Posterior Vertebral Height Research Articles

Surgical management of burst fractures in children and adolescents: A Multicentre Retrospective Study

BackgroundSpinal fractures are rare in children, in whom they contribute only 2% to 5% of all traumatic spinal injuries. The management of burst fractures is well standardised in adults but remains controversial in paediatric patients, due to specific growth-related considerations. The objective of this study was to assess the clinical and radiographic outcomes of surgical management in a multicentre cohort of paediatric patients with burst fractures, in order to devise an optimal therapeutic strategy. HypothesisA therapeutic strategy for burst fractures in children and adolescents can be devised based on data from a patient cohort and on previously published information. Material and methodsPatients younger than 18 years who were managed surgically for one or more burst fractures (Magerl A3) were included in this retrospective multicentre study. Clinical, radiographic, and surgical data were collected before surgery, within 3 months after surgery, and 2 years after surgery. The primary surgical approach was posterior in all patients. Computed tomography (CT) was performed post-operatively to assess the extent of anterior bone loss in order to determine whether anterior fusion was required. The 26 included patients had a mean age of 15±1 years. The thoraco-lumbar spine was involved in 15 (57%) patients. Surgery consisted in correction by instrumentation and posterior fusion only in 14 patients and in posterior correction with anterior fusion in 12 patients. In 10 (38%) patients, the instrumentation extended one vertebra above and one vertebra below the fractured vertebra. ResultsSignificant correction of the vertebral kyphosis was achieved (17°±11° before vs. 4°±2° after surgery, p=0.001). Anterior and posterior vertebral heights were significantly increased (15±3mm vs. 20±3mm, p=0.01 and 23±4mm vs. 26±4mm, p=0.04, respectively). DiscussionThe decision to perform surgery rests on the degree of kyphosis and presence of instability. Anterior bone grafting can be added if the instrumentation is short or a bone defect persists after posterior correction. Correction of the local kyphosis is important to prevent sagittal malalignment with its adverse functional consequences in adulthood. Neural decompression must be performed in patients with neurological deficits. Level of evidenceIV.

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.

Treatment of Osteoporotic Vertebral Compression Fracture with Target-Anchored Vertebral Body Plasty

Objective: To analyze the clinical effect of target-anchored vertebroplasty and traditional percutaneous vertebroplasty on the treatment of osteoporotic vertebral compression fractures. Methods: 50 female New Zealand rabbits were selected for establishing the osteoporotic vertebral compression fracture model and divided into two groups, traditional group and target group followed by analysis of the anterior, posterior, and posterior vertebral body anterior height of the fracture and the injection volume of the bone cement at full filling, and to compare the ultimate compressive strength and stiffness differences between the two groups of specimens by biomechanical testing. Results: In traditional group, the operative time was significantly shorter than that of target group, and the intraoperative bleeding was significantly lower than that of target group (P &lt; 0.05). The fracture area of target group was filled with sufficient bone cement, in the traditional group, 3 cases (12%) showed that bone cement was not filled in the fracture area (P &lt; 0.05), but the total bone cement filling volume was not significantly different between the two groups, but the traditional group had more complete bone cement filling than the bone cement filling, the difference was statistically significant (P &lt; 0.05). In addition, the anterior vertebral body height of each group was significantly higher than other observation points in the group (P &lt; 0.05). However, the distribution of permeability and osmotic type of bone cement between the two groups was not significantly different (P &gt; 0.05). Conclusion: Target-anchored vertebroplasty can improve the quality of clinical treatment of osteoporotic vertebral compression fractures, indicating that it might be a new surgical method.

The Evaluation of Different Radiological Measurement Parameters of the Degree of Collapse of the Vertebral Body in Vertebral Compression Fractures.

For compression fracture, vertebral body height loss (VBHL) and kyphotic angle (KA) are two important imaging parameters for determining the prognosis and appropriate treatment. This study used previous measurement methods to assess the degree of VBHL and KA, compare and examine differences between various measurement methods, and examine the correlation between relevant measurement parameters and intravertebral cleft (IVC) in the vertebral body. The radiographic images (lateral view of the T-L spine) of 18 patients with a single-level vertebral compression fracture were reviewed. We measured 9 characteristic lengths and angles on plain radiographs, including anterior vertebral height (AVH) and AVH of the adjacent upper and lower levels, middle vertebral height (MVH) and MVH of the adjacent upper and lower levels, posterior vertebral height (PVH), and vertebral body width, and assessed 6 parameters, including vertebral compression ratio (VBCR), percentage of anterior height compression (PAHC), percentage of middle height compression (PMHC), kyphotic angle (KA), calculated kyphotic angle (CKA), and IVC. The results showed that VBCR is a simple and rapid method of VBHL assessment, but it may result in an underestimation of the degree of VBHL compared to PAHC. When PMHC < 40% or kyphotic angle > 15°, the probability of IVC occurring on the vertebral body was higher which means the higher risk of vertebral body instability. The results of this study could provide a reference for surgeons when using imaging modalities to assess the degree of vertebral body collapse.

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.

Is Short Same-Segment Fixation Really Better than Short-Segment Posterior Fixation in the Treatment of Thoracolumbar Fractures?

A retrospective study. This retrospective study assessed whether short same-segment fixation (SSSF) is better than short-segment posterior fixation (SSPF) for reducing thoracolumbar fractures, improving the kyphosis angle, maintaining vertebral height, or reducing the incidence of broken screws. In clinical practice, single-segment thoracolumbar fractures were then more likely to be treated with SSPF that included pedicle fixation at the level of the fracture (short same-segment fixation, or SSSF). Whether SSSF could really achieve vertebral height recovery, improve the kyphosis, reduce postoperative kyphosis loss, and reduce the incidence of internal fixation failure better than SSPF. Patients treated with SSPF or SSSF at our institution during 2006 to 2014 were reviewed. Effects of thoracolumbar fracture reduction, improved kyphosis angle, and maintaining vertebral height were compared between groups. Logistic regression analysis was used to identify factors related to instrumentation breakage and correlation analysis to assess possible relations between loss of correction of the kyphosis angle (LAWAC) and other factors. Altogether, 130 patients were enrolled (53 SSPF, 77 SSSF). SSPF (22F, 31M) group's mean (range) age was 37.7 (16-60) years, and the follow-up was 26.2 (9-120) months. SSSF (27F, 50M) group's mean (range) age was 39.3 (17-61) years, and the follow-up was 23.2 (9-60) months. All patients underwent either internal fixation or screw repair. Immediately postoperatively, restoration after middle vertebral fractures was better in SSSF patients than in SSPF patients (P = 0.003), with no differences in other fracture-related factors (P > 0.05). Only LAWAC was significantly associated with instrumentation breakage (P < 0.05). Also, immediately postoperatively, the anterior/posterior vertebral heights ratio was negatively related to LAWAC. Pedicle fixation of the fracture did not obtain better recovery of anterior or posterior vertebral heights nor did it improve AWA restoration. There was no significant difference in LAWAC between groups or in the incidence of broken screws. LAWAC may increase the incidence of broken screws. 4.

Do the dynamic stress mobility radiographs predict the postoperative vertebral height restoration, kyphosis correction, and cement volume injected after vertebroplasty for osteoporotic thoracolumbar vertebral fractures with intravertebral cleft?

This prospective clinical-radiological study was conducted to determine whether the dynamic mobility stress radiographs can predict the postoperative vertebral height restoration, kyphosis correction, and cement volume injected after vertebroplasty. Patients included had the diagnosis of significant back pain caused by osteoporotic vertebral compression fracture secondary to trivial injury. All the patients underwent routine preoperative sitting lateral spine radiograph, supine stress lateral spine radiograph, and supine anteroposterior spine radiograph. The radiological parameters recorded were anterior vertebral height (AVH), middle vertebral height (MVH), posterior vertebral height (PVH), MVH level below, wedge endplate angle (WEPA), and regional kyphotic angle (RKA). The supine stress versus sitting difference (SSD) for all the above parameters were calculated. A total of 28 patients (4 males; 24 females) with the mean age of 75.6 ± 7.7 years were recruited into this study. The mean cement volume injected was 5.5 ± 1.8 ml. There was no difference between supine stress and postoperative radiographs for AVH ( p = 0.507), PVH ( p = 0.913) and WEPA ( p = 0.379). The MVH ( p = 0.026) and RKA ( p = 0.005) were significantly less in the supine stress radiographs compared to postoperative radiographs. There was significant correlation ( p < 0.05) between supine stress and postoperative AVH, MVH, PVH, WEPA, and RKA. The SSD for AVH, PVH, WEPA, and RKA did not have significant correlation with the cement volume ( p > 0.05). Only the SSD-MVH had significant correlation with cement volume, but the correlation was weak ( r = 0.39, p = 0.04). Dynamic mobility stress radiographs can predict the postoperative vertebral height restoration and kyphosis correction after vertebroplasty for thoracolumbar osteoporotic fracture with intravertebral clefts. However, it did not reliably predict the amount of cement volume injected as it was affected by other factors.

Risk Factor of Failed Reduction of Posterior Ligamentatoxis Reduction Instrumentation in Managing Thoracolumbar Burst Fractures: A Retrospective Study

To determine whether radiographic findings associated with thoracolumbar burst fractures could be predictors of failure of short-segment posterior instrumentation with insertion screw at the fracture level (SSPI-f). Seventy-five patients with thoracolumbar burst fracture surgically treated by SSPI-f were enrolled in the study and divided into 2 groups: a reduction group (n=46) and a failed-reduction group (n= 29). Radiographic data including local kyphosis, Cobb angle, anterior vertebral height, posterior vertebral height (PVH), anterior/posterior vertebral height ratio, interpedicle distance (IPD), bony compress area, bony fracture area, and compress-fracture area of the fractured vertebra and clinical data including age and neurologic function were also analyzed. t test, Pearson χ2 test, and binary logistic regression were performed to compare the values. The PVH in the failed-reduction group was smaller than that of the reduction group (83.5% ± 7.2% and 89.1% ± 5.4%, respectively) (P= 0.001). The IPD differed between the reduction and failed-reduction group (18.0% ± 4.1% and 25.8% ± 7.1%, respectively) (P < 0.001). There was a statistical difference between the 2 groups in delayed time before surgery (P= 0.008). There was a significant difference of bony fracture area and compress-fracture area of the fractured vertebra between the failed-reduction and reduction group (both P < 0.001). Binary logistic regression showed that IPD was a risk factor of reduction failure of SSPI-f (P= 0.001). These results showed that increased IPD was a risk factor of failed-reduction of SSPI-f in managing thoracolumbar burst fractures, particularly for patients with neurologic deficit, whereas local kyphosis, Cobb angle, anterior vertebral height, PVH, anterior/posterior vertebral height ratio, bony compress area, bony fracture area, and compress-fracture area of the fractured vertebra were not.

Percutaneous Kyphoplasty: Is Bilateral Approach Necessary?

A multicenter retrospective study of patients who underwent unilateral and bilateral balloon kyphoplasty. The aim of this study was to compare the radiographic and clinical results of unilateral and bilateral balloon kyphoplasty to treat osteoporotic vertebral compression fractures. Percutaneous kyphoplasty has long been used as a successful method in the treatment of osteoporotic vertebral compression fractures. Although the bilateral approach is considered to be the mainstay application of percutaneous kyphoplasty, the unilateral approach has also been shown to be sufficient and even more effective in some cases. A total of 87 patients who underwent percutaneous kyphoplasty due to osteoporotic vertebral compression fractures between 2009 and 2016 were retrospectively evaluated and divided into two groups as patients who underwent unilateral or bilateral percutaneous kyphoplasty. Unilateral percutaneous kyphoplasty was performed in 36 and bilateral percutaneous kyphoplasty in 51 patients. The groups were compared in terms of clinical outcomes, radiological findings, and complications. Clinical outcomes were evaluated using Visual Analogue Scale and Oswestry Disability Index and the radiological findings were evaluated by comparing the preoperative and postoperative day 1 and year 1 values of anterior, middle, and posterior vertebral heights and kyphosis angle. Clinical improvement occurred in both groups but no significant difference was observed. In radiological workup, no significant difference was found between the groups in terms of improvements in vertebral heights and kyphosis angle. Operative time and the amount of cement used for the surgery were significantly lower in the patients that underwent unilateral kyphoplasty. Unilateral percutaneous kyphoplasty is as effective as bilateral percutaneous kyphoplasty both radiologically and clinically. Operative time and the amount of cement used for the surgery are significantly lower in unilateral kyphoplasty, which may play a role in decreasing complication rates. 3.

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.

Correlation of Interpedicular Distance with Radiographic Parameters, Neurologic Deficit, and Posterior Structures Injury in Thoracolumbar Burst Fractures

To correlate interpedicular distance (IPD) with radiographic parameters, neurologic deficit, and posterior structures injury in patients with thoracolumbar burst fractures. A total of 103 patients with a thoracolumbar burst fracture retrospectively reviewed. IPD was measured from the medial sclerotic areas of the pedicles on anteroposterior plain radiographs. Data on local kyphosis (LK), the ratio of anterior to posterior vertebral height (A/P ratio), loss of vertebral body height (LOVBH), spinal canal stenosis (SCS), neurologic status, and injuries to posterior structures (lamina, posterior ligamentous complex, and facet joint) were correlated with IPD using correlation analysis. Logistic regression analysis was used to determine the threshold of IPD predictive of neurologic deficit and posterior structure injury. Of the 103 patients, 98 (95.15%) presented with increased IPD, ranging from 1.41% to 41.53% (mean, 10.92 ± 3.37%). Regarding radiographic parameters, both LK and SCS were linearly correlated with IPD. There was a significant correlation between IPD and neurologic status; logistic regression analysis identified an IPD increase of >20% as an indicator of neurologic deficit. In addition, both facet joint injury and lamina fracture were associated with IPD, with an IPD increase >15% as an indicator of facet joint injury and an IPD increase >20% a predictor of lamina fracture. Our results indicate that IPD is correlated with LK, SCS, neurologic status, facet joint injury, and lamina fracture. Our data demonstrate that IPD measured from plain radiographs is a reliable indicator for assessment of thoracolumbar burst fractures.

Mexican patients with HIV have a high prevalence of vertebral fractures.

Low bone mineral density (BMD) and fragility fractures are common in individuals infected with HIV, who are undergoing antiretroviral therapy (ART). In high-income countries, dual energy X-ray absorptiometrry is typically used to evaluate osteopenia or osteoporosis in HIV infected individuals. However, this technology is unavailable in low andmiddle income countries, so a different approach is needed. The aim of this study was to use X-ray scans of the spine to determine the prevalence of and associated risk factors for vertebral fractures in HIVinfected patients in a tertiary-care hospital in Mexico. We conducted a cross-sectional study of outpatients who were >40 years old and receiving ART at the Hospital de Infectología, La Raza National Medical Center in Mexico City, Mexico. We used semi-quantitative morphometric analysis of centrally digitized X-ray images to assess vertebral deformities in the spine. Anterior, middle and posterior vertebral heights were measured, and height ratios were calculated. For each vertebral body, fractures were graded on the basis of height ratio reductions, and a spine deformity index’ (SDI) value was calculated by summing the grades of the vertebral deformities: An SDI>1 was indicative of a vertebral fracture. We included 104 patients, 87% of whom were men. The median age was 49 years [interquartile range (IQR) 42-52]. The most common stage of HIV infection, as defined by the Centers for Disease Control, was B2 in 40 (39%) of patients. Forty seven (45%) patients were on ART regimens that included protease inhibitors (PIs) and 100 (96%) being treated with tenofovir. The median time of ART was 6.5 years (IQR 1.6-9.0). Of the 104 patients in our study, 83 (80%) had undetectable viral load, as assessed by HIV-1 RNA levels, 32 (31%) showed evidence of a previous fracture, 4 (4%) were co-infected with hepatitis C virus, and 57 (55%) had a history of corticosteroid treatment. The prevalence of vertebral fractures was 25%, 95% confidence interval 17-34%. We assessed whether gender, HCV co-infection, previous corticosteroid use, AIDS, total HIV viral load, and current and previous use of PIs were associated with fractures in our study group, but we did not observe a significant association between any of these factors and vertebral fractures. The prevalence of vertebral fractures was high among HIV-infected patients. We propose that screening for bone disease should be performed in HIV individuals who are at risk of fragility fractures. Furthermore, we suggest that X-ray based assessment of the spine should be considered in patients who are at increased risk of fragility fractures, irrespective of BMD levels, particularly in elderly patients in low and middle income countries.

Bone Cement-Augmented Short-Segment Pedicle Screw Fixation for Kümmell Disease with Spinal Canal Stenosis.

BackgroundThis study aimed to explore the feasibility and efficacy of bone cement-augmented short-segmental pedicle screw fixation in treating Kümmell disease.Material/MethodsFrom June 2012 to June 2015, 18 patients with Kümmell disease with spinal canal stenosis were enrolled in this study. Each patient was treated with bone cement-augmented short-segment fixation and posterolateral bone grafting, and posterior decompression was performed when needed. All patients were followed up for 12–36 months. We retrospectively reviewed outcomes, including the Oswestry disability index (ODI), visual analog scale (VAS) score, anterior and posterior heights of fractured vertebrae, kyphotic Cobb angle, and neurological function by Frankel classification.ResultsThe VAS grades, ODI scores, anterior heights of affected vertebrae, and kyphotic Cobb angles showed statistically significant differences between pre- and postoperative and between preoperative and final follow-up values (P<0.05), whereas the differences between postoperative and final follow-up values were not statistically significant (P>0.05). The differences between posterior vertebral heights at each time point were not statistically significant (P>0.05). Improved neurological function was observed in 12 cases at final follow-up. Three cases had complications, including asymptomatic cement leakage in 2 patients and delayed wound infection in 1 patient.ConclusionsBone cement-augmented short-segment pedicle screw fixation is safe and effective for treating Kümmell disease, and can achieve satisfactory correction of kyphosis and vertebral height, with pain relief and improvement in neurological function, with few complications.

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.

Review of Vertebral Augmentation: An Updated Meta-analysis of the Effectiveness.

To update vertebral augmentation literature by comparing outcomes between vertebroplasty (VP), balloon kyphoplasty (BKP), vertebral augmentation with implant (VAI), and nonsurgical management (NSM) for treating vertebral compression fractures (VCFs). A PubMed literature search was conducted with keywords kyphoplasty, vertebroplasty, vertebral body stent, and vertebral augmentation AND implant for English-language articles from February 1, 2011, to November 22, 2016. Among the results, 25 met the inclusion criteria for the meta-analysis. Inclusion criteria were prospective comparative studies for mid-/lower-thoracic and lumbar VCFs enrolling at least 20 patients. Exclusion criteria included studies that were single arm, systematic reviews and meta-analyses, traumatic nonosteoporotic or cancer-related fractures, lack of clinical outcomes, or non-Level I and non-Level II studies. Standardized mean difference between baseline and end point for each outcome was calculated, and treatment groups were pooled using random effects meta-analysis. Visual analog scale pain reduction for BKP and VP was -4.05 and -3.88, respectively. VP was better than but not significantly different from NSM (-2.66), yet BKP showed significant improvement from both NSM and VAI (-2.77). The Oswestry Disability Index reduction for BKP showed a significant improvement over VAI (P < .001). There was no significant difference in changes between BKP and VP for anterior (P = .226) and posterior (P = .293) vertebral height restoration. There was no significant difference in subsequent fractures following BKP (32.7%; 95% confidence interval [CI]: 8.8%-56.6%) or VP (28.3%; 95% CI: 7.0%-49.7%) compared with NSM (15.9%; 95% CI: 5.2%-26.6%). Based on Level I and II studies, BKP had significantly better and VP tended to have better pain reduction compared with NSM. BKP tended to have better height restoration than VP. Additionally, BKP had significant improvements in pain reduction and disability score as compared with VAI. This meta-analysis serves to further define and support the safety and efficacy of vertebral augmentation.

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.

Prediction of MRI findings including disc injury and posterior ligamentous complex injury in neurologically intact thoracolumbar burst fractures by the parameters of vertebral body damage on CT scan

ObjectiveTo formulate radiological indexes based on CT for further MRI examination to detect posterior ligamentous complex injury (PLC) or disc injury in thoracolumbar burst fractures without neurological deficit in the emergent setting. Materials and methodsPatients with a single thoracolumbar burst fracture and no neurological deficit were included into this study. Radiological indexes on CT included canal compromise (CC), anterior and posterior vertebral height ratio (PVH and AVH ratio), local kyphosis (LK) and regional kyphosis (RK). PLC and disc injury were assessed on MRI. Statistical analysis was performed to identify the predictive power for radiological indexes for any MRI findings either or both disc and PLC injury. ResultsEighty-four patients were included in this study. According to MRI, patients with no PLC and disc injury were allocated into MRI finding negative group, others were defined as positive group. There was no significant difference in AVH ratio, PVH ratio and RK between these two groups. The CC and LK were significant higher in positive group than that in negative group (p < 0.001).The areas under receiver operating characteristic curve were 0.826 and 0.893 for CC and LK respectively and without significant difference. The best thresholds for CC and LK were 0.19 (sensitivity: 69.4%; specificity: 87.5%) and 14.00° (sensitivity: 83.3%; specificity: 83.3%), respectively. ConclusionThe presence of CC > 0.19 and/or LK > 14.00° on CT scan can predict MRI findings including PLC and disc injury. These thresholds may be the guideline for MRI examination in patients with neurologically intact thoracolumbar burst fracture in the emergent condition.

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