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To clarify the relationship between body mass index (BMI) and spinal pathologies including spinal sagittal balance, back extensor strength (BES), paraspinal muscle mass, prevalent vertebral fracture, disc degeneration, Modic changes, low back pain, and quality of life (QOL) in community-dwelling older adults.This study included 380 participants (age: ≥ 65 years, male/female: 152/228) from the Shiraniwa Study. Multivariate nonlinear regression analysis was used to investigate the relationship between BMI and sagittal vertical axis (SVA), BES, paraspinal muscle mass, visual analog scale (VAS) for low back pain, Oswestry Disability Index (ODI), and EuroQoL-5 Dimension (EQ5D) score after adjusting for sex, age, Hospital Anxiety and Depression Scale score, and Charlson Comorbidity Index. In addition, multiple logistic regression analysis was used to investigate the association between BMI and prevalent vertebral fracture, disc degeneration, and Modic changes.BMI was significantly correlated with SVA, BES, paraspinal muscle mass, VAS, ODI, and EQ5D score. The increase in BMI was associated with the deterioration of all outcomes, which accelerated when the BMI increased from approximately 22-23 kg/mIncreased BMI is significantly associated with spinal pathologies such as SVA, BES, paraspinal muscle mass, VAS, QOL, disc degeneration, and Modic changes. The findings suggest that measures for controlling overweight and obesity among older adults can play an important role in the prevention and treatment of spinal pathologies.

Correction surgeries for spinal malalignment showed good clinical outcomes; however, there were concerns including increased invasiveness, complications, and impact on medico-economics. Ideally, an early intervention is needed. To better understand the patho-mechanism and natural course of spinal alignment, the effect of factors such as muscle mass and strength on spinal sagittal imbalance were determined in a multicenter cross-sectional study.After excluding metal implant recipients, 1823 of 2551 patients (mean age: 69.2 ± 13.8 years; men 768, women 1055) were enrolled. Age, sex, past medical history (Charlson comorbidity index), body mass index (BMI), grip strength (GS), and trunk muscle mass (TM) were reviewed. Spinal sagittal imbalance was determined by the SRS-Schwab classification. Multiple comparison analysis among four groups (Normal, Mild, Moderate, Severe) and multinomial logistic regression analysis were performed.On multiple comparison analysis, with progressing spinal malalignment, age in both sexes tended to be higher; further, TM in women and GS in both sexes tended to be low. On multinomial logistic regression analysis, age and BMI were positively associated with spinal sagittal malalignment in Mild, Moderate, and Severe groups. TM in Moderate and Severe groups and GS in the Moderate group were negatively associated with spinal sagittal malalignment.Aging, obesity, low TM, and low GS are potential risk factors for spinal sagittal malalignment. Especially, low TM and low GS are potentially associated with more progressed spinal sagittal malalignment. Thus, early intervention for muscles, such as exercise therapy, is needed, while the spinal sagittal alignment is normal or mildly affected.

Background Context Accurate diagnosis of osteoporotic vertebral fracture (OVF) is important for improving treatment outcomes; however, the gold standard has not been established yet. A deep-learning approach based on convolutional neural network (CNN) has attracted attention in the medical imaging field. Purpose To construct a CNN to detect fresh OVF on magnetic resonance (MR) images. Study Design/Setting Retrospective analysis of MR images Patient Sample This retrospective study included 814 patients with fresh OVF. For CNN training and validation, 1624 slices of T1-weighted MR image were obtained and used. Outcome Measure We plotted the receiver operating characteristic (ROC) curve and calculated the area under the curve (AUC) in order to evaluate the performance of the CNN. Consequently, the sensitivity, specificity, and accuracy of the diagnosis by CNN and that of the two spine surgeons were compared. Methods We constructed an optimal model using ensemble method by combining nine types of CNNs to detect fresh OVFs. Furthermore, two spine surgeons independently evaluated 100 vertebrae, which were randomly extracted from test data. Results The ensemble method using VGG16, VGG19, DenseNet201, and ResNet50 was the combination with the highest AUC of ROC curves. The AUC was 0.949. The evaluation metrics of the diagnosis (CNN/surgeon 1/surgeon 2) for 100 vertebrae were as follows: sensitivity: 88.1%/88.1%/100%; specificity: 87.9%/86.2%/65.5%; accuracy: 88.0%/87.0%/80.0%. Conclusions In detecting fresh OVF using MR images, the performance of the CNN was comparable to that of two spine surgeons.

An osteoporotic vertebral fracture (OVF) is a common disease that causes disabilities in elderly patients. In particular, patients with nonunion following an OVF often experience severe back pain and require surgical intervention. However, nonunion diagnosis generally takes more than six months. Although several studies have advocated the use of magnetic resonance imaging (MRI) observations as predictive factors, they exhibit insufficient accuracy. The purpose of this study was to create a predictive model for OVF nonunion using machine learning (ML).We used datasets from two prospective cohort studies for OVF nonunion prediction based on conservative treatment. Among 573 patients with acute OVFs exceeding 65 years in age enrolled in this study, 505 were analyzed. The demographic data, fracture type, and MRI observations of both studies were analyzed using ML. The ML architecture utilized in this study included a logistic regression model, decision tree, extreme gradient boosting (XGBoost), and random forest (RF). The datasets were processed using Python.The two ML algorithms, XGBoost and RF, exhibited higher area under the receiver operating characteristic curves (AUCs) than the logistic regression and decision tree models (AUC = 0.860 and 0.845 for RF and XGBoost, respectively). The present study found that MRI findings, anterior height ratio, kyphotic angle, BMI, VAS, age, posterior wall injury, fracture level, and smoking habit ranked as important features in the ML algorithms.ML-based algorithms might be more effective than conventional methods for nonunion prediction following OVFs.

We investigated the relationship between trunk muscle mass and spinal pathologies by gender. This multicenter cross-sectional study included patients aged ≥ 30 years who visited a spinal outpatient clinic. Trunk and appendicular muscle mass were measured using bioelectrical impedance analysis. The Oswestry Disability Index (ODI), visual analog scale (VAS) score for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated to evaluate spinal pathology. The association between trunk muscle mass and these parameters was analyzed by gender using a non-linear regression model adjusted for patients’ demographics. We investigated the association between age and trunk muscle mass. We included 781 men and 957 women. Trunk muscle mass differed significantly between men and women, although it decreased with age after age 70 in both genders. Lower trunk muscle mass was significantly associated with ODI, SVA, and EQ5D score deterioration in both genders; its association with VAS was significant only in men. Most parameters deteriorated when trunk muscle mass was

This study revealed the change in the paravertebral muscles in patients with osteoporotic vertebral fracture. Increased pain is likely to be the driver for reduced activity, reduced activities of daily living, and consequent increase in fat infiltration of the paravertebral muscles, assumed to be secondary to reduced activity level or, conversely, partial immobilization. To reveal the time courses and impact of the paravertebral muscles (PVMs) on the healing process of osteoporotic vertebral fractures and risk factors for PVM decrease. Consecutive patients with symptomatic osteoporotic vertebral fractures were enrolled in 11 hospitals. At enrollment and 3- and 6-month follow-up, PVMs, including the multifidus and erector spinae, were examined using magnetic resonance imaging (MRI). The PVM cross-sectional area (CSA) and fat signal fraction (FSF) were measured at L3. Low back pain (LBP), activities of daily living (ADLs), and risk factors for PVM decrease at the 6-month follow-up were investigated. PVM decrease was defined as > 1 standard deviation decrease of the CSA or > 1 standard deviation increase of the FSF. Among 153 patients who completed the 6-month follow-up, 117 (92 women, 79%) had MRI of L3 at enrollment and 3- and 6-month follow-up (mean age at enrollment, 78.5 years). The CSA did not change 6 months from onset (p for trend = 0.634), whereas the FSF significantly increased (p for trend = 0.033). PVM decrease was observed in 30 patients (26%). LBP was more severe, and delayed union was more frequent in patients with PVM decrease (p = 0.021 mixed-effect model and p = 0.029 chi-square test, respectively). The risk factors for PVM decrease were ADL decline at the 3-month follow-up (adjusted odds ratio = 5.35, p = 0.026). PVM decrease was significantly related to LBP and delayed union after osteoporotic vertebral fracture onset. ADL decline at the 3-month follow-up was a risk factor for PVM decrease. Therefore, restoring ADLs within 3 months after onset is important.

Osteoprotic vertebral fractures (OVFs) are common in elderly people. The association between back pain due to OVF with magnetic resonance imaging (MRI) signal change is unclear. In this study we hypothesized that MRI findings would be a predictive factor for back pain measured by visual analogue scale (VAS) at 6 months follow-up.The aim was to study the MRI findings that predict back pain after OVF and the association between radiological findings and scores of back pain.Multicenter prospective cohort study.A total of 153 OVF patients.The outcome measures were VAS back pain and MRI signal change.This study was performed from 2012 to 2015. Consecutive patients with less than 2-week-old OVFs at 11 institutions were enrolled prospectively. MRI was performed at enrollment and at 1, 3, and 6 months follow-up. T1- and T2-weighted images (T1WI and T2W1) were obtained at each time point and their association with VAS scores of back pain at 6 months were investigated. Anterior compression ratio, posterior compression ratio, and angular motion of vertebral bodies were also measured on X-rays at each follow-up. This research had no financial support. There are no conflicts of interest.The 6 months follow-up was completed by 153 patients. At enrollment, the average VAS score of back pain was 75 mm, and it had improved at the 6-month follow-up to an average score of 20 mm. There was a significant correlation between T1 diffuse low signal change and VAS scores at the 6-month follow-up (p.01). T2 high signal changes (odds ratio; 4.01, p.01) and old vertebral fractures (odds ratio; 2.47, p=.04) were independent risk factors for back pain. The correlation between angular motion of vertebrae on X-rays and the VAS score of back pain was significant at all time points.This study demonstrates the radiological factors associated with persistent back pain after an OVF and the association between the VAS score of back pain and radiological findings. In addition, T2 high signal changes in acute phase and old vertebral fractures were independent risk factors for residual back pain.

A propensity score matching study.The aim of this study was to assess the cost-effectiveness of balloon kyphoplasty (BKP) in Japan.Osteoporotic vertebral fracture (OVF) is a common disease in elderly people. In Japan, the incidence of painful OVF in 2008 was estimated as 880,000, and approximately 40% of patients with painful OVF are hospitalized due to the severity of pain. Japan is the front runner among super-aged societies and rising health care costs are an economic problem.BKP and nonsurgical management (NSM) for acute/subacute OVF were performed in 116 and 420 cases, respectively. Quality-adjusted life years (QALY) and incremental costs were calculated on the basis of a propensity score matching study. QALY was evaluated using the SF-6D questionnaire. Finally, using a Markov model, incremental cost-effectiveness ratios (ICERs) were calculated for 71 matched cases.In the comparison between BKP and NSM, mean patients age was 78.3 and 77.7 years, respectively (P = 0.456). The BKP procedure cost 402,988 JPY more than NSM and the gains in QALY at the 6-month follow-up were 0.153 and 0.120, respectively (difference = 0.033). ICERs for 3 and 20 years were 4,404,158 JPY and 2,416,406 JPY, respectively. According to sensitivity analysis, ICERs ranged from 652,181 JPY to 4,896,645 JPY (4418-33,168 GBP).This study demonstrated that BKP is a cost-effective treatment option for OVF in Japan. However, the effect might be blunted in patients aged80 years. Further research is necessary to elucidate the cost-effectiveness of BKP in this population.4.

A multicenter cross-sectional study. To clarify the relationship of trunk muscle mass with low back pain, spinal sagittal balance, and quality of life. Few reports have investigated the relationship of trunk muscle mass with lumbar spine function and spinal balance, and the clinical significance of trunk muscle mass remains unclear. Patients attending spinal outpatient clinics at 10 different medical institutions were enrolled in this study. Patient demographics, trunk muscle mass and appendicular skeletal muscle mass (ASM) measured by bioelectrical impedance analysis (BIA), body mass index (BMI), Charlson Comorbidity Index (CCI), the Oswestry Disability Index (ODI), visual analog scale (VAS) for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated. Multivariate nonlinear regression analysis was used to investigate the association of trunk muscle mass with the ODI, VAS score, SVA, and EQ5D score. Of 2551 eligible patients, 1738 (mean age 70.2 ± 11.0 years; 781 men and 957 women) were enrolled. Trunk muscle mass was significantly correlated with the ODI, VAS score, SVA, and EQ5D score (P

Introduction: The presence of existing osteoporotic vertebral fracture (OVF) increases the mortality risk. However, the influence of the characteristics of OVF is unclear. This study aimed to investigate the influence of new OVF on patients’ long-term prognosis using our past cohort study. Method: This is an extension study of our cohort study carried out between 2005 and 2007. In the present extension study, of 420 patients, 197 whose contact information was available at the 6-month follow-up were included in the telephone survey in 2018. Five patients refused to participate in the survey, and 82 could not be contacted. Eventually, 110 patients were enrolled. Of the Demographic data, radiological findings, medical history, and clinical outcome were investigated at injury onset and at the 6-month follow-up. A proportional hazard model was used to investigate the risk factors for mortality. Results: Among 110 patients, 33 died. Male sex and low body mass index (BMI 2) were significant risk factors for mortality [hazard ratio (HR) = 6.40, 1.01–40.50; 5.24, 1.44–19.04, respectively]. The history of stroke and liver disease increased the risk of mortality (HR = 13.37, 1.93–92.7; 6.62, 1.15–38.14, respectively). As regards radiological findings, local kyphosis progression per 1° or ≥7° were significant risk factors of mortality (HR = 1.20, 1.06–1.36; 5.38, 1.81–16.03, respectively). Conclusions: A telephone survey at 12 years after the occurrence of OVF analyzed risk factors for mortality and showed that a progression of local kyphosis in fractures between injury onset and 6 months after injury was a risk factor of poor prognosis.

We investigated the effect of paravertebral muscle (PVM) on poor prognosis in osteoporotic vertebral fracture (OVF) and remaining lower back pain (LBP) in the thoracolumbar and lower lumbar regions. Additional OVF occurrence in the thoracolumbar and remaining LBP in the lumbar region was significantly related to PVM fat infiltration percentage. Paravertebral muscle (PVM) is an important component of the spinal column. However, its role in the healing process after osteoporotic vertebral fracture (OVF) is unclear. This study aimed to clarify the effect of PVM in thoracolumbar and lower lumbar regions on OVF clinical and radiological outcomes. This was a multicenter prospective cohort study from 2012 to 2015. Patients ≥ 65 years old who presented within 2 weeks after fracture onset were followed up for 6 months. PVM was measured at the upper edge of the L1 and L5 vertebral body in the magnetic resonance imaging (MRI) T2-axial position at registration. The cross-sectional area (CSA), relative CSA (rCSA), and fat infiltration percentage (FI%) were measured. Severe vertebral compression, delayed union, new OVF, and remaining low back pain (LBP) were analyzed. Among 153 patients who were followed up for 6 months, 117 with measurable PVM were analyzed. Their average age was 79.1 ± 7.2 years, and 94 were women (80.3%). There were 48 cases of severe vertebral compression, 21 delayed unions, 11 new OVF, and 27 remaining LBP. Among all poor prognoses, only the FI% of the PVM was significantly associated with new OVF (p = 0.047) in the thoracolumbar region and remaining LBP (p = 0.042) in the lumbar region. The occurrence of additional OVF in the thoracolumbar region and remaining LBP in the lumbar region was significantly related to the FI% of the PVM. Physicians should be aware that patients with such fatty degeneration shown in acute MRI may require stronger treatment.

Compensatory mechanisms, such as a decrease in thoracic spine kyphosis and posterior tilting or rotation of the pelvis, aim to achieve optimal alignment of the spine. However, the effect of muscle strength on these compensatory mechanisms has not been elucidated. This study aimed to investigate the impact of back muscle and lower extremity strength on compensatory mechanisms in elderly people. Overall, 409 community-dwelling elderly participants (164 men, 245 women) were included. Age, disc degeneration, and 2 or more vertebral fractures showed a significant increase of risk for sagittal vertical axis (SVA) deterioration. Conversely, stronger back, hip flexor, and knee extensor muscles reduced the risk for SVA deterioration. To investigate the association of each muscle’s strength with compensatory mechanisms, 162 subjects with pelvic incidence-lumbar lordosis > 10° were selected. The linear regression model for thoracic kyphosis demonstrated a negative correlation with back muscle strength and positive correlation with vertebral fracture. The regression analysis for pelvic tilt demonstrated a positive correlation with knee extensor strength. Back, hip flexor, and knee extensor muscle strength were associated with sagittal spinal alignment. Back muscle strength was important for the decrease in thoracic kyphosis, and knee extensor strength was associated with pelvic tilt.

Balloon kyphoplasty (BKP) sometimes fails to improve patients’ outcomes, with revision surgery, using anterior or posterior reconstruction, being required. The purpose of this study was to investigate the radiological risk factors of failure after BKP in the treatment of osteoporotic vertebral fractures (OVFs). This case-control study included 105 patients treated with single BKP and 14 patients who required revision BKP. We evaluated radiological findings differentiating both groups, using plain radiography and computed tomography, before BKP. Angular flexion-extension motion was significantly greater in the revision than BKP group. While the frequency of pedicle fracture and posterior wall injury was not different between the groups, a split type fracture was more frequent in the revision group. Split type fracture had the highest adjusted odds ratio (OR) for revision (16.5, p = 0.018). Angular motion ≥14° increased the risk for revision surgery by 6-fold (p = 0.013), with endplate deficit having an OR of revision of 5.0 (p = 0.032). The revision rate after BKP was 3.8%, with split type fracture, greater angular motion and large endplate deficit being risk factors for revision. Treatment strategies for patients with these risk factors should be carefully evaluated, considering the inherent difficulties in performing revision surgery after BKP.

Background With the increasing aging population in developed countries, there has been an associated increased prevalence of osteoporotic vertebral fracture (OVF). Many previous reports have attempted to predict the risk of delayed union associated with OVF. However, the role of endplate failure and the degeneration of adjacent intervertebral discs, and their association with delayed union has received little attention. The aim of this study was to evaluate the endplate fracture and disc degeneration rank as risk factors for delayed union. Materials and methods Two hundred and eighteen consecutive patients with fresh OVF were enrolled in the study. MRI and X–ray were performed at the time of enrollment and at the 6 months follow-up. The MR images were used to assess the degeneration grade of adjacent intervertebral discs (using the modified Pfirrmann grading system), and endplate failure. Supine and weight-bearing radiographs were used to define angular motion and compression ratio of the anterior vertebral body wall. Results A total of 139 patients (112 female, 27 male) completed the 6 month follow-up (a 65.1% follow-up rate). The study revealed 27 cases of delayed union (19.4%). A healthier adjacent caudal disc with low grade degeneration was found to be associated with an increased risk of delayed union (P = 0.008). Bi-endplate injury and significant compression of the anterior vertebral body wall were significantly associated with delayed union (P = 0.019, and P = 0.001 respectively). Rapid progression of the adjacent cranial disc degeneration was observed at the end of the 6 month follow-up period (P = 0.001). Conclusion Modified Pfirrmann grading system revealed that a healthier adjacent intervertebral disc at the caudal level and bi-endplate fracture were significantly associated with an increased risk of delayed union. These findings may influence the management strategy for patients with OVF.

Background Conditions of the elderly like sarcopenia, locomotive syndrome, and frailty have been attracting attention recently. However, the relationship of these 3 conditions and the difference in the magnitude of influence each has on deterioration in health status remain unclear. The purpose of this study was to investigate the prevalence and relationship of sarcopenia, locomotive syndrome, and frailty, and to clarify their influence on the dropout from cohort study due to deterioration in health status. Methods The 1st survey of the Shiraniwa Elderly Cohort (Shiraniwa) study was conducted in 2016. We examined 409 participants (aged ≥ 65 years; 164 males, 245 females) and assessed sarcopenia, locomotive syndrome, and frailty. Those who could not attend the 2nd survey (2017) due to deterioration in health status were defined as the Dropout group. We investigated the predictors of Dropout using multiple logistic regression analysis. Results The prevalence of sarcopenia, locomotive syndrome stage 2, and frailty were 4.4%, 40.1%, and 14.2%, respectively; 89.7% of participants with frailty were also diagnosed with locomotive syndrome stage 2. From the results of the 2nd survey, 46 people were classified into the Dropout group. Independent predictors of the Dropout were locomotive syndrome stage 2 (adjusted odds ratio [OR]: 2.42, 95% confidence interval [CI]: 1.11–5.31) and frailty (adjusted OR: 3.37, 95%CI: 1.56–7.30). Conclusions Locomotive syndrome stage 2 was the most common condition in the elderly, and most people with frailty also had locomotive syndrome stage 2. Locomotive syndrome stage 2 and frailty independently influenced the dropout from cohort study due to deterioration in health status. These results suggest that screening for locomotive syndrome is useful for early detection of the elderly with a risk of deterioration in health status, and screening for frailty may contribute to detecting the elderly with higher risk of deterioration in health status.

The incidence of adjacent vertebral fracture (AVFs) is reported to be 10%-38% after balloon kyphoplasty. However, no reports have established a system for prediction of AVF occurrence.To establish a scoring system for predicting AVF occurrence after balloon kyphoplasty for osteoporotic vertebral fractures (OVFs).A prospective cohort study.Consecutive elderly patients aged 65 years and older who underwent balloon kyphoplasty for OVFs within 2 months after the onset.AVF was confirmed by X-ray.From 2015 to 2017, 116 consecutive patients from 10 participating hospitals who underwent balloon kyphoplasty were enrolled in this study. Prior to study enrollment, each patient underwent plain X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) of the thoracic and lumbar spine. Severity of pain was subjectively assessed using a visual analog scale (VAS) based on the average level of back pain that the patient had experienced in the preceding week. After enrollment, subjects underwent balloon kyphoplasty. Quality of life was evaluated using SF-36. Patients were followed up for at least 6 months.Of the 116 patients enrolled, 109 patients with all the required data at the time of enrolment and the 6-month follow-up were included in the study. A total of 32 patients (29%) showed AVFs within the 6-month follow-up. No significant differences were observed in each clinical outcome at 6-month follow-up, although higher VAS score for back pain at 1-month follow-up was observed in the AVF group (37.5) than in the non-AVF group (20.8, p.001). Wedge angle of vertebrae before surgery was greater in the AVF group (21.6°) than in the non-AVF group (15.7°, p.001). The change in wedge angle between pre- and postsurgery was greater in the AVF group than in the non-AVF group, whereas the change in local kyphosis was not significantly different. The multiple logistic regression model showed increased odds ratio (OR) of thoracic or thoracolumbar spine, old OVF presence,25° kyphosis before surgery, and10°correction for AVF. Based on this result, a simple scoring system for predicting AVF occurrence was developed. The total AVF score was calculated as the sum of the individual scores, which varied from 0 to 6. All patients with 5-6 points sustained AVF.More severe wedge angle before surgery, correction degree, old OVF presence, and thoracolumbar level were predictive factors for AVF. All patients with AVF risk score of 5 or more showed AVF. This information may aid preoperative risk assessment, informed shared decision-making, and consideration of potential alternative management strategies.

Trunk muscles play an important role in supporting the spinal column. A decline in trunk muscle mass, as measured by bioelectrical impedance analysis (TMM–BIA), is associated with low back pain and poor quality of life. The purpose of this study was to determine whether TMM–BIA correlates with quantitative and functional assessments traditionally used for the trunk muscles. We included 380 participants (aged ≥ 65 years, 152 males, 228 females) from the Shiraniwa Elderly Cohort (Shiraniwa) study, for whom the following data were available: TMM–BIA, lumbar magnetic resonance imaging (MRI), and back muscle strength (BMS). We measured the cross-sectional area (CSA) and fat-free CSA of the paravertebral muscles (PVM), including the erector spinae (ES), multifidus (MF), and psoas major (PM), on an axial lumbar MRI at L3/4. The correlation between TMM–BIA and the CSA of PVM, fat-free CSA of PVM, and BMS was investigated. TMM–BIA correlated with the CSA of total PVM and each individual PVM. A stronger correlation between TMM–BIA and fat-free CSA of PVM was observed. The TMM–BIA also strongly correlated with BMS. TMM–BIA is an easy and reliable way to evaluate the trunk muscle mass in a clinical setting.

This study revealed the time course of osteoporotic vertebral fracture by magnetic resonance imaging using a simple classification. Signal changes were associated with the compression degree and mobility of the fractured vertebral body. This classification showed sufficient reliability in categorizing magnetic resonance imaging findings of osteoporotic vertebral fractures. Magnetic resonance imaging (MRI) is useful in diagnosing osteoporotic vertebral fractures (OVFs). This study investigated the time course of OVFs by MRI using a simple classification. This multicenter cohort study was performed from 2012 to 2015. Consecutive patients with ≤2-week-old OVFs were enrolled in 11 institutions. MRI was performed at enrollment and at 1-, 3-, 6-, and 12-month follow-up. Signal changes on T1-weighted imaging (T1WI), T2WI, and short τ inversion recovery (STIR) were classified according to signal intensity. Height and angular motion of vertebral bodies were also measured. The 6-month follow-up was completed by 153 patients. At enrollment, fractured vertebrae signal changes were 43 % diffuse and 57 % confined low on T1WI; on T2WI, 56, 24, and 5 % were confined low, high, and diffuse low, respectively; on STIR, 100 % were high. On T1WI, diffuse low remained most common (90 % at 1 month and 60 % at 3 months) until 6 and 12 months, when most were confined low (54 and 52 %, respectively). On T2WI, confined low remained most common (decreasing to 41 % at 12 months). On STIR, high signal change was shown in 98, 87, and 64 % at 3, 6, and 12 months, respectively. At 3, 6, and 12 months, diffuse low signal change was associated with significantly lower vertebral height, and high signal change was associated with significantly greater angular motion. MRI signal changes were associated with the compression degree and angular motion of fractured vertebrae. This classification showed sufficient reliability in categorizing MRI findings of OVFs.

This study demonstrated the predictive values of radiological findings for delayed union after osteoporotic vertebral fractures (OVFs). High-signal changes on T2WI were useful findings.The purpose of the present study is to determine predictive radiological findings for delayed union by magnetic resonance imaging (MRI) and plain X-rays at two time points in the acute phase of OVFs.This multicenter cohort study was performed from 2012 to 2015. A total of 218 consecutive patients with OVFs ≤2 weeks old were enrolled. MRIs and plain X-rays were performed at the time of enrollment and at 1- and 6-month follow-ups. Signal changes on T1-weighted imaging (T1WI) were classified as diffuse low-, confined low-, or no-signal change; those on T2WI were classified as high (similar to the intensity of cerebrospinal fluid), confined low-, diffuse low-, or no-signal change. The angular motion of the fractured vertebral body was measured with X-rays.A total of 153 patients completed the 6-month follow-up. A high-signal change on T2WI was most useful in predicting delayed union. Sensitivity, specificity, and positive predictive values were 53.3, 87.8, and 51.6 % at enrollment and 65.5, 84.8, and 51.4 % at the 1-month follow-up, respectively. The positive predictive value increased to 62.5 % with observation of high- or diffuse low-signal changes at both enrollment and the 1-month follow-up. The cutoff value of vertebral motion was 5 degrees. Sensitivity and specificity at enrollment were 52.4 and 74.1 %, respectively.This study demonstrated the radiological factors predicting delayed union after an OVF. T2 high-signal changes showed the strongest association with delayed union. Consecutive MRIs were particularly useful as a differential tool to predict delayed union following OVFs.

A multicenter, prospective, single-arm, intervention study.The aim of this study was to investigate efficacy of balloon kyphoplasty (BKP) for acute osteoporotic vertebral fractures (OVFs) in patients with poor prognostic factors.The indications for BKP remain unclear. Characteristic magnetic resonance imaging (MRI) findings (high-intensity or diffuse low-intensity area in fractured vertebrae on T2-weighted images) were reportedly predictive of delayed union.This study enrolled 106 patients with poor prognostic MRI findings who underwent BKP within 2 months after injury, and 116 controls with acute OVFs and the same poor prognostic factors who underwent conservative treatment. Patients were propensity score matched in a logistic regression model adjusted for age, sex, number of baseline old fractures, and fracture level. The primary outcome was reduction in activities of daily living (ADLs) at 6 months after fracture, and the secondary outcomes were improvement in short-form (SF)-36 subscales, back pain visual analog scale (VAS) score, and vertebral body deformity.A decrease in ADLs occurred in 5.6% of patients in the BKP group and 25.6% of patients in the conservative treatment group (P 0.001). The SF-36 vitality subscale score improved by 26.9 ± 25.9 points in the BKP group and 14.5 ± 29.4 points in the control group (P = 0.03). The VAS pain score improved by 43.4 ± 34.4 in the BKP group and 52.2 ± 29.8 in the control group (P = 0.44). The vertebral body wedge angle improved by 5.5 ± 6.2° in the BKP group and -6.3 ± 5.0° in the control group (P 0.0001). The percent vertebral body height improved by 15.2 ± 19.2% in the BKP group and -20.6 ± 14.2% in the control group (P 0.0001).ADLs, quality of life, and vertebral deformity showed greater improvement with BKP intervention for acute OVF with poor prognostic factors than with conservative treatment at 6 months after injury. Our treatment strategy uses BKP intervention according to the presence or absence of poor prognostic MRI findings.4.

In this prospective multicenter study of osteoporotic vertebral fractures (OVFs), delayed union of OVF at 6-month follow-up caused prolonged pain, QOL impairment, ADL impairment, cognitive status deterioration, and vertebral collapse progression. Delayed union following osteoporotic vertebral fracture displayed as an intravertebral cleft on plain X-rays was reported to be a factor for prolonged severe pain. However, the difference of clinical course between bone union and delayed union cases still remains unclear. The purpose of this study was to identify how OVF delayed union following conventional conservative treatment influences the clinical course with a prospective multicenter study. A total of 324 OVF patients from 25 institutes in Osaka, Japan, were included in the study. At the 6-month follow-up after initial visit to each institute, the patients were classified into bone union and delayed union groups based on plain X-ray findings. The outcome assessments included a VAS for back pain, SF-36 for quality of life (QOL), severity of bed-ridden state for activities of daily living (ADL), MMSE for cognitive functions, and degree of vertebral collapse on plain X-rays. Overall, 280 patients were included into the union group and 44 into the delayed union group. The VAS score at 6 months was significantly worse in the delayed union group (p = 0.01). The scores for the SF-36 scales of physical functioning and bodily pain at 6 months were significantly lower in the delayed union group (p = 0.019, p = 0.01, respectively). The percentage of nearly or completely bed-ridden patients was significantly higher in the delayed union group. The percentage of newly developed cognitive impairment was significantly higher in the delayed union group (p = 0.02). Progression of vertebral collapse during the 6-month follow-up was more pronounced in the delayed union group (p

Background Balloon kyphoplasty or vertebroplasty is widely performed as a surgical intervention for osteoporotic vertebral fracture (OVF) and the effects have been investigated in many previous studies. However, the influence of the timing of the procedure on patient outcomes has not been studied formally. The purpose of this study was to investigate differences in the surgical outcomes of OVFs according to the timing of balloon kyphoplasty. Methods This was a multicenter cohort study. Participants comprised 72 consecutive patients who underwent balloon kyphoplasty between January 2012 and January 2016. Patients were analyzed in two groups according to the timing of kyphoplasty after onset (Early group: ≤2 months; Late group: >2 months). Follow-up continued for more than 6 months. Results A total of 72 patients were effectively analyzed. Of these, 27 (38%) patients underwent kyphoplasty within 2 months after symptom onset. The Late group showed greater angular motion of fractured vertebrae (p = 0.005) and compression of anterior vertebral height (p = 0.001) before surgery. Final outcomes adjusted for age and preoperative outcome showed lower visual analog scale (VAS) scores for low back pain in the Early group than in the Late group (19.9 vs. 30.4, p = 0.049). Final relative anterior vertebral height and kyphotic angle were more preserved in the Early group than in the Late group (p = 0.002 and p = 0.020, respectively), although absolute differences were not significant. Conclusions Vertebral height and kyphotic angle before and after balloon kyphoplasty were greater in patients who underwent kyphoplasty within 2 months after onset, and the VAS score for low back pain at final follow-up was better. Our results support kyphoplasty within 2 months.

This study demonstrated four distinct patterns in the course of back pain after osteoporotic vertebral fracture (OVF). Greater angular instability in the first 6 months after the baseline was one factor affecting back pain after OVF. Understanding the natural course of symptomatic acute OVF is important in deciding the optimal treatment strategy. We used latent class analysis to classify the course of back pain after OVF and identify the risk factors associated with persistent pain. This multicenter cohort study included 218 consecutive patients with ≤ 2-week-old OVFs who were enrolled at 11 institutions. Dynamic x-rays and back pain assessment with a visual analog scale (VAS) were obtained at enrollment and at 1-, 3-, and 6-month follow-ups. The VAS scores were used to characterize patient groups, using hierarchical cluster analysis. VAS for 128 patients was used for hierarchical cluster analysis. Analysis yielded four clusters representing different patterns of back pain progression. Cluster 1 patients (50.8%) had stable, mild pain. Cluster 2 patients (21.1%) started with moderate pain and progressed quickly to very low pain. Patients in cluster 3 (10.9%) had moderate pain that initially improved but worsened after 3 months. Cluster 4 patients (17.2%) had persistent severe pain. Patients in cluster 4 showed significant high baseline pain intensity, higher degree of angular instability, and higher number of previous OVFs, and tended to lack regular exercise. In contrast, patients in cluster 2 had significantly lower baseline VAS and less angular instability. We identified four distinct groups of OVF patients with different patterns of back pain progression. Understanding the course of back pain after OVF may help in its management and contribute to future treatment trials.

Background Osteoporotic vertebral fractures (OVFs) are the most common cause of intractable back pain and reduced activities of daily living (ADL), which may affect cognitive function. However, no previous studies have reported a change in cognitive function after OVFs. The purpose was to reveal cognitive function changes after OVFs and investigate the risk factors for cognitive decline. Methods Consecutive patients with symptomatic OVFs were enrolled in a prospective multicenter cohort study. The inclusion criteria were age >65 years, diagnosis of acute or subacute OVF, and back pain onset within 2 months prior to presentation. Cognitive function was assessed with the mini-mental state examination. Medical history, radiological findings, and ADL were investigated as risk factors for cognitive decline. Results We recruited a sample of 339 patients (58 men and 281 women) who met the inclusion criteria. Patients underwent examinations and completed questionnaires at both the time of enrollment and at 6-month follow-up. At 6-month follow-up, cognitive decline was observed in 26 (7.7%) patients. Medical history, including comorbidities and sports activities, did not affect odds ratios (ORs). However, elevated ORs were associated with delayed union (OR: 4.67, 95% Confidence interval: 1.22–17.87). In addition, significantly increased ORs were associated with reduced ADL at 6-month follow-up. Conclusions The current results revealed the incidence of cognitive decline after the onset of OVF. Delayed union and reduced ADL at 6-month follow-up were associated with cognitive decline. Patients with cognitive decline experienced significantly reduced quality of life. These results highlight the importance of preventing cognitive impairment in patients with symptomatic OVF. Physical treatment or early surgical treatment may provide appropriate options, particularly for patients with suspected delayed union.

Study design Prospective multicenter study. Objective To examine whether initial conservative treatment interventions for osteoporotic vertebral fractures (OVF) influence patient outcomes. Summary of background data OVFs have been described as stable spinal injuries and, in most cases, are managed well with conservative treatment. However, systematic treatments for OVF have not been clearly established. Methods A total of 362 patients with OVF (59 males and 303 females; mean age, 76.3 yr) from 25 institutes were enrolled in this clinical study. All the patients were treated conservatively without any surgical interventions. The patient outcomes were evaluated 6 months after the fractures on the basis of Short Form-36 (SF-36) physical component summary (PCS) and mental component summary (MCS), activities of daily living (the Japanese long-term care insurance system), back pain (visual analogue scale), cognitive status (mini-mental state examination), and vertebral collapse, which were used as response variables. Furthermore, brace type, hospitalization, bisphosphonates after injury, and painkillers after injury were explanatory variables for the treatment interventions. To evaluate the independent effects of treatment interventions on patient outcomes, we performed multivariate logistic regression analyses and obtained odds ratios that were adjusted for the potential confounding effects of age, sex, level of fracture, presence of middle-column injury, pain visual analogue scale at enrollment, mini-mental state examination score at enrollment, and previous use of steroids. Results There was no significant difference for treatment intervention factors including brace type, hospitalization, bisphosphonates after injury, and painkillers after injury. For adjusting factors, the presence of middle-column injury was significantly associated with SF-36 PCS ≤ 40, reduced activities of daily living, prolonged back pain, and vertebral collapse. Female sex and advanced age were associated with SF-36 PCS ≤ 40. Low mini-mental state examination scores at enrollment were associated with SF-36 PCS ≤ 40 and reduced activities of daily living. The previous use of steroids was associated with SF-36 MCS ≤ 40, prolonged back pain, and vertebral collapse. No other examined variables were significant risk factors for patient outcomes. Conclusion These results showed that treatment intervention factors did not affect patient outcomes 6 months after OVF. Middle-column injury was a significant risk factor for both clinical and radiological outcomes. In the future, establishing systematic treatments for cases with middle-column injuries is needed. Level of evidence 2.

Chondromas are benign tumors that are rarely located in the spine. The authors present a rare occurrence of a spinal chondroma that developed as an intradural but extramedullary tumor in a 60-year-old woman. The location of the tumor at C4–5 was confirmed by MRI, with hyperintensity on T2-weighted images and isointensity on T1-weighted images. The tumor was completely contained intradurally, with no continuity to any vertebrae. It adhered to the anterior dura, indicative of its likely origin from the dura mater. The tumor was completely resected, with no sign of recurrence after 3 years postoperatively. Although reports of chondromas originating from the dura mater have been previously described, these have all been intracranial tumors. To the best of the authors' knowledge, this is the first report of an intradural chondroma located in the spine. Therefore, chondromas should be considered in the differential diagnosis of intradural spinal tumors.

Study design Prospective cohort study. Objective To elucidate the prognostic factors indicating reduced activities of daily living (ADL) at the time of the 6-month follow-up after osteoporotic vertebral fracture (OVF). Summary of background data OVF has severe effects on ADL and quality of life (QOL) in elderly patients and leads to long-term deteriorations in physical condition. Many patients recover ADL with acceleration of bony union and spinal stability, but some experience impaired ADL even months after fracture. Identifying factors predicting reduced ADL after OVF may prove valuable. Methods Subjects in this prospective study comprised 310 OVF patients from 25 institutes. All patients were treated conservatively without surgery. Pain, ADL, QOL, and other factors were evaluated on enrollment and at 6 months. ADL were evaluated using the criteria of the Japanese long-term care insurance system to evaluate the degree of independence. We defined reduced ADL as a reduction of at least single grade at 6 months after fracture and investigated factors predicting reduced ADL after OVF, using uni- and multivariate regression analysis. Results ADL were reduced at 6 months after OVF in 66 of 310 patients (21.3%). In univariate analysis, age more than 75 years (P = 0.044), female sex (P = 0.041), 2 or more previous spine fractures (P = 0.009), presence of middle column injury (P = 0.021), and lack of regular exercise before fracture (P = 0.001) were significantly associated with reduced ADL. In multivariate analysis, presence of middle column injury (odds ratio [OR], 2.26; P = 0.022) and lack of regular exercise before fracture (OR, 2.49; P = 0.030) were significantly associated with reduced ADL. Conclusion These results identified presence of middle column injury of the vertebral body and lack of regular exercise before fracture as prognostic factors for reduced ADL. With clarification and validation, these risk factors may provide crucial tools for determining subsequent OVF treatments. Patients showing these prognostic factors should be observed carefully and treated with more intensive treatment options.

Retrospective study of multivariable analysis for the risk factors of motor deficit associated with lumbar disc herniation (LDH).To identify the risk factors for motor deficit and delayed recovery after surgery in patients with LDH.LDH can cause motor deficit as well as pain and sensory disturbance. Even though motor deficit can lead to disabilities and affect treatment plans, few studies have described motor deficit and its risk factors in LDH patients.Seventy-six consecutive patients who underwent microsurgical or microendoscopic discectomy for LDH at the L4/5 level were retrospectively reviewed. Motor deficit was defined as tibialis anterior muscle strength of lower than grade 4 by the manual muscle test, and delayed recovery was defined as cases requiring longer than 3 months to achieve complete recovery. The possible risk factors including sex, age, symptom duration, preoperative radiographic parameters, and type of herniation were evaluated by multivariate logistic regression analysis.Forty-three patients (56.6%) suffered from motor deficit before surgery. Forty cases (93%) completely recovered within a mean duration of 4 months. Multivariate logistic regression analysis revealed that noncontained-type (P=0.012, odds ratio=13.7) and migrated herniated nucleus pulposus (P=0.033, odds ratio=9.8) were important risk factors for motor deficit. Furthermore, severe motor deficit (preoperative manual muscle test≤3; P=0.019, odds ratio=19.6) and noncontained type (P=0.049, odds ratio=5.17) were identified as important risk factors for delayed recovery.Noncontained-type or migrated herniated nucleus pulposus seem to be the most important risk factors for motor deficit in LDH, whereas severe motor deficit and noncontained type seem to be associated with delayed recovery. The treatment options for patients with these factors at first visit should be carefully chosen during the follow-up period.

Object The authors compared the clinical outcomes of microscopic bilateral decompression via a unilateral approach (MBDU) for the treatment of degenerative lumbar scoliosis (DLS) and for lumbar canal stenosis (LCS) without instability. The authors also compared postoperative spinal instability in terms of different approach sides (concave or convex) following the procedure. Methods The authors retrospectively reviewed data obtained in 50 consecutive patients (25 in the DLS group and 25 in the LCS group) who underwent MBDU; the minimum follow-up period was 2 years. Patients with DLS were divided into 2 subgroups according to the surgical approach side: a concave group (23 segment) and a convex group (17 segments). The Japanese Orthopaedic Association Scale scores for the assessment of low-back pain were evaluated before surgery and at final follow-up. The Japanese Orthopaedic Association Scale scores and recovery rates were compared between the DLS and LCS groups, and between the convex and concave groups. Cobb angle and scoliotic wedging angle (SWA) were evaluated on standing radiographs before surgery and at final follow-up. Facet joint preservation (the percentage of preservation) was assessed on pre- and postoperative CT scans, compared between the LCS and DLS groups, and compared between the concave and convex groups. The influence of approach side on postoperative progression of segmental instability was also examined in the DLS group. Results The mean recovery rate was 58.7% in the DLS and 62.0% in the LCS group. The mean recovery rate was 58.6% in the convex group and 60.6% in the concave group. There were no significant differences in recovery rates between the LCS and DLS groups, or between the DLS subgroups. The mean Cobb angles in the DLS group were significantly increased from 12.7° preoperatively to 14.1° postoperatively (p < 0.05), and mean preoperative SWAs increased significantly from 6.2° at L3–4 and 4.1° at L4–5 preoperatively to 7.4° and 4.9°, respectively, at final follow-up (p < 0.05). There was no significant difference in percentage of preservation between the DLS and LCS groups. The mean percentages of preservation on the approach side in the DLS group at L3–4 and L4–5 were 89.0% and 83.1% in the convex group, and those in the concave group were 67.3% and 77.6%, respectively. The percentage of preservation at L3–4 was significantly higher in the convex than the concave group. The mean SWA had increased in the concave group (p = 0.01) but not the convex group (p = 0.15) at final follow-up. Conclusions The MBDU can reduce postoperative segmental spinal instability and achieve good postoperative clinical outcomes in patients with DLS. The convex approach provides surgeons with good visibility and improves preservation of facet joints.

Study design This work was performed to investigate the role of vitamin K (VK) in the pathogenesis of ossification of posterior longitudinal ligament (OPLL), by analyzing the biochemical markers of the blood samples of OPLL patients and responses of ligament cells derived from OPLL lesion to VK2. Objectives The pathogenesis of OPLL, classified as a form of diffuse idiopathic skeletal hyperostosis, is still unclear. In this study, we investigated the role of menaquinone (VK2) in patients with OPLL (OPLL patients) and the effects of VK2 on ligament cells isolated from OPLL lesion. Methods Serum levels of intact osteocalcin, glu-osteocalcin, MK-4, -7 (VK2 variants) and other minerals in spot blood samples were measured in 24 OPLL patients and in 24 age-matched control patients (non-OPLL patients). The cultured cells isolated from an OPLL patient were treated with MK-4. Alkaline phosphatase (Al-p) activity and osteocalcin release were measured after 2 weeks of culture. Results In the clinical study, the serum MK-4 in male OPLL patients was significantly higher than that in male non-OPLL patients. However, among female patients, the difference was not significant. Although the serum osteocalcin in females was significantly higher than that in males, there was no significant difference between the OPLL and non-OPLL groups. In in vitro study, MK-4 did not increase Al-p activity in the ligament cells isolated from nonossified region of OPLL patient. Osteoblastic activity of the cultured cells was not stimulated by MK-4. Conclusion From these results and previous reports, we propose the possibility of the impediment in VK2 metabolism in OPLL patients. The results also implicate the gender tendency in OPLL, because the difference of serum level of MK-4 in OPLL patients was significant only in male.

Background Appropriate treatment of osteoporotic vertebral fractures (OVF) requires knowledge of the age of the fracture. Although diagnostic imaging has made remarkable progress in recent years, it remains difficult to differentiate acute fractures from old. Our purpose was to investigate chronological changes in radiological findings after OVF and to identify discriminators of acute versus older injuries. Methods We evaluated 139 vertebrae in 136 patients. All patients underwent X-ray and magnetic resonance imaging (MRI) examination within 2 weeks of injury and again after 6 months. The anterior vertebral height ratio (AVHR) was calculated on lateral X-ray, and the intensity change of the posterior wall of the fractured vertebra was evaluated on T1-weighted MRI. The cutoff AVHR value to diagnose acute fracture was determined by receiver operating characteristic (ROC) curve analysis. Results Average AVHR fell from 84.6% at initial visit to 63.7% at 6 months. When acute fracture was defined as AVHR >75%, sensitivity was 85.6%, specificity was 67.6%, and positive predictive value was 72.6%. On MRI, 83.5% of fractured vertebrae showed intensity change in the posterior wall in the acute stage, which fell to 41.7% of vertebrae after 6 months. When intensity change in the posterior wall and AVHR >75% were both present, the specificity and positive predictive value for diagnosing acute fracture improved to 87.1% and 84.7%, respectively. Conclusions This study suggests that vertebral fracture rarely shows significant collapse on X-ray in the first 2 weeks after injury. The combination of intensity change in the posterior wall on MRI and AVHR >75% on X-ray indicates a high probability of acute fracture.

Study design Prospective multicenter study. Objective To identify radiographic or magnetic resonance (MR) images of fresh vertebral fractures that can predict a high risk for delayed union or nonunion of osteoporotic vertebral fractures (OVFs). Summary of background data Vertebral body fractures are the most common fractures in osteoporosis patients. Conservative treatments are typically chosen for OVFs, and associated back pain generally subsides within several weeks with residual persistent deformity of the vertebral body. In some patients, OVF healing is impaired and correlated with prolonged back pain. However, assessments such as plain radiograph or MR images taken during the early phase to predict high risks for nonunions of OVFs and/or poor prognoses have not been identified. Methods A total of 350 OVF patients from 25 institutes were enrolled in this clinical study. Plain radiograph and MR images of the OVFs were routinely taken at enrollment at the respective institutes. The findings on the plain radiograph and MR images were classified after enrollment in the study. All the patients were treated conservatively without any surgical intervention. After a 6-month follow-up, the patients were classified into two groups, a union group and a nonunion group, depending on the presence of an intravertebral cleft on plain radiograph or MR images. The associations of the images from the first visit with those of the corresponding nonunions at the 6-month follow-up were analyzed by multivariate logistic regression to elucidate specific image characteristics that may predict a high risk for nonunion of OVFs. Results Forty-eight patients (49 vertebrae) among the 350 patients (363 vertebrae) were classified as nonunions, indicating a nonunion incidence of 13.5% for conventional conservative treatments for OVFs. The statistical analyses revealed that a vertebral fracture in the thoracolumbar spine, presence of a middle-column injury, and a confined high intensity or a diffuse low intensity area in the fractured vertebrae on T2-weighted MR images were significant risk factors for nonunion of OVFs. Conclusion The results of this study revealed significant relationships between plain radiograph and MR images of acute phase OVFs and the incidence of nonunion. As these risk factors are defined more clearly and further validated, they may become essential assessment tools for determining subsequent OVF treatments. Patients with one or more of the earlier-described risk factors for nonunion should be observed carefully and provided with more intensive treatments.

The authors compared the clinical outcomes of microscopic bilateral decompression via a unilateral approach (MBDU) for the treatment of degenerative lumbar scoliosis (DLS) and for lumbar canal stenosis (LCS) without instability. The authors also compared postoperative spinal instability in terms of different approach sides (concave or convex) following the procedure.The authors retrospectively reviewed data obtained in 50 consecutive patients (25 in the DLS group and 25 in the LCS group) who underwent MBDU; the minimum follow-up period was 2 years. Patients with DLS were divided into 2 subgroups according to the surgical approach side: a concave group (23 segment) and a convex group (17 segments). The Japanese Orthopaedic Association Scale scores for the assessment of low-back pain were evaluated before surgery and at final follow-up. The Japanese Orthopaedic Association Scale scores and recovery rates were compared between the DLS and LCS groups, and between the convex and concave groups. Cobb angle and scoliotic wedging angle (SWA) were evaluated on standing radiographs before surgery and at final follow-up. Facet joint preservation (the percentage of preservation) was assessed on pre- and postoperative CT scans, compared between the LCS and DLS groups, and compared between the concave and convex groups. The influence of approach side on postoperative progression of segmental instability was also examined in the DLS group.The mean recovery rate was 58.7% in the DLS and 62.0% in the LCS group. The mean recovery rate was 58.6% in the convex group and 60.6% in the concave group. There were no significant differences in recovery rates between the LCS and DLS groups, or between the DLS subgroups. The mean Cobb angles in the DLS group were significantly increased from 12.7° preoperatively to 14.1° postoperatively (p0.05), and mean preoperative SWAs increased significantly from 6.2° at L3-4 and 4.1° at L4-5 preoperatively to 7.4° and 4.9°, respectively, at final follow-up (p0.05). There was no significant difference in percentage of preservation between the DLS and LCS groups. The mean percentages of preservation on the approach side in the DLS group at L3-4 and L4-5 were 89.0% and 83.1% in the convex group, and those in the concave group were 67.3% and 77.6%, respectively. The percentage of preservation at L3-4 was significantly higher in the convex than the concave group. The mean SWA had increased in the concave group (p = 0.01) but not the convex group (p = 0.15) at final follow-up.The MBDU can reduce postoperative segmental spinal instability and achieve good postoperative clinical outcomes in patients with DLS. The convex approach provides surgeons with good visibility and improves preservation of facet joints.

The purpose of this study was to examine factors affecting the severity of neurological deficits and intractable back pain in patients with insufficient bone union following osteoporotic vertebral fracture (OVF). Reports of insufficient union following OVF have recently increased. Patients with this lesion have various degrees of neurological deficits and back pain. However, the factors contributing to the severity of these are still unknown. A total of 45 patients with insufficient union following OVF were included in this study. Insufficient union was diagnosed based on the findings of vertebral cleft on plain radiography or CT, as well as fluid collection indicating high-intensity change on T2-weighted MRI. Multivariate logistic regression analysis was performed to determine the factors contributing to the severity of neurological deficits and back pain in the patients. Age, sex, level of fracture, duration after onset of symptoms, degree of local kyphosis, degree of angular instability, ratio of occupation by bony fragments, presence or absence of protrusion of flavum, and presence or absence of ossification of the anterior longitudinal ligament (OALL) in the adjacent level were used as explanatory variables, while severity of neurological deficits and back pain were response variables. On multivariate analysis, factors significantly affecting the severity of neurological deficits were angular instability of more than 15 degrees [adjusted odds ratio (OR), 9.24 (95% confidence interval, CI 1.49-57.2); P0.05] and ratio of occupation by bony fragments in the spinal canal of more than 42% [adjusted OR 9.23 (95%CI 1.15-74.1); P0.05]. The factor significantly affecting the severity of back pain was angular instability of more than 15 degrees [adjusted OR 14.9 (95%CI 2.11-105); P0.01]. On the other hand, presence of OALL in the adjacent level reduced degree of back pain [adjusted OR 0.14 (95%CI 0.03-0.76); P0.05]. In this study, pronounced angular instability and marked posterior protrusion of bony fragments in the canal were factors affecting neurological deficits. In addition, marked angular instability was a factor affecting back pain. These findings are useful in determining treatment options for patients with insufficient union following OVF.

✓ The authors describe a new vertebroplasty technique for the treatment of chronic painful vertebral compression fractures (VCFs). A urinary balloon catheter is introduced into the vertebral body (VB) via a bilateral transpedicular approach and inflated with contrast medium to obtain sufficient space for endoscopic observation. The granulation tissue occupying the VB is then removed using a punch or curette inserted through one pedicle, with the guidance of an endoscope introduced through the contralateral pedicle. After endoscopic resection of granulation tissue in the fractured VB, vertebroplasty is performed by injecting calcium phosphate cement (CPC) into the VB. Fourteen patients in whom chronic painful VCFs were diagnosed underwent surgery involving the aforementioned technique. In all cases, intractable pain and ambulatory function improved after surgery, and there were no significant systemic complications. On radiological evaluation in eight cases in which the follow-up period exceeded 1 year, the mean height of the fractured VB improved from 38% of that of adjacent intact VBs to 85%. Although a slight loss of correction was routinely observed at 1 month postoperatively, an additional loss of VB height was not noted up to 1 year later. Bone formation was commonly seen along the anterior wall of the involved vertebrae in all cases. Vertebroplasty involving the endoscopic removal of granulation tissue proved to be an efficacious procedure for the treatment of chronic painful VCFs. The osteoconductive capacity of CPC facilitated callus formation and ultimately restoration of vertebral bone structure.

We report a rare case of trigger finger caused by an old partial laceration of the flexor digitorum superficialis. The triggering occurred five months after injury. This case was the latest presentation of triggering in the literature. The patient was managed by incising the A1 pulley and suturing the flexor tendon flap after trimming. He was relieved of triggering and there was no recurrence.