Spine deformity index (SDI) versus other objective procedures of vertebral fracture identification in patients with osteoporosis: a comparative study

Radiologic identification of vertebral fractures is most important in the diagnosis and monitoring of patients with spinal osteoporosis. Different methods, using vertebral height measurements for fracture identification, have therefore been developed. We compared four methods for fracture identification in spinal x-rays of 62 female patients with primary osteoporosis. The methods of Hedlund and Gallagher, Melton et al., and Davies et al. are based on the ratio of heights within one vertebra or of the height ratios of adjacent vertebrae; all three methods result in counting the number of vertebral fractures. The fourth method of Minne et al. relates anterior, middle and posterior heights of the vertebrae between T5 and L5 to the respective heights of T4. The relative vertebral heights of patients with osteoporosis are compared to the respective relative heights (anterior, middle, and posterior) of normal subjects (T5-L5). This allows the identification of fractured vertebrae, as well as a quantification of the extent of deformation due to these fractures (spine deformity index, SDI). The same measurement data of 62 spinal x-rays of anterior, middle, and posterior heights between T4 and L5 were used to detect vertebral fractures by the four different methods. Correlation between the number of identified fractures by the different methods ranged between r = 0.56 and 0.83. On the other hand, we found a remarkable difference in the mean number of identified fractures and a discrepancy in the identification of single vertebrae as fractured or not. All four methods revealed an accumulation of fractures in the midthoracic area and in the region of transition from thoracic to lumbar spine. Vertebral fractures as identified by SDI were not detected by the other three methods in 12-29% of the cases, even if vertebral height reduction was more than 6 mm. The reliability of each method was examined by the determination of "decreasing" number of fractures during follow-up. A decrease in the number of fractures was found in about 25% patients, if using the three methods that count only the number of fractures. We obtained a 3.6% decrease in the number of fractures using the fourth method. Furthermore, the decrease in SDI values in follow-up was within the range of variance. We therefore believe that SDI and related procedures are reliable in quantifying spinal osteoporosis and monitoring during follow-up.     

Finite Element Analysis of a New Type of Spinal Protection Device for the Prevention and Treatment of Osteoporotic Vertebral Compression Fractures

ObjectiveTo study the effectiveness of a new spinal protection device for preventing and treating osteoporotic vertebral compression fractures (OVCFs) by finite element analysis (FEA).MethodsOne healthy volunteer and one patient with 1‐segment lumbar vertebral compression fractures were included in this experimental study. The DICOM files of two different lumbar spiral computed tomography (CT) scans were converted into STL files, and 3D finite element models of the lumbar spine were generated for normal and L1 vertebral fracture spines. A new type of spinal protection device was applied to reduce the stress on the anterior vertebral edge and direct the center of gravity posteriorly. The stress distribution characteristics of different finite element models of the lumbar spine were analyzed, revealing the characteristics of the stress distributed along the spine under the action of the new spinal protection device.ResultsUnder normal conditions, the stress was mainly distributed in the middle and posterior columns of the spine. When the anterior border of the L1 vertebral body was fractured and collapsed, the stress distribution shifted toward the anterior column due to the center of gravity being directed forward. According to finite element analysis of the spine with the new protection device, the stress in the middle and posterior columns tended to increase, and that in the anterior column decreased. After the new type of spinal fixation device was applied, the stress at the L1 and L2 vertebral endplates decreased to a certain extent, especially that at the L1 vertebral body. The maximum stress on the L1 vertebral body decreased by 20% after the auxiliary device was applied.ConclusionsAccording to the FEA results, the new spinal protection device can effectively prevent and treat osteoporotic vertebral compression fractures (OVCFs), and can alter the stress distribution in the spine and reduce the stress in the anterior column of the vertebral body, especially in vertebral compression fractures.     

Correlative analysis of the results of surgical treatment of thoracolumbar injuries with long Texas Scottish rite hospital construct: is the use of pedicle screws versus hooks advantageous in the lumbar spine?

This is a prospective, randomized study to compare the efficacy of two similar "long-segment" Texas Scottish Rite Hospital instrumentations with the use of hooks in the thoracic spine and pedicle screws versus laminar hook claw in the lumbar spine for thoracolumbar A3, B, and C injuries. Forty consecutive patients with such thoracolumbar fractures (T11-L1) associated with spinal canal encroachment underwent early operative postural reduction and stabilization. The patients were randomly sampled into two groups: Twenty patients received hooks in "claw configuration" in both the thoracic and the lumbar spine (group A), and 20 patients received hooks in the thoracic vertebrae and pedicle screws in the lumbar vertebrae (group B). Pre- and postoperative plain roentgenograms and computed tomography scans were used to evaluate any changes in Gardner post-traumatic kyphotic deformity, anterior and posterior vertebral body height at the fracture level, and spinal canal clearance (SCC). All patients were followed for an average period of 52 months (range 42-71 months). The correction of anterior vertebral body height was significantly more (P < 0.01) in the spines of group B (33%) than in group A (16%), with a subsequent 11% loss of correction at the latest evaluation in group A and no loss of correction in group B. There were no significant differences in the changes of posterior vertebral body height and Gardner angle between the two groups. The SCC was significantly more (P < 0.05) immediately postoperatively in the spine of group B (32%) than in group A (19%). In the latest evaluation, there was a 9% loss of the immediately postoperatively achieved SCC in group A, while SCC was furthermore increased at 10.5% in group B. All patients with incomplete neurologic lesions in groups A and B were postoperatively improved at 1.1 and 1.7 levels, respectively. There were two hook dislodgements in the thoracic spine, one in each group, while there was no screw failure in group B. There was neither pseudarthrosis nor neurologic deterioration following surgery. Visual Analog Pain Scale and Short Form-36 scores were equally improved and did not differ between the two groups. The use of pedicle screws in the lumbar spine to stabilize the lowermost end of a long rigid construct applied for A3, B, and C thoracolumbar injuries was advantageous when compared with that using hook claws in the lumbar spine because the constructs with screws restored and maintained the fractured anterior vertebral body height better than the hooks without subsequent loss of correction and safeguarded postoperatively a continuous SCC at the injury level.     

Refractures in cemented vertebrae after percutaneous vertebroplasty: a retrospective analysis

Percutaneous vertebroplasty is an efficient procedure to treat pain due to osteoporotic vertebral compression fractures. However, refracture of cemented vertebrae occurs occasionally after vertebroplasty. It is unclear whether such fractures are procedure-related or part of the natural course of osteoporosis. The effect of potentially important covariates on refracture risk in cemented vertebrae has not been evaluated previously. We retrospectively analyzed the incidence and possible causative mechanism of refracture in patients who had received only one vertebroplasty for a single level of vertebral compression fracture. We assessed the following covariates: age, sex, body weight, height, lumbar spine bone mineral density, treated vertebral level, pre-existing untreated vertebral compression fracture, and gas-containing vertebrae before treatment. Surgical variables, including surgical approach, cement injected, and anterior vertebral height restoration, were also analyzed. Anti-osteoporotic treatment after surgery was recorded. Multiple logistic regression analysis was used to determine the relative risk of refractures of cemented vertebrae. Over all, 98 patients were evaluated with a mean follow-up of 26.9 ± 12.4 months (range, 7–55 months). We identified 62 refractures and the mean loss of anterior vertebral height was 13.3% (range 3.2–40.3%). The greater the anterior vertebral height obtained from vertebroplasty, the greater the risk of refracture occurring (P < 0.01). Gas-containing vertebrae were also prone to refracture after the procedure (P = 0.01). Anti-osteoporotic treatment was of borderline significance between refractured and non-refractured vertebrae (P = 0.07). Only restoration of anterior vertebral height was positively associated with refracture during the follow-ups (P < 0.01). In conclusion, refractures of cemented vertebrae after vertebroplasty occurred in 63% of osteoporotic patients. Significant anterior vertebral height restoration increases the risk of subsequent fracture in cemented vertebrae.     

Nontraumatic lumbar vertebral compression fracture as a risk factor for femoral neck fractures in involutional osteoporotic patients

To screen a potential risk factor for femoral neck fracture, we characterized lumbar vertebral fractures in 120 patients with femoral neck fractures (19 men, 101 women; mean age, 78.7 years) by investigating the frequency of patients with lumbar vertebral fracture, the number of vertebral fractures per patient, and the severity of deformity of the fractured vertebral bodies. These findings were compared with data gathered from a population of age- and sex-matched control patients (20 men, 89 women; mean age, 77.6 years) who had no evidence of femoral neck fracture. The heights of the anterior and posterior walls together with the midpart of the lumbar vertebrae were measured on lateral radiographs to identify fractures. The extent of height loss in the fractured vertebrae was calculated for each group. The incidence of patients with vertebral compression fractures was significantly higher in the femoral neck fracture group than in the control group (65.0% vs 41.1%). In terms of age, the difference in the incidence of vertebral fractures in the two groups was greater in the less aged (60–79 years old) than in the more aged (>80 years old) population. The mean number of lumbar vertebral fractures was also significantly greater in the femoral neck fracture group than in the control group (1.59 ± 1.39 vs 0.75 ± 1.19; P < 0.001). The incidence of more deformed vertebral fractures, which were defined as a vertebral height loss of more than 50%, was also significantly higher in the group with femoral neck fracture than in the control group (23.0% vs 7.3%). Based on these results, we concluded that multiple and more severely deformed vertebral fractures might represent a high risk for femoral neck fracture, particularly in patients less than 79 years of age. Care measures that encompass fall prevention and protection of proximal femurs in addition to drug therapy for osteoporosis should be recommended to individuals in this category. Received: Nov. 11, 1998 / Accepted: Jan. 13, 1999     

Long structural allografts in the treatment of anterior spinal column defects.

A retrospective study of 41 patients who had anterior spinal column reconstruction using long-segment allografts between 1983 and 1998 is reported. A long-segment allograft was defined as an allograft strut that replaces a vertebral body or approximates the height of the adjacent vertebral body for the thoracolumbar or lumbar spine, or more than two vertebral bodies for the cervical or cervicothoracic spine. Forty of the 41 patients had successful anterior strut grafting with radiographic evidence of allograft incorporation at the last followup with the majority of patients having radiographic evidence of incorporation by 6 months. There where three early complications related to the allograft (two end plate fractures and one repeated cervical spine allograft dislodgment) and one late complication associated with the posterior adjunct instrumentation unrelated to the allograft (degenerative lumbar stenosis). The only procedural complication was a deep venous thrombosis and a resultant nonfatal pulmonary embolus. No allografts fractured or collapsed. These data suggest that long-segment anterior allografts work exceptionally well in maintaining vertebral height and structural integrity in numerous pathologic deformities including traumatic and infectious etiologies.     

钉棒及钩棒系统治疗胸腰椎多节段脊柱骨折

目的评价钉棒及钩棒系统治疗胸腰椎多节段脊柱骨折的临床疗效。方法23例多节段胸腰椎骨折患者，后路切开复位，选择性椎管减压．钉棒或钩棒系统内固定及后外侧植骨融合进行手术治疗。其中相邻多节段型13例，非相邻多节段型8例，混合型2例。结果全组病例平均随访14个月，未发现内固定物松动、断离，无继发性脊柱后凸畸形加重。椎体高度由术前平均48．4％恢复至术后平均92．4%。2例完全性及11例不完全性脊髓损伤者．脊髓神经功能获改善。结论在椎管进行充分减压的基础上．钉棒及钩棒系统能有效复位椎体骨折，重建脊柱稳定性，是多节段胸腰椎不稳定性骨折合并脊髓神经损伤后路手术的理想选择。     

胸腰椎骨折脱位伤椎固定的可行性研究

目的探讨后路手术治疗合并前、后纵韧带断裂及椎间盘破裂的胸腰椎脊柱骨折脱位的疗效。方法2001年1月至2004年5月收治18例合并前、后纵韧带断裂及椎间盘破裂的脊柱骨折脱位患者，均为男性，年龄19-58岁，平均38岁，均合并截瘫。受伤节段为T11-L3。侧位X线片示骨折椎体楔形变，其中6例椎体后缘高度有丢失。骨折椎体高度压缩程度为1／4～3／4，上位椎体向前脱位25％～100％，2例合并侧方脱位。均于伤后10d内行后路减压椎弓根螺钉植入复位固定融合术。8例采用目前国内通用的在骨折椎体相邻上下椎体植入四枚椎弓根螺钉的复位固定技术，10例采用在骨折椎和相邻上下椎植入六枚椎弓根螺钉的复位固定技术。结果全部病例随访3个月-3年，平均18个月。8例采用二椎体四枚椎弓根螺钉植入者术后骨折椎体高度无改变5例，部分改善3例；骨折椎上位相邻椎脱位部分纠正6例，无变化1例，加重1例。1例出现撑开过度，1例术后3个月出现螺钉松动拔出，1例术后6个月出现断棒。10例三椎体六枚椎弓根螺钉植入者术后骨折椎体复位达80％～100％，骨折椎上位相邻椎脱位均完全复位。术后近期内无严重并发症。结论应用三椎体六枚椎弓根螺钉植入复位固定治疗合并前、后纵韧带断裂及椎间盘破裂的脊柱骨折脱位在操作技术上是可行的，对恢复椎体高度和纠正脱位有效。     

Comparison of anterior and posterior double-rod instrumentation for thoracic idiopathic scoliosis: results of 141 patients

Ventral derotation spondylodesis, according to Zielke, achieves good results in operative treatment of idiopathic thoracic scolioses. Corrections of scoliotic major and secondary curve as well as derotation of the spine are reliably performed. The high rate of rod fractures with subsequent correction loss as well as a proportionate kyphogenic effect represents a problem. By keeping to the correcting principle, anterior double-rod instrumentation (Halm-Zielke Instrumentation) is to be stable in a similar way as posterior double-rod systems. Thus, it is done to facilitate brace-free postoperative care and to prevent excessive kyphotic pattern of the spine. In this prospective study, we retrospectively collected data. We performed radiological follow-up of two groups of patients with idiopathic thoracic scoliosis (King II, III and IV) undergoing an operation with posterior approach (USS instrumentation, posterior group, n=104) in 1997 and 1998 or being corrected with an anterior fusion (Halm-Zielke instrumentation, anterior group, n=37) between 2000 and 2001. Mean age of all patients for operation was 15±4 years. Follow-up was performed after 4±2 years on average. Preoperative measurements of the major and secondary curve, the lateral profile, rotation and frontal balance (C7 to S1) did not show any significant differences apart from a more severe scoliotic curve in the lumbar spine for the anterior group with appropriately higher lumbar rotation. During follow-up we noticed similar corrections of the thoracic major and lumbar curve in both groups ranging from 49 to 56%. In case of hypokyphotic (T4–T12≤20°) scoliosis a kyphogenic effect on the thoracic spine was achieved with both surgical methods. Hyperkyphotic (T4–T12≥40°) scolioses were flattened by posterior spinal fusion; the effect of anterior spinal fusion was not significant. Correction of thoracic and lumbar rotation in the anterior group by 37 or 30% was more significant than in the posterior group by 27 or 20%. There was no impact of anterior technique on the balance of the spine whereas the latter shifted by an average of 7 mm to the left in the posterior group. The number of fused segments was significantly smaller in the anterior group with 7±1 vertebral bodies (posterior, 11±1 vertebral bodies). Rates of complication were identical with 11 or 12% in both groups during follow-up. Anterior and posterior double-rod instrumentations result in comparable corrections for idiopathic thoracic scoliosis of the major and secondary curve. In case of posterior technique, however, four vertebral bodies less were integrated in spondylodesis on average. Balance of the spine did not change after anterior spondylodesis; however, it declined by using the posterior technique. Augmentation of the anterior threaded rod combined with a solid second rod significantly decreases the rate of implant breakages and reliably reduces consecutive correction losses.     

Vertebral fractures in late adolescence: a 27 to 47-year follow-up

The long-term outcome of thoracic and lumbar fractures in late adolescence is sparsely described and it is unclear whether a fractured vertebral body in these years, as in young children, can be resituated in height. The purpose of this study was to in late adolescence determine the incidence, the long-term outcome and the modelling capacity in fractures of the thoracic and lumbar region. The incidence of vertebral fractures 1950–1971 in individuals aged 16–18 years was through the radiological archives evaluated in a city cohort of 228,878 citizens, of whom 13,893 were aged 16–18. A follow-up, 27–47 years after the injury, including subjective, objective and radiological evaluation was conducted in 18 boys and 5 girls. Twenty-nine boys and 11 girls were registered with a thoracic or lumbar vertebral fracture during the study period conferring an annual incidence of 0.14‰. Of the 23 individuals that attended the follow-up, 14 had one-column compression fractures, one a Denis type A, six a Denis type B, one a Denis type D and one a Chance fracture. At injury, one had a partial paresis in one leg and one developed a transient paraparesis during the first week. All were treated non-operatively. At follow-up, 18 individuals had no complaints while 5 had occasional back pain, 20 were classified as Frankel E and 3 as Frankel D. The radiographic ratio of anterior height to posterior height of the fractured vertebral body was unchanged during the study period. Thoracic and lumbar vertebral fractures in late adolescence with no or minor neurological deficits have a predominantly favourable long-term outcome, even if no modelling capacity of the fractured vertebral body remains in late adolescence.     

多节段胸腰椎脊柱骨折的手术治疗

目的探讨椎弓根钉棒系统治疗多节段胸腰椎脊柱骨折的手术方式与疗效。方法采用后路切开复位、椎弓根钉棒系统内固定、选择性椎管减压及后外侧植骨融合手术治疗44例多节段胸腰椎骨折患者,对患者术前与随访时的ASIA分级、伤椎椎体高度矫正率进行分析。结果全部患者平均随访12个月,未发现内固定物松动、断裂,椎体高度由术前平均49.3%恢复至术后平均92.5%。ASIA分级较术前平均提高1.2级。结论后路切开复位、椎弓根钉棒系统内固定基础上选择性椎管减压＋植骨融合是治疗多节段胸腰椎脊柱骨折的理想选择。     

Effect of long-term axial spinal unloading on vertebral body height in adult thoracolumbar spine

The human spine is influenced by mechanical loads. To our knowledge, this is the first study to assess the effect of long-term axial unloading on morphology of healthy vertebras in adults. The objective of this study is to quantify the effects of long-term relative axial unloading on thoracolumbar vertebral body height in adults. In this study, 218 vertebras on 200 plain lateral radiograms of patients with thoracolumbar vertebral body fracture, which underwent long segment instrumentation and fusion and had a relative axial unloading on five vertebrae of thoracolumbar spine were evaluated. Anterior vertebral body height (AVBH) and posterior vertebral body height (PVBH) proximal and distal to the fractured vertebrae were measured before and at least 1 year after the unloading operative procedures. AVBH of the first distal adjacent vertebrae and summative AVBHs of the first distal and proximal adjacent vertebras to the fractured vertebrae were significantly increased after 1 year of unloading, whereas the PVBH changes were not noticeable and the mean of cumulative height of two levels of proximal and distal adjacent vertebras to the fractured vertebrae did not show significant difference. Vertebral body height of lumbar was more influenced by unloading when compared with thoracic spine. Long-term relative axial unloading can affect the height of healthy vertebral bodies in adult spine.     

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.     

Recurrence of deformity after removal of Harrington's fixation of spine fracture. Seventy-six cases followed for 2 years

The radiographic result was assessed in 76 patients with acute unstable fractures of the thoracic or lumbar spine admitted during the years 1977-1984, and who were managed by early reduction and stabilization using Harrington distraction rods and a three-segmental posterolateral fusion. The radiographs were analyzed for anterior and posterior heights plus sagittal and frontal widths of the fractured vertebral body and the angles of kyphosis and scoliosis of the spine. All the measurements were made at admission, immediately postoperatively, and at the latest follow-up at least 3 months after removal of the rods, which was done as a routine procedure 6-12 months after the accident. The mean follow-up was 29 months. The posterior height and sagittal width of the vertebral bodies were best restored, whereas the initially well-reduced anterior height and the angle of kyphosis often had returned to values close to those seen on admission. The best anatomic restoration was obtained in rotation-dislocation injuries of the thoracic and thoracolumbar spine, and was poorest in burst fractures of the lumbar spine.     

Radiographic parameters for evaluating the neurological spaces in experimental thoracolumbar burst fractures

It is important to know the condition of neural spaces during the nonoperative treatment of thoracolumbar burst fractures. The goals of the current study were to identify the correlation between the degree of deformity of a fractured vertebra and the encroachment of neural spaces, and to determine how the encroachment and the deformity can be improved by the extension posture simulating the postural reduction. Experimental burst fractures were produced in L1 vertebrae of nine human thoracolumbar spine segments (T11-L3) with neural spaces lined with tiny steel balls. Lateral radiographs were taken in neutral and extended posture before and after the trauma. Anterior vertebral height, posterior vertebral height, vertebral height ratio, vertebral kyphotic angle, posterior vertebral body angle, and the cross diagonal angle were the geometric parameters used to describe the vertebral deformity. The canal diameter and superior and inferior intervertebral foramen areas were defined as the neural spaces. All parameters were measured on the scanned images of radiographs, as seen on the computer screen. Among the vertebral body parameters, the posterior vertebral height, posterior vertebral body angle, and cross diagonal angle showed significantly higher correlations with the canal encroachment. The extended posture did not improve the canal and intervertebral foramen encroachments. The kyphotic deformity (vertebral kyphotic angle and anterior vertebral height) was improved but the deformity of the vertebral posterior wall (posterior vertebral height and posterior vertebral body angle) was not improved because of the extended posture.     

Recurrence of deformity after removal of Harrington's fixation of spine fracture: Seventy-six cases followed for 2 years

The radiographic result was assessed in 76 patients with acute unstable fractures of the thoracic or lumbar spine admitted during the years 1977-1984, and who were managed by early reduction and stabilization using Harrington distraction rods and a three-segmental posterolateral fusion. The radiographs were analyzed for anterior and posterior heights plus sagittal and frontal widths of the fractured vertebral body and the angles of kyphosis and scoliosis of the spine. All the measurements were made at admission, immediately postoperatively, and at the latest follow-up at least 3 months after removal of the rods, which was done as a routine procedure 6-12 months after the accident. The mean follow-up was 29 months.

The posterior height and sagittal width of the vertebral bodies were best restored, whereas the initially well-reduced anterior height and the angle of kyphosis often had returned to values close to those seen on admission. The best anatomic restoration was obtained in rotation-dislocation injuries of the thoracic and thoracolumbar spine, and was poorest in burst fractures of the lumbar spine.     

An unconventional indication for open kyphoplasty

BACKGROUND CONTEXT: Kyphoplasty is a means of treatment for painful osteoporotic vertebral body compression fractures. Its efficacy has not yet been totally proven. Even though the conventional percutaneous kyphoplasty is a relatively safe procedure, it is not routinely recommended for use in vertebral body fractures that involve posterior cortical compromise/retropulsion or in fractures associated with neurological deficit. PURPOSE: To see whether the open kyphoplasty procedure can be used in patients with painful vertebral body compression fractures who also have bony retropulsion into the spinal canal. STUDY DESIGN/SETTING: This technical report is based on the experience of one patient. METHODS: A 79-year-old woman with a history of osteoporosis presented with a painful vertebral body compression fracture at T12. Magnetic resonance imaging of her lumbar spine demonstrated an acute compression fracture at T12 with significant decrease in vertebral body height and retropulsion of bone resulting in one-third reduction in canal width. She was not considered a candidate for percutaneous kyphoplasty. Three months after the injury, an open kyphoplasty was performed after a decompression laminectomy at T12. RESULTS: The fractured vertebral body was successfully reduced, and there was no leakage of polymethylmethacrylate into the spinal canal through the fractured posterior cortex using the open kyphoplasty procedure. One month after the operation, the patient was free from mid-back pain and was again able to walk. CONCLUSION: Open kyphoplasty procedure allows direct visualization to the spinal canal. It can be performed safely and effectively in selected vertebral body compression fractures with retropulsed bone associated with neurological deficit.     

胸腰椎脊髓损伤侧前方减压的适应证与术式选择

胸腰椎骨折脱位并截瘫主要系椎管前方的椎体骨拆块、椎体后上角与椎间盘突出及大于２０°的脊柱后弓成角所致，是侧前方减压的适应证。经后正中入路椎弓根侧前方减压的优点是手术创伤较小，可同时探查脊髓与安置后方内固定；缺点是不能直视脊髓前方，对侧减压可能不彻底或需对侧辅助减压。适于Ｔ１０以上的胸椎与Ｌ２以下腰椎，亦适于胸腰段，特别是已行椎板切除者。     

An evaluation of densitometric vertebral fracture assessment in men

Summary The utility of, and potential indications for, densitometric vertebral fracture assessment were evaluated in 1,168 men. A bimodal fracture distribution was observed, identifying fractures in 17% of men with no fracture history. Osteopenia or height loss of ≥ 2.5″ may be indications for VFA in men. Introduction Densitometric vertebral fracture assessment (VFA) is an excellent means to detect unappreciated vertebral fractures in women. However, little evaluation of VFA in men has been performed. This study evaluated VFA utility and explored potential VFA indications in men. Methods The study cohort consists of a population of 1,168 men (mean age, weight and BMI of 69.1 years, 188.8 pounds and 28.1 kg/m², respectively) referred for clinically indicated bone mineral density (BMD) measurement at the Wm. S. Middleton VAMC. Lateral VFA images and scans of the lumbar spine, proximal femur and non-dominant radius, were obtained by two technologists using a GE Healthcare Lunar Prodigy densitometer. Vertebral fractures were defined using the Genant visual semi-quantitative approach. Results Seventy-eight percent of vertebrae from T4–L5 and 93% from T8–L5 were adequately visualized on VFA. Vertebral fractures were detected in 32% (374/1,168) of these men. A bimodal distribution was observed with fractures being most common in the mid-thoracic spine and at the thoraco-lumbar junction. As would be expected, the prevalence of VFA-detected fractures increased with age and as BMD declined. Fracture prevalence did not increase until a historical height loss of ≥ 6.4 cm (2.5 inches) was reported. VFA-identified fractures were present in 17% of men who had no history of fracture. Furthermore, in men with densitometric osteopenia, no historical fracture and absence of glucocorticoid use (n = 158), vertebral fractures were detected in 18%. Conclusion VFA allows evaluation of the majority of vertebral bodies in men and identifies a substantial number of individuals with previously unappreciated fracture. Additionally, a more stringent height loss requirement, perhaps 2.5 inches or more, or densitometric osteopenia (low bone mineral density by DXA), may be appropriate as indications for performance of VFA in men.     

青少年特发性脊柱侧凸胸椎形态学的MRI测量及临床意义

目的 通过磁共振成像(MRI)观察青少年特发性脊柱侧凸(AIS)和正常同年龄组青少年胸椎的形态学差异,探讨其临床意义.方法 胸椎轻度侧凸(MS)组患者10例(Cobb角15°～39°),胸椎中度侧凸(SS)组患者10例(Cobb角40°～75°).另选健康青少年10名作为对照(非侧凸组).所有研究对象均为女性,年龄13～14岁.用1.5 T磁共振扫描仪(Sonata,Siemens,Erlanger,德国)对所有研究对象进行全脊柱矢状面扫描,在图像工作站(Easy Vision,Philips Medical Systems,Best,荷兰)上重建脊柱矢状面图像,测量每个胸椎椎体前壁高度,后壁高度,棘突间高度,在横截面测量椎体横径长度,并进行对比分析.结果 椎体前后高度、宽度从T1到T12逐渐增加,并呈线性分布,脊柱侧凸组椎体高度普遍>正常同年龄非侧凸组患者.脊柱侧凸组患者椎体高度横径比值以及脊椎前后高度比值均>无侧凸组.胸椎侧凸顶椎区T6～T9椎体前方高度、椎体高度横径比值以及脊椎前后高度比值,脊柱侧凸组明显>非侧凸组,差异均有统计学意义(P<0.05).结论 AIS胸椎侧凸女性患者胸椎顶椎区存在显著的脊柱生长模式异常,与正常胸椎相比AIS的胸椎更高、并显得更为瘦长.