Spinal fractures are common following underbody blast. Most injuries occur at the thoracolumbar junction, and fracture patterns suggest the spine is flexed at the moment of injury. However, current mechanistic descriptions of vertebral fractures are based on low energy injuries, and there is no evidence to correlate fracture pattern with posture at the loading rates seen in blast injury. The T12-L1 segment of 4 human spines was dissected to preserve the paraspinal ligaments and potted in polymethylmecrylate. The specimens were impacted with a 14 kg mass at 3.5m/s in a drop tower; two specimens were impacted in neutral posture, one in flexion, and one in extension. A load cell measured the load history. CT scans and dissection identified the injury patterns. Each specimen sustained a burst fracture. The neutral specimens demonstrated superior burst fractures, the flexed specimen demonstrated a superior burst fracture with significant anterior involvement, and the extended specimen showed a posterior vertebral body burst fracture. At high loading rates, the posture of the spine at the moment of injury appears to affect the resulting fracture. This supports understanding the behaviour of the spine in blast injury and will allow improved mitigation system design in the future

To explore a novel machine learning model to evaluate the vertebral fracture risk using Decision Tree model and train the model by Bone Mineral Density (BMD) of different compartments of vertebral body. We collected a Computed Tomography image dataset, including 10 patients with osteoporotic fracture and 10 patients without osteoporotic fracture. 40 non-fracture Vertebral bodies from T11 to L5 were segmented from 10 patients with osteoporotic fracture in the CT database and 53 non-fracture Vertebral bodies from T11 to L5 were segmented from 10 patients without osteoporotic fracture in the CT database. Based on the biomechanical properties, 93 vertebral bodies were further segmented into 11 compartments: eight trabecular bone, cortical shell, top and bottom endplate. BMD of these 11 compartments was calculated based on the HU value in CT images. Decision tree model was used to build fracture prediction model, and Support Vector Machine was built as a compared model. All BMD data was shuffled to a random order. 70% of data was used as training data, and 30% left was used as test data. Then, training prediction accuracy and testing prediction accuracy were calculated separately in the two models. The training accuracy of Decision Tree model is 100% and testing accuracy is 92.14% after trained by BMD data of 11 compartments of the vertebral body. The type I error is 7.14% and type II error is 0%. The training accuracy of Support Vector Machine model is 100% and the testing accuracy is 78.57%. The type I error is 17.86% and type II error is 3.57%. The performance of vertebral body fracture prediction using Decision Tree is significantly higher than using Support Vector Machine. The Decision Tree model is a potential risk assessment method for clinical application. The pilot evidence showed that Decision Tree prediction model overcomes the overfitting drawback of Support Vector Machine Model. However, larger dataset and cohort study should be conducted for further evidence

One out of nine Canadian males would suffer prostate cancer (PC) during his lifetime. Life expectancy of males with PC has increased with modern therapy and 90% live >10 years. However, 20% of PC-affected males would develop incurable metastatic diseases. Bone metastases (BM) are present in ~80% of metastatic PC patients, and are the most severe complication of PC, generating severe pain, fractures, spinal cord compression, and death. Interestingly, PC-BMs are mostly osteoblastic. However, the structure of this newly formed bone and how it relates to pain and fracture are unknown. Due to androgen antagonist treatment, different PC phenotypes develop with differential dependency on androgen receptor (AR) signaling: androgen-dependent (AR+), double negative (AR-) and neuroendocrine. How these phenotypes are related to changes in bone structure has not been studied. Here we show a state-of-the-art structural characterization of PCBM and how PC phenotypes are associated to abnormal bone formation in PCBM. Cadaveric samples (n=14) obtained from metastases of PC in thoracic or lumbar vertebrae (mean age 74yo) were used to analyze bone structure. We used micro-computed tomography (mCT) to analyze the three-dimensional structure of the bone samples. After imaging, the samples were sectioned and one 3mm thick section was embedded in epoxy-resin, ground and polished. Scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) and quantitative backscattering electron (qBSE) imaging were used to determine mineral morphology and composition. Another section was used for histological analysis of the PC-affected bone. Collagen structure, fibril orientation and extracellular matrix composition were characterized using histochemistry. Additionally, we obtained biopsies of 3 PCBM patients undergoing emergency decompression surgery following vertebral fracture and used them for immunohistological characterization. By using mCT, we observed three dysmorphic bone patterns: osteolytic pattern with thinned trabecula of otherwise well-organized structures, osteoblastic pattern defined as accumulation of disorganized matrix deposited on pre-existing trabecula, and osteoblastic pattern with minimum residual trabecula and bone space dominated by accumulation of disorganized mineralized matrix. Comparing mCT data with patho/clinical parameters revealed a trend for higher bone density in males with larger PSA increase. Through histological sections, we observed that PC-affected bone, lacks collagen alignment structure, have a higher number of lacunae and increased amount of proteoglycans as decorin. Immunohistochemistry of biopsies revealed that PC-cells inside bone organize into two manners: i) glandular-like structures where cells maintain their polarization in the expression of prostate markers, ii) diffuse infiltrate that spreads along bone surfaces, with loss of cell polarity. These cells take direct contact with osteoblasts in the surface of trabecula. We define that PCBM are mostly composed by AR+ with some double negative cells. We did not observe neuroendocrine phenotype cells. PCBMs generate predominantly osteoblastic lesions that are characterized by high lacunar density, lack of collagen organization and elevated proteoglycan content. These structural changes are associated with the infiltration of PC cells that are mostly androgen-dependent but have lost their polarization and contact directly with osteoblasts, perhaps altering their function. These changes could be associated with lower mechanical properties that led to fracture and weakness of the PCBM affected bone

Introduction. The global rapid growth of the aging population has some likelihood to create a serious crisis on health-care and economy at an unprecedented pace. To extend Healthy Life Expectancy (HALE) in a number of countries, it is desired more than ever to investigate characteristic and prognosis of numerous diseases. This enlightenment and recent studies on patient-reported outcome measures (PROMs) will drive the increasing interest in the quality of life among the world. The demand for primary THAs by 2030 would rise up to 174% in USA. It is expected that the number of the elderly will surge significantly in the future, thus more septuagenarian and octogenarian are undergoing THA. Moreover, HALE of Japanese female near the age of 75 years, followed to Singapore, is still increasing. Therefore, concerns exist about the PROMs of performing THA in this age-group worldwide. Nevertheless almost the well-established procedure, little agreement has been reached to the elderly. We aimed to clarify the mid-term PROMs after THA over 75-year old. Methods. Between 2005 and 2013, we performed 720 consecutive primary cemented THAs through a direct lateral approach. Of these, 503 female patients (655 hips) underwent THA for treatment of osteoarthritis, with a minimum follow-up of 5 years, were retrospectively enrolled into the study. We excluded 191 patients (252 hips) aged less than 65-year at the time of surgery and 58 patients (60) because of post-traumatic arthritis or previous surgery (37), or lack of data (23). Thus, 343 hips remained eligible for our study, contributed by 254 patients. We investigated Quality-adjusted life year (QALY), EuroQol 5-Dimension 5-Level scale (EQ-5D) and the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ, which was a disease-specific and self-administered questionnaire, reflecting the specificity of the Japanese cultural lifestyle) in patients aged 75 years or older (154 hips, Group-E) compared with those aged 65 to 74 years (189 hips, Group-C) retrospectively. We evaluated the association between patients aged 75 years or older and the following potential risk factors, using logistic regression analysis: age, number of vertebral fractures (VFs), American Society of Anesthesiologists physical status (ASA-PS) and Charlson Comorbidity Index (CCI). A p value of < 0.05 was considered significant for the Mann-Whitney U test. Results. At a mean follow-up duration of 7.2 years, QALY, EQ-5D and JHEQ for the domain of patient satisfaction were significantly greater for Group-E than Group-C; however, there were no significant differences in JHEQ for pain, movement and mental-health between groups. On multivariate analysis, the age (odds ratio [OR] 2.48, p < .01 for EQ-5D; OR .32, p < .01 for JHEQ satisfaction), VFs (OR 1.63, p < .01 for satisfaction) and ASA-PS (OR .64, p = .31 for EQ-5D) were independent predictive risk factors for patients aged 75-year or older. Conclusions. Based on mid-term follow-up of PROMs study, we suggest that cemented THA can lead to the extension of HALE towards the super aged society and our results can be applied to a systematic analysis for the Global Burden of Disease Study related frailty

Treat to target is the use of a physiologic marker as a monitor of effectiveness or compliance to an intervention. A recent example has been the progressive use of CTX-1 (Marker of osteoclastic activity) as a surrogate of bone resorptive activity in osteoporosis treatment. CTX-1 levels were demonstrated to be inversely related to drug efficacy in the suppression of bone resorption. As far as fragility fractures are concerned, no reference value of CTX-1 for any index fracture sites was found in the literature. In order to prevent subsequent fractures, efforts to better manage this chronic disease are to be explored. The main objective of this study was to compare and validate the use of serum CTX-1 to the perceived compliance to treatment. Five hundred and forty three patients (men and women) 40 years of age or older who had been treated for a fragility fracture were enrolled. The purpose of this study was to correlate the measurement of CTX-1 with the perceived compliance to treatment of patients at the time of fracture and at six, 12 and 18 months after initiation of treatment. Our secondary objectives were to evaluate two different CTX-1 suppression target levels (CTX-1< 0.3 ng/mL and CTX-1<0.2 ng/mL), to determine CTX-1 values according to fracture sites, and to explore the profile of patients with subsequent fractures. Considering index fractures, compliant patients under treatment at baseline had lower CTX-1 levels than non-compliant patients (p=0.052). Patients who were compliant to treatment at six, 12 and 18 months also had lower CTX-1 levels than non-compliant patients (p=0.000). When index fractures were divided into fracture sites, regardless of CTX-1 suppression target level (i.e. CTX-1< 0.3 or 0.2 ng/mL), significant CTX-1 suppression was observed in non-hip and non-vertebral (NHNV) fractures at six, 12 and 18 months (p0.05). No clinically relevant difference was observed between the profile of patients with and without subsequent fractures. The correlation between serum CTX-1 at the time of fracture and at six, 12, 18 months and the perceived compliance to treatment was validated for NHNV fractures supporting the concept of the available treatments and their effects on bone remodeling for this type of fracture. The correlation was not validated for hip neither for vertebral fracture. There was no correlation between CTX-1 levels and subsequent fracture risk

In recent years internal fixation of the spine by using posterior approach with minimally invasive and percutaneous technique were increasingly used in trauma. The percutaneous surgery lose information and navigation is supposed to provide better data because the lost information is found again. We hypothesise that a percutaneous minimal invasive dorsal procedure by using 3D intra-operative imaging for vertebral fractures allows short operating times with correct screw positioning and does not increase radiation exposure. 59 patients were included in this prospective, monocentric and randomised study. 29 patients (108 implants) were operated on by using conventional surgical procedure (CP) and 30 patients (72 implants) were operated on by using a 3D fluoroscopy-based navigation system (3D fluo). In the two groups, a percutaneous approach was performed for transpedicular vertebroplasty or percutaneous pedicle screws insertion. In the two groups surgery was done from T4 level to L5 levels. Patients (54 years old on average) suffered trauma fractures, fragility fractures or degenerative instabilities. Evaluation of screw placement was done by using post-operative CT with two independent radiologists that used Youkilis criteria. Operative and radiation running time were also evaluated. With percutaneous surgery, the 3D fluo technique was less accurate with 13.88% of misplaced pedicle screws (10/72) compared with 11.11% (12/108) observed with CP. The radiation running time for each vertebra level (two screws) reached on average 0.56 mSv with 3D fluo group compared to 1.57 mSv with the CP group. The time required for instrumentation (one vertebra, two screws) with 3D fluo was 19.75 minutes compared with CP group 9.19 minutes. The results were statistically significant in terms of radiation dose and operative running time (p < 0.05), but not in terms of accuracy (p= 0.24). With percutaneous procedures, 3D fluoroscopy-based navigation (3D fluo) system has no superiority in terms of operative running time and to a lesser degree in terms of accuracy, as compared to 2D conventional procedure (CP), but the benefit in terms of radiation dose is important. Other advantages of the 3D fluo system are twofold: up-to-date image data of patient anatomy and immediate availability to assess the anatomical position of the implanted screws

Introduction. This is the first study to illustrate spinal fracture distribution and the impact of different injury mechanisms on the spinal column during contemporary warfare. Methods. A retrospective analysis of Computed Tomography (CT) spinal images entered onto the Centre for Defence Imaging (CDI) database, 2005-2009. Isolated spinous and transverse process fractures were excluded to allow focus on cases with implications for immediate management and prospective disability burden. Fractures were classified by anatomical level and stability with validated systems. Clinical data regarding mechanism of injury and associated non-spinal injuries for each patient were recorded. Statistical analysis was performed using Fisher's Exact test. Results. 57 cases (128 fractures) were analysed. Ballistic (79%) and non-ballistic (21%) mechanisms contribute to vertebral fracture and spinal instability at all regions of the spinal column. There is a low incidence of cervical spine fracture, with these injuries predominantly occurring due to gunshot wounding. There is a high incidence of lumbar spine fractures which are significantly more likely to be caused by explosive devices than gunshot wounds (p<0.05). 66% of thoracolumbar spine fractures caused by explosive devices were unstable, the majority being of a burst configuration. Associated non-spinal injuries occurred in 60% of patients. There is a strong relationship between spinal injuries caused by explosive devices and lower limb fractures. Conclusion. Explosive devices account for significant injury to both combatants and civilians in current conflict. Injuries to the spine by explosions account for greater numbers, associated morbidity and increasing complexity than other means of injury

Background. High velocity vertical aircraft ejection seat systems are credited with aircrew survival of 80-95% in modern times. Use of these systems is associated with exposure of the aircrew to vertical acceleration forces in the order of 15-25G. The rate of application of these forces may be up to 250G per sceond. Up to 85% of crew ejecting suffer skeletal injury and vertebral fracture is relatively common (20-30%) when diagnosed by plain radiograph. The incidence of subtle spinal injury may not be as apparent. Aim. A prospective study to evaluate spinal injury following high velocity aircraft ejection. Methods. A prospective case series from 1996 to 2006 was evaluated. During this interval 26 ejectees from 20 aircraft were admitted to the spinal studies unit for comprehensive examination, evaluation and management. The investigations included radiographs of the whole spine and Magnetic Resonance Imaging (incorporating T1, T2 weighted and STIR sagittal sequences). All ejections occurred within the ejection envelope and occurred at an altitude under 2000 feet (mean 460 feet) and at an airspeed less than 500 knots (mean 275 knots). Results. in this series 6 ejectees (24%) had clinical and radiographic evidence of vetebral compression fractures. These injuries were located in the thoracic and thoracolumbar spine. 4 cases required surgery (indicated for angular kyphosis greater than 30 degrees, significant spinal canal compromise, greater than 50% or neurological injury. 1 patient had significant neurological compromise, following an AO A3.3 injury involving the L2 vertebra. 11 ejectees (45 %) had MRI evidence of a combined total of 22 occult thoracic and lumbar fractures. The majority of these ejectees with occult injury had multilevel injuries. Conclusion. This study confirms a high incidence of spinal fracture and particularly occult spinal injury

Osteoporosis is common and the health and financial cost of fragility fractures is considerable. The burden of cardiovascular disease has been reduced dramatically by identifying and targeting those most at risk. A similar approach is potentially possible in the context of fragility fractures. The World Health Organization created and endorsed the use of FRAX, a fracture risk assessment tool, which uses selected risk factors to calculate a quantitative, patient-specific, ten-year risk of sustaining a fragility fracture. Treatment can thus be based on this as well as on measured bone mineral density. It may also be used to determine at-risk individuals, who should undergo bone densitometry. FRAX has been incorporated into the national osteoporosis guidelines of countries in the Americas, Europe, the Far East and Australasia. The United Kingdom National Institute for Health and Clinical Excellence also advocates its use in their guidance on the assessment of the risk of fragility fracture, and it may become an important tool to combat the health challenges posed by fragility fractures.