Trabecular Bone Score Is a Useful Parameter for the Prediction of Vertebral Fractures in Patients With Polymyalgia Rheumatica

Update on the clinical use of trabecular bone score (TBS) in the management of osteoporosis: results of an expert group meeting organized by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO), and the International Osteoporosis Foundation (IOF) under the auspices of WHO Collaborating Center for Epidemiology of Musculoskeletal Health and Aging

PURPOSE

Trabecular bone score (TBS) is a grey-level textural measurement acquired from dual-energy X-ray absorptiometry lumbar spine images and is a validated index of bone microarchitecture. In 2015, a Working Group of the European Society on Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) published a review of the TBS literature, concluding that TBS predicts hip and major osteoporotic fracture, at least partly independent of bone mineral density (BMD) and clinical risk factors. It was also concluded that TBS is potentially amenable to change as a result of pharmacological therapy. Further evidence on the utility of TBS has since accumulated in both primary and secondary osteoporosis, and the introduction of FRAX and BMD T-score adjustment for TBS has accelerated adoption. This position paper therefore presents a review of the updated scientific literature and provides expert consensus statements and corresponding operational guidelines for the use of TBS.

METHODS

An Expert Working Group was convened by the ESCEO and a systematic review of the evidence undertaken, with defined search strategies for four key topics with respect to the potential use of TBS: (1) fracture prediction in men and women; (2) initiating and monitoring treatment in postmenopausal osteoporosis; (3) fracture prediction in secondary osteoporosis; and (4) treatment monitoring in secondary osteoporosis. Statements to guide the clinical use of TBS were derived from the review and graded by consensus using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

A total of 96 articles were reviewed and included data on the use of TBS for fracture prediction in men and women, from over 20 countries. The updated evidence shows that TBS enhances fracture risk prediction in both primary and secondary osteoporosis, and can, when taken with BMD and clinical risk factors, inform treatment initiation and the choice of antiosteoporosis treatment. Evidence also indicates that TBS provides useful adjunctive information in monitoring treatment with long-term denosumab and anabolic agents. All expert consensus statements were voted as strongly recommended.

CONCLUSION

The addition of TBS assessment to FRAX and/or BMD enhances fracture risk prediction in primary and secondary osteoporosis, adding useful information for treatment decision-making and monitoring. The expert consensus statements provided in this paper can be used to guide the integration of TBS in clinical practice for the assessment and management of osteoporosis. An example of an operational approach is provided in the appendix. This position paper presents an up-to-date review of the evidence base, synthesised through expert consensus statements, which informs the implementation of Trabecular Bone Score in clinical practice.

Trabecular bone score in rheumatic disease

Patients with rheumatic diseases (RD) are at high risk of osteoporosis (OP) and osteoporotic fractures. The Trabecular bone score (TBS) is a relatively novel method of assessing bone quality, which independently predicts fracture risk regardless of bone mineral density (BMD). A lower TBS in patients with RD compared to controls is shown in most studies concerning TBS and RD. The data obtained indicate that TBS predicts fractures better in RD, especially in patients receiving glucocorticoids, than BMD or the FRAX algorithm. TBS degradation has been associated with disease activity in ankylosing spondylitis, systemic sclerosis, and rheumatoid arthritis in a few studies. However, there is little data in the literature on the effect of rheumatic disease therapy and OP treatment in patients with RD on predictive ability of TBS for incident fracture.

Trabecular Bone Score in Rheumatic Disease

PURPOSE OF REVIEW

Patients with rheumatic disease are at high risk of low bone mass and osteoporotic fracture. Trabecular bone score (TBS), derived from lumbar spine dual-energy x-ray absorptiometry (DXA), is a novel measure of bone texture that independently predicts fracture risk. This review examines the role of TBS in rheumatic disease including fracture prediction.

RECENT FINDINGS

Most studies concerning TBS and rheumatic disease are cross-sectional, with consistent evidence of lower TBS in patients with rheumatic disease compared to controls. Recent studies have shown association and predictive ability of TBS for prevalent fracture, and the few longitudinal studies showed predictive ability of TBS for incident fracture. TBS in ankylosing spondylitis is of interest given the high rates of vertebral fracture and technical difficulty with lumbar spine bone mineral density. TBS degradation has been associated with disease activity in ankylosing spondylitis, systemic sclerosis, and rheumatoid arthritis. Glucocorticoid exposure is associated with lower TBS, and predicts prevalent fracture, in patients with rheumatic conditions.

Retrospective Analysis of Factors Associated with Fracture in 714 Patients with Polymyalgia Rheumatica

Introduction

Polymyalgia rheumatica (PMR) is a disease of the elderly, associated with increased fracture risk due to glucocorticosteroid (GC) treatment with the additional possible influence of chronic inflammation. Risk factors for fracture in PMR have not been extensively studied. Hip structure analysis (HSA) is a way to measure bone morphology in the hip using dual X-ray absorptiometry (DEXA). It has been used as a predictor of fracture in epidemiological settings. HSA has not been studied in PMR before.

Objectives

The object of this retrospective study was to determine if fracture risk in PMR was associated with densitometry data and to determine the influence, if any, of HSA on that association.

Methods

714 patients with PMR referred for a bone density estimate at a district general hospital from June 2004 to October 2010 were studied. Demographic data, GC use, alcohol consumption, smoking status, secondary osteoporosis, and fracture history were recorded. Bone mineral density (BMD), Z score, T score, body composition data, and HSA measurements were collected. These were geometric measurements taken from 2-dimensional DEXA images of the hip. Fracture was modelled as an outcome variable using logistic regression models, adjusted for age and sex. And the fit of the model was assessed by comparing the area under the curve (AUC).

Results

714 patients were studied, 532 (75%) were female, and mean age was 70.5 with SD of 8.8. 703 (98%) had been treated with GCs. Lumbar and femoral BMD models were significantly associated with fracture. Right femur OR 0.062 (0.014-0.285), left femur OR 0.098 (0.023-0.412), right femoral neck 0.078 (0.014-0.43), left femoral neck 0.104 (0.022-0.492), L1 0.192 (0.066-0.56), L2 OR 0.138 (0.053-0.358), L3 0.192 (0.079-0.463), and L4 0.243 (0.108-0.544). Cross-sectional area was the only HSA parameter that was associated with fracture OR 0.988 (0.980–0.997).

Conclusion

L2 association models were strongest. Prospective studies are needed to elucidate whether these factors predict future fracture. GC data were binary, not reflecting dose and duration.

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.

Fracture Risk and Its Prevention Patterns in Korean Patients with Polymyalgia Rheumatica: a Retrospective Cohort Study

BACKGROUND

To evaluate the incidence of fractures and fracture risk factors in Korean patients with polymyalgia rheumatica (PMR).

METHODS

All PMR patients who visited a rheumatology clinic at a tertiary referral hospital between March 2005 and March 2018 were retrospectively assessed. We estimated bone mineral density (BMD) screening rate within 6 months of the first visit and classified the patients according to the performance and results of BMD screening. Incidence rates (IRs) of fractures were calculated in each group and risk factors for fractures were identified using Poisson regression analysis.

RESULTS

A total of 95 PMR patients with median (interquartile range) age of 64.0 (56.0-72.0) years were included. Baseline BMD was assessed in only 55.8% of these patients (n = 53); 24 patients with osteoporosis, 20 with osteopenia, and 9 with normal BMD. During 433.1 person-years (PYs) of observation, 17 fractures occurred in 12 patients (IR, 3.93 [95% confidence interval (CI), 2.46-6.26]/100 PYs); 8.32 (95% CI, 4.09-16.90)/100 PYs in the osteopenia group, 3.40 (95% CI, 1.30-8.90)/100 PYs in the osteoporosis group, and 3.37 (95% CI, 1.53-7.39)/100 PYs in the no BMD test group. Risk factors for fractures were female sex, advanced age (≥ 65 years), longer follow-up duration, initial glucocorticoid dose ≥ 10 mg/day, and higher cumulative glucocorticoid dose over the first 6 months.

CONCLUSION

The incidence rate of fractures in Korean patients with PMR was 3.93/100 PYs. Female sex, advanced age, longer follow-up duration, and increased glucocorticoid dose are risk factors for osteoporotic fracture.

Clinical Utility of Trabecular Bone Score (TBS) in Fracture Risk Assessment of Patients with Rheumatic Diseases Treated with Glucocorticoids

Chronic glucocorticoid therapy is associated with osteoporosis and can cause fractures in up to 50% of patients. Increased risk of fractures in patients with glucocorticoid-induced osteoporosis does not result only from the decreased bone mineral density (BMD) but also bone microarchitecture deterioration. Trabecular bone score (TBS) is a method complementary to DXA, providing additional information about trabecular bone structure. The aim of this study was to assess the clinical utility of TBS in fracture risk assessment of patients treated with glucocorticoids. Patients with rheumatic diseases treated with glucocorticoids for at least 3 months were enrolled. All recruited patients underwent DXA with additional TBS assessment. We analyzed the frequency of osteoporosis and osteoporotic fractures and assessed factors that might be associated with the risk of osteoporotic fractures. A total of 64 patients were enrolled. TBS and TBS T-score values were significantly lower in patients with osteoporosis compared to patients without osteoporosis. Low energy fractures occurred in 19 patients. The disturbed bone microarchitecture was found in 30% of patients with fractures without osteoporosis diagnosis based on BMD. In the multivariate analysis, only TBS and age were significantly associated with the occurrence of osteoporotic fractures. TBS reflects the influence of glucocorticoid therapy on bone quality better than DXA measured BMD and provides an added value to DXA in identifying the group of patients particularly prone to fractures.

Discriminative ability of trabecular bone score over bone mineral density for vertebral and fragility fracture in patients treated with long-term and low-dose glucocorticoid

AIM

To evaluate the ability of the trabecular bone score (TBS) to discriminate vertebral fracture (VF) and fragility fracture (FF) in patients with chronic inflammatory rheumatic diseases on long-term and low-dose glucocorticoid (GC) treatment and those without exposure to GC.

METHODS

This study assessed TBS and bone mineral density (BMD) in chronic GC users, defined as ≥2.5 mg/d of prednisone for >3 months (n = 89, mean age: 62.5 ± 11 years), and in controls (n = 59, mean age: 60.3 ± 9.6 years). Osteoporosis risk factors, radiographs of the thoracolumbar spine, non-VF history, osteoporosis drugs, and current/cumulative GC doses were collected. Patients were classified as high (TBS <1.23), intermediate (1.23-1.31), or low risk (>1.31), according to the fracture risk based on a recent meta-analysis.

RESULTS

The mean current dose and duration of GC treatment were 3.9 ± 1.9 mg/d and 3.9 ± 4.2 years, respectively. The prevalence of VF was significantly higher in chronic GC users than in controls (20.2% vs 5.1%, P = .010), although the prevalence of non-VF was similar (11.2% vs 5.1%). The GC group had significantly lower L1-L4 TBS and femur total BMD than did the controls (all with P < .01) without significantly different lumbar BMD. TBS (<1.31) showed a higher sensitivity for patients with VF and FF (83.3% and 81.8%, respectively) than with densitometric osteoporosis in the GC group (61.1% and 59.1%, respectively). Using the receiver operating characteristic curve, TBS <1.31 showed better diagnostic accuracy than TBS <1.23 and BMD in chronic GC users.

CONCLUSION

TBS is more sensitive than BMD in detecting VF and FF in chronic GC users, even at a lower dose.

Glucocorticoids and Trabecular Bone Score

TBS (Trabecular Bone Score) is the latest tool for clinicians to evaluate bone micro-architecture based on a pixel greyscale, which is provided by lumbar dual-energy X-ray absorptiometry (DXA). Its use enhances fracture prediction in addition to DXA-BMD (Bone Mineral Density). This is independent of fracture risk assessment (FRAX) and DXA results. We present a narrative review regarding the connection between TBS and Glucocorticoids (GC), either as a drug used for different conditions or as a tumor-produced endogenous excess.

TBS is a better discriminator for GC-induced vertebral fractures compared to DXA-BMD. This aspect is similarly available for patients with osteoporosis diagnosed by DXA. TBS is inversely correlated with the cumulative dose of GC (systemic or inhaled), with disease duration, and positively correlated with respiratory function in patients with asthma. Low TBS values are found in females with a T-score at the hip within the osteoporosis range, with diabetes mellitus, or who use GC. Lumbar TBS is a screening tool in menopausal women with type 2 diabetes mellitus. TBS is an independent parameter that provides information regarding skeleton deterioration in diabetic patients receiving GC therapy in a manner complementary to DXA-BMD. TBS might become an essential step regarding the adrenalectomy decision in patients with adrenal incidentaloma in whom autonomous cortisol secretion might damage bone micro-architecture. TBS currently represents a standard tool of fracture risk evaluation in patients receiving GC therapy or with endogenous Cushing’s syndrome, a tool easy to be applied by different practitioners since GCs are largely used

What Role Does Trabecular Bone Score Play in Chronic Inflammatory Rheumatic Diseases?

Patients suffering from rheumatic inflammatory diseases, e.g., systemic sclerosis, rheumatoid arthritis, and ankylosing spondylitis, are at risk of low bone mass. Dual-energy X-ray Absorptiometry (DXA) is the traditional radiological measurement technique for bone mineral density (BMD). The recently developed trabecular bone score (TBS) enhances the skeletal information provided by standard BMD. It re-analyzes the spatial dynamics of pixel intensity changes in lumbar spine DXA images, defining a quantitative index, characterizing trabecular bone microarchitecture. It has been demonstrated that low TBS values are associated with an increased incidence of fractures in patients with rheumatic diseases. These methods used together for bone damage evaluation can be of value to identify individuals who will potentially fracture. The main scientific literature on the clinical aspects of osteoporosis, including the use of TBS in evaluating this pathology, are herein reported aimed at shedding light on the role trabecular bone score plays in chronic inflammatory rheumatic diseases.

Trabecular Bone Score-An Emerging Tool in the Management of Osteoporosis

Areal bone mineral density (aBMD) is currently the gold standard for the diagnosis of osteoporosis, however, it has its own pitfalls. Trabecular bone score (TBS), a novel tool in the evaluation of osteoporosis is an indirect indicator of bone microarchitecture. It is a textural index that evaluates pixel gray-level variations in the lumbar spine DXA (dual energy X-ray absorptiometry) image. Both cross-sectional and longitudinal studies have demonstrated that TBS may independently predict fragility fractures. TBS can also be used to adjust FRAX probabilities of fracture, though data available till date doesn't support any additional benefit. TBS also shows an improving trend with anti-osteoporotic treatment; however, the least significant change (LSC) is high that it takes more than 2 years for the change to manifest. TBS is also used in the evaluation of bone strength in cases of secondary osteoporosis. Though TBS predicts fracture risk independently in both genders, with the currently available data, it cannot be recommended as a standalone tool for decision regarding treatment of osteoporosis. TBS can be used as a tool to complement BMD in assessment of bone health. Additional studies are needed to assess its utility in clinical practice.

[Evaluation of the trabecular bone score (TBS) in routine clinical care of patients with inflammatory rheumatic and non-inflammatory diseases : Correlation with conventional bone mineral density measurement and prevalence of vertebral fractures]

Hintergrund

Osteoporosebedingte Frakturen sind bei Patienten mit rheumatoider Arthritis (RA) häufig. Die Messung der Knochenmineraldichte (KDM) mit der Dual-Energie-Röntgenabsorptionsmessung (DXA) allein sagt das Frakturrisiko nur begrenzt voraus. Der Trabecular Bone Score (TBS) ist ein Surrogatmarker für die trabekuläre Mikroarchitektur des Knochens, der das Frakturrisiko unabhängig von der KDM vorhersagen kann.

Ziel

Ermittlung der Prävalenz von KDM, TBS und osteoporotisch bedingten Wirbelkörperbrüchen („vertebral fractures“ [VF]) bei Patienten mit RA im Vergleich zu Kontrollen mit nichtentzündlichen Muskel-Skelett-Erkrankungen (MSK).

Methoden

Die Daten von Patienten mit von Rheumatologen diagnostizierter RA und verfügbaren TBS- und DXA-Messungen, die in unserem Krankenhaus von 2006 bis 2014 erhoben wurden, wurden retrospektiv analysiert. Den RA-Patienten wurden Kontrollen mit nichtentzündlichen MSK zugeordnet. Eine „reduzierte Knochengesundheit“ wurde definiert als ein T‑Score <−1,0 und/oder ein TBS-Wert <−1,31. Statistische Vergleiche wurden mit dem Mann-Whitney- und dem Wilcoxon-Test durchgeführt.

Ergebnisse

Es wurden 143 Patienten mit RA (Alter 72,1 ± 11,1 Jahre, 72 % weiblich) und 106 Kontrollen (Alter 69,6 ± 12,6 Jahre, 75 % weiblich) eingeschlossen. RA-Patienten hatten häufiger eine erniedrigte KDM (n = 102; 71,3 %) und einen erniedrigen TBS-Wert (n = 125; 87,4 %) als die Kontrollen (n = 63; 59,4 % und n = 79; 74,5 %, p = 0,049 und p = 0,009). RA-Patienten hatten mehr VF (n = 52, 36,4 %) als Kontrollen (n = 24, 22,6 %, p = 0,02). Insgesamt hatten 20 Patienten mit VF (26,3 %) eine normale Wirbelsäulen-KDM und 9 (11,8 %) auch eine normale Hüft-KDM. Bei Patienten mit VF war die Kombination eines niedrigen TBS bei normaler WS-KDM häufiger als ein normaler TBS bei niedriger WS-KDM (p = 0,008 für RA, p = 0,025 für Kontrollen).

Diskussion

VF treten bei Patienten mit normaler KDM auf. Bei Patienten mit VF wurde eine niedrige TBS bei normaler Wirbelsäulen-KDM häufiger gefunden als eine normale TBS bei niedriger Wirbelsäulen-KDM. Die Messung des TBS scheint für die Erkennung eines erhöhten Frakturrisikos bei RA-Patienten mit normaler WS-KDM nützlich zu sein.