Relationship between body mass index and spinal pathology in community-dwelling older adults.

PURPOSE: 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. METHODS: 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. RESULTS: 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/m2. Moreover, overweight/obesity was significantly correlated with disc degeneration and Modic changes. CONCLUSION: Increased 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.

Machine-learning-based approach for nonunion prediction following osteoporotic vertebral fractures.

PURPOSE: 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). METHODS: 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. RESULTS: 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. CONCLUSION: ML-based algorithms might be more effective than conventional methods for nonunion prediction following OVFs.

Decreased muscle mass and strength affected spinal sagittal malalignment.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Predictors of dropout from cohort study due to deterioration in health status, with focus on sarcopenia, locomotive syndrome, and frailty: From the Shiraniwa Elderly Cohort (Shiraniwa) study.

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.

ISSLS PRIZE IN CLINICAL SCIENCE 2019: clinical importance of trunk muscle mass for low back pain, spinal balance, and quality of life-a multicenter cross-sectional study.

STUDY DESIGN: A multicenter cross-sectional study. OBJECTIVES: 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. METHODS: 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. RESULTS: 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 < 0.001) when adjusted for age, sex, BMI, ASM, CCI, and history of lumbar surgery. Patient deterioration was associated with a decrease in trunk muscle mass, and the deterioration accelerated from approximately 23 kg. CONCLUSIONS: Trunk muscle mass was significantly associated with the ODI, VAS score, SVA, and EQ5D score. Trunk muscle mass may assume an important role to elucidate and treat lumbar spinal dysfunction and spinal imbalance. These slides can be retrieved under Electronic Supplementary Material.

The degeneration of adjacent intervertebral discs negatively influence union rate of osteoporotic vertebral fracture: A multicenter cohort study.

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.

Differences in short-term clinical and radiological outcomes depending on timing of balloon kyphoplasty for painful osteoporotic vertebral fracture.

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.

Risk factors for cognitive decline following osteoporotic vertebral fractures: A multicenter cohort study.

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.

Risk Factors for Residual Back Pain After Balloon Kyphoplasty for Osteoporotic Vertebral Fracture.

Background: Balloon kyphoplasty (BKP) is a method for the management of osteoporotic vertebral body fracture (OVF). However, improvement in back pain (BP) is poor in some patients, also previous reports have not elucidated the exact incidence and risk factors for residual BP after BKP. We clarified the characteristics of residual BP after BKP in patients with OVF. Hypothesis: In this study, we hypothesize that some risk factors may exist for residual BP 2 years after the treatment of OVF with BKP. Patients and Methods: A multicenter cohort study was performed where patients who received BKP within 2 months of OVF injury were followed-up for 2 years. BP at 6 months after surgery and final observation was evaluated by Visual Analog Scale (VAS) score. Patients with a score of 40 mm or more were allocated to the residual BP group, and comparisons between the residual back pain group and the improved group were made for bone density, kyphosis, mobility of the fractured vertebral body, total spinal column alignment, and fracture type (fracture of the posterior element, pedicle fracture, presence or absence of posterior wall damage, etc.). Also, Short Form 36 (SF-36) for physical component summary (PCS) and mental component summary (MCS) at the final follow-up was evaluated in each radiological finding. Results: Of 116 cases, 79 (68%) were followed-up for 2 years. Two years after the BKP, 26 patients (33%) experienced residual BP. Neither age nor sex differed between the groups. In addition, there was no difference in bone mineral density, BKP intervention period (period from onset to BKP), and osteoporosis drug use. However, the preoperative height ratio of the vertebral body was significantly worse in the residual BP group (39.8% vs. 52.1%; p = 0.007). Two years after the operation, the vertebral body wedge angle was significantly greater in the residual BP group (15.7° vs. 11.9°; p = 0.042). In the multiple logistic regression model with a preoperative vertebral body height ratio of 50% or less [calculated by receiver operating characteristic (ROC) curve], the adjusted odds ratio for residual BP was 6.58 (95% confidence interval 1.64-26.30; p = 0.007); similarly, patients with vertebral body height ratio less than 50% had a lower score of SF-36 PCS 24.6 vs. 32.2 p = 0.08. Conclusion: The incidence of residual BP 2 years after BKP was 33% in the current study. The risk factor for residual BP after BKP was a preoperative vertebral body height ratio of 50% or less, which should be attentively assessed for the selection of a proper treatment scheme and to provide adequate stabilization. Level of Evidence: III.

Muscle strength rather than appendicular skeletal muscle mass might affect spinal sagittal alignment, low back pain, and health-related quality of life.

Sarcopenia is defined as decreasing in muscle strength and mass, and dynapenia is defined as decreasing in muscle strength and maintained muscle mass. This study elucidated the prevalence and characteristics of sarcopenia and dynapenia and evaluate in elderly spinal disorders patients. 1039 spinal disorders patients aged ≥ 65 years were included. We measured age, grip strength, muscle mass, spinal sagittal alignment parameters, low back pain (LBP) scores and health-related quality of life (HR-QoL) scores. Based on the previous reports, patients were categorised into normal group: NG, pre-sarcopenia group: PG, dynapenia group: DG, and sarcopenia group: SG. Pre-sarcopenia, dynapenia, and sarcopenia were found in 101 (9.7%), 249 (19.2%), and 91 (8.8%) patients, respectively. The spinal sagittal alignment parameters, trunk muscle mass, LBP, and HR-QoL scores were significantly worse in DG and SG compared with those in PG and NG. Spinal alignment, trunk muscle mass, and clinical outcomes, including LBP and HR-QoL scores, were maintained in the PG and poor in the DG and SG. Thus, intervention for muscle strength may be a treatment option for changes of spinal sagittal alignment and low back pain.

Risk factor analysis for motor deficit and delayed recovery associated with L4/5 lumbar disc herniation.

STUDY DESIGN: Retrospective study of multivariable analysis for the risk factors of motor deficit associated with lumbar disc herniation (LDH). OBJECTIVES: To identify the risk factors for motor deficit and delayed recovery after surgery in patients with LDH. SUMMARY OF BACKGROUND DATA: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Relationship of back muscle and knee extensors with the compensatory mechanism of sagittal alignment in a community-dwelling elderly population.

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.

Presence of sarcopenia does not affect the clinical results of balloon kyphoplasty for acute osteoporotic vertebral fracture.

Sarcopenia has been associated with poor clinical outcomes in several diseases. Herein, the clinical results of balloon kyphoplasty (BKP) for acute osteoporotic vertebral fracture (OVF) treatment were assessed and compared between sarcopenia and non-sarcopenia patients. Sixty patients who underwent BKP for treatment of acute OVF with poor prognostic factors between April 2016 and September 2017 and were assessed for sarcopenia were enrolled. Clinical results (back pain on visual analogue scale [VAS]; short-form [SF] 36; vertebral deformity; activities of daily living levels; and incidence of adjacent vertebral fractures) were compared between the two groups at 6 months post-BKP. Data analysis revealed that back pain on VAS, SF-36 scores, and vertebral deformity improved from baseline to 6 months after BKP. Thirty-nine patients (65.0%) were diagnosed with sarcopenia and demonstrated a lower body mass index (21.2 vs. 23.3 kg/m2, p = 0.02), skeletal muscle mass index (5.32 vs. 6.55 kg/m2, p < 0.01), hand-grip strength (14.7 vs. 19.2 kg, p = 0.01), and bone mineral density of the femoral neck (0.57 vs. 0.76 g/cm2, p < 0.01) than those of patients without sarcopenia. However, no significant differences were observed in the clinical results between these groups. Therefore, BKP's clinical results for the treatment of acute OVF are not associated with sarcopenia.

Impact of paravertebral muscle in thoracolumbar and lower lumbar regions on outcomes following osteoporotic vertebral fracture: a multicenter cohort study.

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. PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Trunk Muscle Mass Measured by Bioelectrical Impedance Analysis Reflecting the Cross-Sectional Area of the Paravertebral Muscles and Back Muscle Strength: A Cross-Sectional Analysis of a Prospective Cohort Study of Elderly Population.

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.

Risk factors of the poor long-term prognosis of osteoporotic vertebral fractures: A multicenter cohort study.

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 <18.5 kg/m2) 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.

Relationship between number of radiological risk factors for delayed union after osteoporotic vertebral fracture and clinical outcomes.

This study demonstrated that number of three specific radiological risk factors (MR T2WI confined high-intensity pattern and diffuse low-intensity pattern, thoracolumbar vertebrae involvement, middle column injury) added prognostic information for delayed union, kyphotic deformity, and prolonged pain. PURPOSE: Delayed union after osteoporotic vertebral fracture (OVF) causes prolonged pain, QOL impairment, progression of collapse, kyphotic deformity, and neurologic impairment. Some specific radiological findings can be useful for predicting delayed union. We aimed to explore the prevalence and concomitance of various types of radiological risk factors for delayed union after osteoporotic vertebral fracture (OVF) and to assess the impact of risk factor number on clinical outcomes. METHODS: A total of 508 patients with fresh OVF from 25 institutes were evaluated. All patients were treated conservatively without surgical interventions. At the 6-month follow-up, the patients were classified into bone union and delayed union groups based on plain X-ray findings. We examined the presence and absence of three specific radiological risk factors (MR T2WI confined high-intensity pattern and diffuse low-intensity pattern, thoracolumbar vertebrae involvement, middle column injury) and analyzed clinical outcomes according to numbers of radiological risk factors. RESULTS: Delayed union was observed in 101 patients (19.9%) at the 6-month follow-up. The most common radiological risk factor was thoracolumbar vertebrae involvement (73.8%), followed by middle column injury (33.9%) and specific MRI findings (T2WI confined high-intensity pattern and diffuse low-intensity pattern) (29.7%). Overall, 85 (16.7%) patients had zero radiological risk factors, 212 (42.7%) had one, 137 (27.0%) had two, and 69 (13.6%) had three. When assessing the number of radiographic risk factors which included the MRI findings (the 3-risk factor method), the odds ratio for delayed union after acute OVF was 5.8 in the 2/3-risk factor group and 13.1 in the 3/3-risk factor group. Even when assessing the number of radiographic risk factors without MRI findings (2-risk factor method), the odds ratio was 3.2 in the 1/2-risk factor group and 10.2 in the 2/2-risk factor group. CONCLUSION: Number of radiological risk factors added prognostic information for delayed union, kyphotic deformity, and prolonged pain.

Using artificial intelligence to diagnose fresh osteoporotic vertebral fractures on magnetic resonance images.

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.

Gender-specific analysis for the association between trunk muscle mass and spinal pathologies.

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 < 26 kg in men and < 19 kg in women. Lower trunk muscle mass was associated with lumbar disability, spinal imbalance, and poor quality of life in both genders, with significant difference in muscle mass.

Factors affecting neurological deficits and intractable back pain in patients with insufficient bone union following osteoporotic vertebral fracture.

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); P < 0.05] 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); P < 0.05]. 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); P < 0.01]. 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); P < 0.05]. 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.