Structure and strength of the distal radius in female patients with rheumatoid arthritis: a case-control study

Complications After Open Reduction and Internal Fixation for Distal Radius Fractures in Patients With and Without Rheumatoid Arthritis

PURPOSE

Rheumatoid arthritis (RA) can have severe impact on patients' functional abilities and increase the risk of fragility fractures. Little is known about how patients with RA fare after operative management of distal radius fractures. The purpose of this study was to compare postoperative complications after surgical fixation in patients with RA and controls, hypothesizing that patients with RA would have higher levels of postoperative complications.

METHODS

Patients were identified using Current Procedural Terminology and International Classification of Diseases, Ninth and Tenth Revision, codes for open treatment of distal radius fractures and RA at 3 level 1 trauma centers over a 5-year period (2015-2019). Chart abstraction provided details regarding injuries and treatment. Age- and sex-matched controls were identified in a 2:1 ratio. Postoperative complications were classified according to the Clavien-Dindo-Sink classification system and divided into early (less than 90 days) and late groups.

RESULTS

Sixty-four patients (21 with RA and 43 controls) were included. The patients were predominantly women, with a mean age of 62 years and a mean Charlson comorbidity index of 2.1. The RA medications at the time of injury included conventional synthetic disease-modifying antirheumatic drugs (5/21), biologic disease-modifying antirheumatic drugs (5/21), or chronic oral prednisone (6/21). Rheumatoid medications, except hydroxychloroquine, were withheld for 2-3 weeks after surgery. Rheumatoid patients were significantly more likely to sustain a complication compared with the control group, although this was no longer significant on adjusted analysis. Class I complications were the most common. The incidence of early versus late complications was similar between the groups. A high rate of early return to surgery for fixation failure occurred in the RA group compared with none in the control group.

CONCLUSIONS

Patients with RA undergoing operative management of distal radius fractures are at risk of postoperative complications, particularly fracture fixation failure, necessitating return to the operative room. High levels of pain, stiffness, and mechanical symptoms were noted in the RA group.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Role of denosumab in bone erosions in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic inflammation and synovitis which evolve into joint destruction and deformity. Bone abnormalities are represented by marginal bone erosions and iuxta-articular and generalized osteoporosis. Overactivation of osteoclasts along with dysregulation of osteoblasts are the key events. Bone resorption is mediated by the receptor activator of nuclear factor (NF)-κB (RANK) ligand (RANK-L), responsible for the differentiation, proliferation, and activation of osteoclasts. RANK-L binds its receptor RANK, localized on the surface of preosteoclasts and mature osteoclasts promoting osteoclastogenesis. High levels of RANK-L were demonstrated in active RA patients. Denosumab, a fully human monoclonal antibody, binds RANK-L and suppresses the RANK-RANK-L signaling pathway leading to the inhibition of osteoclastogenesis. A retrospective analysis of published studies such as clinical trials evidenced the efficacy of denosumab in preventing bone erosion progression in RA patients. Key messages Key questions to answer in future include the following: Could denosumab be associated with other biologic therapies in RA patients? Could denosumab block the progression of bone damage in RA? Could denosumab be used for the prevention of bone erosion in RA?

Comparison of bone microstructure and strength in the distal radius and tibia between the different types of primary hypertrophic osteoarthropathy: an HR-pQCT study

Primary hypertrophic osteoarthropathy (PHO) is a hereditary bone disease that is grouped into PHO autosomal recessive 1 (PHOAR1) and PHO autosomal recessive 2 (PHOAR2) due to different causative genes. Data comparing bone microstructure between the two subtypes are scarce. This is the first study to find that PHOAR1 patients had inferior bone microstructure compared with PHOAR2 patients.

PURPOSE

The primary goal of this study was to assess bone microarchitecture and strength in PHOAR1 and PHOAR2 patients and to compare them with age- and sex-matched healthy controls (HCs). The secondary goal was to assess the differences between PHOAR1 and PHOAR2 patients.

METHODS

Twenty-seven male Chinese PHO patients (PHOAR1 = 7; PHOAR2 = 20) were recruited from Peking Union Medical College Hospital. The areal bone mineral density (aBMD) was assessed by dual-energy X-ray absorptiometry (DXA). Peripheral bone microarchitecture at the distal radius and tibia were evaluated by high-resolution peripheral quantitative computed tomography (HR-pQCT). Biochemical markers of PGE2, bone turnover, and Dickkopf-1 (DKK1) were investigated.

RESULTS

Compared with HCs, PHOAR1 and PHOAR2 patients had distinctively larger bone geometry, substantially lower vBMD at the radius and tibia, and compromised cortical microstructure at the radius. For trabecular bone, PHOAR1 and PHOAR2 patients showed different changes at the tibia. PHOAR1 patients had significant deficits in the trabecular compartment, resulting in lower estimated bone strength. Conversely, PHOAR2 patients showed a higher trabecular number, narrower trabecular separation, and lower trabecular network inhomogeneity than HCs, translating into preserved or slightly high estimated bone strength.

CONCLUSION

PHOAR1 patients had inferior bone microstructure and strength compared with PHOAR2 patients and HCs. Additionally, this study was the first to find differences in the bone microstructure between PHOAR1 and PHOAR2 patients.

A novel visceral adiposity index predicts bone loss in female early rheumatoid arthritis patients detected by HR-pQCT

The purpose of this prospective study is to compare the Chinese visceral adiposity index (CVAI) between early rheumatoid arthritis (ERA) patients and healthy controls; and to assess the relationship between CVAI and the bone microstructure using high-resolution peripheral quantitative computed tomography (HR-pQCT) in ERA patients. 104 female ERA and 100 age-, gender- and BMI-matched healthy controls were recruited for the comparison of CVAI. All ERA patients were prospectively followed for 1 year. HR-pQCT scan of the distal radius, tibia and second metacarpal head were performed at baseline and after one-year. ERA patients were divided into two sub-groups according to the median CVAI value (65.73) (low CVAI and high CVAI groups). CVAI in the ERA group was significantly higher than the controls group (p = 0.01). At baseline, the high CVAI group had a higher ESR level (p = 0.004) while the cortical volumetric bone mineral density (vBMD) was lower (at both the distal radius and tibia, all p < 0.05) compared to the low CVAI group. Linear regression analysis revealed that a higher baseline CVAI was an independent predictor of a lower cortical vBMD at month 12 (distal radius: B = - 0.626, p = 0.022, 95%CI - 1.914  to  - 0.153; tibia: B = - 0.394, p = 0.003, 95%CI - 1.366 to - 0.290); and a greater reduction in trabecular vBMD (tibia: B = 0.444, p = 0.001, 95%CI 0.018-0.063; distal radius: B = 0.356, p = 0.008, 95%CI 0.403-0.063). In summary, CVAI is an independent predictor of trabecular bone loss in female patients with ERA, which may be augmented by a chronic inflammatory state in patients with visceral dysfunction of fat metabolism.Trial registration: http://Clinicaltrial.gov no: NCT01768923, 16/01/2013.

Bone Geometry, Density, Microstructure, and Biomechanical Properties in the Distal Tibia in Patients With Primary Hypertrophic Osteoarthropathy Assessed by Second-Generation High-Resolution Peripheral Quantitative Computed Tomography

Periosteosis refers to pathological woven bone formation beneath the cortical bone of the long bones. It is an imaging hallmark of primary hypertrophic osteoarthropathy (PHO) and also considered as one of the major diagnostic criteria of PHO patients. Up to date, detailed information on bone quality changes in long bones of PHO patients is still missing. This study aimed to evaluate bone microarchitecture and bone strength in PHO patients by using high-resolution peripheral quantitative computed tomography (HR-pQCT). The study comprised 20 male PHO patients with the average age of 27.0 years and 20 age- and sex-matched healthy controls. The areal bone mineral density (aBMD) was assessed at the lumbar spine (L₁ -L₄ ) and hip (total hip and femoral neck) by dual-energy X-ray absorptiometry (DXA). Bone geometry, volumetric bone mineral density (vBMD), and microstructure parameters at the distal tibia were evaluated by using HR-pQCT. Bone strength was evaluated by finite element analysis (FEA) based on HR-pQCT screening at distal tibia. Urinary prostaglandin E₂ (PGE₂ ), serum phosphatase (ALP), beta-C-telopeptides of type I collagen (β-CTX), soluble receptor activator of nuclear factor-κB ligand (sRANKL), osteoprotegerin (OPG), and neuronal calcitonin gene-related peptide (CGRP) were investigated. As compared with healthy controls, PHO patients had larger bone cross-sectional areas; lower total, trabecular, and cortical vBMD; compromised bone microstructures with more porous cortices, thinned trabeculae, reduced trabecular connectivity, and relatively more significant resorption of rod-like trabeculae at distal tibia. The apparent Young's modulus was significantly lower in PHO patients. The concentration of PGE₂ , biomarkers of bone resorption (β-CTX and sRANKL/OPG ratio), and the neuropeptide CGRP were higher in PHO patients versus healthy controls. PGE₂ level correlated negatively with vBMD and estimated bone strength and positively with bone geometry at distal tibia. The present HR-pQCT study is the first one illustrating the microarchitecture and bone strength features in long bones. © 2021 American Society for Bone and Mineral Research (ASBMR).

Is There an Association Between Bone Microarchitecture and Fracture in Patients who were Treated for High-grade Osteosarcoma? A Controlled Study at Long-term Follow-up Using High-resolution Peripheral Quantitative CT

BACKGROUND

Neoadjuvant chemotherapy in patients with primary osteosarcoma improves survival rates, but it also causes side effects in various organs including bone. Low bone mineral density (BMD) can occur owing partly to chemotherapy or limited mobility. This can cause a higher risk of fractures compared with those who do not receive such treatment. Changes in BMD alone cannot explain the propensity of fractures. Studying microarchitectural changes of bone might help to understand the effect.

QUESTIONS/PURPOSES

(1) Do patients who were treated for osteosarcoma (more than 20 years previously) have low BMD? (2) Do these patients experience more fractures than controls who do not have osteosarcoma? (3) What differences in bone microarchitecture are present between patients treated for high-grade osteosarcoma and individuals who have never had osteosarcoma?

METHODS

We contacted 48 patients who were treated for osteosarcoma and who participated in an earlier study. These patients underwent multimodal treatment including chemotherapy more than 20 years ago. Of the original patient group, 60% (29 of 48) were missing, leaving 40% (19 of 48) available for inclusion in this study; all 19 agreed to participate. There were nine men and 10 women with a mean age of 46 ± 4 years and a mean time from surgery to examination of 28 ± 3 years. BMD was measured by dual-energy x-ray absorptiometry, and any fracture history was assessed using a questionnaire. Additionally, high-resolution peripheral quantitative CT was performed to compare the groups in terms of microarchitectural changes, such as cortical and trabecular area, cortical and trabecular thickness, cortical porosity, and endocortical perimeter. Participants in the control group were selected from a cohort consisting of a population-based random sample of 499 healthy adult women and men. Osteoporosis or low BMD was not an exclusion criterion for entering this study; however, the patients in the control group were selected based on a normal BMD (that is, T score > -1.0 at both the spine and hip). Also, the participants were matched based on age and sex. Differences between patients and controls were assessed using the Wilcoxon rank sum test for continuous variables and a chi-square test for categorical variables. A multiple regression analysis was performed. Model assumptions were checked using histograms and quantile-quantile plots of residuals.

RESULTS

Twelve of 19 patients who were treated for osteosarcoma had either osteopenia (eight patients) or osteoporosis (four patients). More patients with osteosarcoma reported sustaining fractures (11 of 19 patients) than did control patients (2 of 19 controls; p < 0.001). Among all microarchitectural parameters, only the endocortical perimeter was increased in patients compared with the control group (75 ± 15 mm versus 62 ± 18 mm; p = 0.04); we found no differences between the groups in terms of cortical and trabecular area, cortical and trabecular thickness, or cortical porosity.

CONCLUSION

Although patients who were treated for osteosarcoma had osteopenic or osteoporotic BMD and a higher proportion of patients experienced fractures than did patients in the control group, we could not confirm differences in microarchitectural parameters using high-resolution peripheral quantitative CT. Therefore, it seems that bone geometry and microstructural parameters are not likely the cause of the increased proportion of fractures observed in our patients who were treated for osteosarcoma. Until we learn more about the bone changes associated with chemotherapy in patients with osteosarcoma, we recommend that patients undergo regular BMD testing, and we recommend that physicians consider osteoporosis treatment in patients with low BMD. These data might provide the impetus for future multicenter prospective studies examining the association between chemotherapy and bone microarchitecture.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Bone erosions and osteophytes in premenopausal women with long-standing rheumatoid arthritis: association with systemic bone involvement by HR-Pqct

OBJECTIVE

To evaluate premenopausal women with long-standing RA and to explore the relationship between parameters of systemic and localized bone involvement.

METHODS

Eighty consecutive RA premenopausal women were evaluated. Volumetric bone mineral density (vBMD), microarchitecture and finite element analysis were performed using high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius (DR) and tibia (DT) and compared with parameters from 160 female healthy controls matched by age and body mass index. Localized bone involvement was also analyzed using HR-pQCT in the metacarpophalangeal and proximal interphalangeal joints to identify erosions and osteophytes.

RESULTS

The mean age of RA patients was 39.4±6.7years and disease duration 9.8±5.3years. RA patients had impaired trabecular, cortical and bone strength parameters, at DR and DT, compared with healthy controls (p<0.05). Bone erosions and osteophytes were found in 75% and 41.3% of patients, respectively. Comparing patients with and without erosions, at DR and DT, a lower cortical vBMD (DR: 980±72 versus 1021±47mgHA/cm³ , p=0.03; DT:979±47 versus 1003±34 mgHA/cm³ , p=0.04) and higher cortical porosity (DR:2.8±2.5 versus 1.8±1.6%, p=0.04; and DT:3.7±1.6 versus 2.7±1.6%, p=0.01) were observed in patients with erosions. At the DR, osteophyte volume was positively correlated with trabecular vBMD (0.392, p=0.02), trabecular number (0.381, p=0.03) and stiffness (0.411, p=0.02), and negatively with trabecular separation (-0.364, p=0.04).

CONCLUSION

Our findings showed that premenopausal women with long-standing RA had systemic bone fragility at peripheral sites. Moreover, erosions were associated mainly with cortical bone fragility at the DR and DT, and osteophytes correlated with repair of trabecular bone at the radius.

Bone mineral density and microarchitecture among Chinese patients with rheumatoid arthritis: a cross-sectional study with HRpQCT

BACKGROUND

Patients with rheumatoid arthritis (RA) are at increased risk of fractures. Although their decline in bone mineral density (BMD) is well-established, data regarding the alterations in bone microarchitecture are limited. In this study, we aimed to evaluate bone microarchitecture, geometry, and volumetric BMD among patients with RA in mainland China using high-resolution peripheral quantitative computed tomography (HRpQCT).

METHODS

In this cross-sectional study, patients with RA were recruited from the Peking Union Medical College Hospital site of the Chinese Registry of rhEumatoiD arthrITis (CREDIT). Each participant underwent HRpQCT scanning (Scanco XtremeCT II), thoracolumbar X-ray and dual-energy X-ray absorptiometry. The primary outcomes were HRpQCT-related measures at distal radius and tibia. Data regarding demographic features, RA-related characteristics, and history of fragility fractures were collected. Correlation between HRpQCT parameters and potentially related factors were analyzed using linear regression analysis. A group of age- and sex-matched healthy controls was included for comparison.

RESULTS

A total of 81 patients with RA [69 women, aged 57.9 ± 8.7 years, disease duration 5.7 (IQR 1.4-11.2) years] and 81 matched healthy controls were included. Compared with controls, patients with RA had significantly larger bone area and lower total and trabecular vBMD at both the distal radius and tibia. Lower cortical bone thickness was also shown at the distal tibia. Among patients with RA, advanced age, low BMI, female sex, disease duration, and activity were associated with decreased vBMD and impaired bone microstructure. Female reproductive factors including menopause, late menarche, breast feeding, and early childbirth also showed negative correlation with these parameters. Compared to patients with RA without fractures, patients with fragility fractures (n = 11) showed lower trabecular and cortical vBMD, thinner cortical bone, impaired trabecular microstructure, and a trend of declined bone strength. Current glucocorticoid intake was related to decreased vBMD, trabecular number, increased trabecular separation, and inhomogeneity.

CONCLUSIONS

In this study, we observed alterations in bone mineral density, geometry, and microarchitecture among patients with RA compared to healthy individuals, which may impair bone strength and lead to increased risk of fractures. Both traditional risk factors for osteoporosis and RA-associated factors need to be considered in the assessment of the bone quality.

The Role of Imaging in Predicting the Development of Rheumatoid Arthritis

Rheumatoid arthritis (RA) remains a chronic debilitating disease with a significant negative societal impact, despite the expanding landscape of treatment options. This condition is often preceded by a phase of systemic autoimmunity with circulating autoantibodies, elevated pro-inflammatory cytokines, or subtle structural changes. The capability of identifying individuals in the preclinical phase of RA disease makes a "preventive window of opportunity" possible. Much recent work has focused on the role of imaging modalities including ultrasound (US), magnetic resonance imaging (MRI), and high-resolution peripheral quantitative computer tomography (HR-pQCT) in identifying at-risk individuals with or without early joint symptoms for the development of inflammatory arthritis. This article will review the evidence and discuss the challenges as well as opportunities of proactive risk assessment by imaging in RA.

Determinants of estimated failure load in the distal radius after stroke: An HR-pQCT study

Bone health is often compromised after stroke and the distal radius is a common site of fragility fractures. The macro- and mircoproperties of bone tissue after stroke and their clinical correlates are understudied. The objectives of the study were to use High-Resolution peripheral Quantitative Computed Tomography (HR-pQCT) to investigate the bone properties at the distal radius, and to identify the correlates of estimated failure load for the distal radius in people with chronic stroke. This was a cross-sectional study of 64 people with stroke (age: 60.8 ± 7.7 years, stroke duration: 5.7 ± 3.9 years) and 64 age- and sex-matched controls. Bilateral bone structural, densitometric, geometric and strength parameters of the distal radius were measured using HR-pQCT. The architecture, stiffness and echo intensity of the bilateral biceps brachii muscle and brachial artery blood flow were evaluated using diagnostic ultrasound. Other outcomes included the Fugl-Meyer Motor Assessment (FMA), Motor Activity Log (MAL), and Composite Spasticity Scale (CSS). The results revealed a significant side (paretic vs non-paretic for the stroke group, non-dominant vs dominant for controls) by group (stroke vs control) interaction effect for estimated failure load, cortical area, cortical thickness, trabecular number and trabecular separation, and all volumetric density parameters. Post-hoc analysis showed percent side-to-side differences in bone outcomes were greater in the stroke group than the control group, with the exception of trabecular thickness and intracortical porosity. Among the HR-pQCT variables, percent side-to-side difference in trabecular volumetric bone mineral density contributed the most to the percent side-to-side difference in estimated failure load in the stroke group (R² change = 0.334, β = 1.106). Stroke-related impairments (FMA, MAL, CSS) were found to be significant determinants of the percent side-to-side difference in estimated failure load (R² change = 0.233, β = -0.480). This was the first study to examine bone microstructure post-stroke. We found that the paretic distal radius had compromised bone structural properties and lower estimated failure load compared to the non-paretic side. Motor impairment was a determinant of estimated bone strength at the distal radius and may be a potential intervention target for improving bone health post-stroke.

High-Resolution Peripheral Quantitative Computed Tomography for Bone Evaluation in Inflammatory Rheumatic Disease

High resolution peripheral quantitative computed tomography (HR-pQCT) is a 3-dimensional imaging modality with superior sensitivity for bone changes and abnormalities. Recent advances have led to increased use of HR-pQCT in inflammatory arthritis to report quantitative volumetric measures of bone density, microstructure, local anabolic (e.g., osteophytes, enthesiophytes) and catabolic (e.g., erosions) bone changes and joint space width. These features may be useful for monitoring disease progression, response to therapy, and are responsive to differentiating between those with inflammatory arthritis conditions and healthy controls. We reviewed 69 publications utilizing HR-pQCT imaging of the metacarpophalangeal (MCP) and/or wrist joints to investigate arthritis conditions. Erosions are a marker of early inflammatory arthritis progression, and recent work has focused on improvement and application of techniques to sensitively identify erosions, as well as quantifying erosion volume changes longitudinally using manual, semi-automated and automated methods. As a research tool, HR-pQCT may be used to detect treatment effects through changes in erosion volume in as little as 3 months. Studies with 1-year follow-up have demonstrated progression or repair of erosions depending on the treatment strategy applied. HR-pQCT presents several advantages. Combined with advances in image processing and image registration, individual changes can be monitored with high sensitivity and reliability. Thus, a major strength of HR-pQCT is its applicability in instances where subtle changes are anticipated, such as early erosive progression in the presence of subclinical inflammation. HR-pQCT imaging results could ultimately impact decision making to uptake aggressive treatment strategies and prevent progression of joint damage. There are several potential areas where HR-pQCT evaluation of inflammatory arthritis still requires development. As a highly sensitive imaging technique, one of the major challenges has been motion artifacts; motion compensation algorithms should be implemented for HR-pQCT. New research developments will improve the current disadvantages including, wider availability of scanners, the field of view, as well as the versatility for measuring tissues other than only bone. The challenge remains to disseminate these analysis approaches for broader clinical use and in research.

Comparison of bone structure and microstructure in the metacarpal heads between patients with psoriatic arthritis and healthy controls: an HR-pQCT study

Human cadaveric study has indicated that the metacarpal head (MCH) is intracapsular in location. We hypothesized that exposure to the intra-articular inflammatory milieu in psoriatic arthritis (PsA) will lead to bone loss in the MCH.

INTRODUCTION

To compare the bone structure and microstructure in the MCH between patients with PsA and healthy controls by high-resolution peripheral quantitative CT (HR-pQCT), and to ascertain factors associated with bone loss in PsA patients.

METHODS

Sixty-two PsA patients without joint destruction and 62 age-, gender-, and body mass index-matched healthy subjects underwent HR-pQCT imaging of the second and third MCH (MCH 2&3). The number and volume of bone erosion and enthesiophytes, as well as volumetric bone mineral density (vBMD) and microstructure at the MCH 2&3, were recorded. Correlation analysis and multivariable linear regression models were used to determine the association of demographic and disease-specific variables with compromised bone structure and microstructure in PsA.

RESULTS

At the MCH 2&3, bone erosion (p = 0.003) and enthesiophyte (p = 0.000) volumes in PsA patients were significantly larger than healthy controls. In PsA patients, older age was associated with a larger erosion and enthesiophyte volume. Concerning the mean vBMD and microstructure at the MCH 2&3, PsA patients had significantly lower mean vBMD (average vBMD - 6.9%, trabecular vBMD - 8.8%, peri-trabecular vBMD - 7.7%, meta-trabecular vBMD - 9.8%), trabecular bone volume fraction (- 8.8%), and trabecular thickness (- 8.1%) compared with control subjects. Multivariable regression analysis revealed that older age and a higher C-reactive protein level were associated with trabecular bone loss.

CONCLUSIONS

PsA patients had a higher burden of bone damages (erosions and enthesiophytes) and trabecular bone loss compared with healthy control at the MCH. Inflammation contributed to the deterioration in trabecular microstructure in these patients.

Impaired bone microarchitecture in distal interphalangeal joints in patients with primary hypertrophic osteoarthropathy assessed by high-resolution peripheral quantitative computed tomography

This study aimed to investigate the bone impairment in finger joints in PHO patients by HR-pQCT. Results showed distinguished differences in bone architecture and biomechanics parameters at DIPs between PHO patients and healthy controls using HR-pQCT assessment. Besides, serum PGE2, hsCRP and ESR levels were found negatively correlated with total vBMD.

INTRODUCTION

This study aimed to investigate the bone impairment in finger joints in primary hypertrophic osteoarthropathy (PHO) patients firstly by high-resolution peripheral quantitative computed tomography (HR-pQCT).

METHODS

Fifteen PHO patients and 15 healthy controls were enrolled in this study. Bone erosions in hands at distal interphalangeal joints (DIPs) in both PHO patients and controls were evaluated by X-ray. Bone geometry, vBMD, microstructure parameters, and size of individual bone erosion were also measured at the 3rd DIP by HR-pQCT as well. Blood biochemistry levels between the two groups were also compared.

RESULTS

Compared to X-ray, HR-pQCT assessment were more sensitive for detection of bone erosions, with 14 PHO patients by HR-pQCT versus ten PHO patients by X-ray judged at the 3rd DIP. The average depth, width, and volume of erosions size in PHO patients were 1.38 ± 0.80 mm, 0.79 ± 0.27 mm, and 1.71 ± 0.52 mm³, respectively. The bone cross-areas including total area (+ 25.3%, p ≤ 0.05), trabecular area (+ 56.2%, p ≤ 0.05), and cortical perimeter (+ 10.7%, p ≤ 0.05) at the defined region of interest of 3rd DIP was significantly larger than controls. Total vBMD was 11.9% lower in PHO patients compared with the controls (p ≤ 0.05). Biochemical test results showed the increased levels of inflammatory cytokines, bone resorption markers, and joint degeneration markers in PHO patients. Serum prostaglandin PGE2, high-sensitive C-reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR) levels were found negatively correlated with total vBMD.

CONCLUSIONS

This study demonstrated higher sensitivity of the HR-pQCT measurement at DIPs by showing the differences in architecture and biomechanics parameters at DIPs between the PHO patients and healthy controls, which would be of interest clinically to investigate bone deterioration in PHO patients.

Structural Changes over a Short Period Are Associated with Functional Assessments in Rheumatoid Arthritis

Objective.

To investigate the correlation between changes in radiological quantitative assessment with changes in clinical and functional assessment from baseline to 3 months in patients with rheumatoid arthritis (RA).

Methods.

Twenty-eight patients with RA [methotrexate (MTX) and anti-tumor necrosis factor–α (TNF-α) group with high disease activity (n = 18); and MTX group with low disease activity (n = 10)] underwent assessments at baseline and 3 months: clinical [28-joint count Disease Activity Score (DAS28)], functional [Health Assessment Questionnaire (HAQ) and Michigan Hand Outcome Questionnaire (MHQ)], and imaging-based [3 Tesla magnetic resonance imaging (MRI) and high-resolution peripheral quantitative computed tomography (HR-pQCT)]. MR images were evaluated semiquantitatively [RA MRI scoring (RAMRIS)] and quantitatively for the volume of synovitis and bone marrow edema (BME) lesions. Erosion volumes were measured using HR-pQCT.

Results.

After 3 months, the anti-TNF-α group demonstrated an improvement in disease activity through DAS28, HAQ, and MHQ. MRI showed significant decreases in synovitis and BME volume for the anti-TNF-α group, and significant increases in the MTX group. HR-pQCT showed significant decreases in bone erosion volume for the anti-TNF-α group, and significant increases in the MTX group. No significance was observed using RAMRIS. Changes in synovitis, BME, and erosion volumes, but not RAMRIS, were significantly correlated with changes in DAS28, HAQ, and MHQ.

Conclusion.

Quantitative measures were more sensitive than semiquantitative grading when evaluating structural and inflammatory changes with treatment, and were associated with patient clinical and functional outcomes. Multimodality imaging with 3T MRI and HR-pQCT may provide promising biomarkers that help determine disease progression and therapy response.

Biomechanical properties of bone are impaired in patients with ACPA-positive rheumatoid arthritis and associated with the occurrence of fractures

OBJECTIVES

Bone loss is a well-established consequence of rheumatoid arthritis (RA). To date, bone disease in RA is exclusively characterised by bone density measurements, while the functional properties of bone in RA are undefined. This study aimed to define the impact of RA on the functional properties of bone, such as failure load and stiffness.

METHODS

Micro-finite element analysis (µFEA) was carried out to measure failure load and stiffness of bone based on high-resolution peripheral quantitative CT data from the distal radius of anti-citrullinated protein antibody (ACPA)-positive RA (RA+), ACPA-negative RA (RA-) and healthy controls (HC). In addition, total, trabecular and cortical bone densities as well as microstructural parameters of bone were recorded. Correlations and multivariate models were used to determine the role of demographic, disease-specific and structural data of bone strength as well as its relation to prevalent fractures.

RESULTS

276 individuals were analysed. Failure load and stiffness (both P<0.001) of bone were decreased in RA+, but not RA-, compared with HC. Lower bone strength affected both female and male patients with RA+, was related to longer disease duration and significantly (stiffness P=0.020; failure load P=0.012) associated with the occurrence of osteoporotic fractures. Impaired bone strength was correlated with altered bone density and microstructural parameters, which were all decreased in RA+. Multivariate models showed that ACPA status (P=0.007) and sex (P<0.001) were independently associated with reduced biomechanical properties of bone in RA.

CONCLUSION

In summary, µFEA showed that bone strength is significantly decreased in RA+ and associated with fractures.

Assessment of the effects of switching oral bisphosphonates to denosumab or daily teriparatide in patients with rheumatoid arthritis

The aim of this observational, non-randomized study was to clarify the unknown effects of switching oral bisphosphonates (BPs) to denosumab (DMAb) or daily teriparatide (TPTD) in patients with rheumatoid arthritis (RA). The characteristics of the 194 female patients included in the study were 183 postmenopausal, age 65.9 years, lumbar spine (LS) T score -1.8, femoral neck (FN) T score -2.3, dose and rate of taking oral prednisolone (3.6 mg/day) 75.8%, and prior BP treatment duration 40.0 months. The patients were allocated to (1) the BP-continue group (n = 80), (2) the switch-to-DMAb group (n = 74), or (3) the switch-to-TPTD group (n = 40). After 18 months, the increase in bone mineral density (BMD) was significantly greater in the switch-to-DMAb group than in the BP-continue group (LS 5.2 vs 2.3%, P < 0.01; FN 3.8 vs 0.0%, P < 0.01) and in the switch-to-TPTD group than in the BP-continue group (LS 9.0 vs 2.3%, P < 0.001; FN 4.9 vs 0.0%, P < 0.01). Moreover, the switch-to-TPTD group showed a higher LS BMD (P < 0.05) and trabecular bone score (TBS) (2.1 vs -0.7%; P < 0.05) increase than the switch-to-DMAb group. Clinical fracture incidence during this period was 8.8% in the BP-continue group, 4.1% in the switch-to-DMAb group, and 2.5% in the switch-to-TPTD group. Both the switch-to-DMAb group and the switch-to-TPTD group showed significant increases in LS and FN BMD, and the switch-to-TPTD group showed a higher increase in TBS compared to the BP-continue group at 18 months. Switching BPs to DMAb or TPTD in female RA may provide some useful osteoporosis treatment options.

Micro-structural bone changes in early rheumatoid arthritis persist over 1-year despite use of disease modifying anti-rheumatic drug therapy

Background

We used High Resolution – peripheral Quantitative CT (HR-pQCT) imaging to examine peri-articular bone quality in early rheumatoid arthritis (RA) and explore whether bone quality improved over 12-months in individuals receiving care consistent with practice guidelines.

Methods

A 1-year longitudinal cohort study (Baseline and 12-months) evaluating individuals with early RA compared to age/sex-matched peers. Personal demographic and health and lifestyle information were collected for all. Whereas, active joint count (AJC₂₈), functional limitation, and RA medications were also collected for RA participants. HR-pQCT imaging analyses quantified bone density and microstructure in the Metacarpal Head (MH) and Ultra-Ultra-Distal (UUD) radius at baseline and 12-months. Analyses included a General Linear Modelling repeated measures analyses examined main effects for disease, time, and interaction on bone quality.

Results

Participants (n = 60, 30 RA/30 NRA); 80% female, mean age 53 (varying from 21 to 74 years). At baseline, RA participants were on average 7.7 months since diagnosis, presenting with few active joints (AJC₂₈: 30% none, remaining 70% Median 4 active joints) and minimal self-reported functional limitation (mHAQ-DI_0–3: 0.56). At baseline, 29 of 30 RA participants had received one or more non-biologic disease-modifying anti-rheumatic drugs (DMARD);13 in combination with glucocorticoid and 1 in combination with a biologic medication. One participant only received glucocorticoid medication. Four RA participants withdrew leaving 26 pairs (n = 52) at 12-months; 23 pairs (n = 46) with UUD and 22 pairs (n = 44) with MH baseline and 12-month images to compare. Notable RA/NRA differences (p < 0.05) in bone quality at all three sites included lower trabecular bone density and volume, more rod-like trabeculae, and larger and more variable spaces between trabeculae; fewer trabeculae at the UUD and MH2 sites; and lower cortical bone density and volume in the MH sites. Rate of change over 12-months did not differ between RA/NRA participants which meant there was also no improvement over the year in RA bone quality.

Conclusions

Early changes in peri-articular bone density and microstructure seen in RA are consistent with changes more commonly seen in aging bone and are slow or resistant to recover despite well controlled inflammatory joint symptoms with early DMARD therapy.

Electronic supplementary material

The online version of this article (10.1186/s12891-017-1888-3) contains supplementary material, which is available to authorized users.

The Role of High-resolution Peripheral Quantitative Computed Tomography as a Biomarker for Joint Damage in Inflammatory Arthritis

Since 2011, members of the SPECTRA Collaboration (Study grouP for xtrEme-Computed Tomography in Rheumatoid Arthritis) have investigated the validity, reliability, and responsiveness of high-resolution peripheral quantitative computed tomography (HR-pQCT) as a biomarker for joint damage in inflammatory arthritis. Presented in this series of articles are a systematic review of HR-pQCT-related findings to date, a review of selected images of cortical and subchondral trabecular bone of metacarpophalangeal (MCP) joints, results of a consensus process to standardize the definition of erosions and their quantification, as well as an examination of the effect of joint flexion on width and volume assessment of the joint space.

Evaluation of bone microstructure in CRPS-affected upper limbs by HR-pQCT

INTRODUCTION

Complex regional pain syndrome (CRPS) is a major complication after trauma, surgery, and/or immobilization of an extremity. The disease often starts with clinical signs of local inflammation and develops into a prolonged phase that is characterized by trophic changes and local osteoporosis and sometimes results in functional impairment of the affected limb. While the pathophysiology of CRPS remains poorly understood, increased local bone resorption plays an undisputed pivotal role. The aim of this retrospective clinical study was to assess the bone microstructure in patients with CRPS.

METHODS

Patients with CRPS type I of the upper limb whose affected and unaffected distal radii were analyzed by high-resolution peripheral quantitative computed tomography (HR-pQCT) were identified retrospectively. The osteology laboratory data and dual-energy X-ray absorptiometry (DXA) images of the left femoral neck and lumbar spine, which were obtained on the same day as HR-pQCT, were extracted from the medical records.

RESULTS

Five patients were identified. The CRPS-affected upper limbs had significantly lower trabecular numbers and higher trabecular thicknesses than the unaffected upper limbs. However, the trabecular bone volume to total bone volume and cortical thickness values of the affected and unaffected sides were similar. Trabecular thickness tended to increase with time since disease diagnosis.

DISCUSSION

CRPS associated with significant alterations in the bone microstructure of the affected upper limb that may amplify as the duration of disease increases.

Repair of Bone Erosion in Rheumatoid Arthritis by Denosumab: A High-Resolution Peripheral Quantitative Computed Tomography Study

OBJECTIVE

To compare the bone healing effects of denosumab and alendronate in female rheumatoid arthritis (RA) patients by high-resolution peripheral quantitative computed tomography.

METHODS

This is a post hoc analysis of a randomized controlled trial. Forty patients were randomized in a 1:1 ratio to receive either subcutaneous denosumab (60 mg) once or oral alendronate (70 mg) weekly for 6 months. The size of individual bone erosions and the presence and extent of erosion-associated sclerosis (marginal osteosclerosis) were measured in the second metacarpal head of the nondominant hand at baseline, 3 months, and 6 months.

RESULTS

Forty-two erosions were identified at baseline. After 6 months, the width, depth, and volume of erosion significantly decreased in the denosumab group (-0.23 mm, -0.16 mm, -0.91 mm³ , respectively; all P < 0.01), whereas these parameters significantly increased in the alendronate group (0.19 mm, 0.32 mm, and 1.38 mm³ , respectively; all P < 0.01; between-group differences, P < 0.01 for all). Quantitative analysis showed that the bone mineral density of the erosion margin significantly increased only after treatment by denosumab (19.75 mg/cm³ ; P < 0.05 for denosumab, and -5.44 mg/cm³ ; P = 0.51 for alendronate; P < 0.05 for between-group differences).

CONCLUSION

Inhibition of receptor activator of NF-κB ligand by denosumab can induce partial repair of erosions in patients with RA, while erosions continued to progress in patients treated with alendronate. Combining denosumab with disease-modifying antirheumatic drugs may be considered for RA patients with progressive bone erosions.

Titer-Dependent Effect of Anti-Citrullinated Protein Antibodies On Systemic Bone Mass in Rheumatoid Arthritis Patients

Bone loss in rheumatoid arthritis (RA) is a key feature both local and systemic. Anti-citrullinated protein antibodies (ACPA) have recently been found to directly induce differentiation and activation of osteoclasts and therefore contribute to periarticular bone loss. The aim of this study was to analyze the effect of ACPA on systemic bone mineral density (BMD) in patients with established RA. This is a cross-sectional study with a single-center RA population. BMD was measured with Dual X-ray absorptiometry at lumbar and femoral sites. ACPA were measured by EIA. Multivariate analysis was performed adjusting for the main confounding variables. One hundred twenty-seven RA patients were enrolled. In univariate analysis, ACPA-positive patients showed lower BMD Z-score (SD below the age- and gender-matched mean reference value) at femoral sites (p < 0.01). A negative correlation between ACPA titer and BMD Z-score at all sites was observed (p < 0.01). The multivariate analysis adjusted for the main confounding variables confirmed the negative effect of ACPA at femoral sites (p < 0.05), but not at lumbar spine BMD. No significant effect of rheumatoid factor has been observed. ACPA have a negative titer-dependent effect on BMD at femoral sites, mainly constituted by cortical bone. ACPA-positive patients, especially if at high titer, should undergo bone investigations and be treated with bone protecting agents. Disease-modifying anti-rheumatic drugs lowering ACPA titer might have positive effects on systemic bone mass.

Contribution of high resolution peripheral quantitative CT to the management of bone and joint diseases

Many imaging modalities have been described to diagnose and monitor osteoporosis (OP), osteoarthritis and inflammatory rheumatic diseases. Over the last ten years, High Resolution peripheral Quantitative Computerized Tomography (HR-pQCT) was shown to be a precise and non invasive technique to study bone and joint diseases in clinical research. It allows the study of both cortical and trabecular bone microarchitecture at the distal tibia and radius, and further applications have been developed such as the study of mechanical properties by the finite element analysis. Thus, in case-control and cross-sectional studies, microarchitecture parameters discriminated fractured individuals independently of areal BMD. Also, microstructure parameters can predict incident fracture in postmenopausal women. In metabolic diseases associated with bone fragility, HR-pQCT may also be used to explore bone changes. In joint disease studies, HR-pQCT was a remarkable tool to assess bone erosion and joint space narrowing at the hand. This article gives an overview of this imaging technique.

Quantification of arthritic bone degradation by analysis of 3D micro-computed tomography data

The use of animal models of arthritis is a key component in the evaluation of therapeutic strategies against the human disease rheumatoid arthritis (RA). Here we present quantitative measurements of bone degradation characterised by the cortical bone profile using glucose-6-phosphate isomerase (G6PI) induced arthritis. We applied micro-computed tomography (μCT) during three arthritis experiments and one control experiment to image the metatarsals of the hind paws and to investigate the effect of experimental arthritis on their cortical bone profile. For measurements of the cortical profile we automatically identified slices that are orthogonal to individual metatarsals, thereby making the measurements independent of animal placement in the scanner. We measured the average cortical thickness index (CTI) of the metatarsals, as well as the thickness changes along the metatarsal. In this study we introduced the cortical thickness gradient (CTG) as a new measure and we investigated how arthritis affects this measure. We found that in general both CTI and CTG are able to quantify arthritic progression, whilst CTG was found to be the more sensitive measure.

Heterogeneity of Cortical Breaks in Hand Joints of Patients with Rheumatoid Arthritis and Healthy Controls Imaged by High-resolution Peripheral Quantitative Computed Tomography

Objective.

Conventional radiographs (CR) of the hands are the gold standard for imaging bone erosions. The presence of bone erosions, reflected by the presence of cortical breaks, is a poor prognostic factor in patients with rheumatoid arthritis (RA). The availability of high-resolution peripheral quantitative computed tomography (HR-pQCT) enables detailed investigation of cortical breaks in rheumatic diseases. The aim of this image review is to show HR-pQCT images of the spectrum of cortical breaks with and without underlying trabecular bone changes in metacarpophalangeal (MCP) joints of healthy controls (HC) and patients with RA, with corresponding images on CR and magnetic resonance imaging (MRI).

Methods.

Second and third MCP joints of 41 patients (of which 10 were early RA with ≤ 2 years and 24 longstanding RA with ≥ 10 years of disease duration) and 38 HC were imaged by CR, MRI, and HR-pQCT (XtremeCT1, Scanco Medical AG). Representative images of the spectrum of cortical breaks were selected.

Results.

Cortical breaks were found in early and longstanding RA, but also in HC. They were heterogeneous in size, location, and number per joint, with a variety of surrounding cortical and underlying trabecular bone characteristics.

Conclusion.

Using HR-pQCT images of MCP joints, heterogeneous cortical breaks with and without surrounding trabecular bone changes were found, not only in RA but also in HC. The underlying mechanisms and significance of this spectrum of cortical breaks as found with high 3-D resolution needs further investigation.

Ossicular Bone Damage and Hearing Loss in Rheumatoid Arthritis: A Correlated Functional and High Resolution Morphometric Study in Collagen-Induced Arthritic Mice

Globally, a body of comparative case-control studies suggests that rheumatoid arthritis (RA) patients are more prone to developing hearing loss (HL). However, experimental evidence that supports this hypothesis is still lacking because the human auditory organ is not readily accessible. The aim of this study was to determine the association between bone damage to the ossicles of the middle ear and HL, using a widely accepted murine model of collagen-induced arthritis (RA mice). Diarthrodial joints in the middle ear were examined with microcomputer tomography (microCT), and hearing function was assessed by auditory brainstem response (ABR). RA mice exhibited significantly decreased hearing sensitivity compared to age-matched controls. Additionally, a significant narrowing of the incudostapedial joint space and an increase in the porosity of the stapes were observed. The absolute latencies of all ABR waves were prolonged, but mean interpeak latencies were not statistically different. The observed bone defects in the middle ear that were accompanied by changes in ABR responses were consistent with conductive HL. This combination suggests that conductive impairment is at least part of the etiology of RA-induced HL in a murine model. Whether the inner ear sustains bone erosion or other pathology, and whether the cochlear nerve sustains pathology await subsequent studies. Considering the fact that certain anti-inflammatories are ototoxic in high doses, monitoring RA patients’ auditory function is advisable as part of the effort to ensure their well-being.

Carotid plaque and bone density and microarchitecture in psoriatic arthritis: the correlation with soluble ST2

Psoriatic arthritis (PsA) patients have increased risk of both atherosclerosis and osteoporosis. Previous studies revealed that IL-33/ST2 axis may be related to both conditions; however, these associations were never evaluated in a single patients’ group. Here we explored the association among plasma levels of IL-33 and its decoy receptor soluble ST2 (sST2), carotid plaque determined by ultrasound, and volumetric bone mineral density (vBMD)/microstructure of distal radius measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) in 80 PsA patients (55% male; 53.0 ± 10.1 years). Plasma sST2 levels were significantly higher in 33 (41%) patients with carotid plaques (11.2 ± 4.5 vs 7.7 ± 3.7 ng/ml, P < 0.001). In multivariate analysis, sST2 was an independent explanatory variable associated with carotid plaques (OR = 1.296, 95% CI: [1.091,1.540]; P = 0.003). After adjustment for the osteoporotic risk factors, sST2 was significantly associated with higher cortical porosity (β = 0.184, [0.042,0.325]; P = 0.012) and cortical pore volume (2.247, [0.434,4.060]; P = 0.016); and had a trend to be associated with lower cortical vBMD (−2.918, [−6.111,0.275]; P = 0.073). IL-33 was not associated with carotid plaque or vBMD/microstructure. In conclusion, plasma sST2 levels were independently correlated with both carotid plaque and compromised cortical vBMD/microstructure in PsA patients. IL-33/ST2 axis may be a link between accelerated atherosclerosis and osteoporosis in PsA.

Periarticular osteoporosis of the forearm correlated with joint destruction and functional impairment in patients with rheumatoid arthritis

The relationship between periarticular osteoporosis in the distal forearm and joint destruction or functional impairment in patients with rheumatoid arthritis (RA) is not sufficiently elucidated. From a single institutional cohort study, we found a strong correlation between periarticular forearm bone mineral density (BMD) and joint destruction or functional impairment.

INTRODUCTION

This study was conducted to investigate (1) the difference between various periarticular regions of interest (ROIs) of BMD of the forearm, (2) the correlation between periarticular forearm BMD and joint destruction and physical function, (3) the independent variables for predicting BMD of the forearm, and (4) the forearm BMD of different ROIs in the early stage of RA.

METHODS

We conducted a cross-sectional study in an RA cohort. Measurements included BMD of the distal forearm, joint destruction of the hands assessed by modified total Sharp score (mTSS), functional impairment assessed by a health assessment questionnaire (HAQ), and other clinical data. Variables affecting the forearm BMD values were analyzed by correlation and stepwise regression analyses.

RESULTS

Of the 405 patients enrolled in the present study, 370 (average age; 62.9 years) were identified as having definite RA with a complete set of data. BMD in the distal end of the forearm (BMDud) was significantly reduced compared with that in the distal third of the forearm (BMD1/3). In a stepwise regression analysis, the mTSS in BMD1/3 was an independent predicting variable, while age and partial HAQ scores associated with the upper extremity were common independent variables in BMDud and BMD1/3. BMDud was significantly less than BMD1/3, even in patients with a short duration of the disease. BMD1/3 was significantly less in non-remission group compared with that in remission group in patients with a short duration of the disease.

CONCLUSION

Periarticular BMD in the distal forearm is closely correlated with joint destruction and functional impairment in RA. Periarticular BMD in the distal forearm may be already reduced at the clinical manifestation of the disease.

Cortical thinning and progressive cortical porosity in female patients with systemic lupus erythematosus on long-term glucocorticoids: a 2-year case-control study

In this study, we characterized longitudinal changes of volumetric bone mineral density and cortical and trabecular microstructure at the distal radius using HR-pQCT in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids. Cortical thinning and increased cortical porosity are the major features of longitudinal microstructural deterioration in SLE patients.

INTRODUCTION

The study aims to characterize longitudinal changes of volumetric bone mineral density (vBMD) and bone microstructure at distal radius in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids.

METHODS

This 2-year case-control study consisted of 166 premenopausal subjects (75 SLE patients and 91 controls) and 79 postmenopausal subjects (44 SLE patients and 35 controls). We obtained areal BMD (aBMD) by dual-energy X-ray absorptiometry at multiple skeletal sites and indices of vBMD and microstructure at distal radius by high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline, 12 and 24 months.

RESULTS

In either premenopausal or postmenopausal subjects, changes in aBMD did not differ between patients and controls except that decrease in aBMD at total hip at 24 months in premenopausal patients was significantly higher. In premenopausal subjects, decrease in cortical area (-0.51 vs. -0.06 %, p = 0.039) and thickness (-0.63 vs. 0.02 %, p = 0.031) and increase in cortical porosity (21.7 vs. 7.16 %, p = 0.030) over study period were significantly larger in patients after adjustment of age and body mass index. Decreased in trabecular vBMD was significantly less (-0.63 vs. -2.32 %, p = 0.001) with trabecular microstructure better maintained in patients. In postmenopausal subjects, decrease in cortical vBMD (-2.66 vs. -1.56 %, p = 0.039) and increase in cortical porosity (41.6 vs. 16.3 %, p = 0.021) were significantly higher in patients, and there was no group-wise difference in change of trabecular microstructure.

CONCLUSION

Longitudinal microstructural deterioration in SLE is characterized by cortical thinning and increased cortical porosity. Cortical bone is an important source of bone loss in SLE patients on glucocorticoids.

Quantitative characterization of metacarpal and radial bone in rheumatoid arthritis using high resolution- peripheral quantitative computed tomography

AIM

The objectives of this study were: (i) to develop a standardized method of quantifying bone mineral density (BMD) and microarchitecture in the hand and wrist bones of patients with rheumatoid arthritis (RA) using high resolution- peripheral quantitative computed tomography (HR-pQCT); (ii) to compare quantitative bone parameters between RA and post-menopausal osteopenic (PM-OP) subjects; and (iii) to correlate quantitative bone parameters at the distal radius with those at the metacarpal heads in RA subjects.

METHODS

HR-pQCT imaging of the dominant hand and wrist was performed in 12 female RA patients. BMD and trabecular parameters for the 2-12% head region of the second and third metacarpals were calculated and compared between RA patients and healthy controls. Bone parameters were also calculated for 110 slices of the distal radius in RA patients and compared to data from controls and PM-OP women from a previous study.

RESULTS

Compared to controls, RA patients had significantly decreased BMD, trabecular volume and number, and increased trabecular heterogeneity in the third metacarpal and distal radius. Significantly lower trabecular number and significantly higher ratio of outer annular trabecular BMD to inner trabecular BMD were observed in patients with RA, compared to patients with osteopenia (P < 0.05). Trabecular BMD in the third metacarpal and in the distal radius were significantly correlated (ρ = 0.918, P < 0.0001) in RA patients.

CONCLUSION

This study established a standardized method for quantifying bone density and trabecular properties in the hand and wrist bones of RA patients using HR-pQCT. Deterioration of bone structure in RA patients was found comparable to that in osteopenic women, and trabecular bone loss near affected joints was found to be correlated with bone loss away from joints.

Density, structure, and strength of the distal radius in patients with psoriatic arthritis: the role of inflammation and cardiovascular risk factors

We investigated the densitometric and microstructural features of the distal radius in psoriatic arthritis (PsA) patients using high-resolution peripheral quantitative computed tomography. PsA patients have unique bone microstructural deficits, manifested as lower cortical bone density and higher cortical porosity, which are associated with a propensity to bone fragility.

INTRODUCTION

The aim of this study was to investigate the densitometric, geometric, microstructural, and biomechanical features of the distal radius in psoriatic arthritis (PsA) patients.

METHODS

This study cohort consisted of 53 PsA patients (24 males and 29 females), with an average age of 53.1 years and 53 gender- and age-matched controls. Areal bone mineral density (aBMD) of the hip, lumbar spine, and ultradistal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) was performed at the distal radius to obtain measures of volumetric BMD (vBMD), microstructure, and derived biomechanical indices.

RESULTS

There were no significant between-group differences in aBMD at the femoral neck, total hip, and ultradistal radius, while aBMD at the lumbar spine was significantly higher in patients. The only indices indicating compromised bone quality in PsA patients were related to cortical bone quality. Cortical vBMD were -3.8% significantly lower, while cortical pore volume, porosity index, and pore diameter were 108, 79.5, and 8.6%, respectively, significantly higher in patients. Cortical stress was marginally lower (-1.3%, p = 0.077) in patients with stress significantly more unevenly distributed (4.9%, p = 0.035). Endocortical perimeter and cortical pore volume were significantly higher in patients with vertebral fracture. Deficits in cortical bone quality were associated with indices of disease activity/severity and were more prominent in patients with type 2 diabetes mellitus or hypertension.

CONCLUSIONS

There is an intertwined relationship between chronic inflammation, cardiovascular risk factors, and bone loss in PsA. PsA patients seem to have unique bone microstructural deficits which are associated with a propensity to bone fragility.

High-resolution imaging of bone and joint architecture in rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is characterized by local and systemic bone loss caused by increased bone resorption. We describe the current utilization of high-resolution peripheral quantitative computed tomography (HR-pQCT) in the evaluation of bone and joint in RA.

SOURCES OF DATA

PubMed was searched for publications using keywords that included 'bone microarchitecture', 'high-resolution peripheral quantitative computed tomography' and 'rheumatoid arthritis'.

AREAS OF AGREEMENT

HR-pQCT may simultaneously allow assessment of trabecular and cortical bone parameters and be a useful method for depicting bone erosions.

AREAS OF CONTROVERSY

HR-pQCT only assesses bone microarchitecture at the distal radius and tibia. Controversy exists regarding the optimal way to differentiate cortical and trabecular regions.

GROWING POINTS

Although HR-pQCT is currently a research tool, there is potential for its use in the clinical diagnosis and management in RA. Further research is required to evaluate the clinical relevance of imaging abnormalities identified in RA patients.

Differences in bone structure between rheumatoid arthritis and psoriatic arthritis patients relative to autoantibody positivity

OBJECTIVE

To investigate whether trabecular and cortical bone structure differ between patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA). So far, no study has performed a detailed comparative analysis of bone structure in patients with RA and PsA.

METHODS

110 patients (60 RA, 50 PsA) received high-resolution peripheral quantitative CT of the distal radius. Demographic and disease-specific parameters including anti-rheumatic treatment, bone erosion status and previous fractures were recorded.

RESULTS

RA and PsA patients were comparable in age, gender, body mass index, disease duration, disease activity, functional status, antirheumatic treatment and bone erosion status. No significant differences were found for volumetric bone mineral density (BMD), including total BMD (300±77 vs 316±62 mgHA/cm(3)), trabecular BMD (152±46 vs 165±40 mgHA/cm(3)) and cortical BMD (787±113 vs 818±76 mgHA/cm(3)) when comparing RA patients to PsA patients, respectively. However, in contrast to seronegative RA, seropositive RA showed significantly reduced trabecular BMD (p=0.007), bone volume per tissue volume (p=0.007) and trabecular number (p=0.044), as well as a strong trend towards higher trabecular inhomogeneity compared to PsA patients. In the regression analysis, higher age, female gender and presence of autoantibodies were independently associated with trabecular bone loss.

CONCLUSIONS

Seropositive RA exhibits more profound changes in trabecular bone architecture than seronegative RA or PsA. The data support the concept that seropositive RA is a disease entity that is distinct from seronegative RA and PsA.

Alterations of bone density, microstructure, and strength of the distal radius in male patients with rheumatoid arthritis: a case-control study with HR-pQCT

In this cross-sectional study, we investigated volumetric bone mineral density (vBMD), bone microstructure, and biomechanical competence of the distal radius in male patients with rheumatoid arthritis (RA). The study cohort comprised 50 male RA patients of average age of 61.1 years and 50 age-matched healthy males. Areal BMD (aBMD) of the hip, lumbar spine, and distal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius provided measures of cortical and trabecular vBMD, microstructure, and biomechanical indices. aBMD of the hip but not the lumbar spine or ultradistal radius was significantly lower in RA patients than controls after adjustment for body weight. Total, cortical, and trabecular vBMD at the distal radius were, on average, -3.9% to -23.2% significantly lower in RA patients, and these differences were not affected by adjustment for body weight, testosterone level, or aBMD at the ultradistal radius. Trabecular microstructure indices were, on average, -8.1% (trabecular number) to 28.7% (trabecular network inhomogeneity) significantly inferior, whereas cortical pore volume and cortical porosity index were, on average, 80.3% and 63.9%, respectively, significantly higher in RA patients. RA patients also had significantly lower whole-bone stiffness, modulus, and failure load, with lower and more unevenly distributed cortical and trabecular stress. Density and microstructure indices significantly correlated with disease activity, severity, and levels of pro-inflammatory cytokines (interleukin [IL] 12p70, tumor necrosis factor, IL-6 and IL-1β). Ten RA patients had focal periosteal bone apposition most prominent at the ulnovolar aspect of the distal radius. These patients had shorter disease duration and significantly higher cortical porosity. In conclusion, HR-pQCT reveals significant alterations of bone density, microstructure, and strength of the distal radius in male RA patients and provides new insight into the microstructural basis of bone fragility accompanying chronic inflammation.

Decreased quantity and quality of the periarticular and nonperiarticular bone in patients with rheumatoid arthritis: a cross-sectional HR-pQCT study

Rheumatoid arthritis (RA) is a highly bone destructive disease. Although it is well established that RA leads to bone loss and increased fracture risk, current knowledge on the microstructural changes of bone in RA is still limited. The purpose of this study was to assess the microstructure of periarticular and nonperiarticular bone in female and male RA patients and compare it with respective healthy controls. We performed two high-resolution peripheral quantitative computed tomography (HR-pQCT; Xtreme-CT) scans, one of the distal radius and one of the ultradistal radius in 90 patients with RA (60 females, 30 males) and 70 healthy controls (40 females, 30 males) matched for sex, age, and body mass index. Volumetric bone mineral density (vBMD), bone geometry, and bone microstructure including trabecular bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), cortical thickness (Ct.Th) and cortical porosity (Ct.Po) were assessed. At the distal and ultradistal radius, trabecular (p=0.005 and p<0.001) and cortical BMD (p<0.001 and p<0.001) were significantly decreased in male and female patients with RA, respectively. BV/TV was also decreased at both sites, based on lower Tb.N in female RA (p<0.001 for both sites) and lower Tb.Th (p=0.034 and p=0.005) in male RA patients compared with respective healthy controls. Cortical thinning (p=0.018 and p=0.002) but not Ct.Po (p=0.070 and p=0.275) was pronounced in male and female RA patients at the distal radius. Cortical perimeter was increased in male and female RA patients at both sites. Multiple regression models showed that bone geometry (cortical perimeter) is predominantly influenced by age of the RA patient, cortical thickness by both age and disease duration, and trabecular microstructure predominantly by the disease duration. In summary, these data show profound deterioration of bone microstructure in the appendicular skeleton of RA patients at both periarticular and nonperiarticular sites.

A Digital Model to Simulate Effects of Bone Architecture Variations on Texture at Spatial Resolutions of CT, HR-pQCT, and μCT Scanners

The quantification of changes in the trabecular bone structure induced by musculoskeletal diseases like osteoarthritis, osteoporosis, rheumatoid arthritis, and others by means of a texture analysis is a valuable tool which is expected to improve the diagnosis and monitoring of a disease. The reaction of texture parameters on different alterations in the architecture of the fine trabecular network and inherent imaging factors such as spatial resolution or image noise has to be understood in detail to ensure an accurate and reliable determination of the current bone state. Therefore, a digital model for the quantitative analysis of cancellous bone structures was developed. Five parameters were used for texture analysis: entropy, global and local inhomogeneity, local anisotropy, and variogram slope. Various generic structural changes of cancellous bone were simulated for different spatial resolutions. Additionally, the dependence of the texture parameters on tissue mineralization and noise was investigated. The present work explains changes in texture parameter outcomes based on structural changes originating from structure modifications and reveals that a texture analysis could provide useful information for a trabecular bone analysis even at resolutions below the dimensions of single trabeculae.

A customized protocol to assess bone quality in the metacarpal head, metacarpal shaft and distal radius: a high resolution peripheral quantitative computed tomography precision study

Background

High Resolution-Peripheral Quantitative Computed Tomography (HR-pQCT) is an emerging technology for evaluation of bone quality in Rheumatoid Arthritis (RA). However, there are limitations with standard HR-pQCT imaging protocols for examination of regions of bone commonly affected in RA. We developed a customized protocol for evaluation of volumetric bone mineral density (vBMD) and microstructure at the metacarpal head (MH), metacarpal shaft (MS) and ultra-ultra-distal (UUD) radius; three sites commonly affected in RA. The purpose was to evaluate short-term measurement precision for bone density and microstructure at these sites.

Methods

12 non-RA participants, individuals likely to have no pre-existing bone damage, consented to participate [8 females, aged 23 to 71 y [median (IQR): 44 (28) y]. The custom protocol includes more comfortable/stable positioning and adapted cortical segmentation and direct transformation analysis methods. Dominant arm MH, MS and UUD radius scans were completed on day one; repeated twice (with repositioning) three to seven days later. Short-term precision for repeated measures was explored using intraclass correlational coefficient (ICC), mean coefficient of variation (CV%), root mean square coefficient of variation (RMSCV%) and least significant change (LSC%₉₅).

Results

Bone density and microstructure precision was excellent: ICCs varied from 0.88 (MH₂ trabecular number) to .99 (MS₃ polar moment of inertia); CV% varied from < 1 (MS₂ vBMD) to 6 (MS₃ marrow space diameter); RMSCV% varied from < 1 (MH₂ full bone vBMD) to 7 (MS₃ marrow space diameter); and LSC% ₉₅varied from 2 (MS₂ full bone vBMD to 21 (MS₃ marrow space diameter). Cortical porosity measures were the exception; RMSCV% varying from 19 (MS₃) to 42 (UUD). No scans were stopped for discomfort. 5% (5/104) were repeated due to motion during imaging. 8% (8/104) of final images had motion artifact graded > 3 on 5 point scale.

Conclusion

In our facility, this custom protocol extends the potential for in vivo HR-pQCT imaging to assess, with high precision, regional differences in bone quality at three sites commonly affected in RA. Our methods are easy to adopt and we recommend other users of HR-pQCT consider this protocol for further evaluations of its precision and feasibility in their imaging facilities.

Quantitative in vivo HR-pQCT imaging of 3D wrist and metacarpophalangeal joint space width in rheumatoid arthritis

In this technique development study, high-resolution peripheral quantitative computed tomography (HR-pQCT) was applied to non-invasively image and quantify 3D joint space morphology of the wrist and metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA). HR-pQCT imaging (82 μm voxel-size) of the dominant hand was performed in patients with diagnosed rheumatoid arthritis (RA, N = 16, age: 52.6 ± 12.8) and healthy controls (CTRL, N = 7, age: 50.1 ± 15.0). An automated computer algorithm was developed to segment wrist and MCP joint spaces. The 3D distance transformation method was applied to spatially map joint space width, and summarized by the mean joint space width (JSW), minimal and maximal JSW (JSW.MIN, JSW.MAX), asymmetry (JSW.AS), and distribution (JSW.SD)-a measure of joint space heterogeneity. In vivo precision was determined for each measure by calculating the smallest detectable difference (SDD) and root mean square coefficient of variation (RMSCV%) of repeat scans. Qualitatively, HR-pQCT images and pseudo-color JSW maps showed global joint space narrowing, as well as regional and focal abnormalities in RA patients. In patients with radiographic JSN at an MCP, JSW.SD was two-fold greater vs. CTRL (p < 0.01), and JSW.MIN was more than two-fold lower (p < 0.001). Similarly, JSW.SD was significantly greater in the wrist of RA patients vs. CTRL (p < 0.05). In vivo precision was highest for JSW (SDD: 100 μm, RMSCV: 2.1%) while the SDD for JSW.MIN and JSW.SD were 370 and 110 μm, respectively. This study suggests that in vivo quantification of 3D joint space morphology from HR-pQCT, could improve early detection of joint damage in rheumatological diseases.