Posterior Vertebral Body Research Articles

44 - Is balloon kyphoplasty safe and effective for cancer-related vertebral compression fractures with posterior vertebral body wall defects?

44 - Is balloon kyphoplasty safe and effective for cancer-related vertebral compression fractures with posterior vertebral body wall defects?

Analysis of the spinal nerve roots in relation to the adjacent vertebral bodies with respect to a posterolateral vertebral body replacement procedure.

Objective:This study aims to improve the understanding of the anatomic variations along the thoracic and lumbar spine encountered during an all-posterior vertebrectomy, and reconstruction procedure. This information will help improve our understanding of human spine anatomy and will allow better planning for a vertebral body replacement (VBR) through either a transpedicular or costotransversectomy approach.Summary of Background Data:The major challenge to a total posterior approach vertebrectomy and VBR in the thoracolumbar spine lies in the preservation of important neural structures.Methods:This was a retrospective analysis. Hundred normal magnetic resonance imaging (MRI) spinal studies (T1–L5) on sagittal T2-weighted MRI images were studied to quantify: (1) mid-sagittal vertebral body (VB) dimensions (anterior, midline, and posterior VB height), (2) midline VB and associated intervertebral discs height, (3) mean distance between adjacent spinal nerve roots (DNN) and mean distance between the inferior endplate of the superior vertebrae to its respective spinal nerve root (DNE), and (4) posterior approach expansion ratio (PAER).Results:(1) The mean anterior VB height gradually increased craniocaudally from T1 to L5. The mean midline and posterior VB height showed a similar pattern up to L2. Mean posterior VB height was larger than the mean anterior VB height from T1 to L2, consistent with anterior wedging, and then measured less than the mean anterior VB height, indicating posterior wedging. (2) Midline VB and intervertebral disc height gradually increased from T1 to L4. (3) DNN and DNE were similar, whereby they gradually increased from T1 to L3. (5) Mean PAER varied between 1.69 (T12) and 2.27 (L5) depending on anatomic level.Conclusions:The dimensions of the thoracic and lumbar vertebrae and discs vary greatly. Thus, any attempt at carrying out a VBR from a posterior approach should take into account the specifications at each spinal level.

Growth modulation and remodeling by means of posterior tethering technique for correction of early-onset scoliosis with thoracolumbar kyphosis.

The aim of this study is to evaluate the role of the non-fusion instrumented procedure with compression adjunct to lengthening by distraction in facilitating spinal modulation of the wedged peak vertebra, in patients with congenital thoracolumbar kyphosis/kyphoscoliosis according to the Hueter-Volkmann law. The authors seek to address the progressive modulation of the most wedged vertebra by analyzing the subjects' pre-operative and latest follow-up sagittal radiograph. Ongoing data collection of 14 peak wedged vertebra modulation during surgical management of 13 patients with Type I congenital thoracolumbar kyphosis (5 patients) or kyphoscoliosis (8 patients). Age at initial surgery averaged 58.6months, with mean follow-up of 55.6months (24-78). All were done with hybrid rib construct with clawing fashion through a single posterior approach with at least 4 lengthenings. Two vertebral bodies were selected, the peaked deformed vertebrae within the instrumentation compression level (WICL) and the vertebrae nearest but outside the instrumentation compression process (OICL). Anterior vertebral body height (AVBH) and posterior vertebral body height (PVBH) were measured in both vertebral bodies. Regarding measured vertebrae (WICL), average preoperative AVBH/PVBH ratio significantly increased from 0.54 to 0.77 in the final follow-up. Regarding measured vertebrae (OICL), the average preoperative AVBH/PVBH ratio increased from 0.76 to 0.79 in the final follow-up. Modulation can be confirmed in the most deformed vertebrae (WICL) as the difference between the change in AVBH/PVBH ratio between vertebrae (OICL) and (WICL) was statistically significant (P<0.001). Through the compression model adjunct to lengthening through distraction implemented in the surgical management of early-onset scoliosis, wedging improves through vertebral modulation (WICL) in comparison with the (OICL). This calls for further studies on the impact of surgical correction of EOS on modulation of the vertebrae.

Simultaneous anterior vertebral column resection-distraction and posterior rod contouring for restoration of sagittal balance: report of a technique

With an increasingly aging population, adult spinal deformity is becoming more common. This can be associated with increased morbidity. Results from multicentre studies of deformity surgery correction confirm complication rates as high as 40 percent. Most often a bad result is associated with inadequate restoration of the sagittal balance. Posterior vertebral body resection has been described as a method to correct significant deformity, but this is a complicated procedure. It is possible to do this in the thoracic spine where nerve roots can be sacrificed, but it is difficult in the lumbar spine due to the significant role of the lumbar nerve roots. We describe a safer technique for correction of deformity using a three stage process. This appears to be a good technique for revision surgery.

Which patients risk segmental kyphosis after short segment thoracolumbar fracture fixation with intermediate screws?

IntroductionThe use of intermediate screws in fractured vertebrae has been proposed to decrease the number of fused levels in thoracolumbar fractures and to enable short fixations. The aim of this study was to evaluate the results of this technique and to establish predictive factors involved in loss of segmental kyphosis correction (LKC). MethodsForty-three patients who underwent short-segment spinal fixation with intermediate screws for a thoracolumbar spine fracture in a two-year time period were enrolled in the study. Patients had AO-type A3, A4 and B2 thoracolumbar fractures. Radiological parameters included segmental kyphosis (SK), vertebral wedge angle (VWA) and loss of anterior and posterior vertebral body height. Patients were evaluated up to one-year follow-up. The correlation between LKC and potential risk factors, such as smoking habit, sex, age, neurological status and BMI was evaluated. ResultsMean preoperative SK was 16.5°±6.5°, and it decreased to 3.4°±3.5° postoperatively (P<0.01). At the one-year follow-up mean SK dropped to 5.5°±3.9° (P<0.01). Mean preoperative VWA was 20.0°±8.1°, and significantly improved to 6.3°±3.1° after surgery (P<0.01). There was a mean LKC of 1.8°±2.1°at one year. LKC mildly correlated with body mass index (BMI, r: +0.31), and obese patients (BMI>30) had an increased risk of LKC at the one-year follow-up (P=0.03; odds ratio [OR]=3.2). DiscussionAnalysis of the radiological data at one-year follow-up showed that all the evaluated parameters were associated with a mild loss of correction, with no impact on the clinical outcomes or implant failure. These findings confirm the trends reported in the literature. The correlation between LKC and clinical features, such as BMI, age, sex, smoking habit and preoperative neurological status was investigated. Interestingly, a positive correlation was observed between BMI and LKC, and obese patients with BMI>30 had an increased risk of LKC at one-year follow-up (OR 3.2); to our knowledge this finding has never before been reported. ConclusionShort-segment fixation with intermediate screws is a viable technique with positive clinical and radiological outcomes at one-year follow-up. However, surgeons should be aware that in obese patients (BMI>30) this technique is associated with an increased risk of LKC. Level of evidence3.

Change in Angular Alignment Is Associated With Early Dysphagia After Anterior Cervical Discectomy and Fusion

Study Design: Retrospective analysis of a prospective cohort. Objective: Change in cervical angular alignment may be associated with dysphagia. Summary of Background Data: Bony deformities of the cervical spine may be associated with secondary contractures of soft tissues in the neck. Acute surgical deformity correction causes in changes in soft tissue tension in the anterior neck, resulting in dysphagia. Methods: The study population included patients undergoing 1 and 2 level elective anterior cervical discectomy and fusion for cervical myelopathy or radiculopathy. Preoperative and postoperative radiographs at 2 weeks were measured by a blinded observer for C2–C7 endplate angle, C2–C7 posterior vertebral body length, and occipital condyle plumb line distance on upright lateral radiographs at 2, 6, and 12 weeks postoperatively. Patients were prospectively queried about dysphagia incidence and severity using a numeric rating scale. Multiple linear regression analysis was used to determine the effect of change in radiographic parameters controlling for demographic characteristics. Results: The study population included 25 patients with complete radiographs. The mean change in C2–C7 angle was −0.6 degrees (SD 9), the mean change in C2–C7 length was 1.7 mm (SD 26), the mean change in occipital condyle plumb line distance was 2.3 mm (SD 20). Multiple linear regression analysis was performed including operative time, age, sex, number of levels, and change in radiographic parameters as independent variables and using dysphagia score as the dependent variable. The change in C2–C7 angle and operative time were the only statistically significant predictors of change in dysphagia at 2 and 6 weeks postoperatively. Conclusions: These results indicate that lordotic change in spinal alignment and longer operative times are associated with increased postoperative dysphagia. Surgeons should counsel patients in whom a large angular correction is expected about the possibility for postoperative dysphagia. Furthermore, future studies on dysphagia incidence should include radiographic alignment as an independent predictor of dysphagia.

An Analysis of the Spinal Nerve Roots in Relation to the Adjacent Vertebral Bodies with Respect to a Posterolateral Vertebral Body Replacement Procedure

Introduction This study aims to improve the understanding of the anatomic variations along the thoracic and lumbar spine encountered during an all-posterior vertebrectomy, and reconstruction procedure. This information will help to improve our understanding of human spine anatomy and will allow better planning for a vertebral body replacement via either a transpedicular or costo-transversectomy approach, The major challenge to a total posterior approach vertebrectomy and vertebral body replacement in the thoracolumbar spine lies in the preservation of important neural structures. Materials and Methods Retrospective analysis of 100 normal MRI spinal studies (T1-L5) on sagittal T2 weighted MRI images were studied to quantify: 1) mid-sagittal vertebral body (VB) dimensions (anterior, midline and posterior vertebral body height); 2) midline VB and associated intervertebral discs height; 3) mean distance between adjacent spinal nerve roots (DNN) and mean distance between the inferior endplate of the superior vertebrae to its respective spinal nerve root (DNE) and 4) posterior approach expansion ratio (PAER). Results 1) The mean anterior VB height gradually increased cranio-caudally from T1 to L5. The mean midline and posterior VB height showed a similar pattern up to L2. Mean posterior VB height was larger than the mean anterior VB height from T1 to L2, consistent with anterior wedging, and then measured less than the mean anterior VB height, indicating posterior wedging. 2) Midline VB and intervertebral disc height gradually increased from T1 to L4. 3) DNN and DNE were similar, whereby they gradually increased from T1 to L3. 5) Mean PAER varied between 1.69 (T12) and 2.27 (L5) depending on anatomic level. Conclusions The dimensions of the thoracic and lumbar vertebrae and discs vary greatly. Thus, any attempt at carrying out a VB replacement from a posterior approach should take into account the specifications at each spinal level.

Quantifying Progressive Anterior Overgrowth in the Thoracic Vertebrae of Adolescent Idiopathic Scoliosis Patients: A Sequential Magnetic Resonance Imaging Study.

Anterior and posterior vertebral body heights were measured from sequential magnetic resonance imaging (MRI) scans of adolescent idiopathic scoliosis (AIS) patients and healthy controls. To measure changes in vertebral body height over time during scoliosis progression to assess how vertebral body height discrepancies change during growth. Relative anterior overgrowth has been proposed as a potential driver for AIS initiation and progression. This theory proposes that the anterior column grows faster, and the posterior column slower, in AIS patients when compared with healthy controls. There is a disagreement in the literature as to whether the anterior vertebral body heights are proportionally greater than posterior vertebral body heights in AIS patients when compared with healthy controls. To some extent, these discrepancies may be attributed to methodological differences. MRI scans of the major curve of 21 AIS patients (mean age 12.5 ± 1.4 years, mean Cobb 32.2 ± 12.8 degrees) and between T4 and T12 of 21 healthy adolescents (mean age 12.1 ± 0.5 years) were captured for this study. Of the 21 AIS patients, 14 had a second scan on average 10.8 ± 4.7 months after the first. Anterior and posterior vertebral body heights were measured from the true sagittal plane of each vertebra such that anterior overgrowth could be quantified. The difference between anterior and posterior vertebral body height in healthy, nonscoliotic children was significantly greater than in AIS patients with mild to moderate scoliosis. There was; however, no significant relationship between the overall anterior-posterior vertebral body height difference in AIS and either severity of the curve or its progression over time. Whilst AIS patients have a proportionally longer anterior column than nonscoliotic controls, the degree of anterior overgrowth was not related to the rate of progression or the severity of the scoliotic curve. 3.

Is balloon kyphoplasty safe and effective for cancer-related vertebral compression fractures with posterior vertebral body wall defects?

Balloon kyphoplasty (BKP) is a percutaneous treatment for cancer-related vertebral compression fractures (VCF). Posterior vertebral body wall (PVBW) involvement is considered a contraindication for BKP. This study assesses whether BKP is safe and effective for cancer-related VCFs involving the PVBW. This study analyzed data on 158 patients with 228 cancer-related VCFs who underwent BKP. One hundred and twelve patients had VCFs with PVBW defects, and 46 had VCFs with no PVBW defect. Outcomes were assessed preoperatively and at 3 months. In the PVBW defect group, mean pain score decreased from 7.5 to 3.6 (P < 0.001), EQ5D increased from 0.39 to 0.48 and Oswestry Disability Index (ODI) decreased from 50 to 42. Cement leaks occurred in 31%. In the PVBW intact group, mean pain decreased from 7.3 to 3.3 (P < 0.001), EQ5D increased from 0.35 to 0.48 (P < 0.001), and ODI decreased from 53 to 50. Cement leaks occurred in 20%. No significant difference was observed in functional improvements between groups. Radiographically kyphotic angle and anterior and middle vertebral body heights were significantly worse in the PVBW defect group (P < 0.05). BKP can alleviate pain and improve QoL and function in patients with cancer-related VCFs with PVBW defects with no appreciable increase in risk. J. Surg. Oncol. 2016;113:835-842. © 2016 Wiley Periodicals, Inc.

Morphology of the injured posterior wall causing spinal canal encroachment in osteoporotic vertebral fractures

Background ContextThe relationship between fractured posterior vertebral wall patterns and the protrusion of bony fragments into the spinal canal is not clear. PurposeWe sought to elucidate the effects of fracture patterns of the injured posterior wall on posterior wall instability and spinal canal encroachment using computed tomography myelography (CTM) in two different positions. Study Design/SettingThis is a prospective analysis of CTM in both supine and semi-sitting positions. Patient SampleThe sample includes 36 consecutive elderly patients with delayed neurologic disorders due to insufficient bone union at the posterior vertebral wall after vertebral fracture. Outcome MeasuresRadiological parameters, including the rates of dural compression and of occupation by bony fragments (OBFr) and the posterior vertebral body height ratio (PVBHr), were used. MethodsAll patients were examined using CTM in both supine and semi-sitting positions. According to fracture patterns of the posterior vertebral wall, we classified injured posterior walls with one fragment as the simple type and those with two or more fragments as the comminuted type. ResultsThe simple type was found in 19 of 36 cases, whereas the comminuted type was found in 17 of 36 cases. A significant correlation was identified between changes in OBFr and PVBHr in both the simple and comminuted types. The mean change of PVBHr between the two positions in the comminuted type was significantly larger (9.2%) than that in the simple type (4.8%). Likewise, the mean change in OBFr in the comminuted type (14.0%) was significantly larger than that in the simple type (8.2%), indicating that the injured posterior vertebral wall with the comminuted type would be more likely to collapse and protrude into the spinal canal. ConclusionsBoth simple and comminuted fracture types could cause protrusion of vertebral fragments into the spinal canal because of a collapsing non-united posterior vertebral wall; however, the comminuted type showed more severe spinal canal encroachment, with axial loading. The morphology of the injured posterior wall is thus important for estimating instability.

Teardrop fracture following head-first impact in an ice hockey player: Case report and analysis of injury mechanisms.

We report a case of a young male athlete who sustained a three column displaced teardrop fracture of the C5 vertebra due to a head-first impact in hockey, suffered neurapraxia, yet made full neurological recovery. This full recovery was in sharp contrast to multiple case series which reported permanent quadriplegia in the vast majority of teardrop fracture patients. We investigate the etiology and biomechanical mechanisms of injury. Admission imaging revealed the teardrop fracture which consisted of: a frontal plane fracture which separated an anterior quadrilateral-shaped fragment from the posterior vertebral body; a vertical fracture of the posterior vertebral body in the sagittal plane; and incomplete fractures of the neural arch that initiated superiorly at the anterior aspect of the spinous process and left lamina adjacent to the superior facet. Epidural hematoma in the region of the C5 vertebra was observed in addition to disc and ligamentous disruptions at C4-5 and C5-6. Our patient was ultimately treated surgically with anterior fusion from C4 through C6 and subsequently with bilateral posterior fusion at C5-6. The injuries were caused by high-energy axial compression with the neck in a pre-flexed posture. The first fracture event consisted of the anterior vertebral body fragment being sheared off of the posterior fragment under the compression load due in part to the sagittal plane concavity of the C5 inferior endplate. The etiology of the vertical fracture of the posterior vertebral body fragment in the sagittal plane was consistent with a previously described hypothesis of the mechanistic injury events. First, the C4-5 disc height decreased under load which increased its hoop stress. Next, this increased hoop stress transferred lateral forces to the C5 uncinate processes which caused their outward expansion. Finally, the outward expansion of the uncinate processes caused the left and right sides of the vertebral body to split and spread. Evidence in support of this mechanistic event sequence was provided by the neural arch fractures which initiated superiorly, average angulation of the C5 uncinate processes, and similar well-established mechanisms causing vertical fractures at other spinal regions. Our case study and analyses provide insight into the etiology of the specific teardrop fracture patterns observed clinically.

Winking-owl Sign - An Uncommon Presentation of Spine Metastasis

Introduction: Spinal metastasis is the commonest form of secondary osseous involvement by variety of cancers usually presenting clinically in the form of backache. They may be osteolytic, osteoblastic or mixed types. Spinal radiograph is usually the first investigation used to define the future course of action. Case Presentation: A 50-year old female from a nearby village came to outpatient department of our hospital with an acute history of severe backache since few days. Clinical examination revealed focal tenderness in mid-lumbar region. Laboratory investigations were however, unremarkable. She was advised radiograph of dorsolumbar spine region in anteroposterior and lateral projections. Careful evaluation of radiographs revealed nonvisualisation of left-sided pedicle of L3 vertebra representing winking-owl sign, conspicuously noted on anteroposterior projection associated with surrounding vertebral lucency (Figures 1A and 1B). There was associated early lumbar spondylotic changes and diffuse osteopenia as well. Based on radiological findings, the diagnosis of solitary vertebral metastasis was kept as the first differential diagnosis and further work-up was advised to search for the primary tumour. A thorough clinical history and examination revealed invasive breast carcinoma with history of occasional blood stains on clothes and metastases to lungs on chest radiograph. Histopathological examination confirmed the primary malignancy and metastases. Patient was referred to higher center for further management. Discussion: All types of spinal metastases are usually multiple at the time of presentation, but occasionally they may be solitary at first presentation. Detecting solitary metastasis is important in a patient with known primary malignancy as it predicts progression of disease, poorer prognosis and requires further intervention in the form of chemotherapy or radiotherapy depending on the sensitivity of the primary tumour. At time, solitary metastasis may be the first presentation of cancer thus making aggressive search for primary tumour very imperative for deciding future course of action as seen in our index case. Pedicle destruction of a vertebra is an important radiographically detectable signs of osteolytic metastasis especially carcinoma. Though any part of the neural arch of vertebra may be involved by metastases yet the vertebral pedicle is the commonest site. Involvement of pedicle with adjacent part of posterior vertebral body results in loss of cortical margins that can be detected radiographically as nonvisualisation of vertebral pedicle on anteroposterior radiograph [1]. This is described as one-eyed pedicle or winkingowl sign. It is most commonly noted in the lower dorsal and lumbar vertebrae with solitary involvement being commoner than the multifocal involvement. Rarely both the pedicles may be involved by the above process leading to nonvisualisation of both vertebral pedicles on anteroposterior radiograph resulting in blind-vertebra [1,2]. Differential diagnosis includes congenital absence of pedicle which is usually associated with hypoplastic /agenetic ipsilateral and hyperplastic contralateral pedicles. There may be some degree of abnormal spinal curvature as well. Congenital disease usually presents in early childhood/adolescence. To summarise, it is important to recognise solitary spinal metastasis in form of winking-owl sign on spine radiograph as it affects the prognosis of the patient suffering from the cancers.

Relationship between the vertical craniofacial disproportions and the cervicovertebral morphology in adult subjects.

Orthodontic diagnosis includes the interpretation of the relations between the craniofacial and cervical system, given the potential impact of the irregularities from one system to another. The aim of this study was to examine morphological characteristics of the cervical spine, depending on the parameters of the vertical craniofacial growth and gender in adult subjects. The sample comprised lateral cephalograms of 120 subjects with different vertical facial growth, aged 17.5-35 years. Measured parameters were the following: anterior and posterior vertebral body height (ABHC2-C5, PBHC2-C5), anterior and posterior intervertebral space (AISC2-C5, PISC2-C5), distance between vertebrae and point sella (SC2, SC3, SC4), pterygomaxillare (PmC2), gonion (GoC2) and basion (BaC4); cervical spine angulation (OPT/CVT) and inclination (OPT/HOR, CVT/HOR). Results showed that subjects with anterior facial growth rotation have greater values for BaC4, OPT/HOR, CVT/HOR, OPT/CVT, anterior and posterior vertebral body heights and intervertebral spaces, and lower values for GoC2 and PmC2. Higher values in males were found for anterior and posterior vertebral body heights, distances SC2, SC3, SC4, and BaC4. In females, the greater values were found for GoC2 and OPT/CVT. Subjects with anterior facial growth rotation have greater cervical spine inclination and angulation, higher cervical vertebrae and intervertebral spaces, longer upper cervical spines and shorter distances GoC2 and PmC2. Males show smaller cervical column curvature, but higher cervical vertebrae and greater length of the upper cervical spine.

Predicting the progression of vertebral fractures in patients with multiple myeloma

Background ContextPatients with multiple myeloma (MM) incur significant degradation in quality of life because of progressive osteolytic vertebral fractures. No studies have investigated predictors of fracture progression, and limited data are available for predicting the development of future fractures. PurposeThe purpose of this study was to identify independent predictors of vertebral fracture progression and the development of future vertebral fracture. Study Design/SettingThis is a consecutive retrospective chart review at a single tertiary-care center. Patient SamplePatients with MM and pathologic vertebral fracture with radiographic follow-up between January 2007 and December 2013 were included. Radiographic measurements were recorded at presentation with fracture and first follow-up (FFU) after at least three months. Patients with a history of vertebral fracture not associated with MM were excluded. Outcome MeasuresThe primary outcome measure was the rate of vertebral body height loss. The development of future vertebral fracture was secondary. MethodsAnterior, middle, and posterior vertebral body heights were measured from midline sagittal T1-weighted magnetic resonance imaging (MRI). Future fracture-free survival was calculated using Kaplan-Meier analysis. Multivariable regression was used to identify independent predictors of the rate of vertebral height loss. Multivariable Cox proportional hazards modeling was used to identify predictors of developing future vertebral fracture. ResultsThirty-three patients with 67 fractures were followed for a median of 10.8 months to FFU. Sixty-four percent of the patients were female and the median age was 66. The median additional vertebral height loss between presentation and FFU was 15%, whereas the median rate of vertebral height loss was 1.01%/month. More rapid vertebral height loss was predicted by dyslipidemia (β=0.36, p=.05), previous non-vertebral pathologic fracture related to MM (β=0.51, p=.01), and Durie-Salmon Stage III (β=0.66, p=.06). The median time to future fracture was 25.1 months; the 5-year future fracture-free survival rate was 34%. Osteopenia/osteoporosis (hazard ratio [HR]: 9.28, p<.01), serum light chains (HR: 1.37, p=.06), and serum calcium (HR: 1.62, p=.05) predicted the development of future vertebral fracture. ConclusionsWe observed significant fracture progression over a short follow-up period. Several comorbidities and laboratory measures predicted more rapid vertebral height loss and the development of future fracture. Identifying risk factors for increased fracture burden may allow spine specialists to pursue earlier and appropriate intervention to optimize function and minimize morbidity.

Lumbar spine endplate fractures: Biomechanical evaluation and clinical considerations through experimental induction of injury.

Lumbar endplate fractures were investigated in different experimental scenarios, however the biomechanical effect of segmental alignment was not outlined. The objectives of this study were to quantify effects of spinal orientation on lumbar spine injuries during single-cycle compressive loads and understand lumbar spine endplate injury tolerance. Twenty lumbar motion segments were compressed to failure. Two methods were used in the preparation of the lumbar motion segments. Group 1 (n = 7) preparation maintained pre-test sagittal lordosis, whereas Group 2 (n = 13) specimens had a free-rotational end condition for the cranial vertebra, allowing sagittal rotation of the cranial vertebra to create parallel endplates. Five Group 1 specimens experienced posterior vertebral body fracture prior to endplate fracture, whereas two sustained endplate fracture only. Group 2 specimens sustained isolated endplate fractures. Group 2 fractures occurred at approximately 41% of the axial force required for Group 1 fracture (p < 0.05). Imaging and specimen dissection indicate endplate injury consistently took place within the confines of the endplate boundaries, away from the vertebral periphery. These findings indicate that spinal alignment during compressive loading influences the resulting injury pattern. This investigation identified the specific mechanical conditions under which an endplate breach will take place. Development of endplate injuries has significant clinical implication as previous research identified internal disc disruption (IDD) and degenerative disc disease (DDD) as long-term consequences of the axial load-shift that occurs following a breach of the endplate. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1084-1091, 2016.

Depression of the Thoracolumbar Posterior Vertebral Body on the Estimation of Cement Leakage in Vertebroplasty and Kyphoplasty Operations.

Background:The cross-section of thoracolumbar vertebral body is kidney-shaped with depressed posterior boundary. The anterior wall of the vertebral canal is separated from the posterior wall of the vertebral body on the lateral X-ray image. This study was designed to determine the sagittal distance between the anterior border of the vertebral canal and the posterior border of the vertebral body (DBCV) and to analyze the potential role of DBCV in the estimation of cement leakage during percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP).Methods:We retrospectively recruited 233 patients who had osteoporotic vertebral compression fractures and were treated with PVP or PKP. Computed tomography images of T11–L2 normal vertebrae were measured to obtain DBCV. The distance from cement to the posterior wall of the vertebral body (DCPW) of thoracolumbar vertebrae was measured from C-arm images. The selected vertebrae were divided into two groups according to DCPW, with the fracture levels, fracture grades and leakage rates of the two groups compared. A relative operating characteristic (ROC) curve was applied to determine whether the DCPW difference can be used to estimate the degree of cement leakage. The data were processed by statistical software SPSS version 21.0 using independent sample t-test and Chi-square tests.Results:The maximum DBCV was 6.40 mm and the average DBCV was 3.74 ± 0.95 mm. DBCV appeared to be longer in males than in females, but the difference was not statistically significant. The average DCPW of type-B leakage vertebrae (2.59 ± 1.20 mm) was shorter than that of other vertebrae (7.83 ± 2.38 mm, P < 0.001). The leakage rate of group DCPW ≤6.40 mm was lower than that of group DCPW >6.40 mm for type-C and type-S, but much higher for type-B. ROC curve revealed that DCPW only has a predictive value for type-B leakage (area under the curve: 0.98, 95% confidence interval: 0.95–0.99, P < 0.001), and when the cut-off value was 4.05 mm, the diagnostic sensitivity and the specificity were 94.87% and 93.02%, respectively.Conclusions:Depression of the thoracolumbar posterior vertebral body may be informative for the estimation of cement location on C-arm images. To reduce type-B leakage, DCPW should be made longer than DBCV on C-arm images for safety during PVP or PKP.

Radiographic progression of vertebral fractures in patients with multiple myeloma

Background ContextNearly 70% of patients with multiple myeloma (MM) experience vertebral fracture. As a consequence, these patients suffer significantly poorer quality of life. However, no studies have characterized the natural progression of these fractures. PurposeThe purpose of this study was to characterize the progression of MM-associated vertebral fractures. Study Design/SettingA consecutive retrospective chart review at a single tertiary-care center was carried out. Patient SamplePatients with MM and pathologic vertebral fracture with at least one follow-up between January 2007 and December 2013 were included. Radiographic measurements were recorded until last follow-up (LFU) or until surgical intervention or patient death. Patients with a history of vertebral fracture not associated with MM were excluded. Outcome MeasuresThe primary outcome measure was change in height of the fractured vertebrae. Fractures were characterized by Genant grade and morphology. MethodsAt baseline and each follow-up, anterior, middle, and posterior vertebral body heights were measured from midline sagittal T1-weighted magnetic resonance imaging. Student t tests and Fisher exact tests were performed to identify variables associated with fracture progression. ResultsAmong 33 patients, 67 fractures were followed. Sixty-four percent of patients were female, with a mean age of 66. Baseline mean anterior, middle, and posterior vertebral body height losses were 30%, 36%, and 15%, respectively. Forty-three percent of fractures were Genant grade 3, and 57% were biconcave. Mean time to LFU was 40 months. At LFU, mean anterior, middle, and posterior vertebral body height losses increased to 47% (p<.01), 49% (p<.01), and 28% (p<.01), respectively. More fractures became Genant grade 3 (75%, p<.01) and wedge (54%, p=.03). On average, patients lost 0.83% in vertebral body height per month, with initial Genant grade 1 fractures progressing most rapidly (1.69%/month, p<.01). Patients treated with bisphosphonates suffered less additional height loss compared with untreated patients (14% vs. 24%, p=.07). ConclusionsWe observed significant fracture progression despite high utilization of bisphosphonates. Patients lost nearly 1% of additional vertebral body height per month, with the least severe presenting fractures progressing most rapidly, highlighting the necessity for early referral to spine specialists and evidence-based guidelines for surveillance and treatment in the myeloma population.

Estimation of stature from radiologic anthropometry of the lumbar vertebral dimensions in Chinese.

The recent study was to assess the relationship between the radiologic anthropometry of the lumbar vertebral dimensions and stature in Chinese and to develop regression formulae to estimate stature from these dimensions. A total of 412 normal, healthy volunteers, comprising 206 males and 206 females, were recruited. The linear regression analysis were performed to assess the correlation between the stature and lengths of various segments of the lumbar vertebral column. Among the regression equations created for single variable, the predictive value was greatest for the reconstruction of stature from the lumbar segment in both sexes and subgroup analysis. When individual vertebral body was used, the heights of posterior vertebral body of L3 gave the most accurate results for male group, the heights of central vertebral body of L1 provided the most accurate results for female group and female group with age above 45 years, the heights of central vertebral body of L3 gave the most accurate results for the groups with age from 20-45 years for both sexes and the male group with age above 45 years. The heights of anterior vertebral body of L5 gave the less accurate results except for the heights of anterior vertebral body of L4 provided the less accurate result for the male group with age above 45 years. As expected, multiple regression equations were more successful than equations derived from a single variable. The research observations suggest lumbar vertebral dimensions to be useful in stature estimation among Chinese population.

Combined posterior hemiosteotomies and stabilization with lateral thoracotomy for en bloc resection of thoracic paraspinal primary bone tumors: technical note.

Primary bone tumors of the spine are rare entities with a poor prognosis if left untreated. En bloc excision is the preferred surgical approach to minimize the rate of recurrence. Paraspinal primary bone tumors are even less common. In this technical note the authors present an approach to the en bloc resection of primary bone tumors of the paraspinal thoracic region with posterior vertebral body hemiosteotomies and lateral thoracotomy. They also describe 2 illustrative cases.

Radiofrequency ablation and vertebral augmentation for palliation of painful spinal metastases.

Radiofrequency ablation (RFA) and vertebral augmentation is an emerging combination therapy for painful osseous metastases that cannot be or are incompletely palliated with radiation therapy. Herein, we report our experience performing RFA and vertebral augmentation of spinal metastases for pain palliation. Institutional review board approval was obtained to retrospectively review our tumor ablation database for all patients who underwent RFA of osseous metastases between April 2012 and July 2014. Patient demographics, lesion characteristics, concurrent palliative therapies, and complications were recorded. Pre- and post-procedure mean worst pain scores 1 and 4weeks after treatment were measured using the Numeric Rating Scale (10-point scale) and compared. During the study period, 72 RFA treatments of 110 spinal metastases were performed. Eighty one percent (89/110) of metastases involved the posterior vertebral body and 45% (49/110) involved the pedicles. Vertebral augmentation was performed after 95% (105/110) of ablations. Mean and median pre-procedure pain scores were 8.0±1.9 and 8.0, respectively. Patients reported clinically significant decreased pain scores at both 1-week (mean, 3.9±3.0; median, 3.25; P<0.0001) and 4-week (mean, 2.9±3.0; median, 2.75; P<0.0001) follow-up. No major complications occurred related to RFA and there were no instances of symptomatic cement extravasation. CombinationRFA and vertebral augmentationis a safe and effective therapy for palliation of painful spinal metastases, including tumor involving the posterior vertebral body and/or pedicles.