Magnetic resonance tomography for the early detection of occult fractures of the spinal column in patients with ankylosing spondylitis

Rigid spine injuries - A comprehensive review on diagnostic and therapeutic challenges

Injuries to the rigid spine have a distinguished position in the broad spectrum of spinal injuries due to altered biomechanical properties. The rigid spine is more prone to fractures. Two ossification bone disorders that are of particular interest are Ankylosing Spondylitis (AS) and Diffuse Idiopathic Skeletal Hyperostosis (DISH). DISH is a non-inflammatory condition that leads to an anterolateral ossification of the spine. AS on the other hand is a chronic inflammatory disease that leads to cortical bone erosions and spinal ossifications. Both diseases gradually induce stiffening of the spine. The prevalence of DISH is age-related and is therefore higher in the older population. Although the prevalence of AS is not age-related the occurrence of spinal ossification is higher with increasing age. This association with age and the aging demographics in industrialized nations illustrate the need for medical professionals to be adequately informed and prepared. The aim of this narrating review is to give an overview on the diagnostic and therapeutic measures of the ankylosed spine. Because of highly unstable fracture configurations, injuries to the rigid spine are highly susceptible to neurological deficits. Diagnosing a fracture of the ankylosed spine on plain radiographs can be challenging. Moreover, since 8% of patients with ankylosing spine disorders (ASD) have multiple non-contagious fractures, a CT scan of the entire spine is highly recommended as the primary diagnostic tool. There are no consensus-based guidelines for the treatment of spinal fractures in ASD. The presence of neurological deficit or unstable fractures are absolute indications for surgical intervention. If conservative therapy is chosen, patients should be monitored closely to ensure that secondary neurologic deterioration does not occur. For the fractures that have to be treated surgically, stabilization of at least three segments above and below the fracture zone is recommended. These fractures mostly are treated via the posterior approach. Patients with AS or DISH share a significant risk for complications after a traumatic spine injury. The most frequent complications for patients with thoracolumbar burst fractures are respiratory failure, pseudoarthrosis, pneumonia, and implant failure.

The value of radiomics-based CT combined with machine learning in the diagnosis of occult vertebral fractures

PURPOSE

To develop and evaluate the performance of radiomics-based computed tomography (CT) combined with machine learning algorithms in detecting occult vertebral fractures (OVFs).

MATERIALS AND METHODS

128 vertebrae including 64 with OVF confirmed by magnetic resonance imaging and 64 corresponding control vertebrae from 57 patients who underwent chest/abdominal CT scans, were included. The CT radiomics features on mid-axial and mid-sagittal plane of each vertebra were extracted. The fractured and normal vertebrae were randomly divided into training set and validation set at a ratio of 8:2. Pearson correlation analyses and least absolute shrinkage and selection operator were used for selecting sagittal and axial features, respectively. Three machine-learning algorithms were used to construct the radiomics models based on the residual features. Receiver operating characteristic (ROC) analysis was used to verify the performance of model.

RESULTS

For mid-axial CT imaging, 6 radiomics parameters were obtained and used for building the models. The logistic regression (LR) algorithm showed the best performance with area under the ROC curves (AUC) of training and validation sets of 0.682 and 0.775. For mid-sagittal CT imaging, 5 parameters were selected, and LR algorithms showed the best performance with AUC of training and validation sets of 0.832 and 0.882. The LR model based on sagittal CT yielded the best performance, with an accuracy of 0.846, sensitivity of 0.846, and specificity of 0.846.

CONCLUSION

Machine learning based on CT radiomics features allows for the detection of OVFs, especially the LR model based on the radiomics of sagittal imaging, which indicates it is promising to further combine with deep learning to achieve automatic recognition of OVFs to reduce the associated secondary injury.

Cervical spine fractures in ankylosing spondylitis patients: an analysis of the presentation and clinical results of 110 surgically managed patients in two spine centers

PURPOSE

In this work, a two-center study was performed to study the clinical presentation of cervical spine fractures in ankylosing spondylitis (AS) patients and assess the surgical management of these fractures.

METHODS

A retrospective analysis of prospectively collected data in two level-1 spine surgery centers was performed. Both spine centers have a standard database for all admitted patients. Inclusion criteria were surgically treated AS with cervical spine fracture diagnosis (from C1 to Th3) and postoperative follow-up minimum of 12 months.

RESULTS

One hundred ten patients (105 male/5 female) were included. The mean age was 62 ± 10 years. The mean time between trauma and surgery was 49 ± 42 days. There was a history of mild trauma in 72 patients (65.4%). The clinical presentation was a pain in all patients. Twenty-seven (24.6%) had a neurological deficit at admission. The most common fracture level was C6/7 in 63 patients (57.23%). The VAS was 7 ± 1, and NDI was 34 ± 8 in the preoperative assessment. The mean preoperative kyphosis angle was 48 ± 26° between C2 and C7. Positioning and preparing of the patients on the operation table took a mean of 57 ± 28 min. The surgical approach was dorsal in 59 patients (53.6%), combined in 45 patients (40.9%), and ventral in 6 patients (6,5%). The mean number of the fixed levels was 6 ± 2 levels. Intraoperative complications occurred in 9 patients (8.2%). Postoperative Cobb angle improved to a mean of 17 ± 9 degrees. Neurological improvement occurred in 20/27 patients. In 12 patients, the recovery was complete. The mean postoperative follow-up was 46 ± 18 months. VAS improved to 3 ± 1, and NDI improved to 14 ± 6 at the last postoperative visit. The improvement was clinically significant (p = 0.01 and 0.00, respectively).

CONCLUSION

High suspicion of cervical spine fractures is necessary for patients with AS. CT and MRI images are necessary to rule out cervical spine fractures in AS patients, especially to detect occult fractures. Surgical treatment is safe, and the posterior approach with long-segment fusion is the approach of choice in this group of patients.

Cervical Spine Fracture Prediction by Simple Plain X-Ray in Ankylosing Spondylitis Patients after Low-Energy Trauma

Objective

Timely diagnosis is essential in the management of cervical spine fracture (CSF) in ankylosing spondylitis (AS) patients. However, the value of simple plain X‐ray in the early management of ASCSF has not been well‐studied. This study aimed to explore the prediction ability of simple plain X‐ray for CSF in AS patients who suffer from low‐energy trauma (LET).

Methods

From January 2010 to December 2020, AS patients who experienced LET were retrospectively reviewed. Clinical data including gender, age, body mass index, time interval between AS diagnosis and trauma, smoking or not, and a presence of continuous bony bridge between anterior margin of C1 and C2 body or not were collected. Morphological features including atlanto‐occipital gap, Pavlov ratio of C2–7, Angle A–D, Borden's index, and Harrison's value were measured by the lateral cervical X‐ray. All data was compared between patients who had CSF and those who did not. Binary logistic regression analysis and receiver operator characteristic (ROC) curves were applied to discriminate and assess the predictive parameters.

Results

A total of 129 AS patients were divided into Fracture group (41 cases) and Non‐fracture group (88 cases) based on whether CSF existed. Twelve parameters showed significant differences between two groups (p < 0.05). According to the binary logistic regression model, four of the 12 parameters showed a further correlation with the occurrence of CSF, namely, mean Pavlov ratio (p < 0.001, OR = 0.067, 95% CI: 0.023 to 0.194), Angle D (p = 0.031, OR = 1.057, 95% CI: 1.005 to 1.112), Borden's index (p = 0.042, OR = 1.131, 95% CI: 0.994 to 1.287), the time interval between the AS diagnosis and the trauma (p < 0.020, OR = 0.935, 95% CI: 0.883 to 0.990). The ROC curve further revealed the mean Pavlov ratio had the largest AUC (0.793) with the cut‐off of 0.72. While the optimal cut‐off value was 45.65° for Angle D (sensitivity = 61.0%, specificity = 78.4%), 9.79 for Borden's index (sensitivity = 87.8%, specificity = 37.5%), 15.50 years for the time interval between AS diagnosis and trauma (sensitivity = 70.7%, specificity = 56.8%).

Conclusions

The time interval between the AS diagnosis and the trauma, mean Pavlov ratio, Angle D, and Borden's index showed predictive ability for the occurrence of CSF in AS patients who encounter LET. Surgeons should consider measuring these parameters in the management of AS patient.

Restricted cement augmentation in unstable geriatric midthoracic fractures treated by long-segmental posterior stabilization leads to a comparable construct stability

The goal of this study is to compare the construct stability of long segmental dorsal stabilization in unstable midthoracic osteoporotic fractures with complete pedicle screw cement augmentation (ComPSCA) versus restricted pedicle screw cement augmentation (ResPSCA) of the most cranial and caudal pedicle screws under cyclic loading. Twelve fresh frozen human cadaveric specimens (Th4–Th10) from individuals aged 65 years and older were tested in a biomechanical cadaver study. All specimens received a DEXA scan and computer tomography (CT) scan prior to testing. All specimens were matched into pairs. These pairs were randomized into the ComPSCA group and ResPSCA group. An unstable Th7 fracture was simulated. Periodic bending in flexion direction with a torque of 2.5 Nm and 25,000 cycles was applied. Markers were applied to the vertebral bodies to measure segmental movement. After testing, a CT scan of all specimens was performed. The mean age of the specimens was 87.8 years (range 74–101). The mean T-score was − 3.6 (range − 1.2 to − 5.3). Implant failure was visible in three specimens, two of the ComPSCA group and one of the ResPSCA group, affecting only one pedicle screw in each case. Slightly higher segmental movement could be evaluated in these three specimens. No further statistically significant differences were observed between the study groups. The construct stability under cyclic loading in flexion direction of long segmental posterior stabilization of an unstable osteoporotic midthoracic fracture using ResPSCA seems to be comparable to ComPSCA.

Imaging update in spondyloarthropathy

Although our understanding of axial spondyloarthropathy (axSpA) has increased recently, there has not been a concurrent improvement in patient diagnosis with delays contributing to patient morbidity. Imaging findings of axSpA can be subtle and may be dismissed often due to lack of understanding by reporters and importantly clinicians who do not suspect the disease. Recognition of the importance of imaging has led to the inclusion of MRI as part of the diagnostic criteria for axSpA. With this in mind, a number of advancements have been made in an attempt to increase our diagnostic accuracy on imaging. This article will give an overview of these techniques as well as a recap of the imaging features of axSpA.

Whole-Spine Magnetic Resonance Imaging: A Review of Suggested Indications

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The spinal column has a propensity for lesions to manifest in a multifocal manner, and identification of the lesions can be difficult.

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When used to image the spine, magnetic resonance imaging (MRI) most accurately identifies the presence and location of lesions, guiding the treatment plan and preventing potentially devastating complications that are known to be associated with unidentified lesions.

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Certain conditions clearly warrant evaluation with whole-spine MRI, whereas the use of whole-spine MRI with other conditions is more controversial.

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We suggest whole-spine MRI when evaluating and treating any spinal infection, lumbar stenosis with upper motor neuron signs, ankylosing disorders of the spine with concern for fracture, congenital scoliosis undergoing surgical correction, and metastatic spinal tumors.

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Use of whole-spine MRI in patients with idiopathic scoliosis and acute spinal trauma remains controversial.

Atraumatic thoracic spinal fracture mimicking herpes zoster neuralgia: a case report

Background

Intercostal neuralgia is most common in patients with herpes zoster, but it might be the initial symptom of serious diseases, such as atraumatic spinal fracture, which may lead to serious consequences if not diagnosed and treated early. Severe intercostal neuralgia is rarely reported as the first symptom of ankylosing spondylitis with atraumatic vertebral fractures.

Case presentation

A 70-year-old Chinese Han man previously diagnosed with ankylosing spondylitis presented to the hospital with intense intercostal pain without trauma. The patient was initially suspected of having herpes zoster neuralgia; however, he subsequently experienced numbness and weakness of both lower limbs as well as constipation. Thoracic vertebral fracture and compression of the spinal cord were detected with magnetic resonance imaging, and he underwent emergency posterior thoracic spinal canal decompression, and intercostal neuralgia was relieved after surgery. Spinal tuberculosis and tumors were later excluded by pathological examination and follow-up results. A 6-month postoperative follow-up showed that the weakness and numbness of the left lower limb had significantly improved, and his urinary function had recovered.

Conclusions

Patients with ankylosing spondylitis could develop atraumatic spinal fractures. Severe intercostal neuralgia is an early indicator of spinal fractures, and spinal magnetic resonance imaging is crucial for the diagnosis.