Prevalence of Diffuse Idiopathic Skeletal Hyperostosis Diagnosed by Whole Spine Computed Tomography: A Preliminary Study

Prevalence and characteristics of osseous bridging between vertebral bodies in the cervical spine: A skeletal study

Osseous bridging (OB) in three or more segments of motions (SOMs) of the mobile spine was initially defined as diffuse idiopathic skeletal hyperostosis (DISH), located particularly in the thoracic spine (T-spine). This pathological phenomenon is often characterized by calcification and ossification, which take place simultaneously or separately. The soft tissues, mainly ligaments and entheses, are calcified, with bone formation not originating from the anterior longitudinal ligament (ALL). DISH formation can involve osteophytes, which are created by the ossification process and can involve soft tissue such as the ALL. The ALL can also be calcified. Until recently, the prevalence of DISH in the general population was considered low (0%-5%) and rare in the cervical spine (C-spine). In a cross-sectional observational skeletal study, we investigated the prevalence and location of C-spine OB between vertebral bodies with fewer than three SOMs. We tested a large sample (n = 2779) of C-spines housed in the Cleveland Museum of Natural History (Ohio, USA). The human sources of the samples had died between the years 1912 and 1938 and represented both sexes and two different ethnic groups: Black Americans and White Americans. The process development can be seen on the ALLs as calcification, osteophytosis, and candle-shaped. Among all of the specimens, 139 (5%) were affected by OB, mostly in one SOM. Prevalence tended to be higher in women, White Americans, and the older age group. The levels most affected were C3-C4, followed by C2-C3 and subsequently, C5-C6. OB involving two consecutive SOMs was found only at C5-C7. We believe it is important to respond to the presence of a single SOM with a presumptive diagnosis of OB and to follow up, identify whether the diagnosis is correct, and take preventive action if possible. There is a need for updated diagnostic criteria and research approaches that reflect contemporary lifestyle factors and their impact on spine health.

Cervical spinal cord injury following osteophyte excision for respiratory distress caused by diffuse idiopathic skeletal hyperostosis associated with ossification of posterior longitudinal ligament: a case report and literature review

BACKGROUND

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic non-inflammatory disorder characterized by enthesopathy and osteophyte formation. DISH can also cause several other symptoms. Limited range of motion (ROM) is the most common symptom; however, dysphagia and respiratory distress are clinically important symptoms. Dysphagia caused by cervical DISH is initially treated conservatively, but surgical treatment is performed when conservative treatment is ineffective. Although there are many reports on the surgical excision of osteophytes for refractory dysphagia, only a few reports on surgery for dysphagia caused by DISH associated with ossification of the posterior longitudinal ligament (OPLL) exist. Here, we report a rare case of cervical spinal cord injury following osteophyte excision for a respiratory distress and dysphagia caused by DISH associated with OPLL.

CASE PRESENTATION

A 76-year-old male with hypertension and diabetes presented with dysphagia, respiratory insufficiency, and palpitations. Four months later, he experienced severe dyspnea and was hospitalized. His vital signs indicated respiratory distress, which led to intubation and tracheotomy due to his worsening condition. Imaging revealed massive anterior cervical osteophytes and multisegmental OPLL that caused spinal canal stenosis and tracheal compression. Surgical excision of the osteophytes was performed, but the patient later developed tetraplegia attributed to C5/C6 instability. Posterior fusion and laminoplasty were performed, resulting in neurological improvement but persistent dysphagia and motor deficits. He was transferred to another hospital for rehabilitation but died of aspiration pneumonia.

CONCLUSIONS

Patients with cervical OPLL and spinal cord compression may experience spinal cord injury when intervertebral mobility is slightly increased due to osteophyte excision. If dysphagia or respiratory distress occur in patients with DISH and OPLL, decompression and fusion surgery at the mobile segment is required, in addition to osteophyte excision surgery. Posterior decompression and fusion surgery should be performed before anterior osteophyte excision surgery to avoid implant infection, particularly in patients with respiratory distress who have undergone tracheostomy. Patients receiving long-term mechanical ventilation are less likely to recover their swallowing function and should undergo a total laryngectomy.

Diffuse Idiopathic Skeletal Hyperostosis Prevalence, Characteristics, and Associated Comorbidities: A Cross-Sectional Study of 1815 Whole Spine CT Scans

STUDY DESIGN

A Retrospective Study.

OBJECTIVE

To determine the prevalence and characteristics of DISH using whole spine CT scans and to evaluate the association of DISH with co-morbidities and other ossified lesions.

METHOD

A retrospective study of whole-spine CT scans of polytrauma patients from 2018-2021 above the age of 20 years. The screening was done using modified Resnick criteria. Overall and age-specific prevalence, characteristics, and associations with obesity, diabetes mellitus (DM), ischemic heart disease (IHD), aortic calcification (AC), ossified posterior longitudinal ligament (OPLL), and ossified ligamentum flavum (OLF) were evaluated.

RESULTS

Out of 1815 patients, 347 had DISH, with a prevalence rate of 19.1% and a mean age of 61.7 years. The highest prevalence of DISH was seen in individuals over 80 years of age (45.5%). The prevalence among males (20.2%) was higher than for females (14.9%). The most commonly involved level was T8-T9 (95.4%), followed by T9-T10 (91.9%), and the most common vertebra involved was T9 (96%). All the cases involving T9 had ossification on the right anterior aspect of the vertebral body. The presence of DM, high BMI, and IHD was found to be significantly higher in patients with DISH (P value < .001). The incidence of aortic calcification was 22.5%, OPLL was 13.3%, and OLF was 4.9% in patients with DISH.

CONCLUSION

This study reports a prevalence rate of 19.1% for DISH, with the highest prevalence among individuals above 80 years of age (45.5%). DISH has a higher propensity to affect the right anterior aspect of the vertebral body in the thoracic spine and is strongly associated with obesity, DM, IHD, and AC.

Prevalence of diffuse idiopathic skeletal hyperostosis (DISH) and early-phase DISH across the lifespan of an American population

OBJECTIVES

DISH is a common musculoskeletal disorder; however, the imaging features and disease continuum from early to advanced stages is poorly understood. The purpose of this study was to evaluate the prevalence of DISH and early-phase DISH in an American population and to assess the extent and pattern of ectopic mineralization across the thoracic spine.

METHODS

Data were retrieved in collaboration with the Rochester Epidemiology Project. We conducted a retrospective image evaluation of a sample of individuals over 19 years of age with CT of the thoracic spine from a Northern US catchment area. Stratified random sampling by age and sex was used to populate the study. We examined the prevalence and extent of ectopic mineralization along the thoracic spine using previously established criteria.

RESULTS

A total of 1536 unique images (766 female and 770 male individuals) including 16 710 motion segments were evaluated for imaging features of the continuum of DISH. Collectively, 40.5% of all motion segments evaluated displayed evidence of ectopic mineralization in the thoracic spine. The prevalence of early-phase DISH was 13.2% (10.4% of female and 15.8% of male individuals). The prevalence of established DISH was 14.2% (7.4% of female and 20.9% of male individuals). Remarkable heterogeneity was detected in individuals within each disease classification, based on the extent of the thoracic spine affected and degree of mineralization.

CONCLUSIONS

The continuum of imaging features associated with DISH is detected in more than one in four adults and both sexes in an American population.

High prevalence of diffuse idiopathic skeletal hyperostosis (DISH) among obese young patients - A retrospective observational study

OBJECTIVE

Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by ossification of ligaments and entheses, and most commonly affects the spinal column. The prevalence of DISH is increasing with age and is considered uncommon before the age of 50 years, with an estimated prevalence of less than 5 %. DISH is known to be highly associated with metabolic syndrome and obesity. We aim to assess the prevalence of DISH among young (≤50 yr.) patients suffering from severe obesity (BMI of 35 kg/m2 or higher).

METHODS

A retrospective analysis assessing chest and spine radiographs (including Computed Tomography, CT) of patients with BMI≥35 visiting the bariatric ambulatory clinic in an academic medical center from 2013 to 2022. Patients included in the analysis were 31-50 years old. Diagnosis of DISH was made according to the Resnick criteria. The prevalence of DISH was calculated. Demographic, clinical and laboratory data were collected and compared between the DISH and non-DISH groups.

RESULTS

183 young (mean age: 40.4; 118 females, 64.2 %) obese (BMI median: 40.6; range 35-73) patients were included in the radiographic review. DISH was diagnosed in 33 patients (18.0 %; 95 % CI: 13.1-24.2 %) which was significantly higher than the expected 10 % (Z = 3.62, p<.001); another 8 patients (4.4 %; 95 % CI: 2.2-8.4 %) were considered as "near DISH" (not fulfilling yet the Resnick criteria) as it represents a pre-disease state. Patients diagnosed with DISH were significantly older than patients without DISH (t = 4.54, p<.001), as the prevalence of DISH increased by age (linear association=14.95, p<.001). There was a statistically significantly higher prevalence of hypertension (χ2 = 8.30, p<.004), smoking (χ2 = 4.69, p<.03) and OSA (χ2 = 6.16, p<.013) in the DISH group as compared to their non-DISH counterparts.

CONCLUSION

The prevalence of DISH among obese young patients was 18 %, which is much higher than in the general population. Early-onset DISH should be regarded as a musculoskeletal obesity-related complication.

Not All Osteophytes Are Located on the Right Side of the Vertebrae in Diffuse Idiopathic Skeletal Hyperostosis: A Quantitative Analysis in Relation to the Position of Aorta

OBJECTIVE

Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by osteophytes in the anterior vertebrae, and the presence of aorta may have an impact on their formation. However, the anatomical positional relationship between the aorta and osteophytes in patients with DISH remains controversial. This study aimed to evaluate the position of osteophytes in relation to aorta in DISH, and the influence of aortic pulsation on the formation of osteophytes from the perspective of morphology.

METHODS

We conducted a retrospective review of 101 patients diagnosed with DISH and symptomatic lumbar spinal stenosis between June 2018 and December 2021. A total of 637 segments with heterotopic ossification in DISH were used for quantitative measurements on CT scans. The Cartesian coordinate system was built up on the axial CT scans to reflect the relative position between aorta and osteophytes. Osteophytes were divided into adjacent aorta group (AD group) and non-adjacent aorta group (N-AD group). In terms of the morphology, osteophytes in the AD group were further divided into convex, flat, and concave types. The relative position between aorta and osteophytes, and the aorta-osteophyte distance and morphology of osteophytes were compared. Univariate analysis of variance was performed for multiple groups, and two independent-samples t-tests were used for two groups.

RESULTS

From T5 to L4, aorta gradually descended from left side to middle of vertebrae, and osteophytes gradually shifted from right side of vertebrae (T5-T10) to bilateral sides (T11-L4). Of 637 osteophytes in DISH, 60.1% (383/637) were in AD group, including convex type 0.6% (4/637), flat type 34.7% (221/637), and concave type 24.8% (158/637). The N-AD group accounted for 39.9% (254/637). Flat osteophytes were concentrated in T5-T12, while concave osteophytes in T11-L4. Overall, the aorta-osteophyte distance of concave type was significantly smaller than that of flat type.

CONCLUSION

Osteophytes are not always located on the right side of vertebrae, but move with the position of the descending aorta. Furthermore, the morphology of osteophytes varies by vertebral segment in DISH, which is related to aorta descending anteriorly in the spine.

Radiological Assessment of Morphological Changes of Lumbar Spine: From First to 9th Decade of Life

STUDY DESIGN

Analysis of lumbar spine radiograms of 1,496 Jeju islanders of Korea.

PURPOSE

To look into the age- and gender-matched incidences of morphological changes and their severities.

OVERVIEW OF LITERATURE

There have been several prior research on the prevalence and severity of age-related diseases, both related and unrelated. Those offer some fundamental clinical data for clinicians.

METHODS

Radiograms of 1,496 patients (555 males and 941 females) from the first to 9th decade were examined for this study. Sagittal and coronal alignment, disc space narrowing, spur formation including diffuse idiopathic spinal hyperostosis (DISH), spondylolisthesis, and ballooned discs associated with biconcave bodies due to osteoporosis were among the parameters of lumbar spine morphologies examined on high-quality radiographs by both human observers and computers.

RESULTS

The alignment of the lumbar spine altered after birth and set at growth maturity, and then the curve was maintained till the end of the 5th decade afterward and the curve gradually hypolordotic. There were three types of coronal alignment abnormalities can be seen: idiopathic, osteopathic, and discogenic (degenerative lumbar scoliosis [DLS]). DLS developed after 6th decade. There was no scoliosis associated with spondylolysis or the post-laminofacetectomy period. Disc space narrowing and corporal spur formation were not seen till the end of 3rd decade comparatively speaking, the corporal spurs generated in the non-scoliotic spine were smaller than those in the scoliotic spine. DISH began to appear in the 5th-decade patients and its incidences increased gradually afterward. Porosis-related vertebral body collapse started to happen after 6th decade. There are three different types of spondylolisthesis: anterior, posterior, and lateral. The lateral slip occurred only in the scoliotic spine. All types were related to degenerative discs.

CONCLUSIONS

It has been shown that the morphology of the lumbar spine changes throughout time.

Thoracic spondylotic myelopathy in diffuse idiopathic skeletal hyperostosis: a comparative study

BACKGROUND

To explore the characteristics and clinical management of thoracic spinal stenosis with diffuse idiopathic skeletal hyperostosis (DISH).

METHODS

The patients diagnosed with thoracic spondylotic myelopathy who underwent spinal decompression and fusion surgery in a single center between 2012 and 2020 were retrospectively analyzed. All the patients were followed up for at least 2 years. Patients were classified into DISH and non-DISH groups. Demographic, radiographic and clinical parameters were compared between the two groups.

RESULTS

A total of 100 thoracic spondylotic myelopathy patients were included in the study. 22 patients were diagnosed with DISH. The proportion of male patients in the DISH group was higher, and the average BMI was larger. The incidence of upper thoracic vertebrae with ossification of posterior longitudinal ligament (OPLL) (P < 0.05) and lumbar spine with ossification of ligamentum flavum (OLF) was higher (P < 0.05) in DISH the group. The proportion of patients received staged surgery is higher in the DISH group (P < 0.1). There were no significant differences between the two groups in the amount of surgical bleeding, the ratio of cerebrospinal fluid leakage, the time duration of drainage tube placement and the JOA scores.

CONCLUSION

Thoracic spinal stenosis with DISH occurred more in male patients with larger BMI. The posterior decompression and fusion surgery could achieve comparable satisfying clinical outcomes between DISH and non-DISH patients. More proportion of patients received staged surgery in the DISH group; the underline mechanism may be DISH caused more OPLL in the upper thoracic spine and more OLF in the lumbar spine because of mechanical stress.

Diffuse Idiopathic Skeletal Hyperostosis (DISH): New evidence from micro-XCT scanning

OBJECTIVE

To observe and describe the development and underlying structure of the spinal manifestations of individuals osteologically diagnosed with DISH (Diffuse Idiopathic Skeletal Hyperostosis), using micro-XCT imaging.

MATERIALS

A total of 72 individuals with DISH were identified in two modern skeletal collections in South Africa.

METHODS

Vertebral columns affected by DISH were scanned at the micro-focus x-ray computed tomography facility at the Nuclear Energy Corporation of South Africa. Four features were macroscopically examined: (1) the origin of the new bone growth; (2) retention of the original vertebral cortex at the site of the new bone formation associated with DISH; (3) evidence of trabecular bone with or without sclerosis on the anterolateral surface of affected vertebrae; and (4) abnormal areas of osteosclerosis beyond features associated with DISH.

RESULTS

Considerable variation across and between the four recorded features was found. Of note, 81% (n = 58) of individuals had both developed trabecular bone within the flowing new bone formation (feature 3), without retention of the original vertebral cortex (feature 2).

CONCLUSIONS

Possible localised erosive/inflammatory processes destroyed the original cortex of the vertebral body and resulted in the expansion of trabeculae with new bone formation.

SIGNIFICANCE

Micro-XCT imaging shed new light on the development of DISH, adding to literature suggesting that it could be an inflammatory disease.

LIMITATIONS

Clinical histories of the individuals were not known.

SUGGESTIONS FOR FURTHER RESEARCH

The role of chronic inflammatory disease in the development of DISH should be further explored including both the extra-spinal and spinal manifestations.

Imaging Characteristics of Diffuse Idiopathic Skeletal Hyperostosis: More Than Just Spinal Bony Bridges

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic condition characterized by new bone formation and enthesopathies of the axial and peripheral skeleton. The pathogenesis of DISH is not well understood, and it is currently considered a non-inflammatory condition with an underlying metabolic derangement. Currently, DISH diagnosis relies on the Resnick and Niwayama criteria, which encompass end-stage disease with an already ankylotic spine. Imaging characterization of the axial and peripheral skeleton in DISH subjects may potentially help identify earlier diagnostic criteria and provide further data for deciphering the general pathogenesis of DISH and new bone formation. In the current review, we aim to summarize and characterize axial and peripheral imaging findings of the skeleton related to DISH, along with their clinical and pathogenetic relevance.

Comparison of radiological characteristics between diffuse idiopathic skeletal hyperostosis and ankylosing spondylitis: a multicenter study

To evaluate the radiological differences between diffuse idiopathic skeletal hyperostosis (DISH) and ankylosing spondylitis (AS) using whole spine computed tomography (CT), including the spine and sacroiliac joint (SIJ). The ossification and bridging of spinal ligament and fusion of the facet joint and SIJ were evaluated in 111 patients who were diagnosed with DISH and 27 patients with AS on the whole spine CT. The number of anterior bridging and shape of bridging (candle-wax-type/ smooth-type) were also evaluated. We further evaluated patients with DISH and AS by matching their age and sex. Complete SIJ fusion was more common in AS, whereas anterior and posterior bony bridging around SIJ was more common in DISH. However, 63% of patients with DISH had a partial or complete fusion. In spinal anterior bony bridging, the majority of patients with AS had the smooth-type, whereas those with DISH had the candle-wax-type. However, some of the patients with DISH (11%) had smooth-type. Intervertebral facet joint fusion is more common in AS. The number of anterior spinal bony bridging was greater in AS than in DISH, especially in the lumbar spine. These results are useful in differentiating DISH from AS and should therefore be considered when making a diagnosis.

Prevalence and characteristics of diffuse idiopathic skeletal hyperostosis (DISH) in Italy

Purpose

Diffuse idiopathic skeletal hyperostosis (DISH) is a benign condition characterized by ossification of the spine and prominent enthesopathies. Highly heterogeneous epidemiological figures have been reported in the literature, while in Italy the largest study has been conducted in 1992. The aim of our research is to contribute updated information about prevalence of DISH in Italy and to describe the clinical and radiographic characteristics associated with the disorder.

Material and methods

A retrospective review of lumbosacral spine, thoracic spine and pelvis radiographs was performed. Consecutive patients visiting the emergency department of our Institution over 3 years were enrolled. Presence of DISH was evaluated applying the Resnick and Niwayama criteria. Clinical and radiological features were also assessed.

Results

We included 1012 individuals (60.6% women), and DISH was present in 130 cases. The overall prevalence of DISH was 12.8% (95% CI 10.8–15.1), with higher figures in the male sample (16.8%) than in females (10.3%). In binary logistic regression adjusted for age, BMI (OR 1.50, p < 0.001) diabetes (OR 1.85, p = 0.003), hypertension (OR 2.04, p = 0.007) ischiopubic enthesopathy (OR 7.08, p < 0.001), iliac crest enthesopathy (OR 4.63, p < 0.001) and greater trochanter enthesopathy (OR 3.51, p < 0.001), were significantly associated with the condition.

Conclusion

The prevalence of DISH observed in our study is consistent with previous literature, and we confirm that the disorder is more frequently retrieved in men and that it is associated with the presence of metabolic disorders and pelvic enthesopathy. Knowledge about the epidemiology and characteristics of DISH is needed to properly identify the condition.

Ossification of the Posterior Longitudinal Ligament: Pathophysiology, Diagnosis, and Management

Ossification of the posterior longitudinal ligament (OPLL) occurs as heterotopic bone forms in the posterior longitudinal ligament, resulting in neural compression, myelopathy, and radiculopathy. OPLL is most commonly observed in East Asian populations, with prevalence rates of 1.9% to 4.3% reported in Japan. OPLL rates are lower in North American and European patients, with reported prevalence of 0.1% to 1.7%. Patients typically develop symptoms due to OPLL in their cervical spines. The etiology of OPLL is multifactorial, including genetic, metabolic, and anatomic factors. Asymptomatic or symptomatic patients with OPLL can be managed nonsurgically, whereas patients with neurologic symptoms may require surgical decompression from an anterior, posterior, or combined approach. Surgical treatment can provide notable improvement in neurologic function. Surgical decision making accounts for multiple factors, including patient comorbidities, neurologic status, disease morphology, radiographic findings, and procedure complication profiles. In this study, we review OPLL epidemiology and pathophysiology, clinical features, radiographic evaluation, management, and complications.

Prognostic models for the development of diffuse idiopathic skeletal hyperostosis

INTRODUCTION

Diffuse idiopathic skeletal hyperostosis (DISH) is a common worldwide disease in adults over 50 years of age. The clinical diagnosis at the beginning of the disease is very difficult, even impossible, without typical symptoms and image changes. Mathematical models for searching risk factors include analysing medical history data, comorbidities, biochemical and instrumental results.

Diffuse Idiopathic Skeletal Hyperostosis of the Spine: Pathophysiology, Diagnosis, and Management

Diffuse idiopathic skeletal hyperostosis (DISH) is an ankylosing condition affecting up to 32.5% of the general cohort. Although often asymptomatic, affected individuals may present with back pain, stiffness, dysphagia, functional decline, and neurologic deficits. Radiographically, DISH is characterized by flowing ossifications along the anterior spine spanning ≥4 vertebral bodies. Although the etiology of DISH remains unknown, diabetes mellitus and other metabolic derangements are strongly associated with DISH. Importantly, spinal ankylosis in DISH predisposes patients to unstable spine fractures from low-energy trauma, and careful consideration must be taken in managing these patients. This article reviews the epidemiology and pathophysiology of DISH, and its clinical findings, diagnostic criteria, and management.

Identifying Clinicoradiological Phenotypes in Diffuse Idiopathic Skeletal Hyperostosis: A Cross-Sectional Study

Background and objectives: Diffuse idiopathic skeletal hyperostosis (DISH) is a bone formation disease in which only skeletal signs are considered in classification criteria. The aim of the study was to describe different phenotypes in DISH patients based on clinicoradiological features. Materials and Methods: We evaluated 97 patients who met the Resnick or modified Utsinger classification criteria for DISH and were diagnosed at our hospital from 2004 to 2015. Patients were stratified into: (a) peripheral pattern (PP)—Resnick criteria not met but presenting ≥3 peripheral enthesopathies; (b) axial pattern (AP)—Resnick criteria met but <3 enthesopathies; and (c) mixed pattern (MP)—Resnick criteria met with ≥3 enthesopathies. Statistical analysis was carried out to identify variables that might predict classification in a given group. Results: Fifty-six of the 97 patients included (57.7%) were male and 72.2% fulfilled the Resnick criteria. Applying our classification, 39.7% were stratified as MP, 30.9% as AP and 29.4% as PP. Clinical enthesopathy was reported in 40.2% of patients during the course of the disease. Sixty-eight patients were included in a comparative analysis of variables between DISH patterns. The results showed a predominance of women (p < 0.004), early onset (p < 0.03), hip involvement (p < 0.003) and enthesitis (p < 0.001) as hallmarks of PP. Asymptomatic patients were most frequently observed in AP (28.6%, MP 3.8%, PP 5.0%) while MP was characterized by a more extensive disease. Conclusions: We believe DISH has distinct phenotypes and describe a PP phenotype that is not usually considered. Extravertebral manifestations should be included in the new classification criteria in order to cover the entire spectrum of the disease.

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.

Axial Spondyloarthritis: Mimics and Pitfalls of Imaging Assessment

Axial spondyloarthritis (axSpA) is a chronic inflammatory disorder that predominantly involves the axial skeleton. Imaging findings of axSpA can be divided into active changes, which include bone marrow edema, synovitis, enthesitis, capsulitis, and intra-articular effusion, and structural changes, which include erosions, sclerosis, bone fatty infiltration, fat deposition in an erosion cavity, and bone bridging or ankylosis. The ability to distinguish between imaging lesions suggestive of axSpA and artifacts or lesions suggestive of other disorders is critical for the accurate diagnosis of axSpA. Diagnosis may be challenging, particularly in early-stage disease and magnetic resonance imaging (MRI) plays a key role in the detection of subtle or inflammatory changes. MRI also allows the detection of structural changes in the subchondral bone marrow that are not visible on conventional radiography and is of prognostic and monitoring value. However, bone structural changes are more accurately depicted using computed tomography. Conventional radiography, on the other hand, has limitations, but it is easily accessible and may provide insight on gross changes as well as rule out other pathological features of the axial skeleton. This review outlines the imaging evaluation of axSpA with a focus on imaging mimics and potential pitfalls when assessing the axial skeleton.

Diffuse idiopathic skeletal hyperostosis in elderly Icelanders and its association with the metabolic syndrome: the AGES-Reykjavik Study

Objective: To describe the prevalence of diffuse idiopathic skeletal hyperostosis (DISH) in a large population-based study of elderly Icelanders, with particular reference to weight-related factors and the metabolic syndrome.Method: The study population comprised 5321 participants aged 68-96 years (2276 males, mean ± sd age 76 ± 5 , and 3045 females, age 77 ± 6) from the AGES-Reykjavik Study. DISH diagnosis was based on computed tomography (CT) scans, and interpreted strictly by the Resnick criteria and additional suggestions for CT interpretation by Oudkerk et al. Radiology readings were taken by a radiology resident and sample readings by two experienced radiologists.Results: A diagnosis of DISH was made in 13.7% of males and 2.8% of females. There was no association with age, but a strong association was seen with the metabolic syndrome [odds ratio (OR) 2.12, 95% confidence interval (CI) 1.69-2.64, p = 3.9 × 10^-11]. Among the components of the metabolic syndrome, the association with DISH was significant for the insulin resistance criterion (OR 1.66, 95% CI 1.32-2.01, p < 0.001) and the body mass index (BMI) criterion (OR 2.16, 95% CI 1.70-2.74, p < 0.001). Other weight-related variables (midlife BMI, weight, and abdominal circumference) showed similar associations.Conclusions: This study, which to our knowledge is the largest published study on the prevalence of DISH, shows an association with the metabolic syndrome, particularly with the insulin resistance and BMI criteria. This is analogous with previous reports linking DISH with metabolic causes. In this age category, we did not observe any increase in prevalence with age.

Bibliometric and Visualized Analysis of Scientific Publications on Ossification of the Posterior Longitudinal Ligament Based on Web of Science

BACKGROUND

In recent years, there has been increasing study of ossification of the posterior longitudinal ligament (OPLL), leading to many articles on this topic. We aimed to identify trends in OPLL-related research and to analyze the most highly cited scientific articles on OPLL.

METHODS

We searched the Web of Science Core Collection database for all articles on OPLL. The years of publication, countries, journals, institutions, and total citations were extracted and analyzed. Results related to countries, institutions, and keywords were subjected to co-occurrence analysis using VOSviewer software. The top 100 most-cited articles on OPLL were analyzed.

RESULTS

A total of 876 articles related to OPLL were identified. The frequency of publication on OPLL has increased substantially over time. Among all countries, Japan has contributed the most articles on OPLL (n = 349). The most productive institution has been Hirosaki University (n = 57). Spine topped the list of journals and has published 120 OPLL-related articles, which received 4221 total citations. The surgical treatment of OPLL has been the most common research focus in the OPLL literature.

CONCLUSIONS

The scientific literature on OPLL has rapidly expanded in recent years. This study represents the first bibliometric analysis of scientific articles on OPLL and can serve as a useful guide to clinicians and researchers in the field.

An Analysis of Patient and Fracture Characteristics and Clinical Outcomes in Patients With Hyperostotic Spine Fractures

STUDY DESIGN

Retrospective study.

OBJECTIVE

To evaluate outcomes and complications following operative and nonoperative management of hyperostotic spine fractures.

METHODS

Patients presenting between 2008 and 2017 to a single level 1 trauma center with hyperostotic spine fractures had their information and fracture characteristics reviewed. Bivariate analyses were conducted to compare patients across a number of characteristics and outcomes. Multivariate logistic regression models for complication and mortality were done in a stepwise fashion.

RESULTS

Sixty-five ankylosing spondylitis (AS) or diffuse idiopathic skeletal hyperostosis (DISH) patients with a spine fracture met our inclusion criteria. DISH was slightly more prevalent (55% vs 45%). Overall delayed diagnosis, reoperation, mortality (at 1 year), and complication rates were high at 32%, 13%, 23%, and 57%, respectively. In multivariate logistic regression models, patients undergoing operative management had significantly increased odds of having a complication (odds ratio [OR] = 23.03, 95% confidence interval [CI] = 2.24-236.45, P = .008), while increasing age was associated with increased odds of death (OR = 1.18, 95% CI = 1.06-1.31, P = .003).

CONCLUSIONS

Patients with AS or DISH who fracture their spine are at high risk of complication and death. However, neither operative nor nonoperative treatment increases the odds of mortality. This study helps add to a growing, but still limited, body of literature on the characteristics of patients with spine fractures in the setting of AS or DISH.

Osteopathic Considerations for Peripheral Neuropathy Due to Concomitant Diffuse Idiopathic Skeletal Hyperostosis Syndrome and Lumbar Epidural Lipomatosis: Case Report

Background

Diffuse idiopathic skeletal hyperostosis (DISH) syndrome and lumbar epidural lipomatosis are relatively asymptomatic neurological conditions, with findings often seen incidentally on radiological studies.

Objective

The aim of this paper is to present unique findings of concomitant, symptomatic DISH syndrome and lumbar epidural lipomatosis and to discuss the osteopathic diagnosis and treatment implications.

Methods

Concomitant, symptomatic variants are rare and present challenges to treatment and management, as seen with a 60-year-old African American woman who presented with worsening disequilibrium and new-onset bilateral fingertip numbness. Past medical history was significant for alcohol abuse disorder, hypertension, hyperlipidemia, and multiple episodes of self-resolving vertigo and lower extremity neuropathy.

Results

The patient was referred to the neurology department for stroke workup, which was negative. Osteopathic structural exam revealed thoracolumbar and sacral dysfunctions. Magnetic resonance imaging revealed findings consistent with thoracic DISH syndrome and lumbar epidural lipomatosis in the areas of somatic dysfunctions.

Conclusions

Due to minimal information on osteopathic manipulative treatment in rare neurological diseases, only gentle techniques of myofascial release, balanced ligamentous tension, and muscle energy were performed with resultant minimal improvement, thus highlighting the necessity for better guidelines and further research.

[Differential diagnosis of axial spondyloarthritis-axSpA mimics]

The classification of axial spondyloarthritis (axSpA) comprises the classical ankylosing spondylitis (AS), which is characterized by already existing structural changes in the sacroiliac joints, and the so-called non-radiographic axSpA (nr-axSpA), in which by definition such changes are not present. This distinction is based on the ASAS classification criteria for axSpA, which are however not suitable for a diagnosis. According to the current classification, spondyloarthritis (SpA) includes axSpA, which can be associated with psoriasis and/or chronic inflammatory bowel diseases (CED), such as Crohn's disease and ulcerative colitis, and peripheral SpA, which is further divided into SpA associated with psoriasis, partially synonymous with psoriatic arthritis (PsA), reactive SpA, partially synonymous with reactive arthritis (ReA) and SpA associated with CED, partially synonymous with arthritis associated with CED (e.g. Crohn's disease, ulcerative colitis) and peripheral undifferentiated SpA, which by definition is not associated with any of the above. In this article only the most important differential diagnoses are discussed, i. e. diffuse idiopathic skeletal hyperostosis (DISH), fractures and infections in the axial skeleton. In addition, the frequency of certain musculoskeletal findings in the normal population examined by magnetic resonance imaging (MRI) are also discussed.

Impact of Diffuse Idiopathic Skeletal Hyperostosis on Sagittal Spinal Alignment in the General Elderly Population: A Japanese Cohort Survey Randomly Sampled from a Basic Resident Registry

Interest is mounting regarding diffuse idiopathic skeletal hyperostosis (DISH) as the rate in the elderly increases. Although some studies have demonstrated an effect of DISH on sagittal spinal alignment, the pathogenetic mechanism remains unknown. Random sampling from the basic resident registry of a rural town for subject selection was used to investigate the impact of DISH on sagittal spinal alignment.

Molecular Pathophysiology of Ossification of the Posterior Longitudinal Ligament (OPLL)

Ossification of the posterior longitudinal ligament (OPLL) can be defined as an ectopic ossification in the tissues of spinal ligament showing a hyperostotic condition. OPLL is developed mostly in the cervical spine and clinical presentations of OPLL are majorly myelopathy and/or radiculopathy, with serious neurological pathology resulting in paralysis of extremities and disturbances of motility lowering the quality of life. OPLL is known to be an idiopathic and multifactorial disease, which genetic factors and non-genetic factors including diet, obesity, physical strain on the posterior longitudinal ligament, age, and diabetes mellitus, are involved into the pathogenesis. Up to now, surgical management by decompressing the spinal cord is regarded as standard treatment for OPLL, although there might be the risk of development of reprogression of ossification. The molecular pathogenesis and efficient therapeutic strategy, especially pharmacotherapy and/or preventive intervention, of OPLL has not been clearly elucidated and suggested. Therefore, in this review, we tried to give an overview to the present research results on OPLL, in order to shed light on the potential pharmacotherapy based on molecular pathophysiologic aspect of OPLL, especially on the genetic/genomic factors involved into the etiology of OPLL.

Dysphagia following lumbar spine surgery in the setting of undiagnosed DISH of the cervical spine: a case report

Dysphagia is an often multifactorial pathology affecting many elderly patients. In addition to global neuromuscular change with normal aging, one component of its etiology may be direct compression of the pharynx or esophagus from overgrown bone from the anterior cervical spine. Diffuse idiopathic skeletal hyperostosis (DISH) is one condition that may contribute to this phenomenon. Of relatively high incidence (2.5% to 33.3%) in elderly populations, DISH has been described in the cervical spine though more frequently affects other spinal regions. The clinical case of an elderly man who developed significant dysphagia after undergoing lumbar spine surgery for spinal stenosis caused by DISH is presented. Awareness of the involvement in his cervical spine before surgery would likely have enabled a more prompt diagnosis of the etiology of dysphagia and allowed for peri-operative optimization of swallowing function to reduce morbidity. We recommend routine preoperative imaging of the cervical spine in all patients with a diagnosis of DISH to stratify risk for development of postoperative dysphagia.

Incidence of diffuse idiopathic skeletal hyperostosis from a model of dysphagia

OBJECTIVE

To relate symptoms of dysphagia to Forestier-Rotes Querol disease or diffuse idiopathic skeletal hyperostosis (DISH), a disorder due to ossification in the anterior longitudinal ligament and calcifications in other entheses.

PATIENTS AND METHODS

Review of clinical and radiological findings in 455 outpatients attended at our Centre with dysphagia, for 5years, referred from dental, trauma, neurological or primary health care. A diagnosis of DISH was established using Resnick's criteria.

RESULTS

We detected 51 cases with dysphagia consistent with DISH diagnostic criteria - 11.2% of subjects suffering this symptom- out of 32544 outpatients attended. An incidence of 7:100000 inhabitants per year was observed. Two cases showed significant improvement after removing the new bone in the spine.

CONCLUSIONS

DISH is an ankylosing ossification between the joints, frequently systemic but showing no clinical symptoms. When symptoms manifest, neck movements and upper airways are involved, mainly dysphagia. A few cases need surgery to relieve the calcification processes.

Injuries to the Rigid Spine: What the Spine Surgeon Wants to Know

The biomechanical stability of the spine is altered in patients with a rigid spine, rendering it vulnerable to fracture even from relatively minor impact. The rigid spine entities are ankylosing spondylitis (AS), diffuse idiopathic skeletal hyperostosis, degenerative spondylosis, and a surgically fused spine. The most common mechanism of injury resulting in fracture is hyperextension, which often leads to unstable injury in patients with a rigid spine per the recent AOSpine classification system. Due to the increased risk of spinal fractures in this population, performing a spine CT is the first step when a patient with a rigid spine presents with new back pain or suspected spinal trauma. In addition, there should be a low threshold for performing a non-contrast-enhanced spine MRI in patients with a rigid spine, especially those with AS who may have an occult fracture, epidural hematoma, or spinal cord injury. Unfortunately, owing to insufficient imaging and an unfamiliarity with fracture patterns in the setting of a rigid spine, fracture diagnosis is often delayed, leading to significant morbidity and even death. The radiologist's role is to recognize the imaging features of a rigid spine, identify any fractures at CT and MRI, and fully characterize the extent of injury. Reasons for surgical intervention include neurologic deficit or concern for deterioration, an unstable fracture, or the presence of an epidural hematoma. By understanding the imaging features of various rigid spine conditions and vigilantly examining images for occult fractures, the radiologist can avoid a missed or delayed diagnosis of an injured rigid spine. ^©RSNA, 2019.

Interobserver agreement using Schlapbach graded scale for diffuse idiopathic skeletal hyperostosis (DISH): can we reduce the cut-off point of vertebral affection?

Resnick-Niwayama criteria for diagnosing DISH depict an advanced stage, and a new reduced cut-off point with three contiguous vertebrae affected (two bone bridges) has been proposed. The aim has been to know the interobserver agreement by using a graded scale of DISH in which grade II matches with the new proposed cut-off point and grade III matches with the first criterion of Resnick-Niwayama. Males ≥ 50 years and postmenopausal women included in a population-based prospective study (the Camargo Cohort) were analyzed. Sample size was obtained according to an expected kappa of 0.95 and an accuracy of ± 8%. Three physicians applied independently Schlapbach graded scale (ranged from grade 0, no ossification, to grade III, ≥ 3 consecutive bone bridges) on the lateral radiographs of thoracic and lumbar spine of participants. We calculated inter- and intra-observer agreement and correlation. One hundred and fifty eight radiographs (79 patients, 68 ± 9 years) were assessed. Kappa values (95% confidence interval) for grades 0, I, II, and III were 0.63 (0.50-0.77), 0.49 (0.37-0.62), 0.32 (0.17-0.47), and 0.69 (0.60-0.77), respectively. Weighted kappa for the three pairs of raters were 0.87 (0.82-0.93), 0.84 (0.77-0.91), and 0.81 (0.72-0.90). Grade III was the image that generated greater agreement, while a significant decrease was noted in grade II, the new proposed criterion. The simultaneous presence of an incomplete DISH and osteoarthritis, in a thoracic spinal segment with peculiar anatomical characteristics (reduced disk spaces, kyphotic curve), is thought to be a major cause of variability in the results.