经皮椎体成形术治疗骨质疏松性压缩性骨折的有限元力学分析

目的建立胸腰段骨质疏松性椎体压缩性骨折的病理三维有限元模型,分析手术前后病椎及邻近椎体应力变化情况。方法取CT三维重建资料通过软件MIMICS10.0建立椎体的三维实体模型,以三维有限元分析软件ANSYS12.0模拟经皮椎体成形术(PVP)过程在腰1(L1)椎体中置入不同容量骨水泥(2、4、6、8 ml),分析轴向压缩直立、前屈、后伸、侧弯、旋转5种加载状态下手术前后相邻椎体的应力变化。结果小剂量骨水泥注入(2、4 ml),病椎所受应力逐渐增加,而较大治疗量骨水泥注射入(6、8 ml),随着病椎硬度及刚度加强,其所受应力逐渐下降;而临近椎体在骨水泥注入量逐渐增加过程中,所受应力未见明显改变。结论对于老年骨质疏松性压缩性骨折的力学研究,三维有限元力学分析具有良好的应用前景及临床价值;在能够避免大治疗剂量骨水泥注入所带来并发症(如渗漏)前提下,4⁸ ml骨水泥注入量更加有效,且不增加邻近椎体骨折的风险。     

单侧及双侧PVP治疗骨质疏松性胸腰椎压缩骨折临床效果比较

目的对比单侧及双侧经皮穿刺椎体成形术（PVP）治疗骨质疏松性胸腰椎体压缩骨折的临床疗效。方法将同期收治的43例骨质疏松性胸腰椎压缩骨折患者随机分为单侧组25例、双侧组18例,分别行单侧及双侧PVP治疗。观察两组手术时间、X线透视次数、骨水泥注入量、视觉模拟疼痛评分（VAS）改善率、疗效及并发症发生情况。结果两组VAS改善率及有效率均无显著差异,双侧组手术时间、透视次数及骨水泥用量均显著大于单侧组（P〈0．05）;两组均无脊髓神经损伤、肺栓塞等并发症发生。结论单侧及双侧PVP治疗骨质疏松性胸腰椎压缩骨折效果相似,但前者具有手术时间短、放射暴露少、骨水泥用量小等优点。     

过伸复位治疗胸腰椎压缩性骨折关节突关节动态力学有限元分析

目的建立胸腰段三维有限元模型,观察过伸复位治疗胸腰椎压缩性骨折关节突关节的动态生物力学特性。方法依据1例T12椎体压缩性骨折患者的210层Dieom3．0标准CT图片,建立T12椎体单纯压缩性骨折的胸腰段有限元模型;验证模型的有效性后,模拟过伸复位手法约束L2下端所有面,给T11椎体上端一个纵向牵引力,分别于T11、T12、L1棘突顶点给予垂直朝向椎体、3．0cm的位移。程序运算,读取受压椎骨左右关节突关节的受力情况。结果建立了外形逼真、生物力学全面的T12椎体压缩性骨折的胸腰段三维有限元模型,复位中关节突关节承受了较大的压应力且逐渐增大,以过伸支点在T12棘突顶点时的受力最大、最稳定,骨折复位最彻底。结论建立了胸腰段三维有限元模型。过伸复位支点应在骨折椎骨棘突顶点,关节突关节在过伸复位中起着支点的作用,其承受较大的压应力是胸腰椎骨折患者后期出现腰背痛的原因之一。     

经皮椎体成形术治疗胸腰椎新鲜骨质疏松性压缩骨折

对20例新鲜骨质疏松性胸腰椎压缩骨折21个椎体行经皮椎体成形术(PVP),平均每个椎体注入骨水泥3.7 ml,20例患者腰背疼痛均有不同程度缓解,其中19例疼痛明显减轻或基本消失,椎体高度恢复平均2.2mm,未发生严重并发症。随访3~48个月,无再骨折及疼痛加重者。认为PVP治疗新鲜骨质疏松性压缩骨折安全、有效,适合多数新鲜疼痛性骨质疏松性胸腰椎压缩骨折患者。     

经皮椎体成形术治疗骨质疏松性椎体压缩骨折

目的观察经皮椎体成形术治疗骨质疏松性椎体压缩骨折的临床疗效。方法胸腰椎骨质疏松性椎体压缩骨折患者156例,在X线透视下经皮椎弓根向伤椎椎体内穿针并注入聚甲基丙烯酸甲酯骨水泥3—7ml。结果X线检查显示骨水泥充盈良好,骨折复位满意。视觉模拟评分（VAS）及MiGill-Melzack评分测试疼痛缓解81％;术后2d的VAS评分为（2．43±0．82）分,与术前的（8．53±1．23）分相比,P〈0．01;术后2d的MiGill—Melzack评分为（2．434-0．82）分,与术前的（8．53±1．23）分相比,P〈0．01。对18例患者随访3～6个月,疼痛未复发,椎体形态未见改变。结论经皮椎体成形术治疗骨质疏松性椎体压缩骨折,能够迅速缓解疼痛,增加椎体的稳定性。     

PKP治疗老年骨质疏松性胸腰椎压缩骨折11例疗效观察

对11例(14椎)老年骨质疏松性胸腰椎压缩骨折患者行经皮椎体后凸成形术(PKP)治疗,术后常规应用抗菌药物 3 d ,观察患者腰背部疼痛变化;随访 2 个月,比较手术前后伤椎前、中柱平均高度变化并测量Cobb角.结果11例手术均成功,平均手术时间60 min;无术中死亡及心脑血管系统急性不良反应发生,1例骨水泥外漏,未出现神经压迫症状;患者腰背疼痛完全缓解7例,部分缓解4例;术后伤椎前、中柱平均高度明显提高,Cobb角矫正到正常水平.认为PKP治疗老年骨质疏松性胸腰椎压缩骨折可有效恢复椎体高度,迅速缓解疼痛,改善患者的生活质量,且较为安全.     

术前体位复位结合经皮穿刺椎体后凸成形术治疗新鲜胸腰椎骨质疏松严重压缩骨折24例

目前老年人口占社会总人口的比例逐年增加,越来越多的老年患者因骨质疏松出现胸腰椎压缩骨折,严重影响其生活质量.随着经皮穿刺椎体后凸成形术的日渐成熟,已成为治疗骨质疏松性胸腰椎压缩骨折的重要治疗手段.但对部分椎体压缩严重,椎体高度丢失超过2/3以上的病例,该术式存在穿刺困难、难以有效改善椎体高度、骨水泥渗漏等问题.本文对24例新鲜胸腰椎骨质疏松严重压缩骨折患者采用术前体位复位结合经皮椎体后凸成形术治疗并进行临床疗效分析.     

骨质疏松性椎体骨折后不同躯体姿势对椎体局部应力的影响

获取1例健康老年女性胸腰段CT平扫数据,通过Mimics及Geomagic对胸腰段椎体进行三维实体化,并修饰模型,使之符合分析要求,导入有限元软件ANSYS分析,通过改变椎体骨质、椎间盘的物理属性设定,获得健康及退变腰椎在不同躯体姿势的应力分布情况.结果 显示正常骨质、正常间盘、前屈姿势下,椎体上表面最大应力几乎相同,且应力分布趋向于中央;正常骨质及骨质疏松骨质在退变间盘、前屈姿势下,压缩骨折与非压缩骨折相比,其应力分布更趋于前方,而且其最大应力值较非压缩骨折最大应力值增大了近20%.认为骨质疏松性椎体压缩性骨折后,前屈姿势能够造成椎体局部应力的显著增大,可能导致再骨折风险的增加.     

老年人腰椎椎体变形与椎间盘退变的关系

目的：从生物力学和医学影像学角度研究老年性骨质疏松患者腰椎椎体变形与椎间盘退行性改变的关系。方法：采用三维有限元方法比较椎间盘正常及退变发椎的应力分布。影响学研究着着重观察腰椎椎体变形与椎间盘高度及退主程度的关系。结果：生物力学研究发现，当椎间盘生退变后椎体松质骨中央区的应力集中明显减轻，提示腰椎的载荷传递方式发生了明显变化。     

PKP 治疗骨质疏松性椎体压缩骨折临床观察

目的观察经皮球囊扩张椎体后凸成形术（PKP）治疗骨质疏松性椎体压缩骨折的疗效。方法采用PKP治疗骨质疏松性椎体压缩骨折患者12例,观察手术前后疼痛情况、活动能力及并发症。结果手术前后患者VAS评分分别为（7．2±0．5）、（2．2±0．4）分,活动能力评分分别为（2．8±0．6）、（1．2±0．4）分,两者比较P均〈0．05。复查x线及CT片,均显示压缩骨折高度不同程度恢复,仅1例出现椎间盘的少量骨水泥渗漏。结论PKP治疗骨质疏松性椎体压缩骨折创伤小,可有效缓解患者疼痛,改善活动能力,提高生活质量。     

Bone mineral density in ankylosing spondylitis

Summary Vertebral osteoporosis is a well-recognized feature of ankylosing spondylitis (AS) and also the vertebral compression fractures due to osteoporosis are a common but frequently unrecognized complication of AS. Both may contribute to the pathogenesis of spinal deformity and back pain. The aim of this study was to measure vertebral and femoral neck bone mass in patients with AS by dual photon absorptiometry, to determine the prevalence of compression fractures and to examine the relationship between bone density and disease severity. We found that the bone mass was diminished in the lumbar spine in moderate AS versus mild forms but the patients with advanced disease had the highest BMD values. Examination of spinal radiographs revealed compression and biconcave fractures in 9 (40.9%) cases. Neither the duration of the disease and the degree of sacroiliitis, nor the disease activity assessed by laboratory and clinical parameters was found to significantly affect the results.     

How should clinicians manage osteoporosis in ankylosing spondylitis?

Osteoporosis is a common complication of AS, with an incidence between 18.7% and 62%. The prevalence of osteoporosis is greater in males, and increases with increasing patient age and disease duration. Osteoporosis is also more common in patients with syndesmophytes, cervical fusion, and peripheral joint involvement. These variables are not all independent, as they may be indicators of disease duration. Osteoporosis in patients with AS is largely confined to the axial skeleton, in contrast to the pattern of osteoporosis seen in rheumatoid arthritis. BMD at the lumbar spine and femoral neck may be severely reduced, while most studies indicate that carpal and radial BMD remain within normal limits. The development of syndesmophytes in late AS can lead to difficulties in the use of DEXA scanning to determine lumbar BMD, as the extraspinal bone may obscure osteoporotic vertebrae. Under these circumstances more accurate assessment of lumbar BMD, and one that correlates better with femoral neck BMD, may be obtained by quantitative CT scanning or DEXA scanning of the lateral aspect of the L3 vertebra. Osteoporosis in AS significantly increases the risk of vertebral compression fractures within 5 years of the diagnosis of AS. The risk of a vertebral compression fracture occurring over a 30 year period following the diagnosis of AS is 14%, compared to 3.4% for population controls. In patients with vertebral osteoporosis relatively minor trauma, such as slipping, can lead to spinal fracture and dislocatior with subsequent damage to the spinal cord. There is a higher incidence of spinal cord injury following spinal fracture dislocations in patients with AS, and the resulting neurological deficit can range from mild sensory loss to complete paraplegia. Cytokines such as TNF-alpha and IL-6 may play an important part in the pathogenesis of osteoporosis in early AS, and IL-6 levels have been correlated with markers of disease activity and severity. In late AS, mechanical factors such as decreased mobility and the support provided by extraspinal bone may play a role in vertebral osteoporosis. Screening patients with AS for the presence of osteoporosis is an important, but contentious subject. This and subsequent monitoring needs to be considered in all patients, but longterm studies are needed to determine with confidence which patients should undergo screening, by which methods, and how often. The treatment of osteoporosis in AS is at present similar to that used for primary osteoporosis, except that due to the male predominance and a relatively young age of patients, there is a limited role for hormone replacement therapy. Exercise regimens and bisphosphonates are widely used, but a study of the relative efficacy of different bisphosphonate agents in patients with AS is required.     

经皮椎体成形术及经皮椎体后凸成形术治疗骨质疏松性椎体压缩骨折再发骨折危险因素研究

目的 探讨骨质疏松性椎体压缩骨折（OVCFs）经皮椎体成形术（PVP）及经皮椎体后凸成形术（PKP）后非手术椎体骨折的危险因素。方法回顾性研究2009年2月～2010年3月于河北医科大学第三医院脊柱外科门诊及病房共收治OVCFs患者76例,男11例,女65例,年龄56~87岁,平均（66．7±7-3）岁,随访时间6～22个月,平均13．6个月。44例患者行PVP手术,32例患者行PKP手术。记录两组患者年龄、性别、病程、体质量指数、骨密度、水泥注入量、水泥渗漏率、平均后凸角矫形,分析引起非手术椎体骨折的危险因素。结果PVP组患者水泥注入量及平均后凸角矫形均低于PKP组患者,经两样本t检验,差异有统计学意义（P〈0．05）;水泥渗漏率和新发椎体骨折两组间差异无统计学意义（P〉0．05）;logistic回归分析结果显示,骨密度T值≤-2．5SD是与非手术椎体骨折相关的危险因素,后凸角矫形≥5．0。组患者新发骨折与首次手术间隔时间明显短于对照组,经秩和检验显示差异有统计学意义（P〈O．05）。结论骨密度T值≤-2．5SD是与非手术椎体骨折相关的危险因素,在骨密度T值严重降低的骨质疏松患者中,过多的矫正后凸畸形可能缩短了再发骨折的发病周期。     

绝经后妇女脊椎压缩性骨折与骨密度的关系

目的探讨绝经后妇女脊椎压缩性骨折与骨密度（BMD）的关系。方法为病例一对照研究，入选250例有脊椎压缩性骨折的绝经后妇女，另有250名无脊椎压缩性骨折的绝经后妇女作为对照组。两组均有胸腰椎正侧位X线摄片，并应用双能X线吸收仪检测腰椎1～4和左股骨近端各部位BMD。结果脊椎压缩性骨折组身高、体重、腰椎2～4和股骨近端各部位BMD值均显著低于对照组（均P〈0．01）。腰椎2～4BMD是发生脊柱骨折的预报因子（r=-0．416，P〈0．01）。身高和全髋部BMD与骨折次数和骨折椎体数目呈负相关（均P〈0．01）。按股骨颈和全髋部BMD值，骨折组骨质疏松检出率各为50．8％和50．4％；另外剔除在腰椎2～4发生椎体骨折53例，按腰椎2～4BMD检出骨质疏松占64．5％。同时，腰椎2～4、股骨颈或全髋部BMD值低于-2．5s者发生脊柱压缩性骨折的风险分别是BMD正常者的4．76、2．36和3．52倍。结论腰椎呈低骨量是发生脊椎压缩性骨折的重要危险因素。身高的下降和全髋部低BMD值是骨折发生次数和受累椎体数目的危险因子；对绝经后妇女在重视BMD测量的同时，应重视脊柱X线正侧位检查。     

A case of post-pregnancy osteoporosis combined with ankylosing spondylitis

Post-pregnancy osteoporosis is not a common disease and is hard to diagnosis because their specific situation is post-partum and lactation. It commonly occurs on lumbar spine within a few months after the birth of a patient’s first child and it could lead to be fracture after minor trauma. Although its etiology is not clear, it would not be of sufficient magnitude to cause fractures unless the woman already had a substantial decrease in bone mass. Also, it is rare to be combined with ankylosing spondylitis. Ankylosing spondylitis has a higher risk of osteoporosis and vertebral fracture which increased with the duration of disease. We report a case of post-pregnancy osteoporosis with multiple spinal compression fracture in association of ankylosing spondylitis.     

Men suffer vertebral fractures with similar spinal T-scores to women

OBJECTIVE: To evaluate the applicability of the WHO densitometric criteria for the diagnosis of spinal osteoporosis in men and to compare it with women with vertebral fractures, as well as to analyze the role of vertebral dimensions in the development of spinal fractures. METHODS: For these purposes we analyzed, using DXA, vertebral projected area and lumbar bone mineral density (BMD), as well as T and Z-scores in lumbar spine in a cohort of 66946 individuals; 2556 of these subjects had one or more atraumatic vertebral fracture (396 men and 2160 postmenopausal women). RESULTS: Men and women with fractures showed significantly lower mean BMD, T-score and Z-score values than individuals without fractures while vertebral dimensions were similar in both groups of patients. When comparing men and women with vertebral fractures, the former showed a significantly greater projected area (46.89+/-5.5 vs. 39.13+/-4.6 cm(2) p<0.001) and lumbar BMD (0.991+/- 0.21 vs. 0.938+/- t0.19 g/cm(2) p<0.001). However, the median lumbar T-score values were similar for both sexes (-2.3 in women vs. -2.2 in men; p: NS). In addition, a similar percentage of men and women with vertebral fractures showed T-score values <-2.5 in the lumbar spine (44% vs. 46%, p=NS). CONCLUSION: We conclude that although men with vertebral fractures have greater vertebral dimensions and BMD than women, the lumbar T-scores are similar. Therefore, it seems reasonable to adopt the same T-score values for the diagnosis of osteoporosis in men and women.     

Risk of fractures in celiac disease patients: a cross-sectional, case-control study

OBJECTIVES: Although osteopenia and osteoporosis are well-recognized complications of celiac disease, no controlled studies have been done to assess the prevalence of fractures in a large cohort of patients. The objectives of this study were to determine the prevalence of bone fractures and vertebral deformities in celiacs and to analyze the relationship between fractures and clinical data of patients. METHODS: We studied 165 patients with a well-established diagnosis of celiac disease. A similar number of age- and gender-matched control subjects with functional GI disorders were evaluated. The design of the study was cross-sectional, with a retrospective historical review through a personal interview of all subjects. All patients underwent bone mineral density measurement by dual-energy, x-ray absorptiometry and spinal x-ray. Vertebral deformities were determined by visual inspection of spinal x-rays and by morphometric analysis. RESULTS: Among celiacs, 41 patients (25%) referred have had from one to five fractures in the peripheral skeleton. On the contrary, only 14 (8%) control subjects experienced fractures. This difference was highly significant (odds ratio, 3.5; 95% confidence interval [CI], 1.8-7.2; p<0.0001). Although inspection of spinal x-rays showed evidence of vertebral deformities in the lumbar spine in only two patients, a more detailed examination of lateral x-rays using morphometric criteria detected lumbar spine vertebral deformities in nine (five also had fractures in the peripheral skeleton) and in four controls (odds ratio, 2.8; 95% CI, 0.7-11.5; p = NS). Eighty percent of fractures were detected before the diagnosis of celiac disease or in patients who were noncompliant with the gluten-free diet; only 7% of patients experienced fractures after starting treatment. Regression analysis adjusted for multiple comparisons showed that patients with fractures were diagnosed with celiac disease later (p<0.06) and remained undiagnosed for more prolonged periods (p<0.05). There was a trend, which did not reach statistical significance, for a lower bone mineral density in the lumbar spine and total skeleton among patients with fractures. CONCLUSIONS: This study has demonstrated that patients with celiac disease had a high prevalence of bone fractures in the peripheral skeleton. Most of these events occurred before diagnosis or while patients were noncompliant with gluten-containing diet. Our results suggest that early diagnosis and effective treatment of celiac disease were the most relevant measures to protect patients from the risk of fractures.     

Postmenopausal bone loss at multiple skeletal sites: relationship to estrogen use

Bone mineral content (BMC) was measured in the distal radius, proximal radius, and os calcis in 608 postmenopausal women, and the values were compared to vertebral osteoporosis and compression fractures determined radiographically, as well as to history of estrogen use. Current estrogen users had significantly higher BMC at all appendicular sites as compared to non-users. Prior estrogen users had lower appendicular BMC's than current users, but they were still significantly higher than non-users. However, radiographic assessment of the lumbar spine showed no difference in osteoporosis or compression fracture prevalence between prior users and non-users of estrogen, whereas current estrogen users had a significantly lower prevalence of osteoporosis in the spine. These findings suggest that estrogen effect on trabecular bone in the os calcis may be more transient than on cortical, appendicular bone. They also suggest that long term or permanent estrogen replacement is required to prevent spinal compression fractures.     

Percutaneous vertebroplasty for elderly patients with unhealed osteoporotic spinal fractures

Background:   Vertebroplasty is a procedure in which bone cement is injected percutaneously into the vertebral body.
Methods:   We used this technique with 15 patients who had pseudarthrosis or delayed union of osteoporotic spinal fractures with vacuum clefts, and in whom conservative treatment did not relieve persistent pain. The procedure was performed in a short time with little blood loss, and no generic complications, leakage of bone cement to blood vessels or the spinal canal, or neural compression.
Results:   At 1 week after the operation, pain was eliminated in seven patients, alleviated in seven patients, unchanged in one patient, and worsened in none. The rate of alleviation or elimination of pain after 1 week and 6 months was 93% and 85%, respectively. Recurrence of the pain was seen in four cases, but this was caused by new spinal fractures in separate locations, confirmed with magnetic resonance imaging, in three patients, and by multiple myeloma in one patient.
Conclusion:   Thus, vertebroplasty, which alleviates pain rapidly and with low invasiveness, is a new and promising therapy for osteoporotic spinal fractures in which conservative treatment has failed. It seems to provide a large benefit to elderly patients if performed with prudent care with regard to complications at the time of bone cement injection, and in conjunction with treatment for osteoporosis.