Pelvic enthesopathy on CT is significantly more prevalent in patients with diffuse idiopathic skeletal hyperostosis (DISH) compared with matched control patients

Assessment of enthesopathy in conventional pelvis radiography: Another tool for spondyloarthritis diagnosis beyond sacroiliitis

INTRODUCTION/OBJECTIVES

Enthesitis is a cardinal feature of spondylarthritis (SpA), and the pelvis is a common site of enthesitis. This study aimed to establish the association between pelvic enthesis involvement on pelvic X-ray and SpA diagnosis through a radiographic enthesis index (REI) and to assess the reliability and accuracy of this REI.

MATERIALS AND METHODS

The participants were SpA patients and a control group composed of patients with chronic lumbar pain without SpA. Three blinded observers assessed each pelvic radiography three times. Three zones were used: Zone I (ZI), the iliopubic ramus; Zone II (ZII), the pubic symphysis, and Zone III (ZIII), the ischiopubic ramus. A grading system was created from 0 to 3 [Grade 0, normal; Grade 1, minimal changes (subcortical bone demineralization and/or periosteal wishkering, seen as radiolucency and trabeculation of the cortical bone upon tendon insertion); Grade 2, destructive changes (Grade 1 findings and erosions at the enthesis site); and Grade 3, findings of Grade 2 plus >2 mm whiskering out of the cortical bone) for the REI. The sum of the results of the three zones was called the total REI. For statistical analysis, we used the weighted kappa statistic adjusted for prevalence and bias using Gwet's agreement coefficient.

RESULTS

We enrolled 161 patients, 111 of them with SpA (39.6 % with axial SpA and 47.7 % with peripheral SpA) and 50 without SpA. In the SpA group, 36.7 % and 25.7 % had REI Grades 2 and 3 in ZIII, respectively, while only 6 % of the controls had these grades. For ZI, the frequency of Grades 1 to 3 was 42.3 % in the SpA group (8.1 %, 14.4 %, and 19.8 %, respectively), compared to only 2 % in the controls. ZII was unaffected in most of the patients with SpA (82.9 %) and in the controls (98 %). In the control group, Grade 0 was the most common REI grade in all three zones. The agreement was almost perfect for each zone and between the independent readers. The ROC-curve analysis showed that the highest performance areas were the total REI, ZIII, and ZI. Most (75 %) of the SpA patients without sacroiliitis on X-ray were REI-positive. The sensitivity of the REI for SpA diagnosis was 82 %, while the sensitivity of sacroiliitis on X-ray was 38.7 %.

CONCLUSIONS

The assessment of pelvic enthesis using the REI on pelvic radiography may be useful for SpA diagnosis. Total REI, ZIII, and ZI had the highest accuracy and almost perfect reliability. The REI is especially helpful in patients without sacroiliitis on imaging.

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.

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.

Imaging of diffuse idiopathic skeletal hyperostosis (DISH)

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.

Diffuse Idiopathic Skeletal Hyperostosis (DISH) and a Possible Inflammatory Component

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.

Enthesopathy of the anterior chest wall joints in patients with diffuse idiopathic skeletal hyperostosis (DISH): a retrospective analysis of computed tomography scans

PURPOSE

To evaluate and characterize anterior chest wall (ACW) joint's enthesopathy on CT scans in patients with DISH compared with age- and gender-matched control group.

MATERIAL AND METHODS

Retrospective evaluation for enthesopathy features of ACW joints-sterno-clavicular (SCJ), manubrio-sternal (MSJ), costo-sternal 1-7 (CSJ)-on chest CT scans of subjects with DISH (Resnick criteria) and of age- and gender-matched control subjects was performed. 183 subjects (DISH: 92, control: 91); male:female: 126:57, average age: 71.7 years (range 50-94) were evaluated. Total enthesopathy scores per subjects and per each joint were compared.

RESULTS

Total enthesopathy score of ACW joints was significantly higher among DISH compared to controls (64.03 ± 15.1, 50.47 ± 12.4, p < 0.001). At joint level, SCJ and CSJ enthesopathy, but not MSJ was significantly more prevalent in DISH compared to controls.

CONCLUSION

ACW joints' enthesopathy as seen on CT scans, an entity not included in the Resnick classification criteria, is common among DISH subjects. The difference between SCJ and CSJ prevalence compared to MSJ may result from different joint type. ACW joints' enthesopathy may be considered to be included in future modified radiographic criteria for DISH.

CT-Based Evaluation of Diffuse Idiopathic Skeletal Hyperostosis in Adult Population; Prevalence, Associations and Interobserver Agreement

Diffuse idiopathic skeletal hyperostosis (DISH), being an asymptomatic condition, is generally discovered incidentally on imaging and it has not received much attention for research on clinical grounds. We assessed the prevalence of DISH, its associated factors, and interobserver agreement for computed tomography (CT)-based diagnosis of DISH. CT scans of chest, abdomen, and pelvis performed for various clinical indications were retrospectively reviewed. Resnick criteria were used for the diagnosis of DISH. Moreover, enthesopathy along with comorbidities was assessed. CT scans were observed by 3 observers having different experience levels. Out of total 416 patients, the prevalence of DISH was 30.8%. Strong positive agreement was observed between observer 1 and 2 (k = 0.89), observer 1 and 3 (k = 0.91), and observer 2 and 3 (k = 0.94). Reporting rate of DISH was 59.3%. Regression analyses showed that enthesopathy was 2.45 times (adjusted odds ratio [AOR]: 2.45, 95% confidence intervals [CI]: 1.48-4.05), diabetic patients were 4.74 times (AOR: 4.74, 95% CI: 2.89-7.78) while hypertensive patients were 2.17 times (AOR: 2.17, 95% CI: 1.30-3.62) more likely to have DISH in comparison to those who do not have DISH. A high prevalence of DISH was observed in our cohort. Enthesopathy and comorbidities like diabetes and hypertension were significant factors associated with DISH. Moreover, excellent agreement was observed in defining DISH on CT according to Resnick criteria.

[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.

Diffuse idiopathic skeletal hyperostosis (DISH): where we are now and where to go next

Diffuse idiopathic skeletal hyperostosis (DISH) is a well-recognised entity characterised by calcifications and ossifications of the entheses affecting mainly the spine and peripheral sites. DISH is still insufficiently investigated and understood. The objective of this report is to highlight the present limitations of our understanding of the condition and suggest future research paths.

CT Abnormalities in the Sacroiliac Joints of Patients With Diffuse Idiopathic Skeletal Hyperostosis

OBJECTIVE

The purpose of this study is to characterize sacroiliac joints (SIJs) findings at CT of patients with diffuse idiopathic skeletal hyperostosis (DISH), a condition characterized (using the Resnick classification criteria) by ossification of at least four contiguous vertebrae in the thoracic spine and preserved disk space, but without radiographic evidence of intraarticular SIJ abnormalities.

MATERIALS AND METHODS

Pelvic CT examinations of 104 patients with DISH (fulfilling the Resnick criteria on spinal CT) and 106 age- and sex-matched control subjects whose entire spine lacked CT evidence of DISH (total, 149 men and 61 women; mean [± SD] age, 72.3 ± 8.7 years) were retrospectively evaluated for the presence of intra- and extraarticular bridging osteophytes, spurs, subchondral cystlike changes, erosions, and sclerosis of SIJs. Excluded were patients with known ankylosing spondylitis or inflammatory-related diseases. Data were analyzed using multivariate ANOVA to examine the degree of difference between patients with DISH and control subjects. Logistic regression analysis was used to generate odds ratios to examine their discriminatory ability. ROC analysis was then applied to examine the sensitivity and specificity of the results.

RESULTS

The frequency of anterior bridging, posterior bridging, entheseal bridging, and joint ankylosis was significantly higher among patients with DISH compared with control subjects (48% vs 9%, 20% vs 1%, 34% vs 4%, and 23% vs 0%, respectively; p < 0.001 for all comparisons).

CONCLUSION

Intraarticular ankylosis seen at CT, an entity not included in the Resnick classification criteria, is common among patients with DISH, which implies that the radiologic classification criteria for DISH need to be revised.