Lumbar vertebral body(VB) fractures are increasingly common in an ageing population that is at greater risk of osteoporosis and metastasis. This review aims to identify different models, as alternatives to bone minera...Lumbar vertebral body(VB) fractures are increasingly common in an ageing population that is at greater risk of osteoporosis and metastasis. This review aims to identify different models, as alternatives to bone mineral density(BMD), which may be applied in order to predict VB failure load and fracture risk. The most representative models are those that take account of normal spinal kinetics and assess the contribution of the cortical shell to vertebral strength. Overall, predictive models for VB fracture risk should encompass a range of important parameters including BMD, geometric measures and patient-specific factors. As interventions like vertebroplasty increase in popularity for VB fracture treatment and prevention, such models are likely to play a significant role in the clinical decision-making process. More biomechanical research is required, however, to reduce the risks of post-operative adjacent VB fractures.展开更多
The objective of this study was to study the age-related adaptation of lumbar vertebral trabecular bone at the apparent level, as well as the tissue level in three orthogonal directions. Ninety trabecular specimens we...The objective of this study was to study the age-related adaptation of lumbar vertebral trabecular bone at the apparent level, as well as the tissue level in three orthogonal directions. Ninety trabecular specimens were obtained from six normal L4 vertebral bodies of six male cadavers in two age groups, three aged 62 years and three aged 69 years, and were scanned using a high-resolution micro-computed tomography （micro-CT） system, then converted to micro- finite element models to do micro-finite element analyses. The relationship between apparent stiffness and bone volume fraction, and the tissue level yon Mises stress distribution for each trabecular specimen when compressed separately in the longitudinal direction, medial-lateral and anterior-posterior directions （transverse directions） were derived and compared between two age groups. The results showed that at the apparent level, trabecular bones from 69-year group had stiffer bone structure relative to their volume fractions in all three directions, and in both age groups, changes in bone volume fraction could explain more variations in apparent stiffness in the longitudinal direction than the transverse directions; at the tissue level, aging had little effect on the tissue von Mises stress distributions for the compressions in all the three directions. The novelty of the present study was that it provided quantitative assessments on the age and direction- related adaptation of Chinese male lumbar vertebral trabecular bone from two different levels： stiffness at the apparent level and stress distribution at the tissue level. It may help to understand the failure mechanisms and fracture risks of vertebral body associated with aging and direction for the prevention of fracture risks in elder individuals.展开更多
Purpose: Bone marrow and muscle adiposity have been considered to correlate with osteoporosis and Sarcopenia. Proton Density Fat Fraction (PDFF) can be measured by Magnetic Resonance Imaging (MRI). The purpose of the ...Purpose: Bone marrow and muscle adiposity have been considered to correlate with osteoporosis and Sarcopenia. Proton Density Fat Fraction (PDFF) can be measured by Magnetic Resonance Imaging (MRI). The purpose of the present study was to measure PDFF in the lumbar spine, paraspinal muscle and subcutaneous fat tissue. Methods: Participants were comprised of 30 patients (18 males, 12 females;age range, 14 - 87 years) who underwent MRI due to low back symptoms. PDFFs for the body of the fourth lumbar vertebra (L4), paraspinal muscle, and subcutaneous fat were measured. Results: PDFFs of the vertebral body and subcutaneous fat were significantly higher than that of paraspinal muscle (p < 0.001). PDFF was significantly higher for subcutaneous fat than for the vertebral body (p < 0.001). Although no significant differences in PDFF of the vertebral body, paraspinal muscle, and subcutaneous fat between females and males, PDFFs of the vertebral body and paraspinal muscle were significantly higher in older subjects (>63 years) than in younger subjects (Conclusions: PDFF of the vertebral body was significantly higher than that of paraspinal muscle. PDFFs of the vertebral body and paraspinal muscle were significantly lower in younger subjects than in older subjects.展开更多
Estrogen withdrawal in postmenopausal women increases bone loss and bone fragility in the vertebra. Bone loss with osteoporosis not only reduces bone mineral density (BMD), but actually alters bone quality, which can ...Estrogen withdrawal in postmenopausal women increases bone loss and bone fragility in the vertebra. Bone loss with osteoporosis not only reduces bone mineral density (BMD), but actually alters bone quality, which can be comprehensively represented by bone post-yield behaviors. This study aimed to provide some information as to how osteoporosis induced by estrogen depletion could influence the evolution of post-yield microdamage accumulation and plastic deformation in vertebral bodies. This study also tried to reveal the part of the mechanisms of how estrogen deficiency-induced osteoporosis would increase the bone fracture risk. A rat bilateral ovariectomy (OVX) model was used to induce osteoporosis. Progressive cyclic compression loading was developed for vertebra testing to elucidate the post-yield behaviors. BMD, bone volume fraction, stiffness degradation, and plastic deformation evolution were compared among rats raised for 5 weeks (ovx5w and sham5w groups) and 35 weeks (ovx35w and sham35w groups) after sham surgery and OVX. The results showed that a higher bone loss in vertebral bodies corresponded to lower stiffness and higher plastic deformation. Thus, osteoporosis could increase the vertebral fracture risk probably through microdamage accumulation and plastic deforming degradation.展开更多
目的探讨脊髓型颈椎病患者行颈前路椎体次全切除植骨融合术(anterior cervical corporectomy and fusion,ACCF)手术中保留椎体后壁横联结构的临床价值。方法回顾性分析本科于2015年3月~2021年3月行ACCF手术的脊髓型颈椎病患者60例作为...目的探讨脊髓型颈椎病患者行颈前路椎体次全切除植骨融合术(anterior cervical corporectomy and fusion,ACCF)手术中保留椎体后壁横联结构的临床价值。方法回顾性分析本科于2015年3月~2021年3月行ACCF手术的脊髓型颈椎病患者60例作为研究对象,按ACCF手术方案的不同进行分组:常规ACCF手术30例,纳入常规组;保留椎体后壁横联结构的改良ACCF手术30例,纳入改良组。术后获访1年,对两组患者的围术期指标(手术时间、出血量和住院时间)、减压效果(JOA评分)、影像学指标(颈椎曲度、融合节段高度)、手术安全性和植骨融合情况进行比较。结果改良组的手术时间、术中出血量等数据均显著低于常规组(P<0.05);但两组住院时间无显著性差异(P>0.05)。两组术后共出现7例并发症,其中常规组4例(13.3%),3例为术后肩颈部疼痛,1例声音嘶哑;改良组3例(10%),均为肩颈部疼痛。上述并发症均于1~4周后自行好转。与术前相比,两组患者术后1周的JOA评分均显著改善,且术后3个月和1年的JOA评分呈持续改善趋势(P<0.05),两组间差异均无统计学意义(P>0.05)。两组患者术后的颈椎曲度、融合节段高度等影像学指标均获不同程度改善,但组间差异无统计学意义(P>0.05)。术后1年,两组患者均获得骨性融合。结论保留椎体后壁横联结构的改良ACCF手术治疗脊髓型颈椎病患者,可取得与常规ACCF手术一致的减压效果,且手术时间短、术中出血量少,减少了对椎体结构的破坏程度,手术安全可靠。展开更多
文摘Lumbar vertebral body(VB) fractures are increasingly common in an ageing population that is at greater risk of osteoporosis and metastasis. This review aims to identify different models, as alternatives to bone mineral density(BMD), which may be applied in order to predict VB failure load and fracture risk. The most representative models are those that take account of normal spinal kinetics and assess the contribution of the cortical shell to vertebral strength. Overall, predictive models for VB fracture risk should encompass a range of important parameters including BMD, geometric measures and patient-specific factors. As interventions like vertebroplasty increase in popularity for VB fracture treatment and prevention, such models are likely to play a significant role in the clinical decision-making process. More biomechanical research is required, however, to reduce the risks of post-operative adjacent VB fractures.
基金The project supported by the Hong Kong Polytechnic University Research Grants(G-U273) the National Natural Science Foundation of China(10502021 and 10529202)
文摘The objective of this study was to study the age-related adaptation of lumbar vertebral trabecular bone at the apparent level, as well as the tissue level in three orthogonal directions. Ninety trabecular specimens were obtained from six normal L4 vertebral bodies of six male cadavers in two age groups, three aged 62 years and three aged 69 years, and were scanned using a high-resolution micro-computed tomography （micro-CT） system, then converted to micro- finite element models to do micro-finite element analyses. The relationship between apparent stiffness and bone volume fraction, and the tissue level yon Mises stress distribution for each trabecular specimen when compressed separately in the longitudinal direction, medial-lateral and anterior-posterior directions （transverse directions） were derived and compared between two age groups. The results showed that at the apparent level, trabecular bones from 69-year group had stiffer bone structure relative to their volume fractions in all three directions, and in both age groups, changes in bone volume fraction could explain more variations in apparent stiffness in the longitudinal direction than the transverse directions; at the tissue level, aging had little effect on the tissue von Mises stress distributions for the compressions in all the three directions. The novelty of the present study was that it provided quantitative assessments on the age and direction- related adaptation of Chinese male lumbar vertebral trabecular bone from two different levels： stiffness at the apparent level and stress distribution at the tissue level. It may help to understand the failure mechanisms and fracture risks of vertebral body associated with aging and direction for the prevention of fracture risks in elder individuals.
文摘Purpose: Bone marrow and muscle adiposity have been considered to correlate with osteoporosis and Sarcopenia. Proton Density Fat Fraction (PDFF) can be measured by Magnetic Resonance Imaging (MRI). The purpose of the present study was to measure PDFF in the lumbar spine, paraspinal muscle and subcutaneous fat tissue. Methods: Participants were comprised of 30 patients (18 males, 12 females;age range, 14 - 87 years) who underwent MRI due to low back symptoms. PDFFs for the body of the fourth lumbar vertebra (L4), paraspinal muscle, and subcutaneous fat were measured. Results: PDFFs of the vertebral body and subcutaneous fat were significantly higher than that of paraspinal muscle (p < 0.001). PDFF was significantly higher for subcutaneous fat than for the vertebral body (p < 0.001). Although no significant differences in PDFF of the vertebral body, paraspinal muscle, and subcutaneous fat between females and males, PDFFs of the vertebral body and paraspinal muscle were significantly higher in older subjects (>63 years) than in younger subjects (Conclusions: PDFF of the vertebral body was significantly higher than that of paraspinal muscle. PDFFs of the vertebral body and paraspinal muscle were significantly lower in younger subjects than in older subjects.
基金supported by the National Natural Science Foundation of China (Grants 11472017, 11002004)
文摘Estrogen withdrawal in postmenopausal women increases bone loss and bone fragility in the vertebra. Bone loss with osteoporosis not only reduces bone mineral density (BMD), but actually alters bone quality, which can be comprehensively represented by bone post-yield behaviors. This study aimed to provide some information as to how osteoporosis induced by estrogen depletion could influence the evolution of post-yield microdamage accumulation and plastic deformation in vertebral bodies. This study also tried to reveal the part of the mechanisms of how estrogen deficiency-induced osteoporosis would increase the bone fracture risk. A rat bilateral ovariectomy (OVX) model was used to induce osteoporosis. Progressive cyclic compression loading was developed for vertebra testing to elucidate the post-yield behaviors. BMD, bone volume fraction, stiffness degradation, and plastic deformation evolution were compared among rats raised for 5 weeks (ovx5w and sham5w groups) and 35 weeks (ovx35w and sham35w groups) after sham surgery and OVX. The results showed that a higher bone loss in vertebral bodies corresponded to lower stiffness and higher plastic deformation. Thus, osteoporosis could increase the vertebral fracture risk probably through microdamage accumulation and plastic deforming degradation.
文摘目的探讨脊髓型颈椎病患者行颈前路椎体次全切除植骨融合术(anterior cervical corporectomy and fusion,ACCF)手术中保留椎体后壁横联结构的临床价值。方法回顾性分析本科于2015年3月~2021年3月行ACCF手术的脊髓型颈椎病患者60例作为研究对象,按ACCF手术方案的不同进行分组:常规ACCF手术30例,纳入常规组;保留椎体后壁横联结构的改良ACCF手术30例,纳入改良组。术后获访1年,对两组患者的围术期指标(手术时间、出血量和住院时间)、减压效果(JOA评分)、影像学指标(颈椎曲度、融合节段高度)、手术安全性和植骨融合情况进行比较。结果改良组的手术时间、术中出血量等数据均显著低于常规组(P<0.05);但两组住院时间无显著性差异(P>0.05)。两组术后共出现7例并发症,其中常规组4例(13.3%),3例为术后肩颈部疼痛,1例声音嘶哑;改良组3例(10%),均为肩颈部疼痛。上述并发症均于1~4周后自行好转。与术前相比,两组患者术后1周的JOA评分均显著改善,且术后3个月和1年的JOA评分呈持续改善趋势(P<0.05),两组间差异均无统计学意义(P>0.05)。两组患者术后的颈椎曲度、融合节段高度等影像学指标均获不同程度改善,但组间差异无统计学意义(P>0.05)。术后1年,两组患者均获得骨性融合。结论保留椎体后壁横联结构的改良ACCF手术治疗脊髓型颈椎病患者,可取得与常规ACCF手术一致的减压效果,且手术时间短、术中出血量少,减少了对椎体结构的破坏程度,手术安全可靠。
