Posterior Vertebral Body Height Research Articles

Surgical consideration for thoracolumbar burst fractures with spinal canal compromise without neurological deficit

SummaryBackgroundFor thoracolumbar burst fractures with spinal canal compromise but no neurological deficit, is it necessary to perform additional laminectomy decompression after the currently accepted posterior pedicle-screw internal fixation?MethodsPatients were divided into two groups: decompression group (Group A) and nondecompression group (Group B). A retrospective analysis of the posterior vertebral body height of the fractured vertebral body, the ratio of the volume of the spinal canal, and the change of the Cobb angle, relative to the corresponding preoperative values, was conducted to analyse the reasons for choosing different surgical methods.ResultsCompared the intraoperative findings after fixation with the preoperative data, in Group A, the posterior vertebral body height of the fractured vertebral body was not significantly restored, the volume ratio of the spinal canal was not significantly improved, and the Cobb angle was not significantly reduced (p ​> ​0.05). In comparison, in Group B, the posterior vertebral body height of the fractured vertebral body was significantly restored, the volume ratio of spinal canal was significantly increased, and the Cobb angle was significantly reduced (p ​< ​0.001).ConclusionFor patients with thoracolumbar burst fractures with spinal canal compromise but no neurological deficit, if when the posterior intraoperative fixation is performed, the spinal canal fracture is partially recovered, the posterior vertebral body height of the injured vertebrae is significantly restored, the spinal canal volume ratio is significantly increased, and the large kyphosis is corrected, then the indirect decompression without the posterior laminectomy can be performed.The translational potential of this articleThis study contributes to offer treatment ​consideration for ​patients with thoracolumbar burst fracture without neurological symptoms.

Armed Kyphoplasty: An Indirect Central Canal Decompression Technique in Burst Fractures.

Burst fractures are characterized by middle column disruption and may feature posterior wall retropulsion. Indications for treatment remain controversial. Recently introduced vertebral augmentation techniques using intravertebral distraction devices, such as vertebral body stents and SpineJack, could be effective in fracture reduction and fixation and might obtain central canal clearance through ligamentotaxis. This study assesses the results of armed kyphoplasty using vertebral body stents or SpineJack in traumatic, osteoporotic, and neoplastic burst fractures with respect to vertebral body height restoration and correction of posterior wall retropulsion. This was a retrospective assessment of 53 burst fractures with posterior wall retropulsion and no neurologic deficit in 51 consecutive patients treated with armed kyphoplasty. Posterior wall retropulsion and vertebral body height were measured on pre- and postprocedural CT. Clinical and radiologic follow-up charts were reviewed. Armed kyphoplasty was performed as a stand-alone treatment in 43 patients, combined with posterior instrumentation in 8 and laminectomy in 4. Pre-armed kyphoplasty and post-armed kyphoplasty mean posterior wall retropulsion was 5.8 and 4.5 mm, respectively (P < .001), and mean vertebral body height was 10.8 and 16.7 mm, respectively (P < .001). No significant clinical complications occurred. Clinical and radiologic follow-up (1-36 months; mean, 8 months) was available in 39 patients. Three treated levels showed a new fracture during follow-up without neurologic deterioration, and no retreatment was deemed necessary. In the treatment of burst fractures with posterior wall retropulsion and no neurologic deficit, armed kyphoplasty yields fracture reduction, internal fixation, and indirect central canal decompression. In selected cases, it might represent a suitable minimally invasive treatment option, stand-alone or in combination with posterior stabilization.

Vertebral height restoration following kyphoplasty.

Kyphoplasty is a minimally invasive surgery developed to restore height and stabilize painful vertebral compression fractures (VCFs). Only small retrospective studies have addressed the correlation between the degree of vertebral height restoration as it relates to pain relief and postoperative activity levels. No definitive correlations have been established. The objective of this analysis is to determine how height restoration correlates with improvements in pain, disability and quality of life. We assessed outcomes following kyphoplasty in 59 Medicare-eligible patients with 1-3 painful VCFs between T5 and L5 due to osteoporosis or cancer. Pre and postoperative lateral radiographs were available for fifty-nine patients and were used to measure anterior, middle and posterior vertebral body (VB) heights. The Visual Analog Scale (VAS) [range: 0 (none) to 10 (worst)] was used to prospectively measure back pain pre and post-operatively in all patients. Pre and post-operative measurements of disability and quality of life were retrospectively collected using the Roland Morris Disability Index (RMDI) [range: 0 (no disability) to 24 (high disability)] and EuroQol5-Domain scale (EQ5D) [range: -0.11 (poor quality of life) to 1.0 (perfect health)]. Pearson correlations and linear regression models were analyzed for association of VB height improvement with outcomes. Neither Pearson correlations (r coefficient range: 0.001-0.152) nor linear regression models (R2 value range: 0.0002-0.1133) revealed correlation or association between VB height improvements and outcomes. This is one of the largest studies to date assessing associations of VB height restoration following kyphoplasty with prospective measurements of pain and retrospective evaluation of disability and quality of life using validated instruments. Although a majority of patients in this cohort demonstrated increased vertebral heights and significant improvements in outcomes, none of the outcomes showed association with height improvements. Regardless of vertebral height improvements, most patients had improved pain, function and quality of life.

Morphometric characteristics of the thorac\u03bflumbar and lumbar vertebrae in the Greek population: a computed tomography-based study on 900 vertebrae\u2014\u201cHellenic Spine Society (HSS) 2017 Award Winner\u201d

Background Vertebrae morphology appears to have genetic and ethnic variations. Knowledge of the vertebra and pedicle morphology is essential for proper selection and safe application of transpedicular screws. The aim of this study is to create a morphometric database for thoracolumbar and lumbar vertebrae (T9–L5) among individuals of both sexes in the Greek population.

Kyphotic Angle of the Motion Segment Most Accurately Predicts Injury to the Ligamentous Complex on Computed Tomography Scan of Thoracolumbar Fractures

To define radiologic parameters and the diagnostic accuracy of computed tomography (CT) scan on posterior ligamentous complex (PLC) injury, identified by magnetic resonance imaging (MRI) in patients with thoracolumbar (TL) fracture. We retrospectively analyzed 88 patients with TL fractures divided into 2 groups by PLC status evident on MRI: intact and ruptured. The parameters assessed included the anterior fractured vertebral body height (AVH) and posterior fractured vertebral body height, upper and lower AVH, anterior/posterior vertebral height ratio, AVH ratio, local kyphotic angle (LKA), region angle (RA), sagittal index (SI), Gardner angle (GA), Gardner index (GI), Cobb angle, interspinous distance (ISD), upper and lower ISD, ISD ratio, interspinous distance minus (ISDM), interspinous angle (ISA), and upper and lower ISA. The t test, Pearson χ2 test, and multivariate logistic regression were used. PLC rupture (vs. intact) was associated with RA, GA, GI, ISD, ISD ratio, and ISDM. The positive risk factors for PLC rupture were GA, LKA, SI, and RA. The negative risk factors for PLC rupture were SI greater than 20° and GI. PLC rupture was associated with the SI, upper interspinous distance, ISD ratio, ISDM, and ISA in those with type A1/A2 fractures and the GA, GI, ISD, ISD ratio, and ISDM in those with type A3/A4 fractures. An RA greater than 16°, SI greater than 20°, and GI greater than 24° were associated with PLC injury in patients with type A TL fractures, and an RA greater than 16° and SI greater than 20° predicted PLC injury in type A1 and A2 fractures. An SI greater than 20°, GI greater than 24°, LKA greater than 26°, and ISD ratio greater than 56% predicted PLC injury in type A3 and A4 fractures.

CT assisted goat lumbar vertebrae anatomical measurement and comparison with human lumbar vertebrae

To study the anatomical measurement of goat lumbar vertebrae and to compare with human lumbar vertebrae, so as to build the foundation for establishing animal models of lumbar prosthesis. The anatomical parameters of the vertebral body, pedicle and intervertebral disc in the fresh lumbar vertebrae of Boer goat and the lumbar vertebrae of healthy adults were collected by computer aided software Mimics16.0, and the anatomical characteristics of the two lumbar vertebrae were compared with the statistical software. The anterior vertebral body height(VBHa) of goat lumbar was less than the middle vertebral body height(VBHm), which was less than the posterior vertebral body height(VBHp), and the maximum values were (38.7±2.9), (40.1±2.6) and (40.7±2.7) mm respectively. Its endplate width was greater than its depth, with the whole shaped like a heart or a kidney. The cranial endplate of goats was convex while the caudal endplate was depressed and the depression was small, with a maximum value of (1.6±0.6) mm. The pedicle height of goats increased from L₁1 to L̀ with the maximum of (30.5±1.9) mm; its pedicle width and angle increased firstly and then decreased with the increase of vertebra level and the minimum values were (6.7±0.4) mm and(45.9±2.6)° respectively. The anterior intervertebral disc height was larger than the middle which was larger than the posterior and all varied slightly with the changes of intervertebral spaces; the height and width of intervertebral foramen separately waved at (12.9±0.3) to (14.3±1.0) mm and (5.7±1.0) to (6.7±0.9) mm. The comparative results showed that the vertebral body height, pedicle height and angle of goats were greater than those of humans (P<0.05) while the width and depth of the endplate, the intervertebral disc height, and etc. were significantly smaller than those of humans (P<0.05). In addition, some structures, such as the height of pedicle and intervertebral disc, also showed different changing laws with the increase of vertebra level. Although there are similarities in goat lumbar spine in some aspects, such as endplate and foramen foramen, there are still many differences in many aspects. Understanding the anatomical characteristics of goat lumbar vertebrae and the difference between goat and human is of great guiding significance for the research of goat prosthesis and related technology.

The fates of pedicle screws and functional outcomes ina geriatric population following polymethylmethacrylate augmentation fixation for the osteoporotic thoracolumbar and lumbar burst fractures with mean ninety fivemonth follow-up.

Polymethylmethacrylate (PMMA) augmentation is a common method to increase pullout strength fixed for osteoporotic spines. However, few papers evaluated whether these pedicle screws migrated with time and functional outcome in these geriatrics following PMMA-augmented pedicle screw fixation. From March 2006 to September 2008, consecutive 64 patients were retrospectively enrolled. VAS and ODI were used to evaluate functional outcomes. Kyphotic angle at instrumented levels and horizontal and vertical distances (HD and VD) between screw tip and anterior and upper cortexes were evaluated. To avoid bias, we used horizontal and vertical migration index (HMI and VMI) to re-evaluate screw positions with normalization by the mean of superior and inferior endplates or anterior and posterior vertebral body height, respectively. Forty-six patients with 282 PMMA-augmented screws were analyzed with mean follow-up of 95months. Nine patients were further excluded due to bed-ridden at latest follow-up. Twenty-six females and 11 males with mean T score of - 2.7 (range, - 2.6 to - 4.1) and mean age for operation of 77.6 ± 4.3years (range, 65 to 86). The serial HD and kyphotic angle statistically progressed with time. The serial VD did not statistically change with time (p= 0.23), and neither HMI nor VMI (p = 0.772 and 0.631). Pre-operative DEXA results did not correlate with kyphotic angle. Most patients (80.4%) maintained similar functional outcomes at latest follow-up. The incidence of screws loosening was 2.7% of patients and 1.4% of screws, respectively. The overall incidences of systemic post-operative co-morbidities were 24.3% with overall 20.2days for hospitalization. Most patients (80%) remained similar functional outcomes at latest follow-up in spite of kyphosis progression. The incidence of implant failure was not high, but the post-operative systemic co-morbidities were higher, which has to be informed before index surgery.

Middle-Column Gap Balancing and Middle-Column Mismatch in Spinal Reconstructive Surgery.

Middle-column gap balancing (MCGB) is a reference measurement of the path of the posterior longitudinal ligament (PLL), which is reconstructed under tension and balanced by the combined height of the posterior one-third of the vertebral bodies and the posterior one-third of the disks, including any intervening load-sharing spacers. This measurement allows for a comparison of the ligamentous component of the middle column (PLL) with the load-sharing components (posterior one-third vertebral body + disk ). This difference gives rise to a "middle-column mismatch," which provides a linear measurement of the redundancy of the ligaments and neural elements, which relates to the correct cage, spacer, or load-bearing height, which is optimized. For phase 1 measurement testing, 24 consecutive patients underwent reliable flexion, extension, and neutral lateral radiographic studies with a calibrated marker. The anterior, middle, and posterior columns were measured using a custom software program capable of measuring the length of curved lines specifically written for this purpose. For phase 2 measurement testing, 21 consecutive patients undergoing surgery with multilevel deformities for cervical, thoracic, and lumbar procedures had MCGB height pre- and postoperatively measured by 3 blinded observers. The preoperative and postoperative measurements were compared using a linear regression analysis and Pearson product-moment correlation. In phase 1 measurement testing the flexion, extension, and neutral bending radiographs of spinal segments not containing deformities showed that the middle column had the most reliable measurements of spinal axial height both in the actual measurements of change from flexion to extension (mm) and in percentage of change. In phase 2 measurement testing, a Pearson product-moment correlation was run between each individual's pre- and postoperative middle-column measurements. There was a strong positive correlation between preoperative and postoperative measurements, which was statistically significant (r = 0.983, n = 21, P < .01). This consecutive series of 21 deformity patients demonstrated the utility of measuring the preoperative middle-column length in predicting the optimal height of the spacers and intervertebral disks, and posterior vertebral body height, simultaneously restoring sagittal and coronal plane alignment. Key points of this study include the following: (1) Spinal balance requires optimizing spinal height, which is a curved line in order to accommodate cervical lordosis, thoracic kyphosis, and lumbar lordosis. (2) Software programs can allow measurement of the preoperative curved circuitous course of the PLL and vertebral body misalignment; this curved length is predictive of the optimal postoperative middle-column height after spinal osteotomies and intervertebral spacer insertion. (3) All 3 dimensions are important to optimize in deformity correction: sagittal plane, coronal plane, and axial spinal height.

Evaluation of vertebral body fractures using susceptibility-weighted magnetic resonance imaging.

To test thediagnostic performance of susceptibility-weighted MRI (sMRI) for the evaluation of vertebral body fractures versus standard MRI-sequences, using CT as reference standard. In this prospective study 88 vertebral fractures (45 healed, 43 non-healed) were detected in 39 patients who underwent T1/T2/TIRM MRI-sequences and sMRI. All fractures were evaluated with CT as reference standard. In all modalities/sequences, displacement and height of the posterior vertebral body cortex and visibility of fracture lines and cortical breaks were assessed. Sensitivity, specificity and inter-reader agreement between MRI and CT were calculated. sMRI demonstrated highest diagnostic accuracy for detection of posterior vertebral body cortex involvement (sensitivity: 98 %/specificity: 100 %), fracture lines (86 %/99 %) and cortical breaks (93 %/100 %) versus T1/T2/TIRM sequences. Regarding evaluation of posterior vertebral body cortex displacement and height, sMRI demonstrated the closest intermodality agreement (R2=0.96; 95 % CI -0.92-0.89/R2=0.97; 95 % CI -1.67-1.23) with CT and the closest interobserver agreement (R2=0.97; 95 % CI -0.71-1.01). sMRI allows reliable evaluation of vertebral body fractures with regard to posterior vertebral body cortex displacement and height, cortical breaks and fracture lines with higher accuracy versus standard MRI, especially in patients with non-healed vertebral body fractures. • sMRI allows a reliable evaluation of vertebral body fractures. • sMRI has higher accuracy than standard-MRI for evaluation of vertebral body fractures. • sMRI is especially useful in patients with non-healed vertebral body fractures.

Correlation between disc injury and parameters of vertebral body damage in patients with neurologically intact thoracolumbar bust fractures

Objective To assess the disc injury in neurologically intact thoracolumbar bust fractures and to evaluate the correlation between the severity of disc injury and the parameters of vertebral body damage as as to formulate radiologic index for further MRI examination. Methods A retrospective case series review was made on 22 patients (44 discs) with thoracolumbar burst fractures without neurologic deficit treated from January 2015 to December 2015. Vertebral level involved was from T11-L2. There were 12 males and 10 females, with the mean age of 47.9 years (range, 43-60 years). MRI were used to evaluate the severity of disc injury. Among the 44 discs, 18 were Grade 0, 11 were Grade 1, 12 were Grade 2, and three were Grade 3. Then patients with Grade 0 and 1 were taken as disc intact group and other 12 patients disc rupture group. Vertebral wedge angle, local kyphosis angle, anterior and posterior vertebral body height and canal compromise were measured on CT to determine the damage of fracture. Spearman correlation coefficient was used to analyze the correlation between the severity of disc injury and the parameters of vertebral body damage, and receiver operative curve (ROC) was used to assess the effectiveness of these indexes in predicting disc injury. Results Vertebral wedge angle and anterior/posterior vertebral body height ratio were correlated with the severity of superadjacent disc injury (P 0.05). Threshold of canal compromise, vertebral wedge angle and anterior/posterior vertebral body height ratio were 21%, 15.4°, and 0.69 respectively. Conclusions Vertebral wedge angle and anterior/posterior vertebral body hight ratio are correlated with the severity of superadjacent disc injury. Canal compromise>21%, VWA>15°and anterior/posterior vertebral body height ratio > 0.69 may be the practice preferences of indications for ordering a MRI in patients with neurologically intact thoracolumbar bust fractures. Key words: Thoracic vertebrae; Lumbar vertebrae; Intervertebral disc; Magnetic resonance imaging; Neurologically intact

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.

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.

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.

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.

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.

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.

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.

Radiologic and clinical characteristics of vertebral fractures in multiple myeloma

Background contextNearly 80% of patients with newly diagnosed multiple myeloma (MM) have bony lesions on magnetic resonance imaging (MRI). These lesions may progress to debilitating vertebral fractures. No studies have quantitatively characterized these fractures or identified predictors of fracture burden and severity. PurposeThe purpose of this study was to characterize the clinical and radiologic features of these fractures and to identify independent predictors of fracture burden and severity. Study design/Setting: A consecutive retrospective chart review was conducted from January 2007 to December 2013 at a single tertiary-care institution. Patient samplePatients with diagnoses of both MM and vertebral fracture were included in this study. Those with a history of non-MM vertebral fracture were excluded. Outcome measuresThe primary outcome measure was height loss of the fractured vertebral body, whereas secondary outcome measures included number of fractures and morphology. MethodsData were collected at fracture presentation. Radiologic data were obtained from T1-weighted MRI. Anterior, middle, and posterior vertebral body height losses were recorded, and a Genant grading was made. Multivariable Poisson and logistic regression were performed to identify predictors of fracture burden and severity. ResultsAmong 50 patients presenting with vertebral fracture, 124 fractures were observed. The majority (76%) of these patients did not have a previous MM diagnosis. The most common presenting symptom was back pain (84%), followed by neurologic (54%) and constitutional (50%) symptoms. The mean anterior, middle, and posterior height losses of the fractured vertebral body were 30%, 37%, and 16%, respectively. Twenty percent of fractures were Genant Grade 1 (mild), whereas 32% and 48% were grades 2 (moderate) and 3 (severe). Fifty-five percent of fractures were biconcave, whereas 32% and 13% were wedge and crush fractures. Lower body mass index and albumin and increased myeloma protein, light chains, and creatinine predicted an increased number of fractures at presentation. Increased β2-microglobulin and creatinine predicted more severe vertebral fractures. ConclusionsIn the present study, 124 fractures were observed among 50 patients. These fractures were generally severe, biconcave, and in the thoracic spine. Laboratory signs of advanced MM predict greater fracture burden and severity. In the future, monitoring of these predictors may raise suspicion for an MM-associated vertebral fracture.