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

How Sagittal Spinal Parameters Predict Anterolateral Spinal Ossification Severity: A Study Based on CT Classification

STUDY DESIGN

Retrospective observational study.

OBJECTIVE

The purpose of this study was to establish a CT classification system of anterolateral spinal ossification and analyze the effects of sagittal spinal parameters on ossification.

SUMMARY OF BACKGROUND DATA

Patients with diffuse idiopathic skeletal hyperostosis often present with anterolateral ossification of the spine. Few reports consider anterolateral spinal ossification at each spinal level or explore the influence of sagittal alignment.

MATERIALS AND METHOD

One hundred and twenty patients (79 males and 41 females) over 60 years old who underwent whole spinal CT scans from October 2018 to November 2021 were analyzed. Volume rendering technique images were used to assess the degree of anterolateral spinal ossification in each intervertebral space, and a classification system was established. Sagittal parameters, such as thoracic kyphosis, lumbar lordosis (LL), cervical lordosis, sacral slope, and thoracolumbar junction angle of the patients were measured. Multifactor stepwise linear regression analysis and ordered logistic regression analysis were used to study the effects of the sagittal parameters on ossification grades.

RESULTS

The median age of the study population was 67 years (63-72 IQR). The new classification system classifies the severity of anterolateral spinal ossification in each intervertebral space into grades 0 to 3 with an intra-observer intraclass correlation coefficient value of 0.909 and inter-observer intraclass correlation coefficient value of 0.900. Multivariate stepwise linear regression analysis showed that age (OR=1.30, P <0.001), weight (OR=1.23, P =0.013), and cervical lordosis (OR=1.19, P <0.001) were significantly correlated with total ossification grade. Multifactor ordered logistic regression analysis showed that there was a statistically significant correlation between cervical lordosis and the ossification grades of each intervertebral space of T1~T4 ( P ≤0.005), between thoracic kyphosis and each intervertebral space in T4~T12 ( P ≤0.019), and between thoracolumbar junction angle and each intervertebral space in T10~L3 ( P ≤0.025). LL was significantly and positively correlated with the ossification grades of each intervertebral space in T7~T11 ( P ≤0.041). LL and sacral slope were significantly negatively correlated with the ossification grades of each intervertebral space in L3~S1 ( P ≤0.047).

CONCLUSION

Our new classification scheme demonstrated good accuracy and reliability for the evaluation of the severity of anterolateral spinal ossification. The effect of sagittal parameters on anterolateral spinal ossification was position-specific. The greater the kyphosis or the smaller the lordosis of a spinal region, the more severe the degree of ossification in the corresponding region.

LEVEL OF EVIDENCE

3.

Diffuse idiopathic skeletal hyperostosis (DISH) and trabecular bone score (TBS) in postmenopausal women: The Camargo cohort

OBJECTIVES

The potential relationship between diffuse idiopathic skeletal hyperostosis (DISH) and bone microstructure has not been studied in women. We aimed to assess the association between the trabecular bone score (TBS) and DISH in postmenopausal women, as well as the role of other parameters related to bone metabolism, such as bone mineral density (BMD), calciotropic hormones, and bone remodeling markers.

METHODS

Cross-sectional study, nested in a prospective population-based cohort (Camargo cohort). Clinical covariates, DISH, TBS, vitamin D, parathormone, BMD and serum bone turnover markers, were analyzed.

RESULTS

We have included 1545 postmenopausal women (mean age, 62±9 years). Those with DISH (n = 152; 8.2%) were older and had a significantly higher prevalence of obesity, metabolic syndrome, hypertension, and type 2 diabetes mellitus (p<0.05). Moreover, they had lower TBS values (p = 0.0001) despite having a higher lumbar spine BMD (p<0.0001) and a higher prevalence of vertebral fractures than women without DISH (28.6% vs. 15.1%; p = 0.002). When analyzing DISH through Schlapbach grades, women without DISH had a median TBS value consistent with a normal trabecular structure while the values for women with DISH from grades 1 to 3 were consistent with a partially degraded trabecular structure. Women with vertebral fractures and DISH had a mean TBS corresponding to a degraded trabecular structure (1.219±0.1). After adjusting for confounders, the estimated TBS means were 1.272 (1.253-1.290) in the DISH group, and 1.334 (1.328-1.339) in the NDISH group (p<0.0001).

CONCLUSION

An association between DISH and TBS has been shown in postmenopausal women, in which hyperostosis has been significantly and consistently related to trabecular degradation and, therefore, to deterioration in bone quality after adjusting for confounding variables.

Early stages of diffuse idiopathic skeletal hyperostosis (DISH) and chronic inflammation: the Camargo Cohort Study

INTRODUCTION/OBJECTIVES

DISH has traditionally been considered a non-inflammatory rheumatic disorder. Currently, an inflammatory component has been theorized in the early phases of this condition (EDISH). The study is aimed at investigating a possible relationship between EDISH and chronic inflammation.

METHOD

Analytical-observational study: participants from the Camargo Cohort Study were enrolled. We collected clinical, radiological, and laboratory data. C-reactive protein (CRP), albumin-to-globulin ratio (AGR), and triglyceride-glucose (TyG) index were assessed. EDISH was defined by Schlapbach's scale grades I or II. A fuzzy matching with tolerance factor = 0.2 was performed. Subjects without ossification (NDISH), sex- and age-matched with cases (1:4), acted as controls. Definite DISH was an exclusion criterion. Multivariable analyses were performed.

RESULTS

We evaluated 987 persons (mean age 64 ± 8 years; 191 cases with 63.9% women). EDISH subjects presented more frequently obesity, T2DM, MetS, and the lipid pattern [↑TG ↓TC]. TyG index and alkaline phosphatase (ALP) were higher. Trabecular bone score (TBS) was significantly lower (1.310 [0.2] vs. 1.342 [0.1]; p = 0.025). CRP and ALP showed the highest correlation (r = 0.510; p = 0.0001) at lowest TBS level. AGR was lower, and its correlations with ALP (r =  - 0.219; p = 0.0001) and CTX (r =  - 0.153; p = 0.022), were weaker or non-significant in NDISH. After adjustment for potential confounders, estimated CRP means for EDISH and NDISH were 0.52 (95% CI: 0.43-0.62) and 0.41 (95% CI: 0.36-0.46), respectively (p = 0.038).

CONCLUSIONS

EDISH was associated with chronic inflammation. Findings revealed an interplay between inflammation, trabecular impairment, and the onset of ossification. Lipid alterations were similar to those observed in chronic-inflammatory diseases. Key Points • An inflammatory component has been theorized in early stages of DISH (EDISH) • In EDISH group compared to non-DISH, we observed significantly higher correlations between biomarkers and some relevant variables. In particular, with alkaline phosphatase (ALP) and with trabecular bone score (TBS) • EDISH has shown to be associated with chronic inflammation • The lipid alterations observed in the EDISH group were similar to those observed in chronic-inflammatory diseases.