Diffuse idiopathic skeletal hyperostosis association with thoracic spine kyphosis: a cross-sectional study for the Health Aging and Body Composition Study

Pelvic Roll Back Can Trigger Functional Psoas Impingement in Total Hip Arthroplasty

In most cases, impingement of the iliopsoas tendon after total hip arthroplasty is caused by acetabular component retroversion. The present case report describes a patient with functional iliopsoas impingement following total hip arthroplasty. With increasing flexibility of the hip joint after surgery, the functional adjustment to the stiff thoracolumbar spine in this patient with diffuse idiopathic skeletal hyperostosis resulted in progressive pelvic roll back. This roll back resulted in a functional iliopsoas impingement as the psoas tendon travels over the front of the pecten ossis pubis. Since excessive roll back is usually also addressed in primary total hip arthroplasty by decreasing anteversion of the acetabular component, surgeons should be aware to avoid the combination of roll back and decreased anteversion and their potential impact on iliopsoas impingement.

Construct length analysis of type B and C cervical and thoracolumbar fractures

Objectives

The purpose of this study is to identify if construct length affects the rate of surgical complications and instrumentation revision following surgical fixation of subaxial and thoracolumbar Type B and C fractures. This study evaluates the effect of ankylosing spondylitis/diffuse idiopathic skeletal hyperostosis (AS/DISH) within this population on outcomes.

Methods

Retrospective review of 91 cervical and 89 thoracolumbar Type B and C fractures. Groups were divided by construct length for analysis: short-segment (constructs spanning two or less segments adjacent to the fracture) and long-segment (constructs spanning more than two segments adjacent to the vertebral fracture).

Results

For cervical fractures, construct length did not impact surgical complications (P = 0.641), surgical hardware revision (P = 0.167), or kyphotic change (P = 0.994). For thoracolumbar fractures, construct length did not impact surgical complications (P = 0.508), surgical hardware revision (P = 0.224), and kyphotic change (P = 0.278). Cervical Type B fractures were nonsignificantly more likely to have worsened kyphosis (P = 0.058) than Type C fractures. Assessing all regions of the spine, a diagnosis of AS/DISH was associated with an increase in kyphosis (P = 0.030) and a diagnosis of osteoporosis was associated with surgical hardware failure (P = 0.006).

Conclusion

Patients with short-segment instrumentation have similar surgical outcomes and changes in kyphosis compared to those with long-segment instrumentation. A diagnosis of AS/DISH or osteoporosis was associated with worse surgical outcomes.

How does diffuse idiopathic skeletal hyperostosis affect the sagittal spinopelvic alignment in lumbar spinal stenosis patients?

OBJECTIVE

To compare the differences of spinopelvic morphology among patients with DISH, patients without DISH and normal elderly and to assess the impact of ossification extent on sagittal alignment.

METHODS

Patients with and without DISH aged > 50 years who required surgery because of lumbar spinal stenosis were enrolled in this cohort(DISH and Non-DISH groups). Also, we collected age-matched normal old outpatients as the control group(Normal group). According to ossification extent, DISH group were divided into two subgroups(T-DISH and L-DISH subgroups). Spinopelvic parameters were measured. Distribution differences of Roussouly classification were analyzed between DISH and Non-DISH group, T-DISH and L-DISH subgroup, respectively. Additionally, distribution difference of kyphotic apex vertebrae between T-DISH and L-DISH subgroup was also investigated.

RESULTS

A total of 429 patients (300 males and 129 females) were enrolled in our study, with a mean age of 64.1 ± 5.8 years. Compared to the Normal group, DISH and Non-DISH groups both had significantly higher CSVA, PT, OH, SVA, TPA and lower LL, SS, C7 Tilt, SSA, SPA. Compared to Non-DISH group, DISH group, regardless of ossification extent, had significantly higher T1 slope, CSVA, TK and SVA. Besides, T-DISH subgroup showed significant higher LL, PI, SS and SSA than L-DISH subgroup. There were significant differences of Roussouly classification distribution between T-DISH and L-DISH subgroup. In terms of kyphotic apex location, compared to relatively higher locations in T-DISH subgroup, L-DISH subgroup had apical locations predominantly in the lower thoracic.

CONCLUSION

Sagittal spinopelvic alignment is influenced by the presence of DISH and the extent of ossification. Patients with L-DISH have not only increased thoracic kyphosis and forward trunk, but also insufficient lumbar lordosis.

Stiffness and axial pain are associated with the progression of calcification in a mouse model of diffuse idiopathic skeletal hyperostosis

BACKGROUND

Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by progressive calcification of spinal tissues; however, the impact of calcification on pain and function is poorly understood. This study examined the association between progressive ectopic spine calcification in mice lacking equilibrative nucleoside transporter 1 (ENT1^-/-), a preclinical model of DISH, and behavioral indicators of pain.

METHODS

A longitudinal study design was used to assess radiating pain, axial discomfort, and physical function in wild-type and ENT1^-/- mice at 2, 4, and 6 months. At endpoint, spinal cords were isolated for immunohistochemical analysis of astrocytes (GFAP), microglia (IBA1), and nociceptive innervation (CGRP).

RESULTS

Increased spine calcification in ENT1^-/- mice was associated with reductions in flexmaze exploration, vertical activity in an open field, and self-supporting behavior in tail suspension, suggesting flexion-induced discomfort or stiffness. Grip force during the axial stretch was also reduced in ENT1^-/- mice at 6 months of age. Increased CGRP immunoreactivity was detected in the spinal cords of female and male ENT1^-/- mice compared to wild-type. GFAP- and IBA1-immunoreactivity were increased in female ENT1^-/- mice compared to wild-type, suggesting an increase in nociceptive innervation.

CONCLUSION

These data suggest that ENT1^-/- mice experience axial discomfort and/or stiffness and importantly that these features are detected during the early stages of spine calcification.

Is spinal sagittal alignment of diffuse idiopathic skeletal hyperostosis relevant to thoracolumbar pain? A controlled study

OBJECTIVES

The extension of diffuse idiopathic skeletal hyperostosis (DISH) from the low thoracic spine to the lumbar spine result in adjustment of spinal sagittal alignment in surgical patients. The aim of this study was to investigate changes in sagittal alignment and back pain in the thoracolumbar spine in nonsurgical DISH and control participants selected from a radiological database.

METHODS

Participants in the DISH and the control group were selected by searching for "DISH or degenerative changes in the thoracic spine" in the radiology database of Taizhou Hospital between 2018 and 2021 using Resnick and Niwayama's criteria. The subjects with spinal tumors, previous spinal surgery, vertebral fractures, inflammatory diseases, poor-quality radiographs, or loss of follow-up were excluded. Demographic and clinical characteristics were recorded retrospectively via the hospital information system and telephone follow-up. Segmental disc angles (SDAs), lumbar lordosis (LL), and bridge scores were analyzed using images of three-dimensional CT.

RESULTS

The final participants consisted of 51 individuals with DISH (DISH group) and 102 individuals without DISH (control group). Depending on the presence of thoracolumbar pain, the DISH group was divided into the DISH group with thoracolumbar pain (DISH+Pain) and the DISH group without thoracolumbar pain (DISH-Pain). The LL and SDAs of T11-T12 and T12-L1 were significantly greater in the DISH group than in the control group. In addition, the SDA of L1-L2 was significantly smaller in the DISH+Pain group than in the DISH-Pain group, whereas there was no significant difference in lumbar lordosis between the DISH+Pain group and the DISH-Pain group. The bridge scores in DISH+Pain group was larger in T10-T11 (p = 0.01) and L1-L2 (p < 0.01) spine segments than those in DISH-Pain group.

CONCLUSION

The extension of DISH from thoracic to lumbar spine may increase lumbar lordosis and SDAs in the thoracolumbar spine. The DISH patients with more bony bridging and small L1-L2 SDA may be more likely have thoracolumbar pain. Adjustment of sagittal alignment of the spine in the development of DISH may be of clinical importance.

The impact of the lateral decubitus position in the perioperative period on posterior fixation for thoracolumbar fracture with ankylosing spinal disorder

OBJECTIVE

Patients with ankylosing spinal disorders (ASDs), such as ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis, often have rigid kyphosis of the spine. The fracture site is sometimes unintentionally displaced when surgery is conducted with the patient prone. To prevent this incident, the authors adopted the lateral decubitus position for patients intraoperatively for this pathology. The aim of this study was to retrospectively assess the impact of the lateral decubitus position in the perioperative period on posterior fixation for thoracolumbar fractures with ASD.

METHODS

Thirty-seven consecutive patients who underwent posterior instrumentation for thoracolumbar fracture with ASD at the authors' institute were divided into 15 lateral decubitus positions (group L) and 22 prone positions (group P). Surgical time, estimated blood loss (EBL), number of levels fused, perioperative complications, length of stay (LOS), ratio of fracture voids, and ratio of anterior wall height were investigated. The ratio of fracture void and the ratio of anterior wall height were the radiological assessments showing a degree of reduction in vertebral fracture on CT.

RESULTS

Age, sex, BMI, fracture level, and LOS were similar between the groups. Levels fused and EBL were significantly shorter and less in group L (p < 0.001 and p = 0.04), but there was no significant difference in surgical time. The complication rate was similar, but 1 death within 90 days after surgery was found in group P. The ratio of fracture voids was 85.4% ± 12.8% for group L and 117.5% ± 37.3% for group P. A significantly larger number of patients with a fracture void ratio of 100% or less was found in group L (86.7% vs 36.4%, p = 0.002). The ratio of anterior wall height was 107.5% ± 12.3% for group L and 116.9% ± 18.8% for group P. A significantly larger number of patients with the anterior wall height ratio of 100% or less was also found in group L (60.0% vs 27.3%, p = 0.046).

CONCLUSIONS

The results of this study suggest that the lateral decubitus position can be expected to have an effect on closing or maintaining the fracture void or a preventive effect of intraoperative unintentional extension displacement of the fractured site, which is often seen in the prone position during surgery for thoracolumbar fractures involving ASD.

Long-Term Efficacy of Treatment Effects After a Kyphosis Exercise and Posture Training Intervention in Older Community-Dwelling Adults: A Cohort Study

BACKGROUND AND PURPOSE

Treatments that prevent worsening kyphosis are important due to the progressive nature of kyphosis with aging. We assessed long-term efficacy of treatment effects after a short-term kyphosis exercise and posture training intervention in a cohort study among older adults with hyperkyphosis, and investigated whether long-term treatment effects differ among males and females.

METHODS

In the original kyphosis intervention, 112 older adults enrolled in a waitlist design randomized controlled trial. One hundred three participants, mean age 70.0 (5.7) years and kyphosis 52.0° (7.4°), completed a twice weekly, 3-month, group exercise and posture training intervention, and were eligible to enroll in the follow-up study. We compared (1) change in outcomes pre-/postintervention to change postintervention over the follow-up period, (2) change in outcomes pre-/postintervention and postintervention to follow-up, stratified by sex, and (3) long-term change postintervention to follow-up in males and females. Primary outcome was change in kyphometer-measured thoracic kyphosis. Secondary outcomes were change in lumbar lordosis, objective measures of physical function, self-reported measures of physical activity, and health-related quality of life (HRQoL).

RESULTS AND DISCUSSION

Forty-three participants, 42% of the eligible cohort, returned for follow-up, a mean 3.0 (0.7) years after completing the original intervention. Participants (27 females and 16 males) were 73.8 (6.1) years old, with mean kyphosis 48.9° (11.9°) at follow-up. Kyphosis declined -1.5° (95% confidence interval [CI]: -3.9° to 1.0°) postintervention to follow-up and this was no different than change pre-/postintervention, P = .173. Lordosis improved 8.9° (95% CI: 6.2° to 11.6°), more than change pre-/postintervention, P < .001. Gait speed measure of physical function increased 0.08 (95% CI: 0.02 to 0.14) m/s, Physical Activity Scale for the Elderly (PASE) measure of physical activity increased 4 (95% CI: -16 to 24) points, and Patient-Reported Outcomes Measurement Information System (PROMIS) mental health T-score measure of HRQoL increased 1.1 (95% CI: -1.0 to 3.1) points, but these improvements were not significantly more than change pre-/postintervention, P > .050. Other measures of physical function (modified Physical Performance Test [PPT], Timed Up and Go, and 6-minute walk) and HRQoL (Scoliosis Research Society [SRS-30] self-image and PROMIS physical function and physical health) declined at follow-up, significantly more than change pre/postintervention, P ≤ .050. Comparing change in outcomes pre-/postintervention and postintervention to follow-up, stratified by sex, both males and females increased lordosis, and decreased modified PPT and 6-minute walk measures of physical function, P < .050. Males and females differed in long-term change postintervention to follow-up. Time loaded standing and PASE improved in females compared with males, P = .008 and P = .092, respectively, and PROMIS mental health, physical health, and physical function declined in females compared with males, P = .073, P = .025, and P = .005, respectively.

CONCLUSIONS

In our follow-up study, a mean of 3.0 (0.07) years after a 3-month kyphosis exercise and posture training intervention, kyphosis maintained and did not progress as expected with age. There was long-term improvement in lordosis. Compared with treatment effects from the short-term intervention, gait speed maintained equally well in males and females, while trunk endurance improved in females. Further investigation of long-term benefits of a short-term kyphosis exercise and posture training intervention is warranted.

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.

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.

Diffuse idiopathic skeletal hyperostosis is associated with lumbar spinal stenosis requiring surgery

Factors related to the onset and progression of lumbar spinal stenosis (LSS) have not yet been identified. Diffuse idiopathic skeletal hyperostosis (DISH) increases mechanical loading on the non-fused lumbar levels and may therefore lead to LSS. This cross-sectional study aimed to identify associations between LSS and DISH. This study included 2363 consecutive patients undergoing surgery for LSS and 787 general inhabitants without symptoms of LSS as participants of the population-based cohort study, Research on Osteoarthritis/Osteoporosis Against Disability. Standing whole-spine radiographs were used to diagnose DISH based on the criteria proposed by Resnick and Niwayama. The prevalence of DISH showed a significant step-wise increase among asymptomatic inhabitants without radiographic LSS, asymptomatic inhabitants with radiographic LSS, and patients with LSS requiring surgery (14.4, 21.1, and 31.7%, respectively; p < 0.001). The distribution of DISH was similar between the groups, but the lower thoracic and upper-middle lumbar spine regions were more frequently involved in patients with LSS requiring surgery. Multivariate analysis indicated that DISH was an independent associated factor for LSS requiring surgery (adjusted odds ratio 1.65; 95% confidence interval 1.32-2.07) after adjustment for age, sex, body mass index, and diabetes mellitus. Among patients with LSS requiring surgery, a higher occurrence of stenosis at the upper lumbar levels and multi-level stenosis were observed in patients with DISH requiring surgery than in patients without DISH. In conclusion, DISH is independently associated with LSS requiring surgery. The decrease in the lower mobile segments by DISH may increase the onset or severity of LSS.

The controlled study of diffuse idiopathic skeletal hyperostosis for the assessment of physical function in elderly populations

BACKGROUND

Diffuse idiopathic skeletal hyperostosis (DISH) is associated with increasing age, obesity, and diabetes mellitus. However, little is known about the clinical impacts of DISH on physical function and spinal deformity in elderly populations. The purpose of this study was to elucidate the influence of DISH on physical function, spinal deformity, and health-related quality of life (HRQOL) in elderly populations.

METHODS

We enrolled 504 volunteers (203 men and 301 women, mean age 74.0 years). Height, weight, body mass index (BMI), blood pressure, grip strength, one-leg standing time, sit-and-reach, functional reach, and bone mineral density (BMD) were measured. Using whole spine standing X-rays, the prevalence, location, and numbers of fused vertebra of DISH and spinopelvic parameters were measured. HRQOL measures, including the Oswestry Disability Index and the EuroQuol-5D were also obtained. We compared DISH subjects with control subjects of age and sex matching. We compared DISH subjects in the thoracic spine (T-DISH) to those in the thoraco-lumbar spine (TL-DISH).

RESULTS

DISH occurred more frequently in men (14.3%) than in women (4.3%). The mean age was significantly higher of subjects with DISH than of those without DISH. The mean number of fused vertebra by DISH was 5.5 ± 1.5, and T-DISH was observed in 57% cases. DISH group showed greater body weights, BMIs, blood pressures, and BMD in the lumbar spine compared to the control group. No inter-group differences were observed in physical function, HRQOL and spinopelvic parameters. Subjects with TL-DISH had significantly lower values of sit-and-reach and functional reach than those with T-DISH.

CONCLUSIONS

Subjects with DISH showed greater body weights, BMIs, blood pressures, and BMD compared to age- and sex-matched controls, while physical function, spinal alignment, and HRQOL were comparable between groups.

Sex differences in response to targeted kyphosis specific exercise and posture training in community-dwelling older adults: a randomized controlled trial

BACKGROUND

Hyperkyphosis, an excessive anterior curvature in the thoracic spine, is associated with reduced health status in older adults. Hyperkyphosis is highly prevalent, more common in older women than men. There is no standard intervention to reduce age-related hyperkyphosis. Sex differences in response to a kyphosis-specific exercise intervention are not known.

METHODS

We conducted a randomized controlled trial of a targeted kyphosis-specific exercise and postural training program on the primary outcome Cobb angle of kyphosis, and investigated whether the magnitude of change differed between men and women. One hundred twelve participants aged ≥60 years with kyphosis ≥40° were enrolled and randomized to exercise or waitlist control, and 101 participants had analyzable baseline and follow-up radiographs for Cobb angle measurements. A group intervention including 10 participants per group was delivered by a physical therapist, 1-h, twice a week for 3-months. Controls were placed on a waitlist for 3 months before receiving a delayed intervention. Primary outcome was change from baseline to 3-months in Cobb angle measured from standing lateral spine radiographs. Secondary outcomes included change over 3-months in kyphometer-measured kyphosis, physical function and quality of life. Groups were combined for analysis after both received the intervention, and sex differences in response to the intervention were tested with ANOVA.

RESULTS

Participants (60 women, 41 men) were 70.0 (SD = 5.7) years old with mean Cobb angle 55.9 (SD = 12.2) degrees at baseline. The active group had higher baseline modified Physical Performance Test scores than control, p = 0.03. Men had greater baseline kyphometer-measured kyphosis, p = 0.09, and higher bone mineral density (BMD), spine strength, more vertebral fractures and diffuse idiopathic skeletal hyperostosis (DISH) than women, p ≤ 0.01. There was no statistically significant difference between groups in change in Cobb at 3-months, p = 0.09, however change in kyphometer-measured kyphosis differed by 4.8 (95% CI:-6.8,-2.7) degrees, p < 0.001, favoring the active group. There were no differences between men and women in change in either kyphosis measurement after intervention, p > 0.1.

CONCLUSIONS

A 3-month targeted spine strengthening exercise and posture training program reduced kyphometer-measured, but not radiographic-measured kyphosis. Despite sex differences in baseline kyphosis, BMD, spine strength, fractures and DISH, sex did not affect treatment response.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01766674.

Age-related hyperkyphosis: update of its potential causes and clinical impacts-narrative review

The present study aims to qualitatively review the contributing factors and health implications of age-related hyperkyphosis. We conducted a narrative review of observational and cohort studies describing the risk factors and epidemiology of hyperkyphosis from 1955 to 2016 using the following key words: kyphosis, hyperkyphosis, posture, age-related hyperkyphosis, kyphotic posture, aetiology and causes. This review included 77 studies. Approximately 60-70 % of the most severe hyperkyphosis cases have no evidence of underlying vertebral compression fractures. Other proposed factors contributing to hyperkyphosis are degenerative disc disease, weakness of back extensor muscles and genetic predisposition. Strength and endurance of back extensor muscles are very important for maintaining normal postural alignment. Recent evidence suggests that age-related hyperkyphosis is not equivalent to spinal osteoporosis. Due to the negative impact of hyperkyphosis on physical function, quality of life and mortality rates, physicians should focus not only on osteoporosis, but also on age-related postural changes. More research about the relationship between spinal morphology and modifiable factors, especially the structural and functional parameters of trunk muscles, could further illuminate our understanding and treatment options for hyperkyphosis.

Diffuse Idiopathic Skeletal Hyperostosis (DISH) and Impaired Physical Function: The Rancho Bernardo Study

OBJECTIVES

Investigate associations of diffuse idiopathic skeletal hyperostosis (DISH) with self-reported and measured physical function in older adults.

DESIGN

Cross-sectional analyses of data collected in 1992-96 from a longitudinal cohort.

SETTING

Research clinic within a community.

PARTICIPANTS

Community-dwelling men (n = 630) and women (n = 961), mean age 71.5 years (SD = 10.8), from the Rancho Bernardo Study.

MEASUREMENTS

DISH assessed from lateral thoracic and lumbar spine radiographs; self-reported difficulty bending over to the floor, walking 2-3 level blocks, or climbing 1 flight of stairs; performance-based measures of grip strength and chair-stand testing (ability to stand up and sit down in a chair 5 times without using chair arms).

RESULTS

DISH was present in 25.6% of men and 5.5% of women. In age and sex-adjusted models, those with DISH had 1.72-fold increased odds (95% CI: 1.13, 2.62) of self-reported difficulty bending; this remained significant after further adjustment for Cobb angle, weight, stroke, arthritis, and exercise, OR = 1.69, (95% CI: 1.07, 2.66). In fully adjusted multivariate models, those with DISH had worse grip strength, -1.08 kg, P = .01, but did not differ from those without DISH on walking or climbing stairs. In sex-stratified, fully adjusted models, among men only, those with DISH were 2.17-times (95% CI: 1.04, 4.52) more likely to be unable to complete 5 chair stands without using their arms.

CONCLUSIONS

DISH was less prevalent in women but affected almost one-quarter of older white men. People with DISH are more likely to experience physical functional impairment, suggesting that DISH has clinical correlations and is not an incidental radiographic finding.

Cross-Sectional and Longitudinal Associations of Diffuse Idiopathic Skeletal Hyperostosis and Thoracic Kyphosis in Older Men and Women

OBJECTIVE

To investigate cross-sectional and longitudinal associations of diffuse idiopathic skeletal hyperostosis (DISH) and thoracic kyphosis in older persons.

METHODS

DISH and kyphosis were assessed in 1,500 men from the Osteoporotic Fractures in Men (MrOS) study and in 1,267 women from the Study of Osteoporotic Fractures (SOF). DISH was assessed using baseline lateral spine radiographs, and Cobb angle of kyphosis was measured from baseline and followup radiographs, a mean 4.6 years later in men, and 3.7 and 15 years later in women. Linear regression was used to analyze associations of DISH with baseline Cobb angle and with percent annualized change in Cobb angle. We tested for heterogeneity among studies.

RESULTS

DISH was identified in 222 participants in MrOS (15%) and in 156 participants in SOF (12%). Participants with DISH in both cohorts had higher baseline Cobb angles (P < 0.05), after adjustment for covariates. After approximately 4 years of followup, there was no significant difference in annualized percent change in Cobb angle in those with DISH compared to those without DISH (P > 0.05) for men or women. Women with DISH had less kyphosis progression over 15 years (0.25% less annualized change in Cobb) than those without DISH.

CONCLUSION

Prevalent DISH is associated with greater kyphosis in older men and women, and is not significantly associated with a change in kyphosis over 4-5 years. However, in women followed over 15 years, DISH was associated with less progression of kyphosis. These results suggest that DISH influences kyphosis and may slow progression over the long term. Additional studies of DISH/kyphosis associations are warranted to understand the functional implications of this finding.