Association between MRI findings and back pain after osteoporotic vertebral fractures: a multicenter prospective cohort study

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.

Risk of Revision After Vertebral Augmentation for Osteoporotic Vertebral Fracture: A Narrative Review

Osteoporotic vertebral fractures (OVFs) can hinder physical motor function, daily activities, and the quality of life in elderly patients when treated conservatively. Vertebral augmentation, which includes vertebroplasty and balloon kyphoplasty, is a commonly used procedure for OVFs. However, there have been reports of complications. Although serious complications are rare, there have been instances of adjacent vertebral fractures, cement dislocation, and insufficient pain relief due to cement failure, sometimes necessitating revision surgery. This narrative review discusses the common risks associated with vertebral augmentation for OVFs, such as cement leakage and adjacent vertebral fractures, and highlights the risk of revision surgery. The pooled incidence of revision surgery was 0.04 (0.02-0.06). The risks for revision are reported as follows: female sex, advanced age, diabetes mellitus, cerebrovascular disease, dementia, blindness or low vision, hypertension, hyperlipidemia, split type fracture, large angular motion, and large endplate deficit. Various treatment strategies exist for OVFs, but they remain a subject of controversy. Current literature underscores the lack of substantial evidence to guide treatment strategies based on the risks of vertebral augmentation. In cases with a high risk of failure, other surgeries and conservative treatments should also be considered as treatment options.

Subsequent Domino Osteoporotic Vertebral Fractures Adversely Affect Short-Term Health-Related Quality of Life: A Prospective Multicenter Study

Background and Objectives: Conservative treatment is the gold standard for acute osteoporotic vertebral fractures (AOVFs). However, the treatment strategy for multiple AOVFs remains unknown. We conducted a prospective study using magnetic resonance imaging (MRI) to investigate how rapidly subsequent osteoporotic vertebral fractures (OVFs) occur as domino OVFs within 3 months. This study aimed to assess the incidence and impact of domino OVFs on quality of life (QOL) following conservative treatment for initial AOVFs. Materials and Methods: A prospective multicenter cohort study was conducted at eight hospitals. The included patients were those with AOVFs occurring within 3 weeks, aged >60 years, and diagnosed using MRI. All patients were treated conservatively and underwent MRI after 3 months. Subsequent domino OVFs were defined as newly occurring OVFs within 3 months. Patient characteristics, types of conservative treatment, and patient-reported outcomes, including a visual analogue scale (VAS), the Oswestry disability index (ODI), and the Japanese Orthopaedic Association back pain evaluation questionnaire (JOABPEQ), were evaluated and compared between the domino OVF and non-domino OVF groups. Results: A total of 227 patients were analyzed. The mean age was 80.1 ± 7.3 years and 78% were female. Subsequent domino OVFs were observed in 31 (13.6%) patients within 3 months. An increasing number of prevalent OVFs were significantly associated with domino OVFs (p = 0.01). No significant differences in bone mineral density, type of brace, and anti-osteoporosis medications were found between the two groups. The JOABPEQ (excluding social function), ODI, and VAS were significantly improved after 3 months. Patients with domino OVFs at 3 months had poorer JOABPEQ social life function, ODI, and VAS than those with non-domino OVFs. Conclusions: In this study, the incidence of domino OVFs was 13.6% within 3 months. Domino OVFs had a negative impact on QOL at 3 months and were associated with prevalent OVFs.

Predictors of residual low back pain in patients with osteoporotic vertebral fractures following percutaneous kyphoplasty

Objective

Patients with osteoporotic vertebral fractures (OVFs) often suffer from residual low back pain (LBP) after percutaneous kyphoplasty (PKP). The purpose of this study was to identify risk factors for postoperative residual LBP and to develop a nomogram to predict the occurrence of residual LBP.

Methods

We retrospectively reviewed 236 patients who underwent PKP for OVFs and had a minimum follow-up of 12 months. The mean age was 72.1 ± 6.3, 74.3% were female and 25.7% were male. Patients with LBP VAS scores ≥ 3.5 at the 12th month postoperatively were considered to have residual LBP. Risk factors for residual LBP were identified by univariate and multifactorial logistic regression analysis. Then, a predictive nomogram was constructed and validated using the bootstrap method. The discrimination, calibration, and clinical utility of the nomogram were assessed using a receiver operating characteristic curve (ROC), a calibration curve, and a decision curve analysis (DCA).

Results

univariate and multifactorial logistic regression analysis identified depression (P = 0.02), intravertebral vacuum cleft (P = 0.01), no anti-osteoporosis treatment (P < 0.001), cement volume <3 ml (P = 0.02), and cement distrubution (P = 0.01) as independent risk factors for residual LBP. The area under the ROC was 0.83 (0.74-0.93) and further validated by bootstrap method was 0.83 (0.73-0.92). The calibration curve illustrated the consistency between the predicted probability and the observed results. DCA showed that nomogram exhibits clinical utility and net benefit when the threshold probability is between 6% and 73%.

Conclusions

Our study found that depression, intravertebral vacuum cleft, no anti-osteoporosis treatment, cement volume <3 ml and cement distribution represent independent risk factors for residual LBP. The nomogram containing the above five predictors can accurately predict the risk of residual LBP after surgery.

Factors associated with pain-related disorders and gait disturbance scores from the Japanese orthopedic association back pain evaluation questionnaire and Oswestry Disability Index in patients with osteoporosis

In the current study, multivariate analyses were performed to determine factors associated with low back pain (LBP) in patients with osteoporosis. Aging, high bone turnover, obesity, low trunk muscle mass, spinal global sagittal malalignment, and a high number of previous vertebral fractures were potential independent risk factors of pain-related disorders, gait disturbance, or ADL deficit due to LBP.

PURPOSE

Patients with osteoporosis often experience low back pain (LBP) even in the absence of acute fractures. This study identifies factors that may affect questionnaires about LBP.

METHODS

The data of 491 patients with osteoporosis were retrospectively reviewed. Data included patient age, sex, body mass index (BMI), bone mineral density of the lumbar spine, tartrate-resistant acid phosphatase 5b level (TRACP5b), trunk muscle mass, sagittal vertical axis (SVA), previous vertebral fractures, secondary osteoporosis, controlling nutritional status score, pain-related disorders and gait disturbance scores from the Japanese Orthopedic Association Back Pain Evaluation questionnaire (JOABPEQ), and Oswestry disability index (ODI) scores for activities of daily living (ADL) deficit. Patients with scores of 100 for each subsection of the JOABPEQ, or an ODI scores < 12 were considered to not have dysfunction (dysfunction (-) group). Multivariate analyses were used to determine variables associated with dysfunction.

RESULTS

Pain-related disorders score of JOABPEQ was associated with aging, high BMI, and high SVA. Aging, high TRACP5b, high BMI, low TM, high SVA, and more previous vertebral fractures were associated with gait disturbance score of JOABPEQ. ODI scores were associated with high BMI, low TM, high SVA, and more previous vertebral fractures.

CONCLUSIONS

Aging, high bone turnover, obesity, a low TM, spinal global sagittal malalignment, and a high number of previous VFs were potential independent risk factors of pain-related disorders or gait disturbance according to the JOABPEQ or ODI score in patients with osteoporosis.

Osteoporotic Fractures of the Thoracic and Lumbar Vertebrae: Diagnosis and Conservative Treatment

BACKGROUND

The prevalence of osteoporotic vertebral body fractures in Europe is 18-26%. Although most of these injuries can be treated conservatively, the underlying concepts have not been defined clearly or uniformly. In this article, we present the current state of the evidence on the diagnosis and conservative treatment of osteoporotic fractures of the thoracic and lumbar vertebrae.

METHODS

A systematic review of the literature up to May 2020 was carried out in the PubMed and Web of Science Core Collection databases. 549 articles were identified, of which 36 were suitable for inclusion in the review. Articles were sought in the areas of diagnosis, provision of physical aids, pharmacotherapy, physiotherapy, and treatments from the realm of alternative medicine.

RESULTS

The primary diagnostic technique was conventional x-ray in two planes (with the patient standing, if possible), which had 51.3% sensitivity and 75% specificity. If a fracture was suspected, magnetic resonance imaging (MRI) of the entire spine and regional computed tomography (CT) were carried out. The overall state of the evidence on treatment is poor; the best available evidence is for exercise therapy and physiotherapy, which are supported by three level I and four level II studies. Improvements were seen mainly in mobility and a reduced fear of falling. The use of an active orthosis can be useful as well. No evidence was found on the use of drugs or alternative medicine exclusively in the conservative treatment of osteoporotic vertebral body fractures.

CONCLUSION

It is reasonable to evaluate instability with imaging repeatedly, at regular intervals, over a period of six months. There is still a lack of reliable data on the optimal intensity and duration of physiotherapy, and on the use of orthoses.

Update on vertebral fractures in pituitary diseases: from research to clinical practice

Derangement of pituitary hormone axes can induce changes in bone remodeling and metabolism with possible alterations in bone microarchitectural structure and increased susceptibility to fractures. Vertebral fractures (VFs), which are a hallmark of skeletal fragility, have been described in a very large number of patients with pituitary diseases. These fractures are clinically relevant, since they predispose to further fractures and may negatively impact on patients' quality of life. However, the management of skeletal fragility and VFs in the specific setting of pituitary diseases is a challenge, since the awareness for this disease is still low, prediction of VFs is uncertain, the diagnosis of VFs cannot be solely based on a clinical approach and also needs a radiological and morphometric approach, the risk of fractures may not be decreased via treatment of pituitary hormone disorders, and the effectiveness of bone-active drugs in this setting is not always evidence-based. This review is an update on skeletal fragility in patients with pituitary diseases, with a focus on clinical and therapeutic aspects concerning the management of VFs.

Prevalence and Characteristics of Spinal Sagittal Malalignment in Patients with Osteoporosis

Spinal sagittal malalignment due to vertebral fractures (VFs) induces low back pain (LBP) in patients with osteoporosis. This study aimed to elucidate spinal sagittal malalignment prevalence based on VF number and patient characteristics in individuals with osteoporosis and spinal sagittal malalignment. Spinal sagittal alignment, and VF number were measured in 259 patients with osteoporosis. Spinal sagittal malalignment was defined according to the SRS-Schwab classification of adult spinal deformity. Spinal sagittal malalignment prevalence was evaluated based on VF number. In patients without VFs, bone mineral density, bone turnover markers, LBP scores and health-related quality of life (HRQoL) scores of normal and sagittal malalignment groups were compared. In 205 of the 259 (79.2%) patients, spinal sagittal malalignment was detected. Sagittal malalignment prevalence in patients with 0, 1, or ≥2 VFs was 72.1%, 86.0%, and 86.3%, respectively. All LBP scores and some subscale of HRQoL scores in patients without VFs were significantly worse for the sagittal malalignment group than the normal alignment group (p < 0.05). The majority of patients with osteoporosis had spinal sagittal malalignment, including ≥70% of patients without VFs. Patients with spinal sagittal malalignment reported worse LBP and HRQoL. These findings suggest that spinal sagittal malalignment is a risk factor for LBP and poor HRQoL in patients with osteoporosis.

Predictors of residual low back pain after acute osteoporotic compression fracture

BACKGROUND

Studies on the clinical and radiographic risk factors for the residual low back pain beyond 6 months after osteoporotic vertebral fractures (OVFs) are lacking. Hence, this study aimed to characterize a patient population with residual low back pain 48 weeks after acute OVFs and to identify the risk factors associated with residual low back pain.

METHODS

This prospective multicenter study included 166 female patients aged 65-85 years with acute one-level OVFs. We defined the residual low back pain as visual analog scale (VAS) for low back pain ≥3.5 at 48 weeks in this study, as VAS score ≥3.5 is used to describe moderate or severe pain. Thus, outcome and risk factor analyses were performed by comparing patients with VAS scores <3.5 and ≥ 3.5. In the radiographic analysis, the anterior vertebral body compression percentage was measured at 0, 12, and 48 weeks. Magnetic resonance imaging (MRI) was performed at enrollment and 48 weeks.

RESULTS

Of the 166 patients analyzed, 58 complained of residual low back pain at 48 weeks after OVFs. At 0 weeks, the VAS score was significantly higher, and the JOABPEQ mental health score and anterior vertebral body compression percentage were significantly lower in patients with persistent pain 48 weeks after OVFs. The independent risk factors in the acute phase for persistent pain 48 weeks after OVFs were a high VAS score, MRI T2 fluid-intensity image pattern, and a lower anterior vertebral body compression percentage.

CONCLUSIONS

Severe low back pain, MRI T2 fluid-intensity image pattern, and severe vertebral body collapse in the acute phase were significant risk factors for residual low back pain 48 weeks after OVFs. Patients with acute OVFs who have these risk factors should be carefully monitored for the possible development of residual chronic low back pain.

Vertebral fracture: epidemiology, impact and use of DXA vertebral fracture assessment in fracture liaison services

Vertebral fractures are independent risk factors for vertebral and nonvertebral fractures. Since vertebral fractures are often missed, the relatively new introduction of vertebral fracture assessment (VFA) for imaging of the lateral spine during DXA-measurement of the spine and hips may contribute to detect vertebral fractures. We advocate performing a VFA in all patients with a recent fracture visiting a fracture liaison service (FLS). Fracture liaison services (FLS) are important service models for delivering secondary fracture prevention for older adults presenting with a fragility fracture. While commonly age, clinical risk factors (including fracture site and number of prior fracture) and BMD play a crucial role in determining fracture risk and indications for treatment with antiosteoporosis medications, prevalent vertebral fractures usually remain undetected. However, vertebral fractures are important independent risk factors for future vertebral and nonvertebral fractures. A development of the DXA technology, vertebral fracture assessment (VFA), allows for assessment of the lateral spine during the regular DXA bone mineral density measurement of the lumbar spine and hips. Recent approaches to the stratification of antiosteoporosis medication type according to baseline fracture risk, and differences by age in the indication for treatment by prior fracture mean that additional information from VFA may influence initiation and type of treatment. Furthermore, knowledge of baseline vertebral fractures allows reliable definition of incident vertebral fracture events during treatment, which may modify the approach to therapy. In this manuscript, we will discuss the epidemiology and clinical significance of vertebral fractures, the different methods of detecting vertebral fractures, and the rationale for, and implications of, use of VFA routinely in FLS. • Vertebral fracture assessment is a tool available on modern DXA instruments and has proven ability to detect vertebral fractures, the majority of which occur without a fall and without the signs and symptoms of an acute fracture. • Most osteoporosis guidelines internationally suggest that treatment with antiosteoporosis medications should be considered for older individuals (e.g., 65 years +) with a recent low trauma fracture without the need for DXA. • Younger individuals postfracture may be risk-assessed on the basis of FRAX® probability including DXA and associated treatment thresholds. • Future fracture risk is markedly influenced by both site, number, severity, and recency of prior fracture; awareness of baseline vertebral fractures facilitates definition of true incident vertebral fracture events occurring during antiosteoporosis treatment. • Detection of previously clinically silent vertebral fractures, defining site of prior fracture, might alter treatment decisions in younger or older FLS patients, consistent with recent IOF-ESCEO guidance on baseline-risk-stratified therapy, and provides a reliable baseline from which to define new, potentially therapy-altering, vertebral fracture events.

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.

Treatment of osteoporotic vertebral fractures

Osteoporosis is a public health problem that is contributing to an increasing number of osteoporotic vertebral fractures. The aim of this lecture is to summarize the current state of knowledge about osteoporotic fractures by answering five questions. 1/How does the spine typically age and how is osteoporosis diagnosed? Various normal aging processes will gradually modify the vertebral column (static, dynamic, bone quality). Osteoporosis is diagnosed through a DEXA scan. 2/How is an osteoporotic fracture evaluated clinically and radiologically? Magnetic resonance imaging is the preferred modality for making the diagnosis and selecting the most appropriate treatment. 3/What are the treatment options for an osteoporotic fracture? The options are conservative treatment, conventional surgery, and minimally invasive techniques (cementoplasty, percutaneous instrumentation). 4/Which fractures should be treated, and which technique should be used? The choice is clear when neurological deficits are present, although the indications are less firm when there is no deficit. The treatment can be conservative (back brace) if the fracture is non-displaced and minimally painful, vertebroplasty if the fracture is painful and shows hyperintensity on T2-STIR sequences, vertebral expansion if the radiological deformity worsens along with symptoms. 5/What are the technical challenges and complications related to the presence of osteoporosis when treating vertebral fractures surgically? The reduced bone stock increases the risk of poor implant hold and postoperative mechanical complications (adjacent fracture, junctional kyphosis). Technical solutions have been developed (augmented screw fixation, transitional zone) to limit their impact. It is essential to know and master these techniques, and their indications. Treatment of the osteoporosis itself is crucial. Level of evidence V; Expert opinion.