Study of vertebral fracture and Scanographic Bone Attenuation Coefficient in rheumatoid arthritis and ankylosing spondylitis vs. controls

Using advanced imaging to measure bone density, compression fracture risk, and risk for construct failure after spine surgery

Low bone mineral density (BMD) can predispose to vertebral body compression fractures and postoperative instrumentation failure. DEXA is considered the gold standard for measurement of BMD, however it is not obtained for all spine surgery patients preoperatively. There is a growing body of evidence suggesting that more routinely acquired spine imaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI) can be opportunistically used to measure BMD. Here we review available studies that assess the validity of opportunistic screening with CT-derived Hounsfield Units (HU) and MRI-derived vertebral vone quality (VBQ) to measure BMD of the spine as well the utility of these measures in predicting postoperative outcomes. Additionally, we provide screening thresholds based on HU and VBQ for prediction of osteopenia/ osteoporosis and postoperative outcomes such as cage subsidence, screw loosening, proximal junctional kyphosis, and implant failure.

Assessing the association between a sedentary lifestyle and prevalence of primary osteoporosis: a community-based cross-sectional study among Chinese population

OBJECTIVES

To reveal the association between a sedentary lifestyle and the prevalence of primary osteoporosis (POP).

DESIGN

A community-based cross-sectional study was conducted.

SETTING

This study was conducted in communities in Hefei city, Anhui province, China.

PARTICIPANTS

A total of 1346 residents aged 40 and above underwent POP screening via calcaneus ultrasound bone mineral density (BMD) testing and completed a questionnaire survey.

OUTCOME MEASURES

The average daily sitting time was included in the study variable and used to assess sedentary behaviour. The 15 control variables included general information, dietary information and life behaviour information. Logistic regression was used to analyse the association between the POP prevalence and study or control variables in different models.

RESULTS

1346 participants were finally included in the study. According to the 15 control variables, the crude model and 4 models were established. The analysis revealed that the average daily sitting time showed a significant correlation with the prevalence of POP in the crude model (OR=2.02, 95% CI=1.74 to 2.36, p<0.001), Model 1 (OR=2.65, 95% CI=2.21 to 3.17, p<0.001), Model 2 (OR=2.63, 95% CI=2.19 to 3.15, p<0.001), Model 3 (OR=2.62, 95% CI=2.18 to 3.15, p<0.001) and Model 4 (OR=2.58, 95% CI=2.14 to 3.11, p<0.001). Besides, gender, age and body mass index showed a significant correlation with the POP prevalence in all models.

CONCLUSIONS

This study suggests a potential association between a sedentary lifestyle and the prevalence of POP within the Chinese population. Modifying sedentary behaviours could contribute to a reduction in POP risk. However, longitudinal cohort studies are necessary to confirm this hypothesis in the future.

Low Hounsfield unit values on computed tomography as a potential predictor of vertebral fracture in patients with rheumatoid arthritis: The KURAMA cohort study

OBJECTIVE

Hounsfield units (HU) measured using computed tomography (CT) have gained considerable attention for the detection of osteoporosis. This study aimed to investigate whether opportunistic CT could predict vertebral fractures in patients with rheumatoid arthritis (RA).

METHODS

A total of 233 patients with RA who underwent chest CT were included in this study. The HU values of the anterior 1/3 of the vertebral bodies based on the sagittal plane at T11-L2 after reconstruction were measured. The incidence of vertebral fractures was investigated with respect to the HU value.

RESULTS

Vertebral fractures were identified in 32 patients during a mean follow-up period of 3.8 years. In patients who experienced vertebral fractures within 2 years of CT imaging, the HU values of the vertebral bodies (T11-L2) were lower than those in patients who did not experience fractures. Receiver operating characteristic curve analysis identified that a T11 HU value of <125 was a risk factor for vertebral fracture within 2 years. Multivariate analysis showed that a T11 HU value of <125 and the existence of prevalent vertebral fractures were significant risk factors for fracture.

CONCLUSION

HU measurements of the anterior 1/3 of the vertebral body are a potential predictor for vertebral fractures in patients with RA.

Prevalence of Osteoporosis Assessed by DXA and/or CT in Severe Obese Patients

The primary objective was to evaluate bone fragility prevalence on dual X-ray absorptiometry (DXA) and computed tomography (CT) in patients with severe obesity. The secondary objective was to evaluate the risk factors for bone fragility. This monocentric study was conducted in patients with grade 2 and 3 obesity. Bone mineral density (BMD) and T-score were studied on DXA, and the scanographic bone attenuation coefficient of L1 (SBAC-L1) was measured on CT. Among the 1386 patients included, 1013 had undergone both DXA and CT within less than 2 years. The mean age was 48.4 (±11.4) years, 77.6% were women, and the mean BMI was 45.6 (±6.7) kg/m². Eight patients (0.8%) had osteoporosis in at least one site. The mean SBAC-L1 was 192.3 (±52.4) HU; 163 patients (16.1%) were under the threshold of 145 HU. Older age (OR[CI95] = 1.1 [1.08–1.16]), lower BMD on the femoral neck and spine (OR[CI95] = 0.04[0.005–0.33] and OR[CI95] = 0.001[0.0001–0.008], respectively), and higher lean mass (OR[CI95] = 1.1 [1.03–1.13]) were significantly associated with an SBAC-L1 ≤ 145 HU in multivariate analysis. Approximately 16% of patients with severe obesity were under the SBAC-L1 threshold, while less than 1% were classified as osteoporotic on DXA.

Relationship between ectopic calcifications and bone fragility depicted on computed tomography scan in 70 patients with systemic sclerosis

Background

A higher risk of osteoporotic fracture was described in systemic sclerosis patients than in healthy patients.

Objective

To evaluate the relation between osteoporotic fracture risk measured by the scanographic bone attenuation coefficient of the first lumbar vertebra (SBAC-L1) on computed tomography (CT) scan and the presence of ectopic calcifications: vascular, valvular and spinal.

Methods

This monocentric retrospective study was performed on patients followed between 2000 and 2014 at Nancy University Hospital. Systemic sclerosis patients, according to ACR/EULAR 2013 criteria, followed from 2000 to 2014 and who underwent, during their follow-up, a CT including the first lumbar vertebra were included. The SBAC-L1 was measured with a threshold set at 145 Hounsfield units (HU). Vascular and spinal calcifications were studied on CT. For vascular calcifications, the Agatston score was used. Valvular calcifications were studied on echocardiography.

Results

A total of 70 patients were included (mean age: 62.3 (±15.6) years, women 88.5%). The mean SBAC-L1 was 157.26 (±52.1) HU, and 35 patients (50%) presented an SBAC-L1 ⩽ 145 HU. The reproducibility of the calcification evaluation was good, with kappa coefficients varying between 0.63 and 1. In univariate analysis, spinal and vascular calcifications were associated with an SBAC-L1 ⩽ 145 HU, with ORs of 13.6 (1.6-113.3) and 8 (95%CI: 2.5-25.5), respectively. In multivariate analysis, the SBAC-L1 was not associated with the presence of any ectopic calcifications. The SBAC-L1 decreased with age (p = 0.0001).

Conclusion

Patients with systemic sclerosis with an SBAC-L1 ⩽ 145 HU were older, but they did not have more ectopic calcification.

Trial registration

The ethics committee of Nancy Hospital agreed with this study (referral file number 166). This study was designed in accordance with the general ethical principles outlined in the Declaration of Helsinki.

The prevalence of osteoporosis in rheumatoid arthritis patient: a systematic review and meta-analysis

Osteoporosis (OP) is one of the most commonly known extra-articular complications of rheumatoid arthritis (RA). Since the prevalence of OP is diverse in different studies and there is no general consensus about it, in this systematic review, we aimed to investigate the global prevalence of OP among RA patients. In this review, three databases including Medline via PubMed, Scopus, and Web of Science (Clarivate analytics) were searched by various keywords. After screening of retrieved papers, the related data of included papers were extracted and analyzed. To assess the risk of methodological bias of included studies, quality assessment checklist for prevalence studies was used. Because of heterogeneity among studies, random-effect model was used to pooled the results of primary studies. In this review, the results of 57 studies were summarized and the total included sample size was 227,812 cases of RA with 64,290 cases of OP. The summary point prevalence of OP among RA was estimated as 27.6% (95%CI 23.9-31.3%). Despite significant advances in prevention, treatment and diagnostic methods in these patients, it still seems that the prevalence of OP in these patients is high and requires better and more timely interventions.

Comparison of Clinical Manifestations in Rheumatoid Arthritis vs. Spondyloarthritis: A Systematic Literature Review

INTRODUCTION

Misclassification of spondyloarthritis (SpA) as rheumatoid arthritis (RA) may lead to delayed SpA diagnosis and suboptimal therapeutic outcomes. Here, we evaluate the literature on clinical manifestations in patients with SpA and RA, particularly seronegative RA, to understand the potential overlap, distinctions, and most reliable approaches to accurate diagnosis.

METHODS

In this systematic literature review, conducted according to PRISMA guidelines, we searched key biomedical databases for English-language publications of original research articles (up to July 23, 2020) and rheumatology conference abstracts (January 1, 2018-July 31, 2020) reporting key SpA clinical presentations in patients with SpA or RA. Publications were assessed for eligibility by two independent reviewers; discrepancies were resolved by a third. Studies were evaluated for publication quality using the Downs and Black checklist.

RESULTS

Of 4712 records retrieved, 79 met the inclusion criteria and were included in the analysis. Of these, 54 included study populations with SpA and RA, and 25 with seropositive and/or seronegative RA. Entheseal abnormalities were more frequently reported among patients with SpA than RA and with seronegative vs. seropositive RA. Psoriasis, nail psoriasis, and dactylitis were exclusively seen in SpA vs. RA. In most publications (70 of 79), advanced imaging techniques allowed for more accurate distinction between SpA and RA. Overlapping clinical characteristics occur in SpA and RA, including inflammation and destruction of joints, pain, diminished functional ability, and increased risk for comorbidities. However, of 54 studies comparing SpA and RA populations, only seven concluded that no distinction can be made based on the SpA manifestations and outcomes examined.

CONCLUSIONS

Typical SpA-related clinical symptoms and signs were observed in patients with RA, suggesting that misclassification could occur. Availability of advanced imaging modalities may allow for more prompt and comprehensive evaluation of peripheral manifestations in SpA and RA, reducing misclassification and delayed diagnosis.

Incidence and risk factors for vertebral fracture in rheumatoid arthritis: an update meta-analysis

OBJECTIVES

This study was conducted to investigate the prevalence of vertebral fracture (VF) and its risk in patients with rheumatoid arthritis (RA) as compared to healthy individuals, and to explore the underlying risk factors.

METHODS

The electronic databases of PubMed, EMBASE, and the Cochrane Library were applied to search for the relevant literatures, which reported the prevalence of VF in both RA patients and healthy controls (up to Mar 31, 2021). The non-weighted prevalence of VF, pooled estimates of odds ratio (OR), and its 95% confidence intervals (CI) were calculated with the use of random-effects model; between-study heterogeneity was evaluated by Cochrane Q statistic, then was quantified with I². Publication bias was evaluated using Egger's linear regression test.

RESULTS

A number of 867 literatures were identified after searching for online databases, based on the inclusion and exclusion criteria, 11 eligible studies, which comprising 3805 RA patients and 59,517 healthy participants, were finally incorporated in meta-analysis. The results showed that RA patients had an increased prevalence of VF (20.29 vs 8.63%), and an elevated risk for VF (OR = 3.04, 95% CI 1.97-4.71) as compared to healthy population. Additional subgroup analysis suggested that age, body mass index (BMI), disease activity, and drug therapy might be associated with risk of VF in RA.

CONCLUSIONS

Overall, our study demonstrated an increased risk of VF in patients with RA, suggesting that age, race, BMI, disease activity, and drug therapy may be represented as risk factors contributing to the occurrence of VF in RA. Key Points • RA patients had the increased prevalence and risk of vertebral fracture (VF) as compared to healthy population. • Age, race, BMI, disease activity, and drug therapy might be associated with VF in RA. • Our findings would be helpful for the early evaluation of RA patients with high VF risk.

The Prognostic Value of Vertebral Bone Density on Chest CT in Hospitalized COVID-19 Patients

The aim of this study is to evaluate the prognostic value of the vertebral bone mineral density (BMD) on chest computed tomography (CT) in COVID-19 patients. The chest CT of hospitalized patients with COVID-19 pneumonia were evaluated for Pneumonia Severity Score (PSS) as the ratio of the volume of involved lung parenchyma to the total lung volume. In addition, BMD was manually measured from the vertebral corpus using axial CT images. The relationships of clinical variables, PSS and vertebral BMD with patient outcomes, namely mortality, intensive care unit (ICU) admission and mechanical ventilation were investigated. Lower BMD was defined as ≤100 HU. The study included 209 patients (118 males, 56.4%). As a result of the univariate analysis, the rates of mortality, ICU admission and mechanical ventilation were 17.2% (n = 36), 24.8% (n = 52), and 20.6% (n = 43), respectively, and they were significantly higher among the patients with lower BMD (38.1 vs 13.0%, p < 0.001; 33.4 vs 21.2%, p = 0.002; and 38.1 vs 8.2%, p < 0.001, respectively). In the mortality group, PSS was significantly higher (median, 9 vs 5; p < 0.001) and vertebral BMD was significantly lower (median, 83 vs 139; p < 0.001). Severe clinical incidence was significantly higher in patients with lower BMD compared to those with higher BMD (39.7 vs 24.7% and p = 0.028). There was a significant correlation between clinical classification and lower BMD (r = 0.152 and p = 0.028). The multivariate analysis revealed vertebral BMD [odds ratio (OR), 1.028; 95% CI, 1.011-1.045, p = 0.001) and lower BMD (OR, 4.682; 95% CI, 1.784-12.287, p = 0.002) as significant independent predictors of mortality. Vertebral BMD is a strong independent predictor of mortality that is reproducible and can be easily evaluated on the chest CT images of COVID-19 patients.

Relationship between spinal structural damage on radiography and bone fragility on CT in ankylosing spondylitis patients

To evaluate whether the risk of bone fragility on computed tomography (CT) (scanographic bone attenuation coefficient of the first lumbar vertebra (SBAC-L1)) is associated with the severity of spine structural involvement (mSASSS) in patients with ankylosing spondylitis (AS). This retrospective study included AS patients, followed from 2009 to 2017, who fulfilled the New York criteria and who underwent thoraco-abdomino-pelvic CT and radiography (spine, pelvis). The structural involvement was retained for mSASSS ≥ 2. The SBAC-L1 was measured in Hounsfield units (HU). A SBAC-L1 ≤ 145 HU was used to define patients at risk of vertebral fracture (VF). A total of 73 AS patients were included (mean age: 60.3 (± 10.7) years, 8 women (11%), mean disease duration: 24.6 years (± 13.9)). Sixty patients (82.2%) had a mSASSS ≥ 2 (mean score 20.7 (± 21.2)). The mean SBAC-L1 was 141.1 HU (± 45), 138.1 HU (± 44.8) and 154.8 HU (± 44.9) in the total, mSASSS ≥ 2 and mSASSS < 2 populations, respectively. Patients with bone bridges had lower SBAC-L1 than mSASSS ≥ 2 patients without ankylosis (p = 0.02) and more often SBAC-L1 ≤ 145 HU (73% vs 41.9%, p = 0.006). A SBAC-L1 ≤ 145 HU was not associated with structural spine involvement, but patients with bone bridges had significantly decreased SBAC-L1 and an increased probability of being under the fracture threshold.

No relationship between bone mineral density and syndesmophyte formation at the same level in the lumbar spine of patients with radiographic axial Spondyloarthritis

Objective

To investigate if in radiographic axial Spondyloarthritis (r-axSpA) low vertebral bone mineral density (BMD) is associated with development of new syndesmophytes at the same vertebral level.

Methods

In a post-hoc analysis from the ASSERT trial (infliximab vs placebo), dual-energy X-ray absorptiometry was used to measure baseline BMD (g/cm²) of the lumbar spine L1 to L4. Syndesmophyte formation was assessed in the same vertebrae on conventional radiographs defined as an increase in modified Stoke Ankylosing Spondylitis Spine Score from 0 or 1 to 2 or 3 after 2 years. Radiographs were scored by two readers. Generalised estimating equations (GEE) adjusted for within-patient correlation across multiple vertebrae, taking potential confounders into account.

Results

We analysed 599 vertebrae in 165 r-axSpA patients (78% male, mean (SD) age 38 (10) years, 67% with at least one syndesmophyte anywhere in the spine). In total, 24 to 74 new syndesmophytes developed in 9 (5%) to 30 (18%) patients and 13 (2%) to 39 (7%) vertebrae, if either a syndesmophyte was seen by both or only one of the readers (ie, specific and sensitive definitions) respectively. In multivariable analyses, no association was found between baseline local vertebral BMD and new syndesmophyte formation after 2 years: adjOR (95% CI): 0.56 (0.01, 44.45) (specific definition) and 0.26 (0.03, 2.63) (sensitive definition).

Conclusion

In patients with active and established r-axSpA, with an observed low incidence of lumbar spine syndesmophyte formation over 2 years, no relationship was found between baseline BMD and new radiographic syndesmophyte formation at the same vertebra.

Tocilizumab controls bone turnover in early polymyalgia rheumatica

OBJECTIVES

This study explores changes in the bone homeostasis by testing the N-terminal collagen type I extension propeptide (PINP) marker for osteo-formation and the carboxy-terminal region of collagen type I (CTX-I) marker for osteo-resorption in patients taking tocilizumab for polymyalgia rheumatica (PMR).

METHODS

Twenty patients were included in the prospective open-label TENOR study (Clinicaltrials.gov NCT01713842) and received three monthly tocilizumab infusions, followed by corticosteroids starting at week (W) 12. PINP and CTX-I were tested at inclusion (W0), after tocilizumab but before steroid initiation (W12), at the end of the protocol (W24) and were compared to healthy controls. Information regarding disease activity, bone mineral density using scanographic bone attenuation correlation (SBAC), inflammatory parameters and interleukin (IL)-6 levels were collected during the follow-up of the patients.

RESULTS

PMR patients were characterised by a reduction in bone mineral density and a higher level of CTX-I relative to healthy controls matched in age and sex at baseline. PINP levels increased at W12 (P< 0.001, versus W0) following tocilizumab introduction and CTX-I levels decreased at W24 and after steroid initiation (P=0.001, versus W0). Such modifications explain the altered correlation observed between PINP and CTX-I at W0 (r=0.255 at W0 versus r=0.641 in healthy controls) and its correction after treatment (r=0.760 at W12 and r=0.767 at W24). Finally, greater changes in PINP were observed in patients whose circulating IL-6 levels decreased after tocilizumab therapy.

CONCLUSIONS

Control of bone turnover, in part through the inhibition of the IL-6 axis, is observed during tocilizumab and subsequent steroid treatment of PMR.

Consequences of spinal ankylosis on bone trabecular fragility assessed on CT scans in patients with ankylosing spondylitis. A retrospective study

INTRODUCTION

Ankylosing spondylitis (AS) patients seems to be at risk of osteoporosis but bone screening is not often performed. The objective was to evaluate the effect of vertebral ankylosis on scanographic bone attenuation coefficient (SBAC) on lumbar vertebrae in AS patients.

METHODS

This study included AS patients fulfilling New York criteria who underwent both thoraco-abdomino-pelvic computed tomography and X-rays during routine follow-up. The modified stoke ankylosing spondylitis spinal score (mSASSS) was scored on X-rays, and the presence of at least one syndesmophyte (mSASSS≥2) defined mSASSS+ patients. Ankylosis of a lumbar vertebra was defined by the presence of bone bridges to its two adjacent vertebrae. The SBAC was measured from L1 to L5, and the fracture threshold was set at SBAC≤145 HU.

RESULTS

A total of 73 AS patients were included (mean age: 60.3 [±10.7] years, 65 men [89%]). Sixty patients (82.2%) were mSASSS+; 13 patients (17.8%) presented ankylosis of at least one lumbar vertebra. The SBAC of each lumbar vertebra was not significantly different between mSASSS- and mSASSS+ patients. The SBAC was lower for patients with at least one bone bridge than for patients without (P<0.05). Patients with lumbar vertebral ankylosis had a higher risk of presenting an SBAC≤145 HU (OR: 4.95 (95% CI: 1.1-17.4)).

CONCLUSION

The presence of a bone bridge and complete ankylosis of lumbar vertebra were associated with a higher risk of SBAC under the fracture threshold, suggesting structural deterioration of trabecular bone in ankylosed vertebrae in AS patients.