Biomechanical effects of bone cement volume on the endplates of augmented vertebral body: a three-dimensional finite element analysis

Background Previous studies have suggested that percutaneous vertebroplasty might alter vertebral stress transfer,leading to adjacent vertebral failure.However,no three-dimensional finite element study so far accounted for the stress distributions on different cement volumes.The purpose of this study was to evaluate the stress distributions on the endplate under different loading conditions after augmentation with various volumes of bone cement.Methods L2-L3 motion segment data were obtained from CT scans of the lumbar spine from a cadaver of a young man who had no abnormal findings on roentgenograms.Three-dimensional model of L2-L3 was established using Mimics software,and finite element model of L2-L3 functional spinal unit （FSU） was established using Ansys10.0 software.For simulating percutaneous vertebral augmentation,polymethylmethacrylate （PMMA） was deposited into the bipedicle of the L2 vertebra.The percentage of PMMA volume varied between 15％ and 30％.The stress distributions on the endplate of the augmented vertebral body were calculated under three different loading conditions.Results In general,the stress level monotonically increased with bone cement volume.Under each loading condition,the stress change on the L2 superior and inferior endplates in three kinds of finite element models shows monotonic increase.Compared with the stress-increasing region of the endplate,the central part of the L2 endplate was subject to the greatest stress under three kinds of loading conditions,especially on the superior endplate and under flexion.Conclusions The finite element models of FSU are useful to optimize the planning for vertebroplasty.The bone cement volume might have an influence on the endplate of the augmentation,especially the superior endplate.It should be noted that the optimization of bone cement volume is patient specific; the volume of the bone cement should be based on the size,body mineral density,and stiffness of the vertebrae of individual patients.     

Lumbus dosal spine

<正>209195 Biomechanical analysis of a novel perfusional pedicle screw augmentation with bone cement in osteoporotic vertebra/Yang Huilin(Dept Orthopaed First Affil Hosp Soochow Univ Suzhou 215006)…∥Chin J Orthop.-2009,29(3).-241~247Objective To clarify the biomechanical stability of novel perfusional pedicle screw(NPPS) in spinal vertebrae with osteoporosis.Methods Forty-two vertebrae(T11 to L5) obtained from 6 formalin preserved cadavers (5 males and 1 females; mean age,73 years) were used.The mean bone mineral density was (0.696±0.14)g/cm2.The NPPS was inserted into one pedicle of each vertebra,then early-doughtime cement 2 ml was perfused with the bone cement pusher and perfusion tube under X-ray into the vertebra body through the hollow part of NPPS,and the control screw,an improved CD2 screw,was inserted into the contralateral pedicle.Three vertebrae were chosen to observe the distribution of cement,and the other 39 vertebrae were randomly divided into three groups to make the pull-out test,rotation-out torque test,and cyclic bending resistance test respectively.Ten novel perfusional pedicle screws and ten control screws were respectively examined by three-point bend test.Results Cement perfused around the side holes of the distal screw in all vertebral body and no cement leakage occured.The mean maximum force at pull-out was (760±178) N for the NPPS and (355±87)N for the control screw.The mean maximum rotating-out torque was (1.34±0.377)N·m for the NPPS and (0.488±0.205) N·m for the control screw.In cyclic bending resistance test,the NPPS was found to with stand a greater number of cycles or greater loading before loosening.About 30.8%(4/13) of the NPPS became loosing (displacement>2.000 mm),the mean load of the loosening screws was (150±46)N and the mean displacement of the non-loosening screws was (0.661±0.289) mm.All of the control screws were loosening among 50-200 N before 800 cycles.Conclusion The manipulation of NPPS is simple with the application of cement pusher and pe     

COA:Intervertebral Disc Degeneration and Bone Density in Degenerative Lumbar Scoliosis: A Comparative Study between Patients with Degenerative Lumbar Scoliosis and Patients with Lumbar Stenosis

Objectives: To compare the intervertebral disc degeneration and bone density at major curve in degenerative lumbar scoliosis (DLS) and lumbar spinal stenosis. Methods: 96 patients with degenerative lumbar scoliosis(DLS) were retrospectively enrolled and 96 patients with lumbar spinal stenosis were selected as control group from Jan.2001 to Aug.2010. Cobb angle, the height of the apical disc and the contiguous disc superiorly and inferiorly in convex and concave side, the height of the convex and concave side of the apical and the contiguous vertebral body superiorly and inferiorly was measured in scoliosis group, the height of L2/L3, L3/L4, L4/L5 discs and the height of L2/L4 vertebral body was measured in control group. The grade of intervertebral disc degeneration was evaluated in T2WI sagittal image in both groups. The bone density of lumbar vertebrae was measured with dual-energy x-ray. Results: Scoliosis group: The intervertebral disc height in convex side was greater than the height in the concave side (P﹤0.001), The vertebral body height in convex side was greater than the height in the concave side (P=0.016). While there was significant statistically difference between the scoliosis group and the control groups (P=0.003). There was significant statistically difference of the T-value and the rate of osteoporosis between two groups (P﹤0.001, P﹤0.001). By using multiple linear regression analysis, the above results are further shown. Conclusion: In degenerative scoliotic major curves: the degeneration of intervertebral disc is more severe, bone density is lower in patients with DLS compared with lumbar spinal stenosis patients.     

经皮椎体成形术治疗骨质疏松椎体骨折的远期疗效与影像学表现

Background  Percutaneous vertebroplasty (PVP) has become a popular procedure for painful vertebral osteoporotic fracture (VOF), with immediate pain relief and improved mobility; however, polymethylmethacrylate (PMMA) injected into the vertebral body is not absorbable and little information is available concerning the long-term results. In this retrospective study, we evaluated the long-term clinical results and radiological changes after PVPs for VOFs.

Methods  Fifty-one patients with VOFs were treated by PVPs with PMMA between 2000 and 2004. After >7 years of follow-up, eight patients had died from causes unrelated to the intervention and 12 patients were lost to follow-up, thus leaving 31 patients available for evaluation with an average length of follow-up of 9.2 years (follow-up rate, 72.1%). Among these 31 patients, the PMMA was injected at 43 levels with a mean volume of 4.3 ml per level (range, 2-6 ml). The pain was assessed with a visual analog scale (VAS), and the mobility was graded as walking without difficulty (grade 1), walking with assistance (grade 2), and bedridden (grade 3). Plain radiographs and computed tomography (CT) were obtained and assessed pre-operatively, immediately post-operatively, and after 7 years of follow-up. The PMMA, vertebral height, and Cobb angle were assessed and compared.

Results  All of the patients experienced pain relief and improved mobility after intervention and during the follow-up period. Cement leakage was detected in post-operative CT scans in 9 of 51 patients, but without neurological compromise. For the 31 patients followed up over 7 years, the VAS decreased from 8.3±2.6 pre-operatively, to 2.1±1.6 immediately post-operatively, and 1.0±0.9 at the final follow-up evaluation, with significantly improved mobility. Additional compression fractures occurred at adjacent levels in three patients, and there were no new fractures at the augmented vertebrae. Based on a review of the radiographs, neither loose nor displaced cement was detected. The changes in vertebral height and Cobb angle were not significant. On CT scans, the cement closely contacted or infiltrated the trabecular bone. The boundary between the cement and trabecular bone was indistinct and there was no evident radiolucent gap between the cement and trabecular bone.

Conclusions  At an average follow-up of 9.2 years, PVPs provided sustained pain relief and improved mobility in patients with VOFs. The PMMA injected into the vertebral body combined closely with the host trabecular bone without adverse reactions.

     

Intervertebral disc degeneration and bone density in degenerative lumbar scoliosis: a comparative study between patients with degenerative lumbar scoliosis and patients with lumbar stenosis

Background  Degenerative lumbar scoliosis is common in older patients. Decreased bone density and the degeneration of intervertebral discs are considered to be correlated with degenerative lumbar scoliosis. A means of quantifying the relative signal intensity for degenerative disc disease has not been previously discussed. The purpose of this study was to compare bone mineral density and intervertebral disc degeneration between degenerative lumbar scoliosis and lumbar spinal stenosis patients in a nine-year retrospective study.

Methods  From January 2001 to August 2010, 96 patients with degenerative lumbar scoliosis were retrospectively enrolled and 96 patients with lumbar spinal stenosis were selected as controls. Cobb angle, height of the apical disc and the contiguous disc superiorly and inferiorly on convex and concave sides, the height of the convex and concave side of the apical and the contiguous vertebral body superiorly and inferiorly were measured in the scoliosis group. The height of L2/L3, L3/L4, L4/L5 discs and the height of L2/L4 vertebral body was measured in the control group. The grade of intervertebral disc degeneration was evaluated using T2WI sagittal images in both groups. The bone density of lumbar vertebrae was measured with dual-energy X-ray.

Results  In scoliosis group, the intervertebral disc height on the convex side was greater than the height on the concave side (P <0.001). The vertebral body height on the convex side was greater than the height on the concave side (P=0.016). There was a significant difference between the scoliosis group and the control group (P=0.003), and between T-value and the rate of osteoporosis between the two groups (both P <0.001). Results were verified using multiple linear regression analysis.

Conclusions  Degenerative lumbar scoliosis is accompanied by height asymmetry between the intervertebral disc and vertebral body regarding the convex and concave surfaces. There is a positive correlation between the angle of scoliosis and the disc index, the degree of degeneration of the intervertebral disc, and a negative correlation between the angle of scoliosis and bone density.

     

Treatment of Thoracolumbar Vertebrate Fracture by Transpedicular Morselized Bone Grafting in Vertebrae for Spinal Fusion and Pedicle Screw Fixation

To enhance the fusion of graft bone in thoracolumbar vertebrae and minimize the postoperative loss of correction, short-segment pedicle screw fixation was reinforced with posterior moselizee bone grafting in vertebrae for spinal fusion in patients with thoracrolumbar vertebrate fractures. Seventy patients with thoracrolumbar vertebrate fractures were treated by short-segment pedicle screw fixation and were randomly divided into two groups. Fractures in group A （n=20） were rein-forced with posterior morselized bone grafting in vertebrae for spinal fusion, while patients group B （n=50） did not receive the morselized bone grafting for bone fusion. The two groups were compared in terms of kyphotic deformity, anterior vertebral height, instrument failure and neurological functions after the treatment. Frankel grading system was used for the evaluation of neurological evaluation and Denis scoring scale was employed for pain assessment. The results showed that the kyphosis correction was achieved in both group A and group B （group A： 6.4 degree; group B： 5.4 degree）/At the end of follow-up, kyphosis correction was maintained in group A but lost in group B （P=0.0001）. Postoperatively, greater anterior height was achieved in group A than in group B （P〈0.01）. During follow-up study, anterior vertebral height was maintained only in Group A （P〈0.001）. Both group A and group B showed good Denis pain scores （P1 and P2） but group A outdid group B in terms of control of severe and constant pain （P4 and P5）. By Frankel criteria, the changes in neurological functions in group A was better than those of group B （P〈0.001）. It is concluded that reinforcement of short-segment pedicle fixation with morselized bone grafting for the treatment of patients with thoracolumbar vertebrae fracture could achieve and maintain kyphosis correction, and it may also increase and maintain anterior vertebral height. Morselized bone grafting in vertebrae offers immediate spinal stability in patients with th     

Preliminary study on a single balloon cross-midline expansion via unipedicular approach in kyphoplasty

Background Recently, bilateral transpedicular kyphoplasty with a single balloon was performed for osteoporotic vertebral body compression fractures （OVCFs） to reduce the fees of the operation, but the time of operation and radiation exposure are longer. The aim of this study was to determine the safety and effectiveness of a single balloon cross-midline expansion via unipedicular approach in kyphoplasty for OVCFs. Methods Thirty-six patients with painful OVCFs （61 vertebrae） were enrolled in this research. Unilateral transpedicular puncture was performed under the fluoroscopy monitoring of an oblique angle down the pedicle. A single balloon was introduced through unipedicular approach, The final balloon position was in the midline of the vertebral body with the balloon cross-midline expansion and bone cement filled. Clinical outcomes were determined by comparison of the preoperative and postoperative visual analogue scale （VAS） and Oswestry disability index （ODI）. Radiographic assessment included restoration of vertebral height and correction of kyphosis. Follow-up was conducted for 6-12 months （mean 9.2 months）. Results Thirty-six consecutive patients with 61 vertebrae were successfully operated on with a mean operation time of 37.4 minutes per vertebra. All patients had dramatic pain relief and functional recovery within 96 hours after the procedure with no surgery or device-related complications. VAS score improved from 7.27±1.02 preoperatively to 2.71±0.75 postoperatively （P 〈0.01）. ODI score was decreased from （71.14±10.94）% preoperatively to （26.56±6.35）% postoperatively. The average loss of anterior body height was （14.33±2.76） mm before procedure and （10.03±1.83） mm after procedure （P 〈0.01）, while the average loss of middle body height was （10.15±2.70） mm before procedure and （5.89±1.83） mm after procedure （P 〈0.01）. The kyphotic deformity was corrected from （23.43±5.00） degree to （16.16±2.77） degree （P 〈0.01）. The pain     

Local treatment of osteoporosis with alendronate-loaded calcium phosphate cement

Background A new treatment strategy is to target specific areas of the skeletal system that are prone to clinically significant osteoporotic fractures.We term this strategy as the ＂local treatment of osteoporosis＂.The study was performed to investigate the effect of alendronate-loaded calcium phosphate cement （CPC） as a novel drug delivery system for local treatment of osteoorosis.Methods An in vitro study was performed using CPC fabricated with different concentrations of alendronate （ALE,0,2,5,10 weight percent （wt％））.The microstructure,setting time,infrared spectrum,biomechanics,drug release,and biocompatibility of the composite were measured in order to detect changes when mixing CPC with ALE.An in vivo study was also performed using 30 Sprague-Dawley rats randomly divided into six groups：normal,Sham （ovariectomized （OVX） ＋ Sham）,CPC with 2％ ALE,5％ALE,and 10％ ALE groups.At 4 months after the implantation of the composite,animals were sacrificed and the caudal vertebrae （levels 4-7） were harvested for micro-CT examination and biomechanical testing.Results The setting time and strength of CPC was significantly faster and greater than the other groups.The ALE release was sustained over 21 days,and the composite showed good biocompatibility.In micro-CT analysis,compared with the Sham group,there was a significant increase with regard to volumetric bone mineral density （BMD） and trabecular number （Tb.N） in the treated groups （P ＜0.05）.Trabecular spacing （Tb.Sp） showed a significant increase in the Sham group compared to other groups （P ＜0.01）.However,trabecular thickness （Tb.Th） showed no significant difference among the groups.In biomechanical testing,the maximum compression strength and stiffness of trabecular bone in the Sham group were lower than those in the experimental groups.Conclusions The ALE-loaded CPC displayed satisfactory properties in vitro,which can reverse the OVX rat vertebral trabecular bone microarchitecture and biomechanical p     

Treatment of osteoporotic vertebral body compression fractures by percutaneous vertebroplasty

Objective: To explore the effect of percutaneous vertebroplasty to treat osteoporotic vertebral body compression fractures. Methods: Seventeen patients with compression fractures at 27 different levels came in for percutaneous vertebroplasty. Under the guidance of C-ann image intensifier, bone needle was inserted into the fracture vertebral bodies via a unilateral transpedicular approach.Polymethyl methacrylate (PMMA) was injected slowly under continuous fluoroscopic control. Then the effect was evaluated after operation.Results: Follow-up results among 15 patients were studied, other two patients lost contact. The follow-up period was from three to seven months. No patient had relapse of compression fracture. Leakage of the cement outside the vertebral body was seen in four bodies. All patients had a complete relief after Percutaneous vertebroplasty(PVP). Conclusion: PVP is an efficient minimally invasive technique to treat osteoporotic vertebral body compression fractures.     

Preliminary clinical outcomes of percutaneous kyphoplasty with Sky-bone expander

Background Percutaneous kyphoplasty (PKP) using balloon expander has been proved to be effective in the treatment of painful vertebral compression fractures. Recently, Sky-bone expander, an alternative bone expander for PKP has been developed. The purpose of this study was to show our preliminary clinical outcomes of PKP with Sky-bone expander.Methods PKP with Sky-bone expander was performed in 25 patients (30 vertebrae). The operation time, bleeding volume, cement volume injected were recorded. The pain and functional activities of the patients before and after the operation were compared using Wilcoxon signed-rank test. The cement distribution in the vertebrae, vertebral height restoration, and kyphosis correction after the procedure were evaluated by radiography. The pre- and post-operative absolute values of the vertebral height and kyphotic angle were compared by paired-sample t test. All the patients were followed up by telephone or clinic consulting after being discharged from our hospital.Results The procedure was performed successfully in all the patients. Bipedicular injection was used in 2 of the patients, and unipedicular injection was made in the others. The operation time ranged from 25 to 120 minutes (45 minutes per vertebra on average). The average bleeding volume was about 20 ml. Polymethylmethacrylate1.5－5.0 ml (mean, (3.15±0.78) ml) was injected through each pedicle into all the patients except one, who received calcium sulphate 3.5 ml instead. The patients were followed up for 12－15 months (13.5 months on average). The mean visual analogue scale (VAS) score, Oswestry Disability Index, anterior, midline, and posterior vertebral height, and kyphotic angle of the patients were improved significantly at the end of the follow-up compared with those before the operation. (2.5±1.3, 35.1%, (20.94±6.15) mm, (20.26±4.59) mm, (26.72±3.49) mm, and 8.2( )degrees vs. 8.5±1.9, 61.2%, (19.11±6.72) mm, (15.88±5.73) mm, (25.78±3.67) mm, and 17.3 degrees; all P&lt;0.05). The cement distribution with unipedicular injection was mostly limited within the injection site in the vertebral body. Cement extravasation was seen at ten levels (33.3%). Conclusions PKP with Sky-bone expander is an effective and relatively safe alternative to the PKP using balloon expander. It can relieve pain, improve physical function, and restore the height of the collapsed vertebrae, but the cement extravasation is unsolved.     

经皮椎体成形术骨水泥与终板关系对术后椎体高度丢失的影响

 目的 研究经皮椎体成形术(percutaneous vertebroplasty, PVP)骨水泥与终板关系对术后椎体高度丢失的影响。方法 回顾性分析2013年6月至2016年5月行PVP术治疗84例单一节段骨质疏松性椎体压缩性骨折的老年女性患者的临床资料,根据术后伤椎正侧位X片和CT检查显示骨水泥与终板的接触情况分为骨水泥与终板接触组(40例,平均年龄76.88岁)和骨水泥与终板非接触组(44例,平均年龄77.96岁),比较两组患者骨水泥灌注量、手术时间、伤椎高度恢复率、术后3个月椎体高度丢失率、术后矢状位Cobb角变化值和骨水泥渗漏率等指标。结果 两组患者的年龄、体重指数、术前血钙和磷水平、骨密度值、术前椎体压缩率差异无统计学意义(P＞0.05),骨水泥与终板接触组术后椎体高度丢失率和术后矢状位Cobb角变化值明显小于非接触组,差异具有统计学意义(P＜0.05)。但两组骨水泥渗漏等指标差异无统计学意义(P＞0.05)。 结论 骨水泥与终板的接触可减少术后椎体高度的丢失,且并不增加骨水泥渗漏率。     

经单、双侧椎弓根入路椎体成形术生物力学比较研究

目的：通过对离体椎体经单侧和双侧椎弓根入路行椎体成形．对两种椎体成形方法的生物力学行比较研究。方法：采集尸体的腰椎标本（L1—L5），共20个椎体，分别进行非破坏性生物力学测试。然后在前屈压缩载荷下造成椎体骨折，同时测定极限载荷和刚度值。然后标本随机分成两组．分别经单侧椎弓根注入椎体4ml PMMA．经双侧椎弓根灌注4ml PMMA（每侧2m1）。椎体成形术后再进行生物力学测试．记录相关生物力学参数值。结果：两组椎体成形术后椎体在非破坏性载荷下标本轴向刚度较初始有明显增加（P〈0．05），不同灌注入路组之间无明显差异修0．05），各组抗压极限载荷较初始都有显著性提高（P〈0．05），但各组之间差异无统计学意义修0．05）。结论：两种骨水泥灌注入路都能较好的恢复椎体的生物力学性能．两者之间差别无统计学意义。     

聚甲基丙烯酸甲酯与可吸收骨水泥治疗骨质疏松椎体压缩骨折的临床疗效对照研究

目的：回顾性分析骨质疏松椎体压缩骨折患者在行经皮椎体后凸成形术（percutaneous kyphoplasty, PKP）中使用聚甲基丙烯酸甲酯（polymethylmethacrylate, PMMA）与GeneX骨水泥的治疗结果差异,为PKP手术椎体填充材料的选择提供参考。方法： 回顾性分析2012年6月至2013年6月北京大学第三医院收治的89例骨质疏松椎体压缩骨折患者,于术后1个月、3个月、6个月、1年行问卷、X线片及CT检查随访,通过椎体高度恢复率、椎体Cobb角恢复率、计算机软件辅助CT数据分析、视觉模拟评分（visual analogue scale, VAS）减少情况、Oswestry评分以及并发症评估患者术后恢复情况。结果采用SPSS 18.0统计软件分析。结果： 两组间椎体高度恢复率、椎体Cobb角恢复率、椎体体积恢复率在术后3个月、6个月、1年差异有统计学意义（P<0.05）,GeneX组的椎体高度、Cobb角、椎体体积丢失多于PMMA组。PMMA组发生骨水泥渗漏者3例,邻近椎体再骨折1例,GeneX-组发生骨水泥渗漏2例,均无神经症状,均无致死性并发症。结论： GeneX-骨水泥对于患者术后疼痛的缓解效果与PMMA相当,作为椎体成形材料近期维持椎体高度良好,可以迅速提高椎体的强度和刚度,且其并发症少,但术后中、远期对椎体高度的维持并不十分满意,故骨质疏松压缩骨折患者可使用GeneX-骨水泥作为椎体填充材料,而对于术前椎体压缩程度重且伴有严重骨质疏松患者,可使用PMMA骨水泥作为椎体填充材料,并应避免术后早期负重,更佳的生物可替代材料仍然需要进一步寻找和研究。     

骨水泥在椎弓根钉内固定治疗骨质疏松性椎体骨折中的应用

目的：探讨骨水泥在椎弓根钉内固定治疗骨质疏松性椎体骨折中的应用。方法选取椎弓根钉内固定同时应用骨水泥强化的17例骨质疏松性椎体压缩骨折患者,采用视觉模拟（Visual Analogue Scale,VAS）疼痛评分、X线、椎体高度、检测Cobb角方法进行评定预后效果。结果 VAS疼痛评分术前平均7.5分降至术后平均1.3分,差异有统计学意义（P＜0.05）,其中骨水泥渗漏3例,评分由术前6.5分降至术后3.7分。椎体高度治疗前（1.7±0.9）cm增加至术后（2.7±0.5）cm,手术后Cobb角较手术前减小,差异有统计学意义（P＜0.05）。结论骨水泥参与椎弓根钉内固定治疗骨质疏松性椎体骨折的治疗,效果较好,值得临床推广应用。     

骨水泥强化骨折与非骨折脱钙羊椎骨的生物力学比较

目的通过建立脱钙的羊椎骨模型,比较骨水泥强化骨折与非骨折的脱钙羊椎骨的生物力学,以助于分析骨水泥椎体强化术后临近椎体再发骨折原因及采取预防措施。方法将75个山羊腰椎骨,随机分成3组,A组不脱钙,B组脱钙并骨折椎体强化,C组脱钙非骨折椎体强化,每组25个,记录脱钙前后椎体重量、体积及骨密度,使用力学试验机对B组进行轴向压缩至骨折,记录失效强度、失效位移及刚度,对骨折后B组椎体注射骨水泥强化,C组脱钙后直接骨水泥强化,对两组强化后的椎体进行轴向压缩至骨折,记录失效强度、失效位移及刚度。结果3组椎体的体积、脱钙前的重量、骨密度差异无统计学意义（P>0.05）,B组、C组脱钙前后的骨密度下降比分别达32.6%、31.9%,与脱钙前比较差异有统计学意义（P<0.01）。两组脱钙后重量、骨密度差异无统计学意义（P>0.05）。B组脱钙后的失效强度及刚度分别比A组下降约123%及102.6%,差异有统计学意义（P<0.01）。B组骨折强化后的失效强度及刚度分别是强化前的2.5倍和5倍,是C组失效强度的1.7倍,刚度的4.8倍,C组失效强度比强化前的B组增加48.6%,差异有统计学意义（P<0.01）,刚度稍增加3.3%,但差异无统计学意义（P>0.05）。失效位移无明显差异（P>0.05）。结论利用脱钙方法建立的羊椎骨模型失效强度及刚度均明显下降,在轴向的加载条件下,经骨水泥强化的骨折与非骨折脱钙羊椎骨的失效强度及刚度均有增高,其中骨折椎体增加更加明显。     

经单、双侧椎弓根入路椎体成形术渗漏比较研究

目的：对离体椎体经单侧和双侧椎弓根入路的两种椎体成形方法引发的椎体外骨水泥渗漏进行比较研究。方法：采集尸体的腰椎（L1-L5）共40个,在前屈压缩载荷下造成椎体骨折。然后随机分成两组,A组经单侧椎弓根注入椎体4ml PMMA;B组经双侧椎弓根灌注4ml PMMA（每侧2ml）。注射过程中观察有无骨水泥渗漏发生,按部位计数渗漏的椎体并计算渗漏率。结果：A组有11个椎体发生渗漏,经终板渗漏11个、椎体前侧缘4个、椎体后缘3个、穿刺道渗漏6个、混合渗漏6个（2例椎体前侧缘＋穿刺通道,4例终板＋椎体前侧缘）,渗漏率为41.25%。B组有12个椎体发生渗漏,经终板3个、椎体前侧缘4个、椎体后缘3个、经穿刺道渗漏12个、混合渗漏4个（2例终板＋穿刺道,2例椎体前侧缘＋穿刺通道）,渗漏率为27.5%。两组渗漏率差异有统计学意义。结论：双侧椎弓根入路椎体成形骨水泥渗漏少于单侧,有统计学意义。     

骨水泥充填技术治疗胸腰椎爆裂性骨折

目的：探讨将医用骨水泥灌注进骨折椎体内以充填骨折间隙的方法用于治疗青壮年胸腰椎爆裂性骨折的可行性、安全性及远期效果。方法：对50例年龄在30~55岁的胸腰椎爆裂性骨折且椎体高度丢失40%~70%合并部分瘫痪或无瘫痪的患者先行后路椎弓根螺钉置入及撑开复位,必要时行椎管探查减压;然后经骨折椎体一侧椎弓根放置灌注骨水泥所需的工作套管,在透视监视下推注适量的骨水泥进入骨折块之间的空隙内均匀分布充填。手术后行X线片和CT片扫描并定期随访。结果：50例中有5例发生骨水泥渗漏,其中1例从前方漏出,2例从侧方漏出,2例经终板裂隙漏入椎间盘内,均无相关的临床症状出现。未发生椎管内或血管渗漏。随访时间5~10年(平均7.5年),X线片和CT片显示骨折椎体高度无丢失,椎体内无残留空隙,未见“骨水泥–椎体”之间有分离界面形成。骨折局部未出现后凸畸形。50例患者中15例形成骨折椎体和上、下椎体之间牢固的骨桥连接。50例患者在末次随访时均未见内固定松动断裂。结论：后路复位固定联合伤椎内灌注骨水泥充填的术式治疗青壮年胸腰椎爆裂性骨折是安全可行的、可以有效充填骨折椎体内的大的间隙而获得即刻及永久的稳定性,因而具有良好的近期及远期效果。     

经皮椎体成形术并发骨水泥外溢的预防探讨

目的探讨经皮椎体成形术（PVP）骨水泥外溢的预防措施。方法对50例共76个椎体在透视监视下行PVP,所有患者在术后30min行CT扫描以评价骨水泥有无渗漏,并对其结果进行分析总结,针对外溢的不同部位提出治疗方案。结果术后所有患者的症状完全或部分缓解,PVP术后76个椎体中骨水泥外溢发生率为21％,其中,骨水泥外溢进入椎旁组织3例5个椎体;进入椎间盘2例3个椎体;进入椎管内4例5个椎体;进入椎阀孔3例3个椎体。结论经皮椎体成形术应用于椎体血管瘤、骨质疏松、转移瘤等溶骨性病变,通过术前骨水泥的准备、术中监控等以防止骨水泥外溢,如果骨水泥漏入椎管内引起神经压迫症状,则必须采取开放手术治疗。     

CPC/PMMA复合骨水泥联合明胶海绵预防伴椎体前壁破裂骨质疏松性骨折术中骨水泥渗漏的疗效观察

:目的: 观察采用明胶海绵封堵裂口、经皮CPC/PMMA复合骨水泥椎体后凸成形在治疗伴有椎体前壁破裂的老年骨质疏松性椎体压缩骨折术中防止骨水泥渗漏的临床效果。方法: 回顾性分析自2023-06—2023-11诊治的15例伴有椎体前壁骨皮质破裂的老年骨质疏松性椎体压缩性骨折,以破裂区域为靶点进行穿刺,分多次将明胶海绵顶向椎体前壁破裂区域,再使用CPC/PMMA复合骨水泥注射进行经皮椎体后凸成形,观察骨水泥有无经椎体前壁渗漏的情况。结果: 15例患者均顺利完成手术,骨水泥均未超出椎体范围进入其他组织。结论: 采用明胶海绵封堵裂口、经皮CPC/PMMA复合骨水泥椎体后凸成形可显著降低术中骨水泥渗漏的概率。     

单、双侧椎弓根入路经皮椎体后凸成形术临床回顾的比较研究

目的比较经单、双侧椎弓根入路灌注骨水泥经皮椎体后凸成形术(PKP)治疗骨质疏松性椎体压缩骨折(OVCF),回顾性评价两种手术入路的临床效果。方法选取2008年10月至2011年12月首都医科大学良乡教学医院骨科收治的OVCF患者112例作为研究对象,所有患者均接受PKP治疗,其中经单侧椎弓根入路组65例68个椎体,经双侧椎弓根入路组47例59个椎体。比较两组患者的术前及术后1 d视觉模拟评分(VAS),伤椎高度,后凸Cobb's角、手术时间、骨水泥注入量、伤椎高度丢失,骨水泥渗漏及随访期间邻近椎体骨折情况。结果两组患者在手术时间(t=-11.905,P=0.002)、骨水泥注入量(t=-2.810,P=0.007)、骨水泥渗漏(χ2=5.477,P=0.019)及相邻椎体骨折(χ2=4.394,P=0.036)等方面比较差异有统计学意义;单侧椎弓根入路组患者术后即刻椎体高度增加显著低于双侧椎弓根入路组(t=-2.978,P=0.004),术后12个月椎体高度丢失显著高于双侧椎弓根入路组(t=11.511,P=0.001);两组椎体压缩骨折患者的后凸Cobb's角在不同时点间、组间以及组间·不同时点间比较差异均无统计学意义(F=0.063,3.765,0.072,P>0.05);VAS在不同时点间、组间以及组间·不同时点间比较,差异均有统计学意义(F=5.783,106.558,19.101,P<0.05)。结论两种骨水泥灌注入路都能较好的恢复椎体高度,并达到理想的止痛效果,双侧椎弓根入路PKP远期效果较单侧入路好。