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Background and Context: Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by growing ossifications of spinal entheses and tendons, which may cause trachea and esophagus compression when located anteriorly in the cervical spine., Purpose: Our previous systematic review on the epidemiological and clinical knowledge of dysphagia and airway obstruction caused by cervical DISH was updated, with a focus on (surgical) treatment and outcomes., Study Design: A systematic review of the literature was performed., Methods: Publications in Medline and EMBASE from July 2010 to June 2021 were searched. Two investigators performed data extraction and study specific quality assessment., Results: A total of 138 articles (112 case reports and 26 case series) were included, describing 419 patients with dysphagia and/or airway obstruction. The mean age of the patient group was 67.3 years (range: 35-91 years), and 85.4% was male. An evident increase of published cases was observed within the last decade. Surgical treatment was chosen for 66% of patients with the anterolateral approach most commonly used. The total complication rate after surgery was 22.1%, with 12.7% occurring within 1 month after intervention. Improvement of dysphagia was observed in 95.5% of operated patients. After a mean follow-up of 3.7 years (range: 0.4-9.0 years), dysphagia recurred in 12 surgically treated patients (4%), of which five patients had osteophyte regrowth., Conclusions: The number of published cases of dysphagia in patients with DISH has doubled in the last decade compared to our previous review. Yet, randomized studies or guidelines on the treatment or prevention on recurrence are lacking. Surgical treatment is effective and has low (major) complication rates. Common trends established across the cases in our study may help improve our understanding and management of dysphagia and airway obstruction in cervical DISH., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objectives: Earlier retrospective studies have suggested a relation between DISH and cardiovascular disease, including myocardial infarction. The present study assessed the association between DISH and incidence of cardiovascular events and mortality in patients with high cardiovascular risk., Methods: In this prospective cohort study, we included 4624 patients (mean age 58.4 years, 69.6% male) from the Second Manifestations of ARTerial disease cohort. The main end point was major cardiovascular events (MACE: stroke, myocardial infarction and vascular death). Secondary endpoints included all-cause mortality and separate vascular events. Cause-specific proportional hazard models were used to evaluate the risk of DISH on all outcomes, and subdistribution hazard models were used to evaluate the effect of DISH on the cumulative incidence. All models were adjusted for age, sex, body mass index, blood pressure, diabetes, non-HDL cholesterol, packyears, renal function and C-reactive protein., Results: DISH was present in 435 (9.4%) patients. After a median follow-up of 8.7 (IQR 5.0-12.0) years, 864 patients had died and 728 patients developed a MACE event. DISH was associated with an increased cumulative incidence of ischaemic stroke. After adjustment in cause-specific modelling, DISH remained significantly associated with ischaemic stroke (HR 1.55; 95% CI: 1.01, 2.38), but not with MACE (HR 0.99; 95% CI: 0.79, 1.24), myocardial infarction (HR 0.88; 95% CI: 0.59, 1.31), vascular death (HR 0.94; 95% CI: 0.68, 1.27) or all-cause mortality (HR 0.94; 95% CI: 0.77, 1.16)., Conclusion: The presence of DISH is independently associated with an increased incidence and risk for ischaemic stroke, but not with MACE, myocardial infarction, vascular death or all-cause mortality., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Purpose of Review: Diffuse Idiopathic Skeletal Hyperostosis (DISH) is considered a metabolic condition, characterized by new bone formation affecting mainly at entheseal sites. Enthesitis and enthesopathies occur not only in the axial skeleton but also at some peripheral sites, and they resemble to some extent the enthesitis that is a cardinal feature in spondyloarthritis (SpA), which is an inflammatory disease., Recent Findings: We review the possible non-metabolic mechanism such as inflammation that may also be involved at some stage and help promote new bone formation in DISH. We discuss supporting pathogenic mechanisms for a local inflammation at sites typically affected by this disease, and that is also supported by imaging studies that report some similarities between DISH and SpA. Local inflammation, either primary or secondary to metabolic derangements, may contribute to new bone formation in DISH. This new hypothesis is expected to stimulate further research in both the metabolic and inflammatory pathways in order to better understand the mechanisms that lead to new bone formation. This may lead to development of measures that will help in earlier detection and effective management before damage occurs.

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic bone-forming condition characterized by the presence of at least three bony bridges at the anterolateral spine. The aim of this review was to address the present state of pathophysiological knowledge, the clinical relevance, and diagnosis of DISH. The pathogenesis of DISH is currently unknown. The presence of DISH has been associated with older age, male sex, obesity, hypertension, atherosclerosis, and diabetes mellitus. Because the new bone forms mainly at entheseal sites, local fibroblasts, chondrocytes, collagen fibers, and calcified matrix are probably influenced by genetic, vascular, metabolic, and mechanical factors. Diagnosing the presence of DISH is of clinical importance, because the risk of a spinal fracture increases and associations with the metabolic syndrome, coronary and aortic disease, and respiratory effects are strong. Unravelling the pathogenesis of DISH can impact the field of regenerative medicine and bone tissue regeneration., Competing Interests: Declaration of Competing Interest All authors have no conflicts of interest to report., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: Diffuse idiopathic skeletal hyperostosis (DISH) is a condition characterized by bony proliferation at sites of tendinous and ligamentous insertions in the spine. Spinal mobility is reduced in DISH and may affect movement in the thorax, potentially leading to restrictive pulmonary function. This study investigated whether DISH is associated with restrictive spirometric pattern (RSP) in former and current smokers., Methods: Participants (n = 1784) with complete postbronchodilator spirometry who did not meet spirometric criteria for chronic obstructive pulmonary disease (COPD) at time of enrollment in the COPDGene study were included in this study. Subjects were classified as RSP if they had forced expiratory volume in 1 s(FEV1) to forced vital capacity (FVC) ratio > 0.7 with an FVC < 80%. Computed tomography (CT) scans were scored for the presence of DISH in accordance with the Resnick criteria. Chest CT measures of interstitial and alveolar lung disease, clinical symptoms, health surveys, and 6-min walking distance were recorded. Uni- and multivariable analyses were performed to test the association of DISH with RSP., Results: DISH was present in 236 subjects (13.2%). RSP was twice as common in participants with DISH (n = 90/236, 38.1%) compared to those without DISH (n = 301/1548, 19.4%; p < 0.001). In multivariable analysis, DISH was significantly associated with RSP (OR 1.78; 95% CI 1.22-2.60; p = 0.003) after adjusting for potential confounders. The RSP group with and without DISH had significantly worse spirometry, dyspnea, St. George's Respiratory Questionnaire score, BODE index (Body mass index, airflow Obstruction, Dyspnea and Exercise capacity), and Medical Outcomes Study Short Form-36 questionnaire score., Conclusion: In heavy smokers with an FEV1/FVC ratio > 0.70, DISH is associated with RSP after adjustment for intrinsic and extrinsic causes of restrictive lung function. (Clinical trial registration number: NCT00608764.).

Diffuse idiopathic skeletal hyperostosis (DISH) is a condition characterised by calcification and ossification of ligaments and entheses. The condition usually affects the axial skeleton, in particular, at the thoracic segment, though also other portions of the spine are often involved. DISH often involves also peripheral tendinous and/or entheseal sites either alone, or in association with the involvement of peripheral joints. At times, new bone formation involves the bone itself, but sometimes it involves joints not usually affected by osteoarthritis (OA) which result in bony enlargement of the epiphysis, joints space narrowing and a reduced range of motion. Because of the entheseal involvement, DISH can be mistaken for seronegative spondyloarthropathies or for a "simple" OA. Furthermore, other implications for the recognition of DISH include spinal fractures, difficult intubation and upper endoscopies, decreased response rates in DISH with concomitant spondyloarthritides, and increased likelihood to be affected by metabolic syndrome and cardiovascular diseases. This Atlas is intended to show the imaging finding in DISH in patients diagnosed with the condition by the Resnick classification criteria., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background Diffuse idiopathic skeletal hyperostosis (DISH) is a condition characterized by the formation of new bone along the anterolateral spinal column at four adjacent vertebral bodies. Purpose To propose and validate criteria for the early phase of DISH by using CT data from two large-scale retrospective cohorts, each with 5-year follow-up. Materials and Methods For this retrospective study, CT data at baseline and follow-up in 1367 patients (cohort I) from 2004 to 2011 were evaluated by two observers to define no DISH, early-stage DISH, and definite DISH on the basis of interval development of consecutive complete or incomplete bone bridges. An independent group of 2267 participants from the COPDGene cohort from 2008 to 2016 was used to validate the early DISH criteria (cohort II). The sensitivity and specificity of early DISH criteria were based on findings in the last CT study as the reference standard by using a nested case-control design. κ Values were calculated between seven readers and with a 3-month interval for one reader. Results Cohort I consisted of 100% men, with a mean age of 60.0 years ± 5.6 (standard deviation) and a mean time between baseline and follow-up CT of 5.0 years ± 1.1. Cohort II consisted of 51% men, with a mean age of 59.9 years ± 8.6 and a mean time between baseline and follow-up CT of 5.4 years ± 0.5. In the derivation cohort, 55 patients comprised the early DISH group. Early DISH was defined as the presence of a spinal segment with a complete bone bridge with an adjacent segment of at least a near-complete bone bridge and another adjacent segment with at least the presence of newly formed bone or when three or more adjacent segments were recorded as showing a near-complete bone bridge. In the validation cohort, sensitivity for early DISH (vs no DISH) was 96% (99 of 103 participants; 95% confidence interval [CI]: 90%, 99%). The corresponding specificity was 83% (1695 of 2034 participants; 95% CI: 82%, 85%). The Fleiss κ for interrater reliability was 0.78 (95% CI: 0.77, 0.78), and the κ for intrarater reliability was 0.89 (95% CI: 0.82, 0.96). Conclusion Early diffuse idiopathic skeletal hyperostosis (DISH) criteria had high sensitivity and specificity for predicting the development of DISH. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Block in this issue.

Objectives: AS and DISH are both spinal ankylosing conditions with a 4-fold increased risk of spinal fractures. The most commonly used criteria for DISH were designed to exclude radiographic signs of spondyloarthritis. However, case reports describing the presence of both conditions exist. In this study, the co-occurrence of AS and DISH were reviewed in the literature to explore the potential need to revise the criteria for DISH., Methods: A search was conducted in Pubmed, Embase, Web of Science and the Cochrane library using the terms 'spondyloarthritis' and 'DISH' and their matching synonyms. Full-text articles describing the coexistence of both conditions in the same patient were included. A quality assessment was performed, and the case descriptions were extracted., Results: Twenty articles describing simultaneous occurrence of AS and DISH in 39 cases were retrieved. All articles were case reports or series of moderate quality. Back or neck pain was present in 97% of the patients (mean age 61.2 years, 90% male) and HLA-B27 was positive in 9/27 documented measurements. Radiographic abnormalities were described in the SI joint (82% AS, 13% DISH) and in the spine (49% AS, 100% DISH)., Conclusion: Simultaneous occurrence of AS and DISH has been reported in the literature in at least 39 cases. AS and DISH should not be seen as mutually exclusive. If the results of the current study are confirmed in a large observational study, revision of the current criteria to include the co-existence of both conditions should be considered.

Aim: To evaluate abdominal fat distribution (subcutaneous adipose tissue [SAT] and visceral adipose tissue [VAT]) in two enthesopathy-related diseases with known correlation to metabolic syndrome (MS): diffuse idiopathic skeletal hyperostosis (DISH) and ankylosing spondylitis (AS) compared with controls., Materials and Methods: Abdominal computed tomography (CT) examinations of 43 DISH (Resnick radiographic criteria) patients, 31 AS (Modified New York Criteria) patients and 42 age- and gender-matched (to DISH) controls (males: 29; 29; 27 and mean age: 71.7±7; 56.1±16; 72.7±8 years, respectively) were evaluated and compared for VAT and SAT surface areas on mid L3, L4, L5 levels., Results: AS patients were significantly younger compared to DISH patients and controls. No significant differences were observed between VAT and SAT of DISH and AS patients or between SAT values in all groups even after correction for age. VAT was higher in DISH and AS patients compared to controls on all three levels, but reached significance (p<0.05) only for DISH patients (L3: 24.34/23.6/18.43; L4: 23.85/22.21/18.05; L5: 19.09/18.94/14.24 mm 2 , respectively). This did not change after correction for age. The VAT/SAT ratio was significantly larger in DISH and AS patients on all levels compared to controls., Conclusion: The higher VAT surface area, a known marker for MS, which by itself is associated with bone proliferation, in DISH and AS patients compared to controls substantiates its role as a potential surrogate marker for MS as well as suggests a potential shared pathogenic pathway for enthesopathic excessive bone production in DISH and AS., (Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Diffuse idiopathic skeletal hyperostosis (DISH) is often theorized to be an ossification of the anterior longitudinal ligament (ALL). Using computed tomography (CT) imaging and cryomacrotome sectioning, we investigated the spatial relationship between the ALL and newly formed bone in DISH to test this hypothesis. In the current study, four human cadaveric spines diagnosed with DISH using CT imaging were frozen and sectioned using a cryomacrotome. Photographs were obtained of the specimen at 125 µm intervals. Manual segmentations of the ALL on cryomacrotome photographs were projected onto the three-dimensional reconstructed CT scans. The presence and location of newly formed bone were assessed in relationship to the location of the ALL. The ALL could be identified and segmented on the photographs at all levels. The ALL was located at the midline at levels where no new bone had formed. At the locations where new bone had abundantly formed, the ALL was displaced towards to the contralateral side and not replaced by bony tissue. The displacement of the-morphologically normal appearing-ALL away from the newly formed bone implies that newly formed bone in DISH may not originate from the ALL. © 2018 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society J Orthop Res 36:2491-2496, 2018., (© 2018 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society.)

Objective: Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by flowing bony bridges on the right side of the spine. Knowledge of the development of these spinal bridges is limited. The current longitudinal computed tomography (CT) study was designed to bridge this gap., Methods: Chest CT scans from elderly males with 2 scans (interval ≥ 2.5 yrs) were retrospectively included. Using the Resnick criteria, a pre-DISH group and a definite DISH group were identified. A scoring system based on the completeness of a bone bridge (score 0-3), extent of fluency, and location of the new bone was created to evaluate the progression of bone formation., Results: In total, 145 of 1367 subjects were allocated to the DISH groups with a mean followup period of 5 years. Overall prevalence of a complete bone bridge increased in the pre-DISH group (11.3% to 31.0%) and in the definite DISH group (45.0% to 55.8%). The mean bridge score increased significantly in both the pre-DISH and definite DISH group (p < 0.001). The new bone gradually became more flowing and expanded circumferentially., Conclusion: Over the mean course of 5 years, the new bone developed from incomplete, pointy bone bridges to more flowing complete bridges. This suggests an ongoing and measurable bone-forming process that continues to progress, also in established cases of DISH.

Diffuse idiopathic skeletal hyperostosis (DISH) is an increasingly prevalent ankylosing condition. Patients with DISH have an increased risk of spinal fractures, hypothetically the result of biomechanical changes in the spine. The aim of this study was to analyze the occurrence of biomechanical stress shielding in patients with DISH. To do this, bone mineral density (BMD) was measured longitudinally in the vertebral bodies of subjects with and without DISH and in the newly formed bone of subjects with DISH. The presence of DISH was evaluated using Resnick criteria on two chest computed tomography (CT) scans taken at least 2.5 years apart from subjects over 50 years of age. Three groups were identified: pre-DISH (individuals who developed DISH after the first CT scan), definite DISH (individuals who had DISH on both CT scans), and controls (individuals with no DISH). Hounsfield units (HU) were measured in the newly formed bone and in predefined anterior and posterior portions of the involved vertebral bodies. Mean BMD of the newly formed bone increased significantly (mean ΔHU 137.5; p < 0.01) during a mean interval of 5 years in the cranial, middle, and caudally involved vertebral segments of both DISH groups. Mean BMD of the vertebral bodies in the ankylotic segments in the DISH groups did not significantly differ from that of the non-ankylotic vertebral bodies of the same subject. In contrast to our hypothesis, the HU value of the vertebral body decreased more in the control group than in the DISH groups; however, statistical significance was only reached at the cranial level in the anterior part of the vertebral body (p = 0.048). Our data suggest that 1) vertebral BMD is not influenced by the presence of DISH and 2) increased spinal stiffness may play a more important role than vertebral BMD in the increased fracture risk of and the typical fracture patterns observed in individuals with DISH., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objectives: Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by anterior ossification of the spine and can lead to dysphagia and airway obstruction. The morphology of the newly formed bone in the cervical spine is different compared to the thoracic spine, possibly due to dissimilarities in local vascular anatomy. In this study the spatial relationship of the new bone with the arterial system, trachea and esophagus was analyzed and compared between subjects with and without DISH., Methods: Cervical computed tomography (CT) scans were obtained from five patients with dysphagia and DISH and ten control subjects. The location of the vertebral and carotid arteries, surface area of the hyperostosis and distance between the vertebral body and the trachea and esophagus was assessed in the axial view., Results: The surface area of the newly formed bone was located symmetrically anterior to the vertebral body. The ossifications were non-flowing in the sagittal view and no segmental vessels were observed. Substantial displacement of the trachea/esophagus was present in the group with DISH compared to the controls., Conclusions: The hyperostosis at the cervical level was symmetrically distributed anterior to the vertebral bodies without a flowing pattern, in contrast to the asymmetrical flowing pattern typically found in the thoracic spine. The hypothesis that the vascular system acts as a natural barrier against new bone formation in DISH could be further supported with these findings. The significant ventral displacement of the trachea and esophagus may explain the mechanism of dysphagia and airway obstruction in DISH.

Objectives: DISH is a condition characterized by flowing ossifications of the spine with or without ossifications of entheses elsewhere in the body. Studies on the prevalence and pathogenesis of DISH use a variety of partly overlapping combinations of classification criteria, making meaningful comparisons across the literature difficult. The aim of this study was to systematically summarize the available criteria to support the development of a more uniform set of diagnostic/classification criteria., Methods: A search was performed in Pubmed, Embase, Cochrane Library and Web of Science using the term DISH and its synonyms. Articles were included when two independent observers agreed that the articles proposed a new set of classification criteria for DISH. All retrieved articles were evaluated for methodological quality, and the presented criteria were extracted., Results: A total of 24 articles met the inclusion criteria. In all articles, spinal hyperostosis was required for the diagnosis of DISH. Peripheral, extraspinal manifestations were included as a (co-)requirement for the diagnosis DISH in five articles. Most discrepancies revolved around the threshold for the number of vertebral bodies affected and to defining different developmental phases of DISH. More than half of the retrieved articles described a dichotomous set of criteria and did not consider the progressive character of DISH., Conclusion: This systematic review summarizes the available different classification criteria for DISH, which highlights the lack of consensus on the diagnosis of (early) DISH. Consensus criteria, including consecutive phases of new bone formation that characterize DISH, can be developed based upon established diagnostic/classification criteria., (© The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com)

Objective: To evaluate and improve the interobserver agreement for the CT-based diagnosis of diffuse idiopathic skeletal hyperostosis (DISH)., Methods: Six hundred participants of the CT arm of a lung cancer screening trial were randomly divided into two groups. The first 300 CTs were scored by five observers for the presence of DISH based on the original Resnick criteria for radiographs. After analysis of the data a consensus meeting was organised and the criteria were slightly modified regarding the definition of 'contiguous', the definition of 'flowing ossifications' and the viewing plane and window level. Subsequently, the second set of 300 CTs was scored by the same observers. κ ≥ 0.61 was considered good agreement., Results: The 600 male participants were on average 63.5 (SD 5.3) years old and had smoked on average 38.0 pack-years. In the first round κ values ranged from 0.32 to 0.74 and 7 out of 10 values were below 0.61. After the consensus meeting the interobserver agreement ranged from 0.51 to 0.86 and 3 out of 10 values were below 0.61. The agreement improved significantly., Conclusions: This is the first study that reports interobserver agreement for the diagnosis of DISH on chest CT, showing mostly good agreement for modified Resnick criteria., Key Points: • DISH is diagnosed on fluoroscopic and radiographic examinations using Resnick criteria • Evaluation of DISH on chest CT was modestly reproducible with the Resnick criteria • A consensus meeting and Resnick criteria modification improved inter-rater reliability for DISH • Reproducible CT criteria for DISH aids research into this poorly understood entity.

Diffuse idiopathic skeletal hyperostosis (DISH) is a predominantly radiographic diagnosis and histological knowledge of DISH is limited. The aim of this study was to describe the histological characteristics of DISH in the spinal column and to study the relation between DISH and intervertebral disc (IVD) degeneration. Therefore, 10 human cadaveric spines with fluoroscopic evidence of DISH were compared with 10 controls. Plain radiographs and computed tomography (CT) scans were obtained and tissue blocks were resected from three predefined levels of all specimens. The microscopic sections were scored by two blinded observers using a newly developed scoring system specific for characteristics of DISH and a validated scoring system for IVD degeneration. Maximum IVD height was measured on the CT scans. Analyses were performed using Fisher's exact test and Student's t-test. When compared to controls, the right sided sections from DISH specimens showed partial or complete bone bridges, consisting of cortical woven bone, accompanied by morphological changes in the adjoining part of the IVD. Using the histological scoring system for DISH, all parameters were significantly different between the DISH and control group (p < 0.01). The contralateral location did not show differences between the groups. The overall degree of IVD degeneration and height of IVD was comparable for the two groups. The histopathological changes observed in spines with DISH corresponded to the fluoroscopic images and CT scans. The degree of IVD degeneration and IVD height was comparable for both groups, suggesting a limited role for IVD degeneration in the pathogenesis of DISH. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:140-146, 2017., (© 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

Background Context: The clinical outcome of patients with ankylosing spinal disorders (ASDs) sustaining a spinal fracture has been described to be worse compared with the general trauma population., Purpose: To investigate clinical outcome (neurologic deficits, complications, and mortality) after spinal injury in patients with ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) compared with control patients., Study Design: Retrospective cohort study., Patient Sample: All patients older than 50 years and admitted with a traumatic spinal fracture to the Emergency Department of the University Medical Center Utrecht, the Netherlands, a regional level-1 trauma center and tertiary referral spine center., Outcome Measures: Data on comorbidity (Charlson comorbidity score), mechanism of trauma, fracture characteristics, neurologic deficit, complications, and in-hospital mortality were collected from medical records., Methods: With logistic regression analysis, the association between the presence of an ASD and mortality was investigated in relation to other known risk factors for mortality., Results: A total of 165 patients met the inclusion criteria; 14 patients were diagnosed with AS (8.5%), 40 patients had DISH (24.2%), and 111 patients were control patients (67.3%). Ankylosing spinal disorder patients were approximately five years older than control patients and predominantly of male gender. The Charlson comorbidity score did not significantly differ among the groups, but Type 2 diabetes mellitus and obesity were more prevalent among DISH patients. In many AS and DISH cases, fractures resulted from low-energy trauma and showed a hyperextension configuration. Patients with AS and DISH were frequently admitted with a neurologic deficit (57.1% and 30.0%, respectively) compared with controls (12.6%; p=.002), which did not improve in the majority of cases. In AS and DISH patients, complication and mortality rates were significantly higher than in controls. Logistic regression analysis showed the parameters age and presence of DISH to be independently, statistically significantly related to mortality., Conclusions: Many patients with AS and DISH showed unstable (hyperextension) fracture configurations and neurologic deficits. Complication and mortality rates were higher in patients with ASD compared with control patients. Increasing age and presence of DISH are predictors of mortality after a spinal fracture., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: To revise the definition of DISH and suggest a classification that may better represent our current knowledge of this entity allowing earlier diagnosis., Methods: Seven rheumatologists and an orthopaedic surgeon suggested a list of 63 parameters that might be included in a future classification of DISH. Participants rated their level of agreement with each item, expressed in percentages. In a second session, participants discussed each item again and re-rated all parameters. Thirty items that were granted ≥50% support on average were considered valid for a third round. A questionnaire listing these 30 items was mailed to 39 rheumatologists and orthopaedic surgeons worldwide with a request to answer categorically if they agreed on an item to be included as a criterion for a future classification of DISH. Items were regarded as perfect consensus when at least 95% of the respondents agreed and were regarded as consensus when at least 80% agreed., Results: There was perfect consensus for 2 (6.7%) of the 30 parameters and consensus for another 2 parameters. These items were ossification and bridging osteophytes in each of the three segments of the spine and exuberant bone formation of bone margins., Conclusion: At present there is no agreement about the inclusion of extraspinal, constitutional and metabolic manifestations in a new classification of DISH. Investigators with an interest in this condition should be encouraged to restructure the term DISH in an attempt to establish a more sophisticated definition.

Background Context: Diffuse idiopathic skeletal hyperostosis (DISH) is a common but underdiagnosed condition relating to ossification of spinal ligaments that can cause compression of the esophagus and trachea. According to case reports, dysphagia or airway obstruction resulting from DISH is a rare occurrence., Purpose: This study was intended to identify all published cases of dysphagia and/or airway obstruction resulting from DISH to increase the epidemiologic/clinical knowledge of these related conditions., Study Design: A systematic review of the literature was performed., Methods: The articles resulting from the systematic PubMed/EMBASE search of the literature were closely read, and predefined parameters were scored., Results: The search yielded a total of 118 articles (95 case reports and 23 case series) describing 204 patients with dysphagia and/or airway obstruction resulting from DISH. The number of cases demonstrated a steady increase from 1980 to 2009. This might be a real effect not ascribable to publication bias or expansion of the medical literature alone., Conclusions: Diffuse idiopathic skeletal hyperostosis as a cause of dysphagia and/or airway obstruction may be an increasing and underappreciated phenomenon. Diffuse idiopathic skeletal hyperostosis should be included in the differential diagnosis of dysphagia and airway obstruction., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic condition leading to ossification of spinal ligaments and has been shown to behave similarly to ankylosing spondylitis (AS) often leading to unstable hyperextension fractures. Currently, no quantitative data are available on the spatial relationship between the bridging anterolateral ossification mass (ALOM) and the vertebral body/intervertebral disc to explain the propensity in DISH to fracture through the vertebral body instead of through the intervertebral disc as more often seen in AS. Furthermore, no reasonable explanation is available for the typical flowing wax morphology observed in DISH. In the current study, a quantitative analysis of computed tomography (CT) data from human cadaveric specimens with DISH was performed to better understand the newly formed osseous structures and fracture biomechanics. Additionally, the results were verified using computed tomography angiography data from ten patients with DISH and ten controls. Transverse CT images were analyzed to obtain ALOM area and centroid angle relative to the anteroposterior axis; intervertebral disc and adjacent cranial and caudal levels. The ALOM area at the mid-vertebral body level averaged 57.9 ± 50.0 mm(2); at the mid-intervertebral disc space level it averaged 246.4 ± 95.9 mm(2). The mean ALOM area at the adjacent level caudal to the mid-vertebral body level was 169.6 ± 81.3 mm(2); at the adjacent cranial level, it was 161.7 ± 78.2 mm(2). The main finding was the significant difference between mean ALOM area at the mid-vertebral body level and other three levels (p < 0.0001). The subsequent verification study showed the presence of vertebral segmental arteries at the mid-vertebral body level in nearly all images irrespective of the presence of DISH. A larger area of ALOM seemed associated with increased counter-clockwise rotation (away from the aorta) of the centroid relative to the anteroposterior axis. The results from the present study suggest a predisposition for fractures through the vertebral body and a role for the arterial system in the inhibition of soft tissue ossification.

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic disorder of the axial and peripheral skeleton in humans and has incidentally been described in dogs. The aims of this retrospective radiographic cohort study were to determine the prevalence of DISH in an outpatient population of skeletally mature dogs and to investigate if dogs can be used as an animal model for DISH. The overall prevalence of canine DISH was 3.8% (78/2041). The prevalence of DISH increased with age and was more frequent in male dogs, similar to findings in human studies. In the Boxer breed the prevalence of DISH was 40.6% (28/69). Dog breeds represent closed gene pools with a high degree of familiar relationship and the high prevalence in the Boxer may be indicative of a genetic origin of DISH. It is concluded that the Boxer breed may serve as an animal model for DISH in humans.

DISH is a condition characterized by calcification and/or ossification of soft tissues, mainly entheses, ligaments and joint capsules. Its prevalence increases with age and, therefore, DISH is a relatively common entity in the elderly. The classical site of involvement is the spinal column with right anterolateral soft tissue ossification being the most characteristic feature. However, DISH is not limited to the spine, and may affect multiple peripheral sites independently. Extraspinal entheseal ossifications are common and observing their isolated presence may lead to the diagnosis of DISH. Furthermore, hypertrophic or atypical OA observed in joints usually not affected by primary OA has frequently been reported in DISH. Several metabolic derangements and concomitant diseases have been suggested to be associated with DISH including obesity, increased waist circumference, hypertension, dyslipidaemia, diabetes mellitus (DM), hyperuricaemia, metabolic syndrome and an increased risk for cardiovascular diseases. Witnessing the present increase in lifespan, obesity, DM and metabolic syndrome in the Western population, the prevalence of DISH should be expected to rise. In order to increase the awareness for DISH, this review focuses on the extraspinal features of the condition.

Objectives: BMD has been described to be increased in patients with DISH. The contribution of the ossified anterior longitudinal ligament (ALL) on vertebral body BMD is currently unknown. We investigated the influence of DISH on BMD measurements using an experimental DXA scanning protocol., Methods: Ten DISH specimens and 10 matched human cadaveric spines were used. After assessment of the localization and orientation of the ossified ALL with CT, BMD was measured using an experimental DXA protocol, exploiting the asymmetry of DISH in the thoracic spine. For controls, identical orientations were used and both groups were compared for differences in BMD., Results: Specimens with DISH displayed a significantly higher BMD than their matched controls when the ossified ALL was present in the scanning field. Measurements of the left half of the spine were comparable for DISH specimens and controls (P = 0.446). The right-left difference in anteroposterior view was statistically significant within DISH specimens (P = 0.001), but not in controls (P = 0.825)., Conclusions: The variability in measurements in different scanning orientations suggests a substantial contribution of the ossified ALL to the total BMD in DISH specimens, ranging from 23.6 to 39.0%. Vertebral body BMD does not seem to be increased, as demonstrated by comparable BMDs in the unaffected left half of the spine. It is suggested that routine anteroposterior DXA scanning may overestimate the true vertebral body BMD in DISH patients.

The ankylosed spine is prone to fracture after minor trauma due to its changed biomechanical properties. Although many case reports and small series have been published on patients with ankylosing spondylitis (AS) suffering spine fractures, solid data on clinical outcome are rare. In advanced diffuse idiopathic skeletal hyperostosis (DISH), ossification of spinal ligaments also leads to ankylosis. The prevalence of AS is stable, but since DISH may become more widespread due to its association with age, obesity and type 2 diabetes mellitus, a systematic review of the literature was conducted to increase the current knowledge on treatment, neurological status and complications of patients with preexisting ankylosed spines sustaining spinal trauma. A literature search was performed to obtain all relevant articles concerning the outcome of patients with AS or DISH admitted with spinal fractures. Predefined parameters were extracted from the papers and pooled to study the effect of treatment on neurological status and complications. Ninety-three articles were included, representing 345 AS patients and 55 DISH patients. Most fractures were localized in the cervical spine and resulted from low energy impact. Delayed diagnosis often occurred due to patient and doctor related factors. On admission 67.2% of the AS patients and 40.0% of the DISH patients demonstrated neurologic deficits, while secondary neurological deterioration occurred frequently. Surgical or nonoperative treatment did not alter the neurological prospective for most patients. The complication rate was 51.1% in AS patients and 32.7% in DISH patients. The overall mortality within 3 months after injury was 17.7% in AS and 20.0% in DISH. This review suggests that the clinical outcome of patients with fractures in previously ankylosed spines, due to AS or DISH, is considerably worse compared to the general trauma population. Considering the potential increase in prevalence of DISH cases, this condition may render a new challenge for physicians treating spinal injuries.

Objective: In diffuse idiopathic skeletal hyperostosis (DISH), spinal ankylosis may occur due to longitudinal ligament ossification. DISH can lead to back pain, impaired mobility, and displaced fractures after minor trauma. Its etiology is unknown, but is associated with obesity and type 2 diabetes mellitus. We investigated the prevalence of DISH in an outpatient population in the Netherlands., Methods: Chest radiographs of 501 patients (age > 50 yrs) referred to our institution by general practitioners for non-spine-related conditions were reviewed. DISH was established according to defined criteria; 3-level involvement was defined as pre-stage DISH. Logistic regression analysis was used to investigate the influence of age and sex on the prevalence of DISH., Results: The overall prevalence of DISH was 17.0% (95% CI 13.7-20.3). A significant increase with age was observed (odds ratio 1.03, 95% CI 1.01-1.05; p = 0.006). The odds ratio of male sex was 1.85 (95% CI 1.20-2.86; p = 0.006). The individual predicted probability of developing DISH was 32.1% in 80-year-old men and 16.9% in women of the same age. Pre-stage DISH was found in 4.6% of the individuals and was more frequent in women., Conclusion: The prevalence of DISH in this outpatient cohort was 17.0%, which is high compared to recent reports. Age and sex were significantly related to the presence of DISH, suggesting that men and older individuals have a higher probability of developing DISH.

Diffuse idiopathic skeletal hyperostosis (DISH) is a common but often unrecognized systemic disorder observed mainly in the elderly. DISH is diagnosed when the anterior longitudinal ligament of the spine is ossified on at least four contiguous spinal levels or when multiple peripheral enthesopathies are present. The etiology of DISH is unknown but previous studies have shown a strong association with obesity and insulin-independent diabetes mellitus. DISH can lead to back pain, dysphagia, myelopathy, musculoskeletal impairment and grossly unstable spine fractures after minor trauma. In archeological studies a high prevalence of DISH has been demonstrated in ancient clergymen. The present study describes the pathological changes of human remains excavated from the abbey court (Pandhof) in the city of Maastricht, The Netherlands. Human remains of 51 individuals buried between 275 and 1795 CE: were excavated and examined. The remains were investigated according to a standardized physical anthropological report and individuals demonstrating ossification of spinal ligaments and/or multiple peripheral enthesopathies were included in the study group. The authors reviewed all available material and after reaching consensus, each abnormality found was given a diagnosis and subsequently recorded. After examination, 28 individuals were considered to be adult males; 11 adult females; three adults of indeterminate sex and nine individuals were of sub adult age. The mean age at death for adults was 36.8 years. Seventeen adult individuals (40.4% of all adults), displayed ossifications of at least four contiguous spinal levels and/or multiple enthesopathies of the appendicular skeleton and were therefore, assigned the diagnosis DISH. The mean age of these individuals was 49.5 +/- 13.0 years. In at least three of these individuals, DISH had led to extensive ossification and subsequent ankylosis of axial and peripheral skeletal structures. In this population of (presumably) clergymen and high-ranking citizens, DISH was observed in unusual high numbers at a relatively young age. Some of the examined cases suggest that DISH may be a seriously incapacitating disorder when the more advanced stages of the disease have been reached. It is hypothesized that "a monastic way of life" can predispose to DISH. Present demographic trends in obesity and diabetes mellitus as potential co-factors for the development of DISH warrant further study to investigate its future prevalence.