Evolution of bone mineral density after percutaneous kyphoplasty in fresh osteoporotic vertebral body fractures and adjacent vertebrae along with sagittal spine alignment

STUDY DESIGN: Prospective controlled cohort study of 27 adult osteoporotic patients who underwent kyphoplasty for fresh osteoporotic spinal fractures. OBJECTIVES: To define the evolution of vertebral bone mineral density (BMD) at kyphoplasty and adjacent levels along with sagittal spinal alignment to contribute to the etiology of adjacent vertebral fractures after augmentation. SUMMARY OF BACKGROUND DATA: Osteoporotic compression fractures can be effectively treated with methylmethacrylate vertebral augmentation. However, to the authors' knowledge the effect of vertebral augmentation on the vertebral endplate BMD of the augmented and adjacent nonaugmented levels has not as yet been described. METHODS: Twenty-seven consecutive selected patients (9 men, 18 women), with an average age of 72+/-9 years underwent 1, 2, or 3-level percutaneous kyphoplasty for painful fresh osteoporotic vertebral fractures at the thoracolumbar spine. All patients were radiologically examined with plain roentgenograms, computed tomography, and magnetic resonance imaging. Lateral dual energy x-ray absorptiometry in the augmented and on the adjacent vertebrae (1 level above and below kyphoplasty) was used to measure BMD preoperatively to the last postoperative observation in the subchondral bone of the vertebral endplates. Anthropometric data, sagittal global balance (plumbline), and segmental spine reconstruction (vertebral body height, Gardner kyphotic angle) were recorded and analyzed. The patients were followed for at least 2 years. RESULTS: Kyphoplasty was performed between T12 and L5. A total of 48 vertebral bodies were augmented. Thirteen patients received 1 level and the remaining 14 received 2 or 3-level kyphoplasty. No significant changes in the sagittal spinal balance were shown postoperatively. Gardner kyphotic angle and posterior vertebral body height improved postoperatively, however, insignificantly. Significant [analysis of variance (ANOVA), P=0.008] increase of anterior vertebral body height in the fractured vertebra was achieved postoperatively without subsequent loss of correction. BMD increased significantly in the lower endplate of the augmented vertebra (ANOVA, P=0.05). In 1-level augmentation, no BMD changes were shown at the adjacent vertebrae above and below kyphoplasty. On the contrary, in the multilevel augmentation, a statistically significant (ANOVA, P=0.05) decrease of the BMD was shown in the upper endplate of the adjacent level above kyphoplasty. During the 2-year follow-up, there were 5 (18%) new fractures at the T11-T12 area above the augmented vertebra. All of the fractures occurred in patients who received 2 and 3-level kyphoplasty. CONCLUSIONS: The observed 2-year evolution of vertebral endplate BMD, after kyphoplasty under stable global sagittal spinal balance, might contribute to the pathogenesis of new fractures in adjacent vertebra. However, other studies with control series and longer follow-up are necessary to show if these BMD changes are the result of vertebral augmentation or are merely natural history.     

Outcome of percutaneous balloon kyphoplasty in vertebral compression fractures

Background:Incidence of vertebral compression fractures (VCFs) is increasing due to increase in human life expectancy and prevalence of osteoporosis. Vertebroplasty had been traditional treatment for pain, but it neither attempts to restore vertebral body height nor eliminates spinal deformity and is associated with a high rate of cement leakage. Balloon kyphoplasty involves introduction of inflatable balloon into the fractured body of vertebra for elevation of the end-plates prior to fixation of the fracture with bone cement. This study evaluates short term functional and radiological outcomes of balloon kyphoplasty. The secondary aim is to explore short-term complications of the procedure.Results:Statistically significant improvements in SF-36 (from 34.29 to 48.53, an improvement of 14.24, standard deviation (SD) - 20.08 P < 0.0001), VAS (drop of 4.49, from 6.74 to 2.24, SD - 1.44, P < 0.0001), percentage restoration of lost vertebral height (from 30.62% to 16.19%, improvement of 14.43%, SD - 15.37, P < 0.0001) and kyphotic angle correction (from 17.41° to 10.59°, improvement of 6.82, SD - 7.26°, P < 0.0001) were noted postoperatively. Six patients had cement embolism, 65 had cement leak and three had adjacent level fracture which required repeat kyphoplasty later. One patient with history of ischemic heart disease had cardiac arrest during the procedure. No patients had neurological deterioration in the followup period.Conclusions:Kyphoplasty is a safe and effective treatment for VCFs. It improves physical function, reduces pain and corrects kyphotic deformity.     

Changes of pulmonary function for patients with osteoporotic vertebral compression fractures after kyphoplasty

One of the consequences of osteoporotic vertebral compression fractures (OVCFs) is progressive collapse of the fractured osteoporotic vertebral body. This can lead to spinal kyphosis that may cause restriction of respiratory function. The balloon kyphoplasty procedure can reduce kyphosis and relieve the pain. There are few studies that have appropriate data and follow-up to evaluate the effect of deformity correction on pulmonary function after the kyphoplasty procedure. The current study explores changes of pulmonary function of 30 older women who suffered from OVCFs in the thoracolumbar segment after kyphoplasty. After kyphoplasty was performed on these women, thoracic kyphotic angle, local kyphotic angle, pain scores, and pulmonary function parameters-vital capacity, inspiratory capacity, residual volume, functional residual capacity, total lung capacity, forced vital capacity (FVC), and maximum voluntary ventilation (MVV) were measured. All measurements were taken before, 3 days after, and 1 month after the kyphoplasty. The height of the vertebral body was restored, the local kyphotic angle was improved, and pain scores were significantly decreased after kyphoplasty. FVC and MVV were significantly increased 3 days after the procedures; whereas only MVV had gone on to improve 1 month later. The decreased values of pain scores had a remarkably positive correlation with the percentage of improvement of FVC (r=0.536) and MVV (r=0.614) measured 3 days after kyphoplasty. In patients with OVCFs, kyphoplasty could partially improve their impaired lung function.     

Minimal invasive stabilization of osteoporotic vertebral fractures: a prospective nonrandomized comparison of vertebroplasty and balloon kyphoplasty

OBJECTIVE: During recent years, the benefits of balloon kyphoplasty and vertebroplasty have been frequently discussed for the treatment of osteoporotic vertebral compression fractures. Because of the lack of comparative studies, we performed an investigation to describe the mechanical effects and the impact on life quality during a follow-up period of 2 years. METHODS: Patients with nonrecent fractures of vertebral bodies, ongoing bone remodeling, and major kyphotic deformity were treated with minimal invasive stabilization. The median duration of pain was 8 weeks before surgery. Because of the availability of the equipment, 28 patients were nonrandomly assigned to balloon kyphoplasty and 23 patients to vertebroplasty. The follow-up was performed 2 years after surgery. RESULTS: The kyphotic wedge of the vertebral bodies was decreased 6 degrees by balloon kyphoplasty but not by vertebroplasty. With both methods, we found a rapid decrease of pain down to one-half of the preoperative value. A long-lasting effect on pain was found only after balloon kyphoplasty. In the kyphoplasty group, a decrease of the Oswestry Disability Index (ODI) score was found during the first postoperative year. After 2 years, the ODI was not different from preoperative values in both groups. CONCLUSIONS: In nonrecent fractures, the reduction of the kyphotic wedge by balloon kyphoplasty was superior in decreasing pain persisting over a period of 2 years. The ability to improve disability after kyphoplasty was limited to 1 year. In nonrecent fractures, the consequences of age and osteoporosis seem to equalize the effects of the restored sagittal profile on disability but not on pain.     

Balloon kyphoplasty versus vertebroplasty for treatment of osteoporotic vertebral compression fracture: a prospective, comparative, and randomized clinical study

Summary  

Bone pain and spinal axial deformity are major concerns in aged patients suffering from osteoporotic vertebral compression fracture (VCF). Pain can be relieved by vertebroplasty or kyphoplasty procedures, in which the compressed vertebral body is filled with substitutes. We randomly assigned 100 patients with osteoporotic compression fracture at the thoraco-lumbar (T-L) junction into two groups: vertebroplasty and kyphoplasty; we used polymethylmethacrylate (PMMA) as the bone filler. Pain before and after treatment was assessed with visual analog scale (VAS) scores and vertebral body height and kyphotic wedge angle were measured from reconstructed computed tomography images. More PMMA was used in the kyphoplasty group than in the vertebroplasty group (5.56 ± 0.62 vs. 4.91 ± 0.65 mL, p < 0.001). Vertebral body height and kyphotic wedge angle of the T-L spine were also improved (p < 0.001). VAS pain scores did not differ significantly between the treatment groups. The duration of follow-up was 6 months. Two patients in the kyphoplasty group had an adjacent segment fracture. In terms of clinical outcome there was little difference between the treatment groups. Thus, owing to the higher cost of the kyphotic balloon procedure, we recommend vertebroplasty over kyphoplasty for the treatment of osteoporotic VCFs.     

A prospective two-year follow-up of thoracic and lumbar osteolytic vertebral fractures caused by multiple myeloma treated with balloon kyphoplasty

PURPOSE: Balloon kyphoplasty is a minimally invasive procedure for the stabilization of osteoporotic and osteolytic vertebral fractures. The purpose of this prospective study was to evaluate this operative procedure in the treatment of osteolytic vertebral fractures with regard to the reduction of pain and functional improvement of the patients and further to evaluate the restoration of vertebral height postoperatively. MATERIALS AND METHODS: In this study 26 patients (21 male, 5 female) with osteolytic vertebral fractures were treated with balloon kyphoplasty. In total, 59 vertebral fractures were treated with balloon kyphoplasty. Preoperatively conventional radiographs in lateral and a. p. views, CT and/or MRI were preformed. Pre- and postoperatively the clinical parameters using VAS (visual analogue scale) and the Oswestry score were evaluated. Radiographic scans were performed pre- and postoperatively and after 3, 6, 12 and 24 months. The vertebral height and endplate angles were measured. RESULTS: The median pain scores (VAS) decreased from pre- to post-treatment significantly (p < 0.05) as also did the Oswestry score (p < 0.05). Balloon kyphoplasty led to a significant and sustained reduction of pain resulting in a significant functional improvement for the patients. A significant restoration of vertebral height and reduction of the kyphotic angle could be achieved with the balloon technique (p < 0.05). Furthermore, the minimal-invasive procedure was able to stabilize the spine also over a longer period of 24 months. A radiation therapy and/or chemotherapy could be performed without loss of time. CONCLUSION: In the treatment of osteolytic vertebral fractures balloon kyphoplasty led to a quick and sustained reduction of pain and as well as a functional improvement for the patients. A restoration of the vertebral height and reduction of the kyphotic angle was especially attributable to the balloon technique. The balloon kyphoplasty was able to stabilize the fractured vertebrae in the long-term and was able to prevent an increase of kyphotic deformity. Balloon kyphoplasty is an outstanding alternative in comparison to the established therapeutic concepts in the treatment of osteolytic vertebral fractures.     

磷酸钙骨水泥球囊撑开椎体成形术治疗骨质疏松性椎体骨折

目的：评估磷酸钙骨水泥（calciumphosphatecement,CPC）球囊撑开椎体成形术治疗骨质疏松性椎体骨折（osteoporoticvertebralfractures,OVF）的临床疗效。方法：自2009年1月至2011年1月采用CPC球囊撑开椎体成形术治疗26例（31椎体）骨质疏松性椎体骨折患者,其中男15例,女11例;年龄60-89岁,平均（71．67±4．36）岁;病程0．5～7d,平均3．2d。采用视觉模拟评分visualanalogueSCale,VAS）和功能障碍指数（oswestrydisabilityindex,ODI）对疼痛和功能进行评定。通过X线对椎体高度的丢失和后凸畸形角度进行观察。结果：所有患者获得随访,时间10-24个月,平均18个月。术前、术后24h、末次随访时VAS评分分别为7.91±1．20、3．22±1．12、1．92±0．83,ODI评分分别为40．00±1．15、17．00±2．12、13．00±1．42,椎体高度分别为（18．21±3．21）、（23．82±3．10）、（21．85±3．24）mm,后凸畸形角度分别为（18．21±3．21）°、（7．42±3．13）°、（10．01°±3．11）°,术后24h、末次随访与术前比较差异有统计学意义（P〈0．05）,术后24h与末次随访比较差异无统计学意义（P〉0．05）。结论：CPC球囊撑开椎体成形术是治疗骨质疏松性椎体骨折的有效方法,能迅速缓解疼痛,有效的恢复椎体骨折椎体高度及纠正后凸畸形角度,具有创伤小、安全性好的优点。     

Preliminary outcomes and efficacy of the first 360 consecutive kyphoplasties for the treatment of painful osteoporotic vertebral compression fractures.

BACKGROUND CONTEXT: Osteoporosis is a major cause of morbidity in worldwide elderly populations. Patients may become susceptible to vertebral compression fractures (VCFs) from low-impact situations. For patients who have failed conventional, palliative medical therapy, kyphoplasty not only reduces pain associated with vertebral fractures, but also offers a minimally invasive procedure with the potential to address fracture reduction and spinal sagittal alignment. Kyphoplasty involves expanding an inflatable balloon tamp to create a cavity within a vertebral body before cement deposition. PURPOSE: To evaluate the safety and efficacy of kyphoplasty to reduce and fix painful osteoporotic VCFs. STUDY DESIGN/SETTING: A retrospective, single-arm cohort study of consecutive kyphoplasty patients treated at a single center. PATIENT SAMPLE: Three hundred sixty VCFs were treated during 254 kyphoplasty procedures on 222 osteoporotic patients (mean age, 76 years [range, 28-98]; 28% male and 72% female). OUTCOME MEASURES: Patient-reported pain ratings were examined. Cement extravasation was monitored by intraoperative fluoroscopy and on postoperative radiographs. Anterior and midline vertebral height were assessed from standing, lateral radiographs obtained preoperatively and postoperatively. The number of patients who returned with symptomatic, new fractures was monitored. Perioperative complications were recorded. Mean follow-up occurred 21 months after kyphoplasty (range, 6 months through 36 months). RESULTS: Immediate pain relief was reported by 89% of patients by the first follow-up visit. One patient experienced postoperative pain as a result of radiculopathy related to bone filler leakage into the foramen. The remaining patients had persistent pain and were diagnosed with either a new fracture or underlying degenerative disc disease. Greater than or equal to 20% restoration of lost vertebral height (anterior) was observed in 63% of fractures with an overall mean restoration of 30%, and > or = 20% restoration of lost vertebral height (midline) was detected in 69% of fractures with an overall mean restoration of 50%. In this cohort, 12% (30/254) of the patients required additional kyphoplasty procedures to treat 36 symptomatic, new adjacent and remote fractures. No device-related complications occurred. CONCLUSIONS: Kyphoplasty is a safe and effective, minimally invasive procedure for relief of pain associated with VCF. In our series we also demonstrated some restoration of vertebral height and partial correction of sagittal alignment.     

Kyphoplasty for treatment of osteoporotic vertebral fractures

Cement reinforcement for the treatment of osteoporotic vertebral fractures is efficient mean with high success in pain release and prevention of further sintering of the reinforced vertebrae; however, the technique does not allow to address the kyphotic deformity. Kyphoplasty was designed to address the kyphotic deformity and help to realign the spine. It involves the percutaneous placement of an inflatable bone tamp into a vertebral body. Restoration of VB height and kyphosis correction is achieved by inflation of the bone tamp with liquid. After deflation, a cavity is created that eases the cement application. The potential of kyphosis reduction is given in fresh fractures with a range of 0–90% for height restoration and absolute correction of the kyphotic angle of 8.5°. The cavity formation, on one hand, and the different cementing technique leads to lower risk for cement extravasation. An alternative method for kyphosis correction represents the so-called lordoplasty where the adjacent vertebrae are reinforced first and with the cannulas in place acting as a lever the reduction of the collapsed vertebra can be performed. The results with respect to kyphosis correction are superior in comparison with a kyphoplasty procedure.     

Lordoplasty: report on early results with a new technique for the treatment of vertebral compression fractures to restore the lordosis

Cement augmentation using PMMA cement is known as an efficient treatment for osteoporotic vertebral compression fractures with a rapid release of pain in most patients and prevention of an ongoing kyphotic deformity of the vertebrae treated. However, after a vertebroplasty there is no chance to restore vertebral height. Using the technique of kyphoplasty a certain restoration of vertebral body height can be achieved. But there is a limitation of recovery due to loss of correction when deflating the kyphoplastic ballon and before injecting the cement. In addition, the instruments used are quite expensive. Lordoplasty is another technique to restore kyphosis by indirect fracture reduction as it is used with an internal fixateur. The fractured and the adjacent vertebrae are instrumented with bone cannulas bipediculary and the adjacent vertebrae are augmentated with cement. After curing of the cement the fractured vertebra is reduced by applying a lordotic moment via the cannulas. While maintaining the pretension the fractured vertebra is reinforced. We performed a prospective trial of 26 patients with a lordoplastic procedure. There was a pain relief of about 87% and a significant decrease in VAS value from 7.3 to 1.9. Due to lordoplasty there was a significant and permanent correction in vertebral and segmental kyphotic angle about 15.2° and 10.0°, respectively and also a significant restoration in anterior and mid vertebral height. Lordoplasty is a minimal invasive technique to restore vertebral body height. An immediate relief of pain is achieved in most patients. The procedure is safe and cost effective.     

球囊扩张椎体成形术联合降钙素治疗老年骨质疏松性椎体骨折的疗效

目的回顾性分析球囊扩张椎体后凸成形术联合降钙素治疗骨质疏松性椎体骨折的疗效。方法 2007年2月～2010年1月,对25例35个椎体发生骨质疏松性椎体骨折患者行球囊扩张椎体后凸成形术联合降钙素综合治疗。术中在透视机监视下采用单侧椎弓根穿刺,置入1枚可扩张球囊使骨折塌陷椎体复位,灌注骨水泥充填由球囊扩张所形成的椎体内空腔。术后每天静脉注射鲑鱼降钙素,通过观察患者术后症状改善及骨折复位情况来评估其疗效。结果所有患者随访6～32个月,平均（21.3±0.2）个月。全部患者均顺利完成手术,无症状性并发症发生。术后疼痛明显减轻或消失。术后椎体高度平均恢复率59.5%。结论球囊扩张椎体后凸成形术治疗骨质疏松性椎体骨折可有效缓解疼痛、改善功能及恢复脊柱序列,联合降钙素的应用能有效缓解骨质疏松性椎体压缩骨折引起的疼痛,是治疗骨质疏松性椎体骨折的较好微创方法之一。     

不同手术方法治疗脊柱骨质疏松压缩性骨折的疗效分析

目的 比较不同手术方法治疗脊柱骨质疏松压缩性骨折(OVCF)的疗效。方法 对自2005年3月至2009年3月治疗且获得随访的65例OVCF患者资料进行回顾性研究,其中男25例,女40例;年龄58 ～81岁,平均73岁;骨折部位：T10 5例,T11 8例,T12 14例;L1 15例,L2 13例,L3 10例。手术方法分为微创手术组（A组）和开放手术组（B组）,A组又分为Sky手术组（A1组,20例）和球囊成形组（A2组,22例）。B组又分为双皮质固定组（BI组,10例）和骨水泥强化组（B2组,13例）。评价4组患者手术前、后疼痛评分、脊柱后凸变化及并发症发生情况,以及B组手术前、后的脊髓神经功能改善情况。结果 所有患者术后获8 ～45个月（平均23个月）随访。A组疼痛评分、功能评分术后改善迅速;B组术后1个月左右的疼痛评分、功能评分较术前明显改善,差异有统计学意义(P＜0.05);A1组手术前、后脊柱后凸的矫正效果差异无统计学意义(P＞0.05)。B组脊髓神经功能评分术后有明显改善,差异有统计学意义(P＜0.05)。A、B组均出现了相邻椎体的骨折。结论 微创手术和开放手术都是治疗OVCF的有效方法,但两者有不同的适应证;微创手术在缓解疼痛方面迅速有效,但Sky手术在后凸矫形方面存在明显不足;手术后相邻节段的骨折是手术治疗OVCF的主要并发症。     

单节段经皮椎体成形术后继发相邻椎体骨折的危险因素

目的探讨经皮椎体成形术(PVP)治疗单节段骨质疏松性椎体压缩性骨折(OVCF)术后继发相邻椎体骨折的危险因素。方法回顾性分析2013年3月—2017年3月在宁波市第二医院骨科因单节段OVCF行PVP治疗的140例患者的临床资料,以术后是否继发相邻椎体骨折将患者分为继发骨折组(A组,38例)和无继发骨折组(B组,102例)。记录所有患者术后继发相邻椎体骨折的潜在影响因素,包括非手术因素(年龄、性别、体质量指数、椎体骨密度、楔形角范围、骨折位置、有无外力参与、是否合并糖尿病、是否有糖皮质激素治疗史)和手术因素(骨水泥填充材料、注入量、注入方式、渗漏情况),采用独立样本t检验和χ2检验分析以上因素组间差异是否具有统计学意义,并对差异有统计学意义的因素采用Logistic回归分析评价其与术后相邻椎体骨折的相关性。结果组间比较,椎体骨密度、楔形角范围、骨折位置、有无糖皮质激素治疗史及有无外力参与5个方面差异有统计学意义(P 0.05),纳入相关分析;其余统计数据组间差异无统计学意义。Logistic回归分析显示上述5个指标进入方程,与术后相邻椎体骨折具有相关性。结论椎体骨密度低、楔形角≥15°、骨折位于胸腰交界处、有糖皮质激素治疗史及外力作用5个指标是术后继发相邻椎体骨折的影响因素,手术因素不会增加继发相邻椎体骨折风险。     

椎体后凸成形术治疗新鲜性与陈旧性骨质疏松椎体压缩骨折的疗效分析

目的: 探讨经皮椎体后凸成形术治疗新鲜性和陈旧性骨质疏松性椎体压缩骨折(OVCF)的疗效比较. 方法: 对2006年6月至2011年10月收治的应用经皮椎体后凸成形术(PKP)治疗的42例骨质疏松椎体压缩骨折患者进行回顾性分析,其中男5例,女37例;年龄60～86岁,平均(73.3±7.5)岁. 根据病程、MRI检查及是否经过系统的保守治疗将患者分为新鲜组和陈旧组. 应用视觉疼痛模拟评分(VAS)和日常活动能力评分(ADL)评估患者疼痛和日常活动能力的改善情况;同时利用手术节段X线测量计算伤椎椎体前壁及中间高度的恢复率及受伤节段脊柱的后凸矫正率. 结果: 所有患者获得随访,时间10～64个月,平均17个月. 新鲜组和陈旧组患者术前、术后1周及术后6个月的VAS评分和ADL评分分别进行两两比较,术后1周和6个月的评分均明显降低(P<0.05);术后6个月的VAS及ADL评分略高于术后1周的(P>0.05).而术后1周与术前的疼痛改善率及日常活动能力改善率相比较,新鲜组优于陈旧组(P<0.05).两组患者术后1周的伤椎前壁、中间高度的恢复率及后凸畸形矫正率比较,新鲜组明显优于陈旧组(P<0.05).结论: PKP对治疗新鲜性和陈旧性骨质疏松性椎体压缩骨折均有疗效,但对新鲜性骨质疏松性椎体压缩骨折疗效更明显,其在止痛、矫正后凸畸形及恢复椎体高度方面有明显优势,可改善患者生活质量.     

Balloon kyphoplasty for the treatment of pathological vertebral compressive fractures

Background Previous clinical studies have shown the safety and effectiveness of balloon kyphoplasty in the treatment of pathological vertebral compression fractures (VCFs). However, they have not dealt with the impact of relatively common comorbid conditions in this age group, such as spinal stenosis, and they have not explicitly addressed the use of imaging as a prognostic indicator for the restoration of vertebral body height. Neither have these studies dealt with management and technical problems related to surgery, nor the effectiveness of bone biopsy during the same surgical procedure. This is a prospective study comparing preoperative and postoperative vertebral body heights, kyphotic deformities, pain intensity (using visual analogue scale) and quality of life (Oswestry disability questionnaire) in patients with osteoporotic vertebral compression fractures (OVCFs) and osteolytic vertebral tumors treated with balloon kyphoplasty.Methods Thirty-two consecutive patients, 27 OVCFs (49 vertebral bodies [VBs]) and 5 patients suffering from VB tumor (12 VBs) were treated by balloon kyphoplasty. The mean age was 68.2 years. All patients were assessed within the first week of surgery, and then followed up after one, three and six months; all patients (27 OVCFs and 5 tumor patients) were followed up for 12 months, 17 patients (14 OVCFs and 3 tumors) were followed up for 18 months and 9 patients (8 OVCFs and 1 tumor) were followed up for 24 months (mean follow up 18 months). The correction of kyphosis and vertebral heights were measured by comparing preoperative and postoperative radiographic measurements.Results Thirty-one patients (96.9%) exhibited significant and immediate pain improvement: 90% responded within 24 h and 6.3% responded within 5 days. Daily activities improved by 53% on the Oswestry scale. In the OVCF group, kyphosis correction was achieved in 24/27 patients (89.6%) with a mean correction of 7.6°. Anterior wall height was restored in 43/49 VBs (88%) (mean increment of 4.3 mm), and mid vertebral body height was restored in 45/49 VBs (92%) (mean increment of 4.8 mm). Edema (high intensity signal) on short tau inversion recovery (STIR) was evidenced in all OVCF patients who experienced symptoms for less than nine months and was associated with correction of deformity. Cement leakage was the only technical problem encountered; it occurred in 5/49 VBs (10.2%) of the osteoporotic group and 1/12 VBs (8.3%) of the tumor group but had no clinical consequences. The incidence of leakage to the anterior epidural space was 2%. Spinal stenosis was present in three patients (11.1%) who responded successfully to subsequent laminectomy. Retrieval of tissue samples for biopsy was successful in 10/15 cases (67%). New fractures occurred in the adjacent level in 2/27 OVCF patients (7.4%).Conclusions Associated spinal stenosis with OVCF should not be overlooked; STIR MRI is a good predictor of deformity correction with balloon kyphoplasty. The prevalence of a new OVCF in the adjacent level is low.     

Spinal loads after osteoporotic vertebral fractures treated by vertebroplasty or kyphoplasty

Vertebroplasty and kyphoplasty are routine treatments for compression fractures of vertebral bodies. A wedge-shaped compression fracture shifts the centre of gravity of the upper body anteriorly and generally, this shift can be compensated in the spine and in the hips. However, it is still unclear how a wedge-shaped compression fracture of a vertebra increases forces in the trunk muscle and the intradiscal pressure in the adjacent discs. A nonlinear finite element model of the lumbar spine was used to estimate the force in the trunk muscle, the intradiscal pressure and the stresses in the endplates in the intact spine, and after vertebroplasty and kyphoplasty treatment. In this study, kyphoplasty represents a treatment with nearly full fracture reduction and vertebroplasty one without restoration of kyphotic angle although in reality kyphoplasty does not guarantee fracture reduction. If no compensation of upper body shift is assumed, the force in the erector spine increases by about 200% for the vertebroplasty but by only 55% for the kyphoplasty compared to the intact spine. Intradiscal pressure increases by about 60 and 20% for the vertebroplasty and kyphoplasty, respectively. In contrast, with shift compensation of the upper body, the increase in muscle force is much lower and increase in intradiscal pressure is only about 20 and 7.5% for the vertebroplasty and kyphoplasty, respectively. Augmentation of the vertebral body with bone cement has a much smaller effect on intradiscal pressure. The increase in that case is only about 2.4% for the intact as well as for the fractured vertebra. Moreover, the effect of upper body shift after a wedge-shaped vertebral body fracture on intradiscal pressure and thus on spinal load is much more pronounced than that of stiffness increase due to cement infiltration. Maximum von Mises stress in the endplates of all lumbar vertebrae is also higher after kyphoplasty and vertebroplasty. Cement augmentation has only a minor effect on endplate stresses in the unfractured vertebrae. The advantages of kyphoplasty found in this study will be apparent only if nearly full fracture reduction is achieved. Otherwise, differences between kyphoplasty and vertebroplasty become small or vanish. Our results suggest that vertebral body fractures in the adjacent vertebrae after vertebroplasty or kyphoplasty are not induced by the elevated stiffness of the treated vertebra, but instead the anterior shift of the upper body is the dominating factor.     

Treatment of acute thoracolumbar burst fractures with kyphoplasty and short pedicle screw fixation: Transpedicular intracorporeal grafting with calcium phosphate: A prospective study

Background:

In the surgical treatment of thoracolumbar fractures, the major problem after posterior correction and transpedicular instrumentation is failure to support the anterior spinal column, leading to loss of correction and instrumentation failure with associated complaints. We conducted this prospective study to evaluate the outcome of the treatment of acute thoracolumbar burst fractures by transpedicular balloon kyphoplasty, grafting with calcium phosphate cement and short pedicle screw fixation plus fusion.

Materials and Methods:

Twenty-three consecutive patients of thoracolumbar (T₉ to L₄) burst fracture with or without neurologic deficit with an average age of 43 years, were included in this prospective study. Twenty-one from the 23 patients had single burst fracture while the remaining two patients had a burst fracture and additionally an adjacent A1-type fracture. On admission six (26%) out of 23 patients had neurological deficit (five incomplete, one complete). Bilateral transpedicular balloon kyphoplasty with liquid calcium phosphate to reduce segmental kyphosis and restore vertebral body height and short (three vertebrae) pedicle screw instrumentation with posterolateral fusion was performed. Gardner kyphosis angle, anterior and posterior vertebral body height ratio and spinal canal encroachment were calculated pre- to postoperatively.

Results:

All 23 patients were operated within two days after admission and were followed for at least 12 months after index surgery. Operating time and blood loss averaged 45 min and 60 cc respectively. The five patients with incomplete neurological lesions improved by at least one ASIA grade, while no neurological deterioration was observed in any case. The VAS and SF-36 (Role physical and Bodily pain domains) were significantly improved postoperatively. Overall sagittal alignment was improved from an average preoperative 16° to one degree kyphosis at final followup observation. The anterior vertebral body height ratio improved from 0.6 preoperatively to 0.9 (P<0.001) postoperatively, while posterior vertebral body height improved from 0.95 to 1 (P<0.01). Spinal canal encroachment was reduced from an average 32% preoperatively to 20% postoperatively. Cement leakage was observed in four cases (three anterior to vertebral body and one into the disc without sequalae). In the last CT evaluation, there was a continuity between calcium phosphate and cancellous vertebral body bone. Posterolateral radiological fusion was achieved within six months after index operation. There was no instrumentation failure or measurable loss of sagittal curve and vertebral height correction in any group of patients.

Conclusions:

Balloon kyphoplasty with calcium phosphate cement secured with posterior short fixation in the thoracolumbar spine provided excellent immediate reduction of posttraumatic segmental kyphosis and significant spinal canal clearance and restored vertebral body height in the fracture level.     

Vertebral height restoration in osteoporotic compression fractures: kyphoplasty balloon tamp is superior to postural correction alone

Introduction Kyphoplasty has been shown to restore vertebral height and sagittal alignment. Proponents of vertebroplasty have recently demonstrated that many vertebral compression fractures (VCFs) are mobile and positional correction can lead to clinically significant height restoration. The current investigation tested the hypothesis that positional maneuvers do not achieve the same degree of vertebral height correction as kyphoplasty balloon tamps for the reduction of low-energy VCFs.Methods Twenty-five consecutive patients with a total of 43 osteoporotic VCFs were entered into a prospective analysis. Each patient was sequentially evaluated for postural and balloon vertebral fracture reduction. Preoperative standing and lateral radiographs of the fractured vertebrae were compared with prone cross-table lateral radiographs with the patient in a hyper-extension position and on pelvic and sternal rolls. Following positional manipulation, patients underwent a unilateral balloon kyphoplasty. Postoperative standing radiographs were evaluated for the percentage of height restoration related to positioning and balloon kyphoplasty.Results In the middle portion of the vertebrae, the percentage available for restoration restored with extension positioning was 10.4% (median 11.1%) and after balloon kyphoplasty was 57.0% (median 62.2%). This difference was statistically significant (p<0.001). Thus, kyphoplasty provided an additional 46.6% of the height available for restoration from the positioning alone. With operative positioning, 51.2% of VCFs had >10% restoration of the central portion of the vertebral body, whereas 90.7% of fractures improved at least 10% following balloon kyphoplasty (p<0.002).Conclusion Although this study supports the concept that many VCFs can be moved with positioning, balloon kyphoplasty enhanced the height reduction >4.5-fold over the positioning maneuver alone and accounted for over 80% of the ultimate reduction. If height restoration is the goal, kyphoplasty is clearly superior in most cases to the positioning maneuver alone.     

Comparative study of balloon kyphoplasty with unilateral versus bilateral approach in osteoporotic vertebral compression fractures

This study analyses the radiological and clinical results according to the two techniques of unilateral and bilateral balloon kyphoplasty in osteoporotic vertebral compression fractures. Fifty-two patients with osteoporotic vertebral compression fractures occurring at the thoracolumbar junction were enrolled in this study. All patients were classified into two groups; group I was treated with a unilateral approach and group II with a bilateral approach. The Cobb angle was measured each time to evaluate the kyphotic angle during the pre- and post-operative periods and at last follow-up, and a 10-point visual analog scale for pain was recorded at the same time. We found that the bilateral approach had a greater advantage in the reduction of kyphosis and the loss of reduction was less than the unilateral approach for the treatment of osteoporotic vertebral compression fractures.     

后凸成形术结合体位复位治疗创伤性胸腰椎椎体骨折的临床观察

目的：观察在体位复位辅助下后凸成形术治疗创伤性胸腰椎椎体骨折的临床疗效。方法：37例新鲜单节段胸腰椎椎体骨折患者,男28例,女9例;年龄24～79岁,平均48岁。通过体位复位及Sky扩张器撑开复位后,经双侧椎弓根穿刺充填自固化磷酸钙人工骨（CPC）。根据Denis胸腰椎骨折的分型：压缩性骨折,B型27例,C型3例,D型5例;爆裂性骨折2例,均为B型。利用体位复位,经皮穿刺,Sky椎体成形器扩张椎体,注入可降解的自固化磷酸钙人工骨。根据术前和术后侧位X线片测量椎体高度、后凸畸形角度,并计算椎体高度丢失率和后凸畸形矫正率,记录分析视觉模拟评分（VAS）及伤椎形态变化。结果：术后随访9～24个月,平均13个月。术后伤椎处疼痛均显著缓解,VAS评分改变从术前平均（7.6±2.5）分降至术后平均（1.8±1.5）分,椎体前壁高度和中间高度明显恢复,后凸畸形得到矫正。随访期间疗效满意,伤椎高度无明显丢失。结论：在严格掌握适应证、选择合适病例的前提下,采用体位复位辅助下经皮椎体后凸成形术治疗创伤性胸腰椎椎体骨折,能迅速缓解疼痛,有效恢复椎体高度和矫正后凸畸形。