Progression of Ossification of the Anterior Longitudinal Ligament Associated With Diffuse Idiopathic Skeletal Hyperostosis by Age: A Study of Computed Tomography Findings Over 5 Years

Spatiotemporal changes in imaging features associated with diffuse idiopathic skeletal hyperostosis (DISH)

OBJECTIVES

The purpose of our study was to characterise spatiotemporal features of disease progression in people with diffuse idiopathic skeletal hyperostosis (DISH), early-phase DISH, and those not meeting either criterion who had repeated CT scans of the thoracic spine.

METHODS

A retrospective study was designed in collaboration with the Rochester Epidemiology Project to evaluate completeness of ectopic bridging across the thoracic spine and corresponding disease status over an average of 2.7 years (range from 0.2 to 15.0 years) in a cohort of 83 female and 74 male individuals.

RESULTS

Over 15% of individuals displayed changes in imaging features over time that resulted in a revised diagnosis along the continuum of DISH. Early-phase DISH was marked by new involvement of previously unaffected motion segments, estimated to occur over 2.1 years. Advanced presentations of DISH were marked by increased prevalence of complete bridging (average two of three available motion segments), estimated to occur over 2.6-2.9 years. Localised nodules of ectopic mineralisation external to and within the intervertebral disc were regularly observed in early-phase DISH.

CONCLUSIONS

This is the first characterisation of spatiotemporal features across all phases of DISH, indicating that progression of DISH is characterised by distinct features at different phases along the disease continuum. Localised nodules of mineralisation in the spinal ligaments and within the intervertebral discs coincident with early phases of the disease may be a key factor in the pathogenesis of DISH.

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.

Long-term effects of diffuse idiopathic skeletal hyperostosis on physical function: A longitudinal analysis

BACKGROUND

Cross-sectional studies on diffuse idiopathic skeletal hyperostosis have focused on its incidence and related factors. However, the long-term changes caused by the disease remain unclear. This longitudinal cohort study aimed to elucidate the progression of diffuse idiopathic skeletal hyperostosis and its effects on physical function, health-related quality of life, and spinal alignment.

METHODS

We recruited 255 older adults (87 men and 168 women; average age, 71.3 years in 2014) who attended local health checkups in 2014 and 2020. Height, body weight, body mass index, blood pressure, grip strength, functional reach, and bone mineral density were measured. The prevalence, location, number of ossified contiguous vertebrae, and spinopelvic parameters were estimated using whole-spine standing radiographs. For health-related quality of life assessment, the Oswestry disability index and EuroQuol-5D were obtained. We performed a 1:1 case-control study with age and sex-matched patients with and without diffuse idiopathic skeletal hyperostosis and analyzed progression over a 6-year period.

RESULTS

In 2014, 39 (15.3%) of 255 patients were diagnosed with diffuse idiopathic skeletal hyperostosis (24 males and 15 females), which occurred more frequently in the elderly and males. In 2020, 12 (4.3%) patients were newly diagnosed with diffuse idiopathic skeletal hyperostosis, and 28 (71.7%) of 39 patients diagnosed in 2014 showed varying degrees of progression. Compared with age- and sex-matched patients without diffuse idiopathic skeletal hyperostosis, patients with the condition had higher body mass index and lumbar bone mineral density, larger sagittal vertical axis, and greater T1-pelvic angle. Changes in physical function and spinal-pelvic parameters during the 6-year period did not differ between the groups.

CONCLUSIONS

Over a 6-year period, the prevalence of diffuse idiopathic skeletal hyperostosis increased by 4.3%, and it progressed in 71.7% of patients. However, it had little effect on longitudinal physical function, health-related quality of life, and spinopelvic parameters in older adults.

Examining the Association Between the Extent of Anterior Longitudinal Ligament Ossification Progression and Comorbidities in Diffuse Idiopathic Skeletal Hyperostosis

BACKGROUND

 It has been documented that diffuse idiopathic skeletal hyperostosis (DISH) exhibits a higher prevalence among elderly, male, and obese individuals. Additionally, diabetes mellitus and other comorbidities are more frequently observed in this patient population. However, there is a lack of reports exploring the correlation between the extent of ossification and these demographic and clinical characteristics.

OBJECTIVE

To examine the correlation between comorbidities and the severity of ossification of the anterior longitudinal ligament in patients with DISH.

MATERIALS AND METHODS

The study included 468 patients who visited our hospital in 2018-2022. They were divided into DISH and non-DISH groups based on computed tomography image evaluation according to the Resnick criteria. The patients in the two groups were matched for age and sex. We compared comorbidity-related factors including body mass index (BMI), serum markers for metabolic syndrome and renal function, and hemoglobin A1c (HbA1c) levels between the matched groups. Moreover, we examined the correlation between the number of fused vertebral bodies and comorbidity-related factors, age, and sex within the DISH group.

RESULTS

The DISH group included significantly more men and elderly patients than the non-DISH group. Furthermore, the average BMI and HbA1c levels were significantly higher in the matched-DISH group than in the matched-non-DISH group, whereas no differences were observed in other markers. In the DISH group, the number of fused vertebral bodies did not correlate with age, sex, BMI, or HbA1c levels.

DISCUSSION

BMI and HbA1c levels were significantly higher in patients with DISH than those without; however, the number of fused vertebral bodies and the possibility of having coexisting obesity or diabetes mellitus showed no correlation with the age or sex of the patient. Therefore, each patient should be carefully assessed for ossification severity regardless of age, sex, and the comorbidities they possess.

Imaging Features of Early Diffuse Idiopathic Skeletal Hyperostosis (pre-DISH): Analysis of Progression of Ligament Ossification over 5 Years by Computed Tomography

Introduction

Some patients who have not been diagnosed with diffuse idiopathic skeletal hyperostosis (DISH) (patients in the preclinical stage of DISH [pre-DISH]) may develop DISH in the future. However, there are currently no clearly defined diagnostic criteria for pre-DISH. This study aims to define pre-DISH by analyzing the change in the ossification extent in each intervertebral space in the thoracic and lumbar spines over time using computed tomography (CT).

Methods

Of the patients who underwent CT of the thoracic to pelvic region at least twice from 2009 to 2018, 188 who underwent CT at an interval of 5 years to 5 years and 2 months were enrolled. The prevalence of DISH during the first and second CT scans was investigated. The pre-DISH feature was defined, and the prevalence of pre-DISH on the first CT and the change after 5 years in patients with pre-DISH was investigated.

Results

Of the 188 patients, 37 (19.7%) and 48 (25.5%) were diagnosed with DISH on the first and second CT scans, respectively. Pre-DISH was defined as the ossification characterized by the modified Mata score of three contiguous intervertebral spaces with a score of ≥2 points (222; 2 points, ligament ossification of half or more of the intervertebral disc height but incomplete fusion), and 52 patients were diagnosed with pre-DISH. Of the 52 patients with a score of ≥(222), 11 (21.2%) were diagnosed with DISH 5 years later.

Conclusions

Patients who have three contiguous intervertebral spaces with a modified Mata score of 2 or 3 points should be considered pre-DISH.