A 3D Radiomics-Based Artificial Neural Network Model for Benign Versus Malignant Vertebral Compression Fracture Classification in MRI.

To train an artificial neural network model using 3D radiomic features to differentiate benign from malignant vertebral compression fractures (VCFs) on MRI. This retrospective study analyzed sagittal T1-weighted lumbar spine MRIs from 91 patients (average age of 64.24 ± 11.75 years) diagnosed with benign or malignant VCFs from 2010 to 2019, of them 47 (51.6%) had benign VCFs and 44 (48.4%) had malignant VCFs. The lumbar fractures were three-dimensionally segmented and had their radiomic features extracted and selected with the wrapper method. The training set consisted of 100 fractured vertebral bodies from 61 patients (average age of 63.2 ± 12.5 years), and the test set was comprised of 30 fractured vertebral bodies from 30 patients (average age of 66.4 ± 9.9 years). Classification was performed with the multilayer perceptron neural network with a back-propagation algorithm. To validate the model, the tenfold cross-validation technique and an independent test set (holdout) were used. The performance of the model was evaluated using the average with a 95% confidence interval for the ROC AUC, accuracy, sensitivity, and specificity (considering the threshold = 0.5). In the internal validation test, the best model reached a ROC AUC of 0.98, an accuracy of 95% (95/100), a sensitivity of 93.5% (43/46), and specificity of 96.3% (52/54). In the validation with independent test set, the model achieved a ROC AUC of 0.97, an accuracy of 93.3% (28/30), a sensitivity of 93.3% (14/15), and a specificity of 93.3% (14/15). The model proposed in this study using radiomic features could differentiate benign from malignant vertebral compression fractures with excellent performance and is promising as an aid to radiologists in the characterization of VCFs.

Reverse Cortical Sign in Lumbar Burst Fracture.

"Reverse cortical sign" is a rare entity described in lumbar burst fracture that corresponds to the fracture fragment of the posterior wall of vertebral body, which has rotated 180 degrees with the cortical surface facing anteriorly and the cancellous surface facing posteriorly in the canal. Identifying this sign is crucial in deciding the line of management as it is a contraindication for ligamentotaxis. The advent of computed tomography scans with axial and sagittal reconstruction has allowed us to better describe these rare entities. We present a lumbar burst fracture with a reverse cortical sign describing its appearance in axial computed tomography scans, sagittal reconstruction, and magnetic resonance imaging.

SATB2-associated syndrome: characterization of skeletal features and of bone fragility in a prospective cohort of 19 patients.

BACKGROUND: Individuals with pathogenic variants in SATB2 display intellectual disability, speech and behavioral disorders, dental abnormalities and often features of Pierre Robin sequence. SATB2 encodes a transcription factor thought to play a role in bone remodeling. The primary aim of our study was to systematically review the skeletal manifestations of SATB2-associated syndrome. For this purpose, we performed a non-interventional, multicenter cohort study, from 2017 to 2018. We included 19 patients, 9 females and 10 males ranging in age from 2 to 19 years-old. The following data were collected prospectively for each patient: clinical data, bone markers and calcium and phosphate metabolism parameters, skeletal X-rays and bone mineral density. RESULTS: Digitiform impressions were present in 8/14 patients (57%). Vertebral compression fractures affected 6/17 patients (35%). Skeletal demineralization (16/17, 94%) and cortical thinning of vertebrae (15/17) were the most frequent radiological features at the spine. Long bones were generally demineralized (18/19). The distal phalanges were short, thick and abnormally shaped. C-telopeptide (CTX) and Alkaline phosphatase levels were in the upper normal values and osteocalcin and serum procollagen type 1 amino-terminal propeptide (P1NP) were both increased. Vitamin D insufficiency was frequent (66.7%). CONCLUSION: We conclude that SATB2 pathogenic variants are responsible for skeletal demineralization and osteoporosis. We found increased levels of bone formation markers, supporting the key role of SATB2 in osteoblast differentiation. These results support the need for bone evaluation in children and adult patients with SATB2-associated syndrome (SAS).

Development and Assessment of a Predictive Score for Vertebral Compression Fracture After Stereotactic Body Radiation Therapy for Spinal Metastases.

IMPORTANCE: Vertebral compression fracture (VCF) is a potential adverse effect following treatment with stereotactic body radiation therapy (SBRT) for spinal metastases. OBJECTIVE: To develop and assess a risk stratification model for VCF after SBRT. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study conducted at a high-volume referral center included 331 patients who had undergone 464 spine SBRT treatments from December 2007 through October 2019. Data analysis was conducted from November 1, 2020, to August 17, 2021. Exclusions included proton therapy, prior surgical intervention, vertebroplasty, or missing data. EXPOSURES: One and 3 fraction spine SBRT treatments were most commonly delivered. Single-fraction treatments generally involved prescribed doses of 16 to 24 Gy (median, 20 Gy; range, 16-30 Gy) to gross disease compared with multifraction treatment that delivered a median of 30 Gy (range, 21-50 Gy). MAIN OUTCOMES AND MEASURES: The VCF and radiography components of the spinal instability neoplastic score were determined by a radiologist. Recursive partitioning analysis was conducted using separate training (70%), internal validation (15%), and test (15%) sets. The log-rank test was the criterion for node splitting. RESULTS: Of the 331 participants, 88 were women (27%), and the mean (IQR) age was 63 (59-72) years. With a median follow-up of 21 months (IQR, 11-39 months), we identified 84 VCFs (18%), including 65 (77%) de novo and 19 (23%) progressive fractures. There was a median of 9 months (IQR, 3-21 months) to developing a VCF. From 15 candidate variables, 6 were identified using the backward selection method, feature importance testing, and a correlation heatmap. Four were selected via recursive partitioning analysis: epidural tumor extension, lumbar location, gross tumor volume of more than 10 cc, and a spinal instability neoplastic score of more than 6. One point was assigned to each variable, and the resulting multivariable Cox model had a concordance of 0.760. The hazard ratio per 1-point increase for VCF was 1.93 (95% CI, 1.62-2.30; P < .001). The cumulative incidence of VCF at 2 years (with death as a competing risk) was 6.7% (95% CI, 4.2%-10.7%) for low-risk (score, 0-1; 273 [58.3%]), 17.0% (95% CI, 10.8%-26.7%) for intermediate-risk (score, 2; 99 [21.3%]), and 35.4% (95% CI, 26.7%-46.9%) for high-risk cases (score, 3-4; 92 [19.8%]) (P < .001). Similar results were observed for freedom from VCF using stratification. CONCLUSIONS AND RELEVANCE: The results of this cohort study identify a subgroup of patients with high risk for VCF following treatment with SBRT who may potentially benefit from undergoing prophylactic spinal stabilization or vertebroplasty.

Factors Associated With Skeletal Muscle Mass Increase by Rehabilitation in Older Adults With Vertebral Compression Fractures.

Age-related sarcopenia and osteoporosis-related fractures are critical health issues. Therefore, this study aimed to assess skeletal muscle mass changes in older patients with vertebral compression fractures undergoing rehabilitation and to evaluate factors associated with muscle increases. This study included 179 patients aged ≥80 years in rehabilitation wards with vertebral compression fractures. Appendicular skeletal muscle index was significantly higher at discharge (5.22 ± 1.04 kg/m2, p < .001) than on admission (5.03 ± 1.00 kg/m2). Multiple logistic regression analysis showed that length of hospital stay was significantly associated with increased skeletal muscle index (odds ratios, 1.020; 95% confidence intervals [1.000, 1.032]), whereas age, sex, body mass index, functional independence measure, protein intake, and exercise therapy duration were not. Participants with vertebral compression fractures aged ≥80 years achieved significantly increased skeletal muscle mass in rehabilitation wards. In addition, length of hospital stay was the factor independently associated with increased skeletal muscle index.

Clinical and imaging features of surgically treated low lumbar osteoporotic vertebral collapse in patients with Parkinson's disease.

Osteoporosis and Parkinson's disease (PD) are age-related diseases, and surgery for osteoporotic vertebral collapse (OVC) in PD patients become more common. OVC commonly affects the thoracolumbar spine, but low lumbar OVC is frequent in patients with lower bone mineral density (BMD). The aim of this study was to identify differences in clinical and imaging features of low lumbar OVC with or without PD and to discuss the appropriate treatment. The subjects were 43 patients with low lumbar OVC below L3 who were treated surgically, including 11 patients with PD. The main clinical symptoms were radicular pain in non-PD cases and a cauda equina sign in PD cases. Rapid progression and destructive changes of OVC were seen in patients with PD. The morphological features of OVC were flat-type in non-PD cases with old compression fracture, and destruction-type in PD cases without old compression fracture. Progression of PD was associated with decreased lumbar lordosis, lower lumbar BMD, and severe sarcopenia. High postoperative complication rates were associated with vertebral fragility and longer fusion surgery. Progression of postural instability as a natural course of PD may lead to mechanical stress and instrumentation failure. Invasive long-fusion surgery should be avoided for single low lumbar OVC.

A deep learning algorithm for automated measurement of vertebral body compression from X-ray images.

The vertebral compression is a significant factor for determining the prognosis of osteoporotic vertebral compression fractures and is generally measured manually by specialists. The consequent misdiagnosis or delayed diagnosis can be fatal for patients. In this study, we trained and evaluated the performance of a vertebral body segmentation model and a vertebral compression measurement model based on convolutional neural networks. For vertebral body segmentation, we used a recurrent residual U-Net model, with an average sensitivity of 0.934 (± 0.086), an average specificity of 0.997 (± 0.002), an average accuracy of 0.987 (± 0.005), and an average dice similarity coefficient of 0.923 (± 0.073). We then generated 1134 data points on the images of three vertebral bodies by labeling each segment of the segmented vertebral body. These were used in the vertebral compression measurement model based on linear regression and multi-scale residual dilated blocks. The model yielded an average mean absolute error of 2.637 (± 1.872) (%), an average mean square error of 13.985 (± 24.107) (%), and an average root mean square error of 3.739 (± 2.187) (%) in fractured vertebral body data. The proposed algorithm has significant potential for aiding the diagnosis of vertebral compression fractures.

Accuracy and precision of the spinal instability neoplastic score (SINS) for predicting vertebral compression fractures after radiotherapy in spinal metastases: a meta-analysis.

Radiotherapy has played an important role in the treatment of spinal metastases. One of the major complications of radiotherapy is vertebral compression fracture (VCF). Although the spinal instability neoplastic score (SINS) was developed for evaluating spinal instability in patients with spinal metastases, it is also commonly used to predict VCF after radiotherapy in patients with spinal metastases. However, its accuracy for predicting radiotherapy-induced VCF and precision remain controversial. The aim of this study was to clarify the diagnostic value of the SINS to predict radiotherapy-induced VCF and to make recommendations for improving its diagnostic power. We searched core databases and identified 246 studies. Fourteen studies were analyzed, including 7 studies (with 1269 segments) for accuracy and 7 studies (with 280 patients) for precision. For accuracy, the area under the summary receiver operating characteristic curve was 0.776. When a SINS cut-off value of 7 was used, as was done in the included studies, the pooled sensitivity was 0.790 and the pooled specificity was 0.546. For precision, the summary estimate of interobserver agreement was the highest dividing 2 categories based on a cut-off value of 7, and the value was 0.788. The body collapse showed moderate relationship and precision with the VCF. The lytic tumor of bone lesion showed high accuracy and fair reliability, while location had excellent reliability, but low accuracy. The SINS system can be used to predict the occurrence of VCF after radiotherapy in spinal metastases with moderate accuracy and substantial reliability. Increasing the cut-off value and revising the domains may improve the diagnostic performance to predict the VCF of the SINS.

Creation of a planned or central-clefted puncture combined with a second puncture during vertebroplasty to treat osteoporotic vertebral compression fractures with large clefts.

BACKGROUND: Cemented vertebrae frequently re-fracture after vertebroplasty to treat osteoporotic vertebral compression fractures (OVCFs) with large clefts. We compared the efficacy of planned and central-clefted puncture, both followed by a second puncture, as treatments for OVCFs with large clefts. METHODS: We retrospectively studied 38 patients. 18 of whom underwent planned puncture (group A) and 20 central-clefted puncture (group B). A second puncture was performed when the initially injected cement was restricted to the cleft. We recorded a visual analog scale (VAS) pain scores, vertebral kyphotic angles (KAs), and compression ratios (CRs) preoperatively and at 2 days and 6 months postoperatively. We recorded the cement dispersion patterns and complications. RESULTS: Second punctures succeeded in 15/18 and 7/20 patients of groups A and B, respectively. At 2 days postoperatively, the VAS score, KA, and CR were significantly better than the preoperative values (P < 0.01); no significant difference was found between the two groups (P > 0.05). At the 6-month follow-up, all scores were poorer than at 2 days postoperatively (all P < 0.05), significantly more so in group B than group A (P < 0.05). Significant differences in terms of the cement dispersion patterns, and the cemented vertebral re-fracture and cement leakage rates, were observed between the two groups (all P < 0.05). CONCLUSION: The two-puncture techniques were initially effective when treating large-clefted OVCFs. However, compared to the central-clefted puncture, the planned puncture improved the success rate of the second puncture, allowed better cement dispersion, and reduced the incidence of vertebral re-fracture during follow-up.

Differentiation of usual vertebral compression fractures using CT histogram analysis as quantitative biomarkers: A proof-of-principle study.

PURPOSE: To investigate the utility of CT histogram analysis (CTHA) for discrimination of traumatic, osteoporotic and malignant fractures in patients with vertebral compression fractures (VCFs). To evaluate the feasibility and accuracy of CTHA in differentiating non-malignant (traumatic and osteoporotic) from malignant VCFs. MATERIALS AND METHODS: Totally, 235 patients with VCFs were enrolled in the current experimental study. There were 132 patients with traumatic VCFs, 51 with osteoporotic VCFs and 52 with malignant VCFs, with MRI and histology as the standard references. All the patients underwent unenhanced CT scans. Nineteen histogram-based parameters were derived using Omni-Kinetics software (Omni-Kinetics, GE Healthcare). The reproducibility of those parameters was evaluated using two independent delineations conducted by two observers. These histogram parameters were compared among the three different VCFs using Kruskal-Wallis H test. Traumatic VCFs and osteoporotic VCFs were combined as non-malignant VCFs and compared with malignant VCFs using Mann-Whitney U test Multivariable logistic regression analysis was performed on the significantly different features and built a diagnosis model. Receiver operating characteristic (ROC) curve was carried out to observe the difference of diagnostic performance between the single positive parameter and the combination of parameters. RESULTS: All the 19 parameters presented excellent reproducibility, with intraclass correlation coefficient values from 0.789 to 0.997. At quantitative evaluation, the best predictive histogram parameters in discrimination of the three different types of VCFs were relative min intensity (p = 0.022), relative entropy (p = 0.043), and relative frequency size (p < 0.001). Relative frequency size (p < 0.001) and relative quantile5 (p = 0.012) resulted in statistically significant difference between non-malignant and malignant VCFs. The area under ROC curve indicated that relative frequency size combined with relative quantile5 (0.754; 95 % confidence intervals: 0.661∼0.829; p < 0.001) was of best performance in differentiating malignant from non-malignant VCFs. CONCLUSIONS: Our results are encouraging and suggest that histogram parameters derived from unenhanced CT could be reliable quantitative biomarkers for diff ;erential diagnosis of usual VCFs.

CT based quantitative measures of the stability of fractured metastatically involved vertebrae treated with spine stereotactic body radiotherapy.

Mechanical instability secondary to vertebral metastases can lead to pathologic vertebral compression fracture (VCF) mechanical pain, neurological compromise, and the need for surgical stabilization. Stereotactic body radiation therapy (SBRT) as a treatment for spinal metastases is effective for pain and local tumor control, it has been associated with an increased risk of VCF. This study quantified computed tomography (CT) based stability measures in metastatic vertebrae with VCF treated with spine SBRT. It was hypothesized that semi-automated quantification of VCF based on CT metrics would be related to clinical outcomes. 128 SBRT treated spinal metastases patients were identified from a prospective database. Of these, 18 vertebral segments were identified with a VCF post-SBRT. A semi-automated system for quantifying VCF was developed based on CT imaging before and after SBRT. The system identified and segmented SBRT treated vertebral bodies, calculated stability metrics at single time points and changes over time. In the vertebrae that developed a new (n = 7) or progressive (n = 11) VCF following SBRT, the median time to VCF/VCF progression was 1.74 months (range 0.53-7.79 months). Fractured thoracolumbar vertebrae that went on to be stabilized (cemented and/or instrumented), had greater fractured vertebral body volume progression over time (12%) compared to those not stabilized (0.4%, p < 0.05). Neither the spinal instability neoplastic score (SINS) or any single timepoint stability metrics in post-hoc analyses correlated with future stabilization. This pilot study presents a quantitative semi-automated method assessing fractured thoracolumbar vertebrae based on CT. Increased fractured vertebral body volume progression post-SBRT was shown to predict those patients who were subsequently stabilized, motivating study of methods that assess temporal radiological changes toward augmenting existing clinical management in the metastatic spine.

Changes of Bone Turnover Markers and Bone Tissue Content After Severe Osteoporotic Vertebral Compression Fracture.

BACKGROUND The incidence of osteoporotic vertebral fractures (OVCFs) has increased significantly in recent years. In order to assess osteoporotic fracture healing process, it is necessary to study the characteristics after this type of vertebral fracture. However, there are few researches on fracture healing process in severe OVCFs. We aim to investigate the histological healing process and the kinetics of bone turnover markers following severe OVCFs. MATERIAL AND METHODS There were 149 patients with severe OVCFs included in this study. Fasting blood samples were obtained to detect bone turnover markers levels. A transpedicular bone biopsy was performed to collect bone biopsy specimens during vertebroplasty surgery. Stratification of healing process was performed: stage I (1-3 days), stage II (4-10 days), stage III (11-20 days), stage IV (21-30 days), stage V (1-3 months), stage VI (3-6 months). RESULTS Quantitative analysis of bone histomorphometry showed that a large amount of necrotic bone tissue was observed in stage VI (12.92±3.66%). Bone turnover markers showed the concentration of ß-isomerized C-terminal telopeptide (ß-CTX) which reflects activity in osteoclast continued to increase in stage VI (0.9±0.33 ng/mL). These results differed from previous reports of other type vertebral fractures. CONCLUSIONS Bone histomorphometric analysis and bone turnover markers showed that severe osteoporotic vertebral compression fractures often associated with delayed union and nonunion during the healing process.

Stereotactic Body Radiation Therapy With Simultaneous Integrated Boost in Patients With Spinal Metastases.

Stereotactic body radiation therapy in patients with spine metastases maximizes local tumor control and preserves neurologic function. A novel approach could be the use of stereotactic body radiation therapy with simultaneous integrated boost delivering modality. The aim of the present study is to report our experience in the treatment of spine metastases using a frameless radiosurgery system delivering stereotactic body radiation therapy-simultaneous integrated boost technique. The primary endpoints were the pain control and the time to local progression; the secondary ones were the overall survival and toxicity. A total of 20 patients with spine metastases and 22 metastatic sites were treated in our center with stereotactic body radiation therapy-simultaneous integrated boost between December 2007 and July 2018. Stereotactic body radiation therapy-simultaneous integrated boost treatments were delivered doses of 8 to 10 Gy in 1 fraction to isodose line of 50%. The median follow-up was 35 months (range: 12-110). The median time to local progression for all patients was not reached and the actuarial 1-, 2-, and 3-years local free progression rate was 86.36%. In 17 of 20 patients, a complete pain remission was observed and 3 of 20 patients had a partial pain remission (complete pain remission + partial pain remission: 100%). The median overall survival was 38 months (range 12-83). None of the patients experienced neither radiation adverse events (grade 1-4) nor reported pain flair reaction. None of the patients included in our series experienced vertebral compression fracture. Spine radiosurgery with stereotactic body radiation therapy-simultaneous integrated boost is safe. The use of this modality in spine metastases patients provides an excellent local control.

A Unique "Reverse" Crescent Fragment in an Anterior-Posterior Compression Fracture: A Case Report.

CASE: We describe a patient with an anterior-posterior compression type pelvic fracture sustained after a motorcycle crash, with pubic symphysis disruption and a "reverse" crescent fragment. The injury force ruptured the anterior sacroiliac ligaments and travelled posterior medially, creating a complete Denis zone 2 sacral fracture, rather than rupturing the posterior sacroiliac ligaments as would be expected. The patient underwent open reduction and internal fixation of the pubic symphysis and closed reduction and percutaneous pinning of the right sacroiliac joint. CONCLUSIONS: This case presents a unique "reverse" crescent fragment not previously described in the literature as an anterior-posterior compression type III variant.

Reduced leg muscle mass and lower grip strength in women are associated with osteoporotic vertebral compression fractures.

Lower limb muscle mass and grip loss may be risk factors for vertebral compression fractures in women. PURPOSE: We examined the relationship between bone mineral density, bone strength, skeletal muscle mass, grip strength, and skin autofluorescence (SAF) in women with osteoporotic vertebral compression fractures (VCF). METHODS: A total of 1039 women (mean age 73.3 years) were included in our study. These included 222 cases of VCF (mean 77.8 years) and 817 controls (mean 72.0 years). Lumbar and femur BMD were measured for all participants using dual-energy X-ray absorptiometry (DXA). Bone strength surrogates, such as cross-sectional area (CSA) of the proximal femur, were evaluated using Advanced Hip Assessment software. SAF was measured with an autofluorescence reader. We used a bioelectrical impedance analyzer (BIA) to analyze body composition, including appendicular skeletal muscle mass index (SMI; appendicular lean mass (kg)/(height (m))2. We measured bone density, geometric parameters related to bone strength, skeletal muscle mass, grip strength, and SAF in both groups. We also examined factors related to vertebral fracture using multiple logistic regression analysis. RESULTS: Women with vertebral fractures had lower SMI (5.55 vs 5.76 kg/m2, p = 0.0006), smaller femoral cross-sectional area (97.20 vs 100.09, p = 0.014), lower grip strength (16.81 vs 19.16 kg, p < 0.0001), and increased skin autofluorescence (2.38 vs 2.25, p = 0.0002) compared to women without fractures. The prevalence of sarcopenia (SMI < 5.75) was 63.51% in VCF subjects and 52.02% in controls, revealing a high prevalence in VCF (p = 0.002). Skeletal muscle mass and grip strength were not significantly different between patients with acute and old VCF, suggesting that low skeletal muscle mass and muscle weakness may exist before fracture. From the multiple logistic regression analysis, lower femoral density (p = 0.0021), CSA (p = 0.0166), leg muscle mass (p = 0.0127), and left arm grip strength (p = 0.0255) were risk factors for vertebral compression fractures; all were negatively correlated with increased vertebral fractures. CONCLUSIONS: Lower limb muscle mass and grip loss may be closely related to the onset of vertebral compression fracture.

Evaluation of Incidentally Detected Pathology Results of Patients with Vertebral Fracture Treated by Vertebroplasty and Kyphoplasty: A Retrospective Study.

BACKGROUND: Vertebroplasty and kyphoplasty are minimally invasive techniques used to treat vertebral compression fractures. The etiology of vertebral compression fractures varies among patients. Although osteoporosis and trauma are major etiologic factors in patients with a vertebral compression fracture, unexpected results were found in 11 patients in the present study. The aim of the present retrospective study was to determine the incidentally detected pathology results of patients with vertebral fracture treated by vertebroplasty and kyphoplasty. METHODS: From February 2010 to November 2015, 616 patients with a vertebral compression fracture were treated by kyphoplasty and vertebroplasty at our institution. Vertebral biopsies were obtained from 533 patients during a vertebral augmentation technique. The average patient age was 62.4 years. Of the 616 patients, 388 were female and 228 were male. Histological evaluation of the biopsy specimens from the vertebral compression fractures was performed. RESULTS: The biopsy results of 505 patients showed various stages of bone healing. Among these patients, malignancy was identified in 23 patients, and 43 patients had a history of malignancy. In 6 patients, an unsuspected malignancy was found, and 1 patient had Paget's disease. Infection was detected in 4 patients. In our study, the rate of unsuspected malignancy was 1.1%. CONCLUSIONS: Tissue examination is useful and could reveal pathologic fractures. An incidentally detected biopsy result could change the treatment of patients; however, bone biopsy should be reserved for those patients whose preoperative radiological diagnosis raises suspicion of a nonosteoporotic etiology.

Percutaneous curved vertebroplasty in the treatment of thoracolumbar osteoporotic vertebral compression fractures.

OBJECTIVE: To evaluate the clinical efficacy of percutaneous curved vertebroplasty (PCVP) in treating thoracic and lumbar osteoporotic vertebral compression fractures (OVCFs). METHODS: Patients with thoracolumbar OVCFs were recruited and randomly divided into three treatment groups: PCVP, unilateral percutaneous vertebroplasty (PVP) or bilateral PVP. Bone cement dispersion in the fractured vertebrae was observed. Surgery duration, X-ray frequency, bone cement injection volume, bone cement leakage rate and visual analogue scale (VAS) scores were recorded. RESULTS: Among 78 patients included, surgery duration and X-ray frequency were significantly lower in the PCVP and unilateral PVP groups versus bilateral PVP group. Bone cement injection volume was significantly higher in the bilateral PVP group (6.3 ± 1.4 ml) versus unilateral PVP (3.5 ± 1.1 ml) and PCVP groups (4.6 ± 1.2 ml). VAS scores at 24 h and 3 months post-surgery were significantly decreased versus baseline in all groups. The bone cement leakage rate was lowest in the PCVP group (8.8% [3/34 patients]). CONCLUSION: PCVP is associated with reduced trauma, less complicated surgery with shorter duration, fewer X-rays, lower complication rate, and quicker postoperative recovery versus unilateral and bilateral PVP.

Lumbar muscle volume in postmenopausal women with osteoporotic compression fractures: quantitative measurement using MRI.

OBJECTIVE: To investigate the relationship between paraspinal and psoas muscle volumes and acute osteoporotic or low-bone-mass compression fractures of the lumbar spine in postmenopausal women. METHODS: Patient data were retrieved retrospectively for postmenopausal women with L-spine magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry showing osteoporosis/low bone mass. Group 1 comprised eight women aged 60-80 years with MRI showing a single acute compression fracture. The age-matched group 2a (N = 12) and younger group 2b (N = 12) comprised of women whose MRIs showed no fractures. Cross-sectional MRIs of the paraspinal and psoas muscles and intramuscular fat volume for each muscle group were measured. Operator repeatability and reproducibility were obtained. RESULTS: Group 1 showed significantly smaller lean muscle volume for all muscle groups at L5/S1. Intramuscular fat volume was also smaller in most muscle groups in group 1, though only reaching statistical significance at variable muscle groups and levels. Measurements show both good intrarater repeatability and interrater reproducibility of lean muscle volume estimations (intraclass correlation coefficient (ICC), 0.999 for rater A and 0.997 for rater B; Cronbach's alpha 0.995) and intramuscular fat volume estimations (ICC, 0.995 for rater A and 0.982 for rater B; Cronbach's alpha was 0.981). CONCLUSIONS: This study provides the first quantitative evidence that compression fractures in postmenopausal women with underlying osteoporosis/low bone mass are associated with less paraspinal and psoas muscle volumes. Further longitudinal studies with larger cohorts are needed to verify this relationship. KEY POINTS: • The risk of osteoporotic compression fractures is higher in older women with smaller paraspinal muscle volume. • Older women show smaller paraspinal muscle volume and more intramuscular fat compared to younger controls.

Age, Gender, Level and Side Differences in the Anatomical Distinctions of Unilateral Percutaneous Kyphoplasty through the Transverse Process-Pedicle Approach.

BACKGROUND: Unilateral and bilateral percutaneous kyphoplasty (PKP) have been widely adopted to treat osteoporotic vertebral compression fractures (OVCFs). Unilateral PKP has a shorter operation time and less radiation exposure time compared with bilateral PKP, but the anatomical distinctions of unilateral PKP are not identical in all cases. OBJECTIVE: The aim of this study was to examine the significance of age, gender, level, and side in relation to the anatomical distinctions of unilateral PKP for lumbar OVCFs through the transverse process-pedicle approach (TPPA). STUDY DESIGN: This was a retrospective study of 200 patients. SETTING: The research took place at General Hospital of Shenyang Military Area Command of Chinese PLA. METHODS: Researchers examined 1000 lumbar spines (L1-L5) of 200 patients and simulated PKP on the 3D-CT scans through unilateral TPPA. The distance between the entry point and the midline of the vertebral body (DEM), the puncture inclination angle (PIA), the safe range of the inner inclination angles (SRA), and the success rate (SR) of puncture were measured and compared. RESULTS: There were significant differences (P < 0.05) in the mean DEM between men and women, and between the left and right sides. The DEM was significantly larger in men than women and in right than left. The DEM from L1 to L5 was significantly increased (P < 0.05), from 22.4 ± 2.0 mm to 34.1 ± 4.3 mm. The right maximum PIA was significantly larger than the left. The maximum puncture angle and SRA in men was larger than that in women except for L5. The SRA from L1 to L5 was significantly increased (P < 0.05), from 20.1 ± 6.0 mm to 44.2 ± 8.8 mm. The SR from L1 to L5 was significantly increased (P < 0.05), from 88.3% to 100%. The SR in men was significantly higher than that in women for L1 and L2. LIMITATIONS: Sample size was relatively small. CONCLUSIONS: The DEM was 22.4 mm to 34.1 mm according to different levels. There were significant gender, side, and age differences in the DEM and PIA. The values of DEM, PIA, SRA and SR were significantly increased from L1 to L5. KEY WORDS: Lumbar, osteoporotic vertebral compression fracture, unilateral, percutaneous kyphoplasty, transverse process.

Fat Quantification in the Vertebral Body: Comparison of Modified Dixon Technique with Single-Voxel Magnetic Resonance Spectroscopy.

Objective: To compare the lumbar vertebral bone marrow fat-signal fractions obtained from six-echo modified Dixon sequence (6-echo m-Dixon) with those from single-voxel magnetic resonance spectroscopy (MRS) in patients with low back pain. Materials and Methods: Vertebral bone marrow fat-signal fractions were quantified by 6-echo m-Dixon (repetition time [TR] = 7.2 ms, echo time (TE) = 1.21 ms, echo spacing = 1.1 ms, total imaging time = 50 seconds) and single-voxel MRS measurements in 25 targets (23 normal bone marrows, two focal lesions) from 24 patients. The point-resolved spectroscopy sequence was used for localized single-voxel MRS (TR = 3000 ms, TE = 35 ms, total scan time = 1 minute 42 seconds). A 2 × 2 × 1.5 cm3 voxel was placed within the normal L2 or L3 vertebral body, or other lesions including a compression fracture or metastasis. The bone marrow fat spectrum was characterized on the basis of the magnitude of measurable fat peaks and a priori knowledge of the chemical structure of triglycerides. The imaging-based fat-signal fraction results were then compared to the MRS-based results. Results: There was a strong correlation between m-Dixon and MRS-based fat-signal fractions (slope = 0.86, R2 = 0.88, p < 0.001). In Bland-Altman analysis, 92.0% (23/25) of the data points were within the limits of agreement. Bland-Altman plots revealed a slight but systematic error in the m-Dixon based fat-signal fraction, which showed a prevailing overestimation of small fat-signal fractions (< 20%) and underestimation of high fat-signal fractions (> 20%). Conclusion: Given its excellent agreement with single-voxel-MRS, 6-echo m-Dixon can be used for visual and quantitative evaluation of vertebral bone marrow fat in daily practice.