各时相点摄X线片，行组织学、扫描电镜观察；术后24周行MRI检查．结果：实验组术后16～24周复合人工椎板界面观察到软骨细胞及板层骨，硬膜粘连程度比对照组明瞳减轻（P〈0．01）。术后24周时MRi显示实验组椎管完整性恢复。结论：n-HA／PA66复合材料具有良好的生物相容性，能有效阻止硬膜外粘连。     

An experimental study of the construction of a new right ventricle

This study was undertaken to design and estimate the method to construct a new right ventricle in single ventricle. Twenty five mongrel dogs were used. In this study three types of conduits were used. In Group A vinyl tube, in Group B Woven Dacron tube and in Group C organized Woven Dacron tube were used. Under total cardiopulmonary bypass right atrium was incised. The conduit was inserted through tricuspid annulus and right ventricle into pulmonary trunk. The conduit was fixed at pulmonary trunk and tricuspid annulus. Right ventricle was made closed cavity, and right ventricular pressure affected pulmonary arterial pressure through the conduit wall. In this study right ventricle was regarded as single ventricle. Hemodynamic investigation revealed that central venous pressure must be elevated to get the normal cardiac output. Effective pulse pressure was obtained in the pulmonary artery. Pulmonary vascular resistance decreased as increasing of the pulmonary pulse pressure. Pulmonary pulse pressure was significantly low in group C. It was considered that the intra-ventricular elastic conduit was new method to obtain the pulmonary pulse pressure.     

Vertebral body stenting: a new method for vertebral augmentation versus kyphoplasty

Vertebroplasty and kyphoplasty are well-established minimally invasive treatment options for compression fractures of osteoporotic vertebral bodies. Possible procedural disadvantages, however, include incomplete fracture reduction or a significant loss of reduction after balloon tamp deflation, prior to cement injection. A new procedure called “vertebral body stenting” (VBS) was tested in vitro and compared to kyphoplasty. VBS uses a specially designed catheter-mounted stent which can be implanted and expanded inside the vertebral body. As much as 24 fresh frozen human cadaveric vertebral bodies (T11-L5) were utilized. After creating typical compression fractures, the vertebral bodies were reduced by kyphoplasty (n = 12) or by VBS (n = 12) and then stabilized with PMMA bone cement. Each step of the procedure was performed under fluoroscopic control and analysed quantitatively. Finally, static and dynamic biomechanical tests were performed. A complete initial reduction of the fractured vertebral body height was achieved by both systems. There was a significant loss of reduction after balloon deflation in kyphoplasty compared to VBS, and a significant total height gain by VBS (mean ± SD in %, p < 0.05, demonstrated by: anterior height loss after deflation in relation to preoperative height [kyphoplasty: 11.7 ± 6.2; VBS: 3.7 ± 3.8], and total anterior height gain [kyphoplasty: 8.0 ± 9.4; VBS: 13.3 ± 7.6]). Biomechanical tests showed no significant stiffness and failure load differences between systems. VBS is an innovative technique which allows for the possibly complete reduction of vertebral compression fractures and helps maintain the restored height by means of a stent. The height loss after balloon deflation is significantly decreased by using VBS compared to kyphoplasty, thus offering a new promising option for vertebral augmentation.     

Biomechanical compression tests with a new implant for thoracolumbar vertebral body replacement

The authors present an investigation into the biomechanical functioning of a new titanium implant for vertebral body replacement (Synex). Possible indications are fractures and/or dislocations with damage of the anterior column, posttraumatic kyphosis and tumors of the thoracolumbar spine. The construction must be supplemented by a stabilizing posterior or anterior implant. For best fit and contact with adjacent end-plates, Synex is distractable in situ. We performed comparative compression tests with Synex and MOSS ("Harms mesh cage") on human cadaveric specimens of intact vertebrae (L1). The aim of the study was to measure the compressive strength of the vertebral body end-plate in uniaxial loading via both implants to exclude collapse of Synex in vivo. Twelve human cadaveric specimens of intact vertebrae (L1) were divided into two identical groups (matched pairs) according to bone mineral density (BMD), determined using dual-energy quantitative computed tomography (DE-QCT). The specimens were loaded with an axial compression force at a constant speed of 5 mm/min to failure, and the displacement was recorded with a continuous load-displacement curve. The mean ultimate compression force (Fmax) showed a tendency towards a higher reading for Synex: 3396 N versus 2719 N (non-significant). The displacement until Fmax was 2.9 mm in the Synex group, which was half as far as in the MOSS group (5.8 mm). The difference was significant (P < 0.001). The compression force was twice as high, and significantly (P < 0.05) higher with Synex at displacements of 1 mm, 1.5 mm and 2 mm. A significant (P < 0.001) correlation (R = 0.89) between Fmax and BMD was found. Synex was found to be at least comparable to MOSS concerning the compressive performance at the vertebral end-plate. A possible consequence of the significantly higher mean compression forces between 1 and 2 mm displacement might be decreased collapse of the implant into the vertebral body in vivo.     

人工椎体在胸腰椎病变中的应用

[目的]观察人工椎体在胸腰椎肿瘤、结核及骨折治疗中的外科疗效。[方法]对169例胸腰椎患者(其中包括64例肿瘤、66例结核、39例爆裂性骨折)的外科疗效进行回顾性分析。其中有57例伴有胸腰椎后凸畸形,术前Cobb s角27.1°~65.4°,平均(38.5±10.7)°。对所有患者进行病变椎体大部或完整切除,椎间撬拔撑开复位,可调式中空笼状钛合金人工椎体植骨替代,辅以前路椎体钉板(棒)系统或后路椎弓根钉系统行邻近椎节固定,Ⅰ期重建脊柱稳定性,观察术后局部疼痛缓解,脊髓神经功能恢复、脊柱椎节的稳定性及后凸畸形的矫治情况。[结果]随访12~46个月,平均32个月。所有患者术后疼痛缓解,肿瘤、结核病人术后局部均无复发,脊髓神经功能无加重损伤,73例患者脊髓神经功能得到不同程度恢复。术后影像学检查提示:脊柱内固定物在位,椎体序列恢复良好,椎间高度恢复。后凸畸形者术后矫正角度(31.6±8.3),°最后随访时矫正角度丢失(4.1±3.8)°。[结论]胸腰椎病椎切除、人工椎体植骨替代并内固定,能彻底减压、缓解疼痛,能有效重建脊柱稳定,恢复脊柱序列。