Bazedoxifene: a new selective estrogen receptor modulator for postmenopausal osteoporosis

An ongoing need for safe and effective pharmacological therapies exists for postmenopausal osteoporosis, which imposes a significant burden on both women and the health-care system. Bazedoxifene is a novel selective estrogen receptor modulator with a unique tissue-selectivity profile. In phase 3 clinical trials of nearly 10,000 postmenopausal women, bazedoxifene was shown to significantly reduce the risk of new vertebral fracture versus placebo, with favourable effects on bone mineral density, bone turnover markers and the lipid profile. Moreover, in a subgroup of women at increased risk of fracture, bazedoxifene significantly decreased non-vertebral fracture risk versus both placebo and raloxifene. Bazedoxifene has been shown to be safe and well tolerated, with no evidence of endometrial or breast stimulation. These data suggest that bazedoxifene may offer significant clinical benefit for postmenopausal women with or at risk of developing osteoporosis, which may subsequently lessen the medical and economic burden of this disease.

Development and preliminary validation of a magnetic resonance imaging joint space narrowing score for use in rheumatoid arthritis: potential adjunct to the OMERACT RA MRI scoring system

OBJECTIVE

To develop and validate a magnetic resonance imaging (MRI) method of assessment of joint space narrowing (JSN) in rheumatoid arthritis (RA).

METHODS

Phase A: JSN was scored 0-4 on MR images of 5 RA patients and 3 controls at 15 wrist sites and 2nd-5th metacarpophalangeal (MCP) joints by 8 readers (7 once, one twice), using a preliminary scoring system. Phase B: Image review, discussion, and consensus on JSN definition, and revised scoring system. Phase C: MR images of 15 RA patients and 4 controls were scored using revised system by 5 readers (4 once, one twice), and results compared with radiographs [Sharp-van der Heijde (SvdH) method].

RESULTS

Phase A: Intraobserver agreement: intraclass correlation coefficient (ICC) = 0.99; smallest detectable difference (SDD, for mean of readings) = 2.8 JSN units (4.9% of observed maximal score). Interobserver agreement: ICC = 0.93; SDD = 6.4 JSN units (9.9%). Phase B: Agreement was reached on JSN definition (reduced joint space width compared to normal, as assessed in a slice perpendicular to the joint surface), and revised scoring system (0-4 at 17 wrist sites and 2nd-5th MCP; 0: none; 1: 1-33%; 2: 34-66%; 3: 67-99%; 4: ankylosis). Phase C: Intraobserver agreement: ICC = 0.90; SDD = 6.8 JSN units (11.0%). Interobserver agreement: ICC = 0.92 and SDD = 6.2 JSN units (8.7%). The correlation (ICC) with the SvdH radiographic JSN score of the wrist/hand was 0.77. Simplified approaches evaluating fewer joint spaces demonstrated similar reliability and correlation with radiographic scores.

CONCLUSION

An MRI scoring system of JSN in RA wrist and MCP joints was developed and showed construct validity and good intra- and interreader agreements. The system may, after further validation in longitudinal data sets, be useful as an outcome measure in RA.

Vertebral fracture risk (VFR) score for fracture prediction in postmenopausal women

SUMMARY

Early prognosis of osteoporosis risk is not only important to individual patients but is also a key factor when screening for osteoporosis drug trial populations. We present an osteoporosis fracture risk score based on vertebral heights. The score separated individuals who sustained fractures (by follow-up after 6.3 years) from healthy controls at baseline.

INTRODUCTION

This case-control study was designed to assess the ability of three novel fracture risk scoring methods to predict first incident lumbar vertebral fractures in postmenopausal women matched for classical risk factors such as BMD, BMI, and age.

METHODS

This was a case-control study of 126 postmenopausal women, 25 of whom sustained at least one incident lumbar fracture and 101 controls that maintained skeletal integrity over a 6.3-year period. Three methods for fracture risk assessment were developed and tested. They are based on anterior, middle, and posterior vertebral heights measured from vertebrae T12-L5 in lumbar radiographs at baseline. Each score's fracture prediction potential was investigated in two variants using (1) measurements from the single most deformed vertebra or (2) average measurements across vertebrae T12-L5. Emphasis was given to the vertebral fracture risk (VFR) score.

RESULTS

All scoring methods demonstrated significant separation of cases from controls at baseline. Specifically, for the VFR score, cases and controls were significantly different (0.67 ± 0.04 vs. 0.35 ± 0.03, p < 10 (-6)) with an AUC of 0.82. Dividing the VFR scores into tertiles, the fracture odds ratio for the highest versus lowest tertile was 35 (p < 0.001). Sorting the combined case-control group according to VFR score resulted in 90% of cases in the top half.

CONCLUSION

At baseline, the three scores separated cases from controls and, especially, the VFR score appears to be predictive of fractures. Control experiments, however also, indicate that VFR-based fracture prediction is operator/annotator dependent and high-quality annotations are needed for good fracture prediction.

Advanced imaging assessment of bone fragility in glucocorticoid-induced osteoporosis

Advanced bone imaging techniques provide structural information, beyond bone mineral density (BMD), and growing evidence indicates that BMD only partially explains bone strength and fracture resistance. Assessing glucocorticoid-induced osteoporosis (GIO) is important, especially the documentation of glucocorticoid (GC) impact on trabecular and cortical bone and on macro and microstructural features. Advanced methods for assessing macrostructure of bone include volumetric quantitative computed tomography (vQCT), high-resolution computed tomography (hrCT), and high-resolution magnetic resonance imaging (hrMRI). The methods for assessing bone microstructure include micro computed tomography (μCT) and micro magnetic resonance imaging (μMRI). Many advanced imaging techniques have been used in vitro and in vivo to examine structural effects of GIO in animals and in humans, and these applications are explored in this review. In human in vitro studies, investigators have used standard bone histomorphometry and μCT to compare trabecular microarchitecture and bone remodeling in postmenopausal women and in males with GIO, and have found that high-dose GC produces dramatic bone loss, accompanied by major reduction in trabecular connectivity and increases in trabecular perforations. In animal studies, investigators have used standard histomorphometry along with pQCT, vQCT, hrMRI or μCT to examine GIO in a variety of animal models including rats, minipigs and sheep. They generally have found excellent relationships between treatment-induced structural changes assessed by these advanced imaging techniques and changes in BMD and biomechanical properties. They also have examined various therapeutic interventions in animals and monitored their efficacy using quantitative imaging methods. In human in vivo studies, investigators have serially examined postmenopausal women and males with GIO in order to assess the extent of skeletal deterioration and to determine the best advanced measures of BMD and structure, with which to monitor disease activity and therapeutic response, and to predict fracture risk. They generally have found that bone density and structural measures obtained by pQCT, vQCT and hrMRI contributed substantially to understanding the skeletal effects of glucocorticoids and to predicting the risk of fracture in human GIO. These animal and human applications, illustrating advanced imaging in GIO, are still in early stages of development. However, as discussed in this review, the novelty and power of the imaging approaches are compelling, and their utility is promising.

New imaging modalities in bone

The digital era has witnessed an exponential growth in bone imaging as new modalities and analytic techniques improve the potential for noninvasive study of bone anatomy, physiology, and pathophysiology. Bone imaging very much lends itself to input across medical and engineering disciplines. It is in part a reflection of this multidisciplinary input that developments in the field of bone imaging over the past 30 years have in some respects outshone those in many other fields of medicine. These developments have resulted in much deeper knowledge of bone macrostructure and microstructure in osteoporosis and a much better understanding of the subtle changes that occur with age, concurrent disease, and treatment. This new knowledge is already being translated into improved day-to day clinical care with better recognition, treatment, and monitoring of the osteoporotic process. As "the more you know, the more you know you don't know" certainly holds true with osteoporosis and bone disease, there is little doubt that further advances in bone imaging and analytical techniques will continue to hold center stage in osteoporosis and related research.

Reliability of vertebral fracture assessment using multidetector CT lateral scout views: the Framingham Osteoporosis Study

Two radiologists evaluated images of the spine from computed tomography (CT) scans on two occasions to diagnose vertebral fracture in 100 individuals. Agreement was fair to good for mild fractures, and agreement was good to excellent for more severe fractures. CT scout views are useful to assess vertebral fracture.

INTRODUCTION

We investigated inter-reader agreement between two radiologists and intra-reader agreement between duplicate readings for each radiologist, in assessment of vertebral fracture using a semi-quantitative method from lateral scout views obtained by CT.

METHODS

Participants included 50 women and 50 men (age 50-87 years, mean 70 years) in the Framingham Study. T4-L4 vertebrae were assessed independently by two radiologists on two occasions using a semi-quantitative scale as normal, mild, moderate, or severe fracture.

RESULTS

Vertebra-specific prevalence of grade ≥ 1 (mild) fracture ranged from 3% to 5%. We found fair (κ = 56-59%) inter-reader agreement for grade ≥ 1 vertebral fractures and good (κ = 68-72%) inter-reader agreement for grade ≥ 2 fractures. Intra-reader agreement for grade ≥ 1 vertebral fracture was fair (κ = 55%) for one reader and excellent for another reader (κ = 77%), whereas intra-reader agreement for grade ≥ 2 vertebral fracture was excellent for both readers (κ = 76% and 98%). Thoracic vertebrae were more difficult to evaluate than the lumbar region, and agreement was lowest (inter-reader κ = 43%) for fracture at the upper (T4-T9) thoracic levels and highest (inter-reader κ = 76-78%) for the lumbar spine (L1-L4).

CONCLUSIONS

Based on a semi-quantitative method to classify vertebral fractures using CT scout views, agreement within and between readers was fair to good, with the greatest source of variation occurring for fractures of mild severity and for the upper thoracic region. Agreement was good to excellent for fractures of at least moderate severity. Lateral CT scout views can be useful in clinical research settings to assess vertebral fracture.

Phenotypic characterization of skeletal abnormalities of Osteopotentia mutant mice by micro-CT: a descriptive approach with emphasis on reconstruction techniques

PURPOSE

The novel protein osteopotentia (Opt) has recently been described as an essential regulator of postnatal osteoblast maturation and might possibly be responsible for some of the rarer types of osteogenesis imperfecta. Our aim was the evaluation of micro CT for the qualitative morphological assessment of skeletal abnormalities of Osteopotentia-mutant mice in comparison to radiography and histology.

MATERIALS AND METHODS

Four homozygous mice with insertional mutations in the Opt gene and three wild-type controls were examined ex vivo using radiography and micro-CT. Two of the homozygous animals were evaluated histologically (trichrome reagent). For the micro-CT evaluation three-dimensional (3D) surface reconstructions and two-dimensional (2D) multiplanar reformations (MPRs) were applied.

RESULTS

The Opt-homozygous mice exhibited severe growth. The radiographic examinations showed osteopenia and fractures with hypertrophic callus formation and pseudarthroses of the forelimbs and ribs. Micro-CT confirmed these findings and was able to demonstrate additional fractures especially at smaller bones such as the metacarpals and phalanges. Additional characterization and superior delineation of cortices and fracture fragments was achieved by 2D MPRs. Histological correlation verified several of these imaging findings.

CONCLUSION

Micro-CT is able to screen Opt-mutant mice for osseous pathologies and furthermore characterize these anomalies. The modality seems superior to conventional radiography, but is not able to demonstrate cellular pathology. However, histology is destructive and more time- and material-consuming than micro-CT. Additional information may be gathered by 2D MPRs.

Atypical subtrochanteric and diaphyseal femoral fractures: report of a task force of the American Society for Bone and Mineral Research

Reports linking long-term use of bisphosphonates (BPs) with atypical fractures of the femur led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address key questions related to this problem. A multidisciplinary expert group reviewed pertinent published reports concerning atypical femur fractures, as well as preclinical studies that could provide insight into their pathogenesis. A case definition was developed so that subsequent studies report on the same condition. The task force defined major and minor features of complete and incomplete atypical femoral fractures and recommends that all major features, including their location in the subtrochanteric region and femoral shaft, transverse or short oblique orientation, minimal or no associated trauma, a medial spike when the fracture is complete, and absence of comminution, be present to designate a femoral fracture as atypical. Minor features include their association with cortical thickening, a periosteal reaction of the lateral cortex, prodromal pain, bilaterality, delayed healing, comorbid conditions, and concomitant drug exposures, including BPs, other antiresorptive agents, glucocorticoids, and proton pump inhibitors. Preclinical data evaluating the effects of BPs on collagen cross-linking and maturation, accumulation of microdamage and advanced glycation end products, mineralization, remodeling, vascularity, and angiogenesis lend biologic plausibility to a potential association with long-term BP use. Based on published and unpublished data and the widespread use of BPs, the incidence of atypical femoral fractures associated with BP therapy for osteoporosis appears to be very low, particularly compared with the number of vertebral, hip, and other fractures that are prevented by BPs. Moreover, a causal association between BPs and atypical fractures has not been established. However, recent observations suggest that the risk rises with increasing duration of exposure, and there is concern that lack of awareness and underreporting may mask the true incidence of the problem. Given the relative rarity of atypical femoral fractures, the task force recommends that specific diagnostic and procedural codes be created and that an international registry be established to facilitate studies of the clinical and genetic risk factors and optimal surgical and medical management of these fractures. Physicians and patients should be made aware of the possibility of atypical femoral fractures and of the potential for bilaterality through a change in labeling of BPs. Research directions should include development of animal models, increased surveillance, and additional epidemiologic and clinical data to establish the true incidence of and risk factors for this condition and to inform orthopedic and medical management.

Denosumab improves density and strength parameters as measured by QCT of the radius in postmenopausal women with low bone mineral density

BACKGROUND

Bone strength is determined by both cortical and trabecular bone compartments and can be evaluated radiologically through measurement of bone density and geometry. Quantitative computed tomography (QCT) separately assesses cortical and trabecular bone reliably at various sites, including the distal radius where there is a gradation of cortical and trabecular bone. We evaluated the effect of denosumab, a fully human monoclonal antibody that inhibits RANK ligand, on distal radius QCT in women with low bone mass to assess the impact of this novel therapy separately on trabecular and cortical bone.

METHODS

Postmenopausal women (n=332) with spine areal bone mineral density (BMD) T-scores between -1.0 and -2.5 received denosumab 60 mg or placebo every 6 months during the 24-month study. QCT measurements along the distal radius were made using a whole-body computed tomography scanner and were used to determine the percentage change from baseline in volumetric BMD; volumetric bone mineral content (BMC); cortical thickness; volume; circumference; and density-weighted polar moment of inertia (PMI), a derived index of bone strength.

RESULTS

Denosumab treatment significantly increased total BMD and BMC along the radius (proximal, distal, and ultradistal sections). At 24 months, the ultradistal region had the greatest percentage increase in total BMD (4.7% [95% CI, 3.6-5.7]; P<0.001) and total BMC (5.7% [95% CI, 4.8-6.6]; P<0.001) over placebo. When cortical and trabecular bone at the proximal and distal regions were separately assessed, cortical bone had significant (P<0.001) increases in BMD, BMC, and thickness, and trabecular bone had a significant increase in BMD relative to placebo (P<0.05). Bone strength, estimated by density-weighted PMI, significantly increased compared with placebo after 6 months of treatment, with the largest percentage increase occurring at 24 months in the ultradistal region (6.6% [95% CI, 5.6-7.6]; P<0.0001).

CONCLUSIONS

QCT measurements demonstrated that denosumab significantly increased BMD, BMC, and PMI along the radius over 24 months. Additionally, denosumab prevented the decrease in QCT-measured cortical thickness observed in the placebo group. These data extend the evidence from previous dual-energy X-ray absorptiometry studies for a positive effect of denosumab on both the cortical and trabecular bone compartments and propose a possible mechanism for the reduction in fracture risk achieved with denosumab therapy.

Regional distribution of spine and hip QCT BMD responses after one year of once-monthly ibandronate in postmenopausal osteoporosis

In the published placebo-controlled Ibandronate Quality (IQ) study, 12 months of once-monthly oral ibandronate increased femoral and vertebral integral and trabecular bone mineral density (BMD) measured by quantitative computed tomography (QCT). Ibandronate showed significant improvements versus placebo in finite element analysis of femoral and vertebral strength. This post hoc analysis examined QCT BMD changes in novel superior and inferior vertebral volumes of interest (VOIs) and femoral and vertebral subcortical, extended cortical, and extended trabecular VOIs. Ninety-three postmenopausal women (BMD(a)T-scores< or =-2.0 at lumbar spine, total hip, or femoral neck) received ibandronate 150 mg/month (n=47) or placebo (n=46) for 12 months. QCT with Medical Imaging Analysis Framework (MIAF)-Spine and MIAF-Femur used automated segmentation and coordinate system-based identification of integral, cortical, subcortical, and trabecular VOIs and combinations (extended cortical=cortical+subcortical; extended trabecular=trabecular+subcortical). Between-group differences in mean percentage changes from baseline were determined by treatment- and center-adjusted analysis of variance. P values were post hoc, exploratory, descriptive, and unadjusted for multiple comparisons. Ibandronate increased vertebral superior and inferior trabecular and extended cortical midsection BMD (4.9%, p=0.032; 4.6%, p=0.055; 3.9%, p=0.014, respectively) versus placebo. Femoral BMD treatment differences (ibandronate versus placebo) were significant in total hip (extended trabecular 4.0%, p=0.005; extended cortical 1.5%, p=0.047; subcortical 3.7%, p=0.009), trochanter (extended trabecular 5.2%, p=0.007; extended cortical 2.4%, p=0.01), and extended trabecular femoral neck (4.0%, p=0.02). Monthly oral ibandronate for 12 months improved QCT BMD versus placebo in the vertebral periphery, subcortical total hip, and all femoral extended trabecular regions.

Bisphosphonates and fractures of the subtrochanteric or diaphyseal femur

BACKGROUND

A number of recent case reports and series have identified a subgroup of atypical fractures of the femoral shaft associated with bisphosphonate use. A population-based study did not support this association. Such a relationship has not been examined in randomized trials.

METHODS

We performed secondary analyses using the results of three large, randomized bisphosphonate trials: the Fracture Intervention Trial (FIT), the FIT Long-Term Extension (FLEX) trial, and the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly (HORIZON) Pivotal Fracture Trial (PFT). We reviewed fracture records and radiographs (when available) from all hip and femur fractures to identify those below the lesser trochanter and above the distal metaphyseal flare (subtrochanteric and diaphyseal femur fractures) and to assess atypical features. We calculated the relative hazards for subtrochanteric and diaphyseal fractures for each study.

RESULTS

We reviewed 284 records for hip or femur fractures among 14,195 women in these trials. A total of 12 fractures in 10 patients were classified as occurring in the subtrochanteric or diaphyseal femur, a combined rate of 2.3 per 10,000 patient-years. As compared with placebo, the relative hazard was 1.03 (95% confidence interval [CI], 0.06 to 16.46) for alendronate use in the FIT trial, 1.50 (95% CI, 0.25 to 9.00) for zoledronic acid use in the HORIZON-PFT trial, and 1.33 (95% CI, 0.12 to 14.67) for continued alendronate use in the FLEX trial. Although increases in risk were not significant, confidence intervals were wide.

CONCLUSIONS

The occurrence of fracture of the subtrochanteric or diaphyseal femur was very rare, even among women who had been treated with bisphosphonates for as long as 10 years. There was no significant increase in risk associated with bisphosphonate use, but the study was underpowered for definitive conclusions.

Vertebral fracture assessment: impact of instrument and reader

PURPOSE

Many osteoporotic vertebral fractures are not clinically recognized but increase fracture risk. We hypothesized that a newer generation densitometer increases the number of evaluable vertebrae and vertebral fractures detected. We also explored the impact of reader experience on vertebral fracture assessment (VFA) interpretation.

METHODS

VFA images obtained using Prodigy and iDXA densitometers in 103 older adults were evaluated for vertebral visualization and fracture presence in the T4-L5 region. A "true" read for each densitometer was achieved by consensus. If readers disagreed, the evaluation of a third expert physician was taken as true. Main outcomes were evaluable vertebrae, vertebral fractures, and intrareader/interreader reproducibility.

RESULTS

Using the "true" reads, 92% of vertebrae were visualized on iDXA and 76% on Prodigy. Numerically, more fractures were identified with iDXA; the "true" reads found 43 fractures on iDXA and 21 on Prodigy. The experienced reader had better intrareader and interreader reproducibility than the inexperienced reader when compared with the "true" read.

CONCLUSIONS

Using the newer iDXA densitometer for VFA analysis improves vertebral body visualization and fracture detection. Training and experience enhance result reproducibility.

Impact of T-cell costimulation modulation in patients with undifferentiated inflammatory arthritis or very early rheumatoid arthritis: a clinical and imaging study of abatacept (the ADJUST trial)

Background

Several agents provide treatment for established rheumatoid arthritis (RA), but a crucial therapeutic goal is to delay/prevent progression of undifferentiated arthritis (UA) or very early RA.

Objective

To determine the impact of T-cell costimulation modulation in patients with UA or very early RA.

Methods

In this double-blind, phase II, placebocontrolled, 2-year study, anti-cyclic citrullinated peptide (CCP)2-positive patients with UA (not fulfilling the ACR criteria for RA) and clinical synovitis of two or more joints were randomised to abatacept (∼10 mg/kg) or placebo for 6 months; the study drug was then terminated. The primary end point was development of RA (by ACR criteria) at year 1. Patients were monitored by radiography, MRI, CCP2, rheumatoid factor and 28 joint count Disease Activity Score (DAS28) over 2 years.

Results

At year 1, 12/26 (46%) abatacept-treated versus 16/24 (67%) placebo-treated patients developed RA (difference (95% CI) −20.5% (−47.4% to 7.8%)). Adjusted mean changes from baseline to year 1 in Genant-modified Sharp radiographic scores for abatacepttreated versus placebo-treated patients, respectively, were 0 versus 1.1 for total score, and 0 versus 0.9 for erosion score. Mean changes from baseline to year 1 in MRI erosion, osteitis and synovitis scores were 0, 0.2 and 0.2, respectively, versus 5.0, 6.7 and 2.3 in the abatacept versus placebo groups. Safety was comparable between groups; serious adverse events occurred in one patient (3.6%) in each group.

Conclusion

Abatacept delayed progression of UA/very early RA in some patients. An impact on radiographic and MRI inhibition was seen, which was maintained for 6 months after treatment stopped. This suggests that it is possible to alter the progression of RA by modulating T-cell responses at a very early stage of disease.

Trial registration number

NCT00124449.

Evaluation of vertebral fracture assessment by dual X-ray absorptiometry in a multicenter setting

SUMMARY

The utility of vertebral fracture assessment (VFA) by DXA to detect prevalent vertebral fracture in a multicenter setting was investigated by comparison to conventional radiography. While limited by lower image quality, overall performance of VFA was good but had a tendency to miss mild prevalent fractures.

INTRODUCTION

In osteoporosis clinical trials standardized spine radiographs are used to detect vertebral fractures as a study endpoint. Lateral spine imaging with dual X-ray absorptiometry (DXA) scanners, known as vertebral fracture assessment (VFA) by DXA, presents a potential alternative to conventional radiography with lower radiation dose and greater patient convenience.

METHODS

We investigated in a multicenter setting the ability of VFA to detect fractures in comparison with conventional radiography. The study examined 203 postmenopausal women who had imaging of the spine by DXA and radiography. Three radiologists experienced in vertebral fracture assessment independently read the VFA scans and radiographs using the Genant semiquantitative method on two occasions.

CONCLUSIONS

Analyzing the data from all readable vertebrae, the kappa statistic, sensitivity, and specificity ranged from 0.64-0.77, 0.65-0.84, and 0.97-0.98, respectively. Considering only moderate and severe fractures improved the kappa statistic (0.80-0.91) and sensitivity (0.70-0.86). While image quality of VFA is inferior to radiography, the detection of vertebral fractures using visual scoring is feasible. However, VFA underperformed due to unreadable vertebrae and reduced sensitivity for mild fractures. Nevertheless, VFA correctly identified most moderate and severe vertebral fractures. Despite this limitation, VFA by DXA provides an important tool for clinical research.

Quantitative computed tomography (QCT) of the forearm using general purpose spiral whole-body CT scanners: accuracy, precision and comparison with dual-energy X-ray absorptiometry (DXA)

BACKGROUND

Dual-energy X-ray absorptiometry (DXA) allows clinically relevant measurement of bone mineral density (BMD) at central and appendicular skeletal sites, but DXA has a limited ability to assess bone geometry and cannot distinguish between the cortical and trabecular bone compartments. Quantitative computed tomography (QCT) can supplement DXA by enabling geometric and compartmental bone assessments. Whole-body spiral CT scanners are widely available and require only seconds per scan, in contrast to peripheral QCT scanners, which have restricted availability, limited spatial resolution, and require several minutes of scanning time. This study evaluated the accuracy and precision of whole-body spiral CT scanners for quantitatively assessing the distal radius, a common site of non-vertebral osteoporosis-related fractures, and compared the CT-measured densitometric values with those obtained from dual-energy-X-ray absorptiometry.

SUBJECTS AND METHODS

A total of 161 postmenopausal women with baseline lumbar spine BMD T-scores between -1.0 and -2.5 underwent left forearm QCT using whole-body spiral CT scanners twice, 1 month apart. QCT volumes of interest were defined and analyzed at 3 specific radial regions: the ultradistal region by using slices at 8, 9, and 10 mm proximal to the ulnar styloid tip; the distal region by a slice 20 mm proximal; and the middle region by a slice 40 mm proximal. BMD, bone mineral content (BMC), volume, and average cortical thickness and circumference were measured. We evaluated QCT accuracy and precision and also report correlations between QCT and DXA for BMD and BMC.

RESULTS

Overall accuracy and precision errors for BMD, BMC and volume were consistent with known skeletal QCT technology precision and were generally less than 3%. BMD and BMC assessed by QCT and DXA were correlated (r=0.55 to 0.80).

DISCUSSION

Whole-body spiral CT scanners allow densitometric evaluations of the distal radius with good accuracy and very good precision. This original and convenient method provides a tool to further investigate cortical and trabecular bone variables in the peripheral skeleton in osteoporotic patients. These assessments, coupled with evaluation of the effects on cortical and trabecular bone measured in response to therapies for osteoporosis, may advance our understanding of the contributors to non-vertebral fracture occurrence.

Once-monthly oral ibandronate improves biomechanical determinants of bone strength in women with postmenopausal osteoporosis

CONTEXT

Bone strength and fracture resistance are determined by bone mineral density (BMD) and structural, mechanical, and geometric properties of bone. DESIGN, SETTING, AND OBJECTIVES: This randomized, double-blind, placebo-controlled outpatient study evaluated effects of once-monthly oral ibandronate on hip and lumbar spine BMD and calculated strength using quantitative computed tomography (QCT) with finite element analysis (FEA) and dual-energy x-ray absorptiometry (DXA) with hip structural analysis (HSA).

PARTICIPANTS

Participants were women aged 55-80 yr with BMD T-scores -2.0 or less to -5.0 or greater (n = 93).

INTERVENTION

Oral ibandronate 150 mg/month (n = 47) or placebo (n = 46) was administered for 12 months.

OUTCOME MEASURES

The primary end point was total hip QCT BMD change from baseline; secondary end points included other QCT BMD sites, FEA, DXA, areal BMD, and HSA. All analyses were exploratory, with post hoc P values.

RESULTS

Ibandronate increased integral total hip QCT BMD and DXA areal BMD more than placebo at 12 months (treatment differences: 2.2%, P = 0.005; 2.0%, P = 0.003). FEA-derived hip strength to density ratio and femoral, peripheral, and trabecular strength increased with ibandronate vs. placebo (treatment differences: 4.1%, P < 0.001; 5.9%, P < 0.001; 2.5%, P = 0.011; 3.5%, P = 0.003, respectively). Ibandronate improved vertebral, peripheral, and trabecular strength and anteroposterior bending stiffness vs. placebo [7.1% (P < 0.001), 7.8% (P < 0.001), 5.6% (P = 0.023), and 6.3% (P < 0.001), respectively]. HSA-estimated femoral narrow neck cross-sectional area and moment of inertia and outer diameter increased with ibandronate vs. placebo (respectively 3.6%, P = 0.003; 4.0%, P = 0.052; 2.2%, P = 0.049).

CONCLUSIONS

Once-monthly oral Ibandronate for 12 months improved hip and spine BMD measured by QCT and DXA and strength estimated by FEA of QCT scans.

Improved precision with Hologic Apex software

The precision of Hologic Apex v2.0 analysis software is significantly improved from Hologic Delphi v11.2 software and is comparable to GE Lunar Prodigy v7.5 software. Apex and Delphi precisions were, respectively, 1.0% vs. 1.2% (L1-L4 spine), 1.l % vs. 1.3% (total femur), 1.6% vs. 1.9% (femoral neck), and 0.7% vs. 0.9% (dual total femur).

INTRODUCTION

Precision of bone mineral density (BMD) measurements by dual-energy X-ray absorptiometry (DXA) is known to vary by manufacturer, model, and technologist. This study evaluated the precision of three analysis versions: Apex v2.0 and Delphi v11.2 (Hologic, Inc.), and Prodigy v7.5 (GE Healthcare, Inc.) independent of technologist skill.

METHODS

Duplicate spine and dual hip scans on 90 women were acquired on both Delphi and Prodigy DXA systems at three clinics. BMD measures were converted to standardized BMD (sBMD) units. Precision errors were described as a root-mean-square (RMS) standard deviations and RMS percent coefficients of variation across the population.

RESULTS

Apex and Delphi values were highly correlated (r ranged from 0.90 to 0.99). Excluding the right neck, the Apex precision error was found to be 20% to 25% lower than the Delphi (spine: 1.0% versus 1.2% (p < 0.05), total hip: 1.1% versus 1.3% (p < 0.05), right neck: 2.3% versus 2.6% (p > 0.1)). No statistically significant differences were found in the precision error of the Apex and Prodigy (p > 0.05) except for the right neck (2.3% versus 1.8% respectively, p = 0.03).

CONCLUSION

The Apex software has significantly lower precision error compared to Delphi software with similar mean values, and similar precision to that of the Prodigy.

Bone mass and architecture determination: state of the art

Bone fracture occurs when the bone strength (i.e. the ability of the bone to resist a force) is less than the force applied to the bone. In the elderly, falls represent the more severe forces applied to bone. Bone density is a good marker of bone strength, and has been used widely in this respect. Nevertheless, many aspects of bone strength cannot be explained by bone density alone. For this reason there has been increasing interest in studying architectural parameters of bone, beyond bone density, which may affect bone strength. Macro-architectural parameters include e.g. bone size and geometry assessed with techniques such as radiography, dual-energy x-ray absorptiometry (DXA), peripheral quantitative computed tomography (QCT), computed tomography (CT) and magnetic resonance imaging (MRI). Micro-architectural parameters include fine cortical and trabecular structural detail which can be evaluated using high-resolution imaging techniques such as multidetector CT, MRI, and high-resolution peripheral QCT. These techniques are providing a great deal of new information on the physiological architectural responses of bone to aging, weightlessness, and treatment. This will ultimately lead to the prediction of fracture risk being improved through a combined assessment of bone density and architectural parameters.

Computer-assisted technique to delineate osteolytic lesions around the femoral component in total hip arthroplasty

There are currently no ideal quantitative measures assessing osteolysis after total joint arthroplasty. This study reports a new approach for quantification of osteolytic lesions on radiographs of total hip arthroplasty with the hypothesis that computer-assisted lesion quantification improves analysis precision over currently used qualitative visual assessment and thus improves progression monitoring. Duplicate exposure sets of anterior-posterior and frog-leg view radiographs of 15 volunteer total hip arthroplasty patients with radiographically evident periprosthetic lucencies were used. Two independent readers delineated the lesions using on-screen digital marker tools. Based on duplicate readings of the first exposure set only, intraoperator precision had a coefficient of variation (CV) from 1.5% to 3.4%, whereas interoperator precision CV ranged from 3.2% to 4.6%. The reproducibility of the x-ray technique as assessed by single readings of both sets of x-rays was CV 3.2% to 4.8%. The new technique compares favorably to precision of qualitative visual assessment and permits more accurate detection and quantitation of osteolytic lesions.

Occupation-related squatting, kneeling, and heavy lifting and the knee joint: a magnetic resonance imaging-based study in men

OBJECTIVE

We examined the relation between occupational exposures to frequent squatting/kneeling and/or heavy lifting with cartilage morphology, based on magnetic resonance imaging (MRI), at the tibiofemoral and patellofemoral joints in men and determined which compartments are most affected.

METHODS

We evaluated 192 men with symptomatic knee osteoarthritis (OA). The more symptomatic knee was imaged using MRI. Cartilage was scored using the Whole Organ MRI Score semiquantitative method at the medial and lateral tibiofemoral joint and patellofemoral joint. Occupational exposures to frequent squatting, kneeling, and/or heavy lifting were assessed using a validated questionnaire.

RESULTS

Among the 192 men [mean (+/- standard deviation) age 69 +/- 9 yrs, body mass index (BMI) 30.8 +/- 4.7 kg/m(2)], those reporting occupational exposure to squatting/kneeling alone, heavy lifting alone, both squatting/kneeling and heavy lifting, or none of these activities numbered 7, 40, 47, and 98, respectively. Compared with men with no occupational exposure to these activities, and following adjustment for age, BMI, and history of knee injury or surgery, we found that men reporting occupational exposures to both squatting/kneeling and heavy lifting had a modest increased risk for worse cartilage morphology scores at the patellofemoral joint [odds ratio (OR) 1.8, 95% confidence interval (CI) 1.1 to 3.2] and medial tibiofemoral joint (OR 1.6, 95% CI 0.9, 3.0), although the latter did not reach statistical significance.

CONCLUSION

Men with frequent occupational squatting/kneeling and heavy lifting have a greater likelihood for worse cartilage morphology scores at the patellofemoral joint. These findings add support to the important role of biomechanical loading on the pathogenesis of knee OA, particularly patellofemoral OA.

Advanced CT bone imaging in osteoporosis

Non-invasive and/or non-destructive techniques can provide structural information about bone, beyond simple bone densitometry. While the latter provides important information about osteoporotic fracture risk, many studies indicate that BMD only partly explains bone strength. Quantitative assessment of macro- and microstructural features may improve our ability to estimate bone strength. Methods for quantitatively assessing macrostructure include (besides conventional radiographs) DXA and CT, particularly volumetric quantitative CT (vQCT). Methods for assessing microstructure of trabecular bone non-invasively and/or non-destructively include high-resolution CT (hrCT), microCT (μCT), high-resolution magnetic resonance (hrMR) and microMR (μMR). vQCT, hrCT and hrMR are generally applicable in vivo; μCT and μMR are principally applicable in vitro. Despite recent progress made with these advanced imaging techniques, certain issues remain. The important balances between spatial resolution and sampling size, or between signal-to-noise and radiation dose or acquisition time, need further consideration, as do the complexity and expense of the methods vs their availability and accessibility. Clinically, the challenges for bone imaging include balancing the advantages of simple bone densitometry vs the more complex architectural features of bone or the deeper research requirements vs the broader clinical needs. The biological differences between the peripheral appendicular skeleton and the central axial skeleton must be further addressed. Finally, the relative merits of these sophisticated imaging techniques must be weighed with respect to their applications as diagnostic procedures, requiring high accuracy or reliability, compared with their monitoring applications, requiring high precision or reproducibility.

Results of a two-year followup study of patients with rheumatoid arthritis who received a combination of abatacept and methotrexate

OBJECTIVE

To evaluate the efficacy, radiographic changes, and safety of abatacept and methotrexate therapy through 2 years in a long-term extension of a previously published 1-year study.

METHODS

Patients who received placebo during year 1 were switched to abatacept. Patients taking abatacept continued to take it. Efficacy and safety were assessed through 2 years.

RESULTS

Of 539 patients enrolled in the initial 1-year study, 488 completed 1 year of the long-term extension (2% discontinued for lack of efficacy). At 2 years, patients taking abatacept had maintained their responses on the American College of Rheumatology (ACR) improvement criteria and the Disease Activity Score in 28 joints (DAS28; using the C-reactive protein [CRP] level), as well as their physical function (according to the Health Assessment Questionnaire [HAQ] disability index [DI]) and health-related quality of life (HRQOL; assessed with the Short Form 36 [SF-36] health survey), that were observed at the end of the double-blind period (year 1 versus year 2 values were 81.9% versus 80.3% for ACR 20% improvement, 25.4% versus 30.9% for a DAS28 [CRP] of <2.6, 71.8% versus 66.8% for the HAQ DI, and 9.7 versus 10.6 and 7.3 versus 7.2, respectively, for the mean change in the physical and mental components summary scores of the SF-36). In the abatacept group, post hoc analysis demonstrated further inhibition of radiographic progression during year 2 (57% reduction in mean change of total score in year 2 versus year 1; P<0.0001), and minimal radiographic progression was observed (mean change in total score from baseline was 1.1 and 1.6 at year 1 and 2, respectively). Rates of adverse events (AEs) and severe AEs were consistent throughout the cumulative period.

CONCLUSION

The improvements in signs and symptoms, physical function, and HRQOL observed after 1 year of abatacept treatment were maintained through 2 years of treatment. This durability was accompanied by a safety profile consistent with that in the double-blind portion of the study. Radiographic progression was further inhibited in year 2 compared with year 1, suggesting an increasing effect of abatacept on the inhibition of structural damage in year 2.

Advanced imaging of bone macrostructure and microstructure in bone fragility and fracture repair

Research into the molecular and cellular pathways focusing on bone fragility and fracture-healing has led to new potential treatments to aid in fracture-healing. This research has focused on physical as well as biological modes of treatment. As new products and methods are derived, it is essential to develop effective and sensitive noninvasive means by which early changes in the fracture repair process can be detected. Specialized noninvasive and/or nondestructive techniques can provide structural information about local and systemic skeletal health, the propensity to fracture, and the pathophysiology of bone fragility. The methods available to quantitatively assess macrostructure include computed tomography and, particularly, volumetric quantitative computed tomography. Methods for assessing microstructure of trabecular bone include high-resolution computed tomography, microquantitative computed tomography, high-resolution magnetic resonance imaging, and micromagnetic resonance imaging. These new techniques help to illustrate the process of fracture-healing by defining the skeletal response to innovative therapies and assessing biomechanical relationships. This review presents perspectives on the advanced imaging modalities that are currently available and on recent developments that may improve the detection and understanding of bone fragility and fracture-healing.

Meniscal damage associated with increased local subchondral bone mineral density: a Framingham study

OBJECTIVE

Because menisci and the medial vs lateral tibial plateau bone mineral density ratio (M:L BMD) are associated with loading within the knee, we postulated there to be an association between compartment-specific meniscal damage and M:L BMD. We hypothesized that knees with higher M:L BMD, consistent with increased medial subchondral BMD, would be associated with medial meniscal damage, and lower ratios with lateral meniscal damage.

METHODS

We conducted a cross-sectional study evaluating participants in the Framingham Osteoarthritis Cohort having magnetic resonance images (MRIs), BMDs, and x-rays of the knee. Medial and lateral meniscal damage were defined on MRI. We performed a logistic regression with medial meniscal damage as the outcome testing M:L BMD groups as predictor variables. We adjusted for age and sex; we used generalized estimating equations (GEE) to adjust for correlation between knees. Identical analyses were performed evaluating lateral meniscal damage.

RESULTS

When evaluating the relation of M:L BMD to medial meniscal damage, the odds ratios (ORs) of prevalent medial meniscal damage from lowest to highest quartile of M:L BMD were 1.0 (referent), 1.9, 2.4 and 8.9, P for trend <0.0001. When evaluating the relation of M:L BMD to lateral meniscal damage, the ORs of prevalent lateral meniscal damage from lowest to highest quartile of M:L BMD were 1.0 (referent), 0.3, 0.2, and 0.2, P for trend = 0.001.

CONCLUSIONS

Meniscal damage is associated with higher regional tibial BMD in the same compartment. Our findings highlight the close relationship between meniscal integrity and regional tibial subchondral BMD.

Abatacept inhibits progression of structural damage in rheumatoid arthritis: results from the long-term extension of the AIM trial

OBJECTIVE

Assess the effect of abatacept on progression of structural damage over 2 years in patients with rheumatoid arthritis who had an inadequate response to methotrexate.

METHODS

539 patients entered an open-label extension of the AIM (Abatacept in Inadequate responders to Methotrexate) trial and received abatacept. Radiographic assessment of the hands and feet was performed at baseline, year 1 and year 2. At year 2, each patient's radiographs were scored for progression blinded to sequence and treatment allocation.

RESULTS

In patients treated with abatacept for 2 years, greater reduction in progression of structural damage was observed in year 2 than in year 1. The mean change in total Genant-modified Sharp scores was reduced from 1.07 units in year 1 to 0.46 units in year 2. Similar reductions were observed in erosion and joint space narrowing scores. Following 2 years of treatment with abatacept, 50% of patients had no progression of structural damage as defined by a change in the total score of < or =0 compared with baseline. 56% of patients treated with abatacept had no progression during the first year compared with 45% of patients treated with placebo. In their second year of treatment with abatacept, more patients had no progression than in the first year (66% vs 56%).

CONCLUSIONS

Abatacept has a sustained effect that inhibits progression of structural damage. Furthermore, the mean change in radiographic progression in patients treated with abatacept for 2 years was significantly lower in year 2 versus year 1, suggesting that abatacept may have an increasing disease-modifying effect on structural damage over time.

Enhanced prediction of fracture risk combining vertebral fracture status and BMD

Prevalent vertebral fractures are associated with increased fracture risk, but the magnitude of this effect across a range of BMD T-scores has not been quantified. In this analysis, for any given BMD T-score, incident fracture risk varied up to twelve fold when information regarding prevalent radiographic vertebral fracture status was considered.

BACKGROUND

Clinical fracture risk evaluation of older women usually includes assessment of bone mineral density (BMD) but often not vertebral fracture status. In this analysis, we quantified the impact of vertebral fracture burden on two year fracture risk across a range of BMD T-scores.

METHODS

Data were from 2,651 postmenopausal women who were assigned to the placebo groups of the Fracture Prevention Trial (median observation 21 months) and the Multiple Outcomes of Raloxifene Evaluation Trial (MORE; observation 2 years). Using the Genant visual semiquantitative criteria, we defined prevalent vertebral fracture status as: a) presence or absence of fracture; b) fracture number; c) maximum semi-quantitative (SQ) score (normal=0, mild fracture=1, moderate fracture=2, severe fracture=3); and d) spinal deformity index (SDI) score (sum of SQ scores of T4 to L4 vertebrae). Incident fractures over two years were identified via lateral spine radiographs and outside the spine by questioning of patients and review of radiographs or radiographic reports.

RESULTS

Femoral neck BMD T-score provided significant information regarding fracture risk. Across the range of T-scores, vertebral fracture status provided additional prognostic information. The risk increased with increasing number and severity of prevalent vertebral fractures and SDI, a summary measure of spine fracture burden. Across a range of BMD values, prevalent spine fracture burden as assessed by SDI increased the risk of incident vertebral fractures by up to 12-fold, nonvertebral fractures by about twofold, and any fractures by up to sevenfold.

CONCLUSIONS

These findings indicate that at any given BMD T-score, the risk of incident vertebral, non-vertebral, and any fracture depended heavily on prevalent radiographic vertebral fracture status. Assessment of vertebral fracture status, in addition to BMD, provides practical and relevant clinical information to aid in predicting fracture risk in postmenopausal women.

Severity of vertebral fracture reflects deterioration of bone microarchitecture

INTRODUCTION

Bone microarchitecture, a component of bone strength, is generally measured on transiliac bone biopsy samples. The objective of this study was to determine whether assessment of four grades of vertebral fracture severity could serve as a noninvasive surrogate marker for trabecular bone volume and microarchitecture.

METHODS

Baseline vertebral fracture severity was determined by semiquantitative assessment of spine radiographs from 190 postmenopausal women with osteoporosis. Bone-structure indices were obtained by 2D histomorphometry and 3D microcomputed tomography (CT) analyses. Significance of differences was determined after adjusting for age, height, and lumbar spine bone mineral density.

RESULTS

There were significant (P < 0.05) trends in decreasing bone volume, trabecular number, and connectivity, and increasing trabecular separation with greater vertebral fracture severity. Histomorphometric bone volume was 25 and 36% lower (P < 0.05) in women with moderate and severe fractures than in women with no fractures, respectively. Compared with women without fractures, women with mild, moderate, and severe fractures had lower (P < 0.05) microCT bone volume (23, 30, and 51%, respectively).

CONCLUSIONS

Microarchitectural deterioration was progressively worse in women with increasing severity of vertebral fractures. We conclude that assessment of vertebral fracture severity is an important clinical tool to evaluate the severity of postmenopausal osteoporosis.

Cigarette smoking and the risk for cartilage loss and knee pain in men with knee osteoarthritis

OBJECTIVE

To examine the effects of smoking on cartilage loss and pain at the knee in individuals with knee osteoarthritis.

METHODS

159 men with symptomatic knee osteoarthritis who participated in a 30-month, prospective, natural history study of knee osteoarthritis were examined. The more symptomatic knee was imaged using magnetic resonance imaging (MRI) at baseline, and again at 15 and 30 months of follow-up. Cartilage was scored using the Whole-Organ MRI Score semiquantitative method at the medial and lateral tibiofemoral joints and at the patellofemoral joint. At baseline and follow-up visits, the severity of knee pain was assessed using a Visual Analogue Scale pain score (0-100 mm).

RESULTS

Among the 159 men, 19 (12%) were current smokers at baseline. Current smokers were younger (mean (standard deviation (SD)) age 62 (9) v 69 (9) years) and leaner (mean (SD) body mass index (BMI): 28.9 (3.2) v 31.3 (4.8) kg/m(2)) than men who were not current smokers. When adjusted for age, BMI and baseline cartilage scores, men who were current smokers were found to have an increased risk for cartilage loss at the medial tibiofemoral joint (odds ratio (OR) 2.3, 95% confidence interval (CI) 1.0 to 5.4) and the patellofemoral joint (OR 2.5, 95% CI 1.1 to 5.7). Current smokers also had higher adjusted pain scores at baseline (60.5 v 45.0, p<0.05) and at follow-up (59.4 v 44.3, p<0.05) than men who were not current smokers.

CONCLUSIONS

Men with knee osteoarthritis who smoke sustain greater cartilage loss and have more severe knee pain than men who do not smoke.

Incidence and risk factors for vertebral fracture in women and men: 25-year follow-up results from the population-based Framingham study

This study evaluates baseline characteristics of 704 women and men in the Framingham Study with respect to long-term risk of incident vertebral fracture. Incidence was 24% in women and 10% in men. Few factors in middle-aged persons, except prevalent (moderate) fracture and alcohol consumption (in men), predicted long-term incidence of vertebral fracture.

INTRODUCTION

We studied potential risk factors in women and men in middle adult years to help identify individuals at increased long-term risk of vertebral fracture in advanced age.

MATERIALS AND METHODS

Participants included Framingham cohort members who underwent radiographic examinations at baseline in 1967-1969 (mean age, 53 years) and follow-up in 1992-1993. Semiquantitative methods were used to determine incident fracture, defined as any vertebral body graded normal at baseline and at least mildly deformed (20-25% reduction or more in any vertebral height) at follow-up. Information on potential risk factors was obtained from examinations conducted at or before baseline radiography.

RESULTS

Prevalence of vertebral fracture was similar (14%) in women and men, although incidence was greater in women (24%) than men (10%). Alcohol consumption increased fracture risk in men. Multivariable-adjusted ORs increased from 1.78 in men who consumed 1-3 oz of alcohol per week in middle-age years to 4.61 in those with intakes of > or =4 oz/week (trend, P = 0.0099). Age, height, weight, grip strength, physical activity, metacarpal cortical area, and estrogen use (in women) had little or no influence on cumulative incidence of vertebral fracture. Results were similar when fracture was restricted to (at least) moderate severity; however, participants with moderate to severe fracture prevalent at baseline had five times the incidence of moderate to severe fracture during follow-up compared with those without moderately to severe prevalent fractures.

CONCLUSIONS

Few factors in middle-aged persons, except prevalent fracture and alcohol consumption (in men), predict long-term incidence of vertebral fracture. The explanation underlying this finding is not readily apparent, however, risk factors for vertebral fracture may be more relevant to older individuals, with respect to short-term fracture risk, than to middle-aged adults in relation to long-term risk with aging.

Effects of abatacept in patients with methotrexate-resistant active rheumatoid arthritis: a randomized trial

BACKGROUND

The selective co-stimulation modulator abatacept demonstrated efficacy for treating rheumatoid arthritis in early clinical studies.

OBJECTIVE

To evaluate the effects of abatacept in patients with persistent, active rheumatoid arthritis despite methotrexate treatment.

DESIGN

One-year, multicenter, randomized, double-blind, placebo-controlled trial (November 2002 to October 2004).

SETTING

116 centers worldwide.

PATIENTS

652 patients with active rheumatoid arthritis despite methotrexate treatment.

INTERVENTION

Once-monthly infusion of a fixed dose of abatacept, approximately 10 mg/kg of body weight, or placebo.

MEASUREMENTS

Co-primary end points were a 20% improvement in American College of Rheumatology (ACR) response criteria (ACR 20) at 6 months, clinically meaningful improvements in physical function, and change from baseline in joint erosion score at 1 year.

RESULTS

Four hundred thirty-three and 219 patients were randomly assigned to abatacept or placebo, respectively, and 385 (89%) and 162 (74%), respectively, completed 1 year of treatment. In a modified intention-to-treat analysis, 6-month ACR 20, ACR 50, and ACR 70 responses were 67.9% for abatacept versus 39.7% for placebo (difference, 28.2 percentage points [95% CI, 19.8 to 36.7 percentage points]), 39.9% for abatacept versus 16.8% for placebo (difference, 23.0 percentage points [CI, 15.0 to 31.1 percentage points]), and 19.8% for abatacept versus 6.5% for placebo (difference, 13.3 percentage points [CI, 7.0 to 19.5 percentage points]), respectively. At 1 year, the responses increased to 73.1% for abatacept versus 39.7% for placebo (difference, 33.4 percentage points [CI, 25.1 to 41.7 percentage points]), 48.3% for abatacept versus 18.2% for placebo (difference, 30.1 percentage points [CI, 21.8 to 38.5 percentage points]), and 28.8% for abatacept versus 6.1% for placebo (difference, 22.7 percentage points [CI, 15.6 to 29.8 percentage points]), respectively (P < 0.001 for all). Physical function significantly improved in 63.7% versus 39.3% of patients (P < 0.001). At 1 year, abatacept statistically significantly slowed the progression of structural joint damage compared with placebo. Abatacept-treated patients had a similar incidence of adverse events (87.3% vs. 84.0%; difference, 3.3 percentage points [CI, -2.5 to 9.1 percentage points]) and a higher incidence of prespecified serious infections (2.5% vs. 0.9%; difference, 1.6 percentage points [CI, -0.3 to 3.6 percentage points]) and infusion reactions (acute, 8.8% vs. 4.1%; difference, 4.7 percentage points [CI, 0.9 to 8.4 percentage points]; peri-infusional, 24.5% vs. 16.9%; difference, 7.6 percentage points [CI, 1.2 to 14.0 percentage points]) compared with placebo recipients.

LIMITATIONS

The study involved only 1 group of patients over 1 year.

CONCLUSIONS

Abatacept statistically significantly reduced disease activity in patients with rheumatoid arthritis and an inadequate response to methotrexate. Longer treatment in different patient populations is needed to establish its appropriate role in rheumatoid arthritis.

Responsiveness, effect size, and smallest detectable difference of Magnetic Resonance Imaging in knee osteoarthritis

OBJECTIVE

The aim of this study was to determine the responsiveness, effect size (ES) and smallest detectable difference (SDD) of two Magnetic Resonance Imaging (MRI) measures for osteoarthritis (OA) of the knee: a whole-organ semiquantitative evaluation and cartilage volume.

DESIGN

This analysis was performed on a dataset from a randomized, double-blind trial (Roche NI-15713) conducted in 1998 of a novel therapy in subjects with mild-moderate knee OA, with MRI at baseline and 6-month follow-up. The trial measurements included (1) cartilage volume measured using a proprietary software method; and (2) semiquantitative scoring of other parameters important for "whole organ" evaluation of OA knee joint pathology, using the Whole-Organ MRI Score (WORMS). The analysis initially examined the distributional characteristics of WORMS items, such as cartilage morphology. Standardized response mean (SRM), ES, and SDD between baseline and 6-month follow-up were then calculated in the whole group and the placebo group alone.

RESULTS

In general, the differences were small and this was reflected in the small ESs and SRMs. There was also a suggestion of a treatment effect with reduction in differences between baseline and follow-up in the treatment group.

CONCLUSION

Of the MRI semiquantitative measures, cartilage morphology, synovitis and osteophytes appeared to be responsive to change and the focus of repeat measures should highlight these articular features. In general, the ESs and SRMs were small.

A Selective p38α Mitogen-Activated Protein Kinase Inhibitor Reverses Cartilage and Bone Destruction in Mice with Collagen-Induced Arthritis

Destruction of cartilage and bone is a poorly managed hallmark of human rheumatoid arthritis (RA). p38 Mitogen-activated protein kinase (MAPK) has been shown to regulate key proinflammatory pathways in RA, including tumor necrosis factor alpha, interleukin (IL)-1beta, and cyclooxygenase-2, as well as the process of osteoclast differentiation. Therefore, we evaluated whether a p38alpha MAPK inhibitor, indole-5-carboxamide (SD-282), could modulate cartilage and bone destruction in a mouse model of RA induced with bovine type II collagen [collagen-induced arthritis (CIA)]. In mice with early disease, SD-282 treatment significantly improved clinical severity scores, reduced bone and cartilage loss, and reduced mRNA levels of proinflammatory genes in paw tissue, including IL-1beta, IL-6, and cyclooxygenase-2. Notably, SD-282 treatment of mice with advanced disease resulted in significant improvement in clinical severity scoring and paw swelling, a reversal in bone and cartilage destruction as assessed by histology, bone volume fraction and thickness, and three-dimensional image analysis. These changes were accompanied by reduced osteoclast number and lowered levels of serum cartilage oligomeric matrix protein, a marker of cartilage breakdown. Thus, in a model of experimental arthritis associated with significant osteolysis, p38alpha MAPK inhibition not only attenuates disease progression but also reverses cartilage and bone destruction in mice with advanced CIA disease.

Advanced Imaging Assessment of Bone Quality

Noninvasive and/or nondestructive techniques can provide structural information about bone, beyond simple bone densitometry. While the latter provides important information about osteoporotic fracture risk, many studies indicate that bone mineral density (BMD) only partly explains bone strength. Quantitative assessment of macrostructural characteristics, such as geometry, and microstructural features, such as relative trabecular volume, trabecular spacing, and connectivity, may improve our ability to estimate bone strength. Methods for quantitatively assessing macrostructure include (besides conventional radiographs) dual X ray absorptiometry (DXA) and computed tomography (CT), particularly volumetric quantitative computed tomography (vQCT). Methods for assessing microstructure of trabecular bone noninvasively and/or nondestructively include high-resolution computed tomography (hrCT), microcomputed tomography (micro-CT), high-resolution magnetic resonance (hrMR), and micromagnetic resonance (micro-MR). vQCT, hrCT, and hrMR are generally applicable in vivo; micro-CT and micro-MR are principally applicable in vitro. Despite progress, problems remain. The important balances between spatial resolution and sampling size, or between signal-to-noise and radiation dose or acquisition time, need further consideration, as do the complexity and expense of the methods versus their availability and accessibility. Clinically, the challenges for bone imaging include balancing the advantages of simple bone densitometry versus the more complex architectural features of bone, or the deeper research requirements versus the broader clinical needs. The biological differences between the peripheral appendicular skeleton and the central axial skeleton must be further addressed. Finally, the relative merits of these sophisticated imaging techniques must be weighed with respect to their applications as diagnostic procedures, requiring high accuracy or reliability, versus their monitoring applications, requiring high precision or reproducibility.

Racial differences in the prevalence of vertebral fractures in older men: the Baltimore Men's Osteoporosis Study

Older black men have higher adjusted bone mineral density (BMD) and a lower adjusted rate of decline in hip BMD than older white men. There are few published data on the prevalence of morphometric vertebral fractures in older white men and no published data for older black men. The study's objective was to estimate the prevalence of vertebral fractures in older men and explore differences in prevalence between older white and black men. Subjects included five hundred forty-two men (415 white and 127 black) aged 65 and above (mean age of 74.0+/-5.7 years) participating in the longitudinal component of the Baltimore Men's Osteoporosis Study. Radiographs of the thoracic and lumbar spine were obtained using standard protocols and read for the presence of vertebral deformities using binary semiquantitative techniques. Quantitative morphometry was performed and vertebral fractures were defined using the Melton-Eastell method. BMD was measured at the femoral neck, total hip and lumbar spine. Participants also completed self- and interviewer-administered questionnaires and underwent standardized clinical examinations. One or more vertebral fractures were present in 30 of 514 men with available radiographs: estimated prevalence 5.8% (95% confidence intervals [CI]: 4.0, 8.3%). Prevalence was significantly higher in white than black men, 7.3% vs 0.9% (Fishers' exact p =0.01): age-adjusted odds ratio=8.3 (95% CI: 1.1, 62.5). Among white men, there was no significant difference in age-adjusted femoral neck or total hip BMD or frequency or severity of back pain between men with and without vertebral fractures. In conclusion, older white men have a higher prevalence of vertebral fractures than older black men. This may be related to differences in BMD between these groups.

Comparison of BMD precision for Prodigy and Delphi spine and femur scans

INTRODUCTION

Precision error in bone mineral density (BMD) measurement can be affected by patient positioning, variations in scan analysis, automation of software, and both short- and long-term fluctuations of the densitometry equipment. Minimization and characterization of these errors is essential for reliable assessment of BMD change over time.

METHODS

We compared the short-term precision error of two dual-energy X-ray absorptiometry (DXA) devices: the Lunar Prodigy (GE Healthcare) and the Delphi (Hologic). Both are fan-beam DXA devices predominantly used to measure BMD of the spine and proximal femur. In this study, 87 women (mean age 61.6+/-8.9 years) were measured in duplicate, with repositioning, on both systems, at one of three clinical centers. The technologists were International Society for Clinical Densitometry (ISCD) certified and followed manufacturer-recommended procedures. All scans were acquired using 30-s scan modes. Precision error was calculated as the root-mean-square standard deviation (RMS-SD) and coefficient of variation (RMS-%CV) for the repeated measurements. Right and left femora were evaluated individually and as a combined dual femur precision. Precision error of Prodigy and Delphi measurements at each measurement region was compared using an F test to determine significance of any observed differences.

RESULTS

While precision errors for both systems were low, Prodigy precision errors were significantly lower than Delphi at L1-L4 spine (1.0% vs 1.2%), total femur (0.9% vs 1.3%), femoral neck (1.5% vs 1.9%), and dual total femur (0.6% vs 0.9%). Dual femur modes decreased precision errors by approximately 25% compared with single femur results.

CONCLUSIONS

This study suggests that short-term BMD precision errors are skeletal-site and manufacturer specific. In clinical practice, precision should be considered when determining: (a) the minimum time interval between baseline and follow-up scans and (b) whether a statistically significant change in the patient's BMD has occurred.

Osteoblast-derived PTHrP is a potent endogenous bone anabolic agent that modifies the therapeutic efficacy of administered PTH 1-34

Mice heterozygous for targeted disruption of Pthrp exhibit, by 3 months of age, diminished bone volume and skeletal microarchitectural changes indicative of advanced osteoporosis. Impaired bone formation arising from decreased BM precursor cell recruitment and increased apoptotic death of osteoblastic cells was identified as the underlying mechanism for low bone mass. The osteoporotic phenotype was recapitulated in mice with osteoblast-specific targeted disruption of Pthrp, generated using Cre-LoxP technology, and defective bone formation was reaffirmed as the underlying etiology. Daily administration of the 1-34 amino-terminal fragment of parathyroid hormone (PTH 1-34) to Pthrp+/- mice resulted in profound improvement in all parameters of skeletal microarchitecture, surpassing the improvement observed in treated WT littermates. These findings establish a pivotal role for osteoblast-derived PTH-related protein (PTHrP) as a potent endogenous bone anabolic factor that potentiates bone formation by altering osteoblast recruitment and survival and whose level of expression in the bone microenvironment influences the therapeutic efficacy of exogenous PTH 1-34.

The evidence for magnetic resonance imaging as an outcome measure in proof-of-concept rheumatoid arthritis studies

Magnetic resonance imaging (MRI) has now been used extensively in cross-sectional and observational studies as well as in controlled clinical trials to assess disease activity and joint damage in rheumatoid arthritis (RA). MRI measurements or scores for erosions, bone edema, and synovitis have been developed and validated by several groups. The OMERACT criteria require that outcome measures demonstrate adequate validity, discriminative power, and feasibility if they are to be useful in clinical trials. Specific performance targets for these criteria depend on the scientific, regulatory, logistical, and financial context of the study in question. We review the extent to which MRI assessments of joint erosion, bone edema, and synovitis fulfil these criteria, particularly as they relate to proof-of-concept RA clinical trials.

Magnetic resonance imaging in rheumatoid arthritis advances and research priorities

This article updates the work and results of the OMERACT MRI in RA Working Group as presented at the OMERACT 7 meeting in May 2004, focusing on the development of the EULAR-OMERACT rheumatoid arthritis magnetic resonance imaging reference image atlas, and on areas for future research.

Metacarpal index and bone mineral density in healthy African-American women

Bone mineral density (BMD) reference data of non-Caucasian women is scarce but greatly needed for African-American women. The objective of this study was to establish a metacarpal normative reference database for African-American women using digital X-ray radiogrammetry (DXR) and hand radiographs and compare these values to existing Caucasian data. Two hundred and fifty healthy African-American women between the ages of 20 and 79 years old, 14 of whom were excluded, were recruited to participate from four different clinical sites. The study population was recruited in approximately equal number into the following groups: 20-29, 30-39, 40-49, 50-59, 60-69 and 70-79 years of age. A radiograph was acquired of each subject's non-dominant hand. The radiographs were scanned and analyzed using radiogrammetric techniques, and the BMD, MCI (Metacarpal Index), bone width and cortical thickness were calculated. The regression curve that best fit the data was a second order polynomial. The BMD and MCI of young adult women (20-40 years of age) were used to calculate T-score parameters. The young reference BMD and MCI with their associated standard deviations were found to be 0.6045 g/cm2+/-0.0529 g/cm2 and 0.5096 and 0.0792, respectively. However, the MCI was found to be approximately 2.5% lower (-0.0118) compared to Caucasian women. The African-American metacarpal BMD was found to be 3.5% (0.0207 g/cm2) higher across all ages when compared to existing Caucasian reference data acquired in a similar way. The differences were found to be entirely due to larger bone size, cortical diameter and bone width in the African-American women.

Lateral vertebral assessment: a valuable technique to detect clinically significant vertebral fractures

Although many vertebral fractures are clinically silent, they are associated with increased risk for subsequent osteoporotic fractures. A substantial number of these fractures are demonstrable using instant vertebral assessment with Hologic densitometers. Whether similar recognition is possible using dual-energy lateral vertebral assessment (LVA) with GE Lunar densitometers remains uncertain. Thus, we evaluated the ability of clinicians using LVA to detect prevalent vertebral fractures. Dual-energy LVA and conventional thoracic and lumbar spine radiographs were concurrently obtained in 80 postmenopausal women. Using an established visual semiquantitative system, vertebral fractures were identified individually by two non-radiologist clinicians on LVA images, and the results were compared with spinal radiograph evaluation by an expert radiologist. Using LVA, 95% of vertebral bodies from T7 through L4 were evaluable, but a majority (66%) of vertebrae from T4 to T6 were not adequately visualized. In the LVA-evaluable vertebrae, prevalent fractures were identified in 40 vertebral bodies by radiography. In this regard, the clinicians using LVA detected 17 of 18 radiographically evident vertebral fractures of grade 2 or 3, a false negative rate of 6%. They identified 50% (11/22) of grade 1 fractures. Additionally, the vast majority of evaluable non-fractured vertebrae, (764/794, 96.2%) were correctly classified as normal by LVA. Thus, clinicians utilizing LVA correctly identified the vast majority of grade 2 or 3 vertebral compression fractures and normal vertebral bodies, although detection of grade 1 fractures was less effective. In conclusion, the low-radiation, dual-energy LVA technique provides a rapid and convenient way for clinicians to identify patients with, and without, grade 2 or 3 vertebral fractures, thereby enhancing care of osteoporotic patients.

Bone marrow lesions in the knee are associated with increased local bone density

OBJECTIVE

Bone marrow lesions are associated with pain and compartment-specific progression of joint space narrowing in patients with knee osteoarthritis (OA). Bone marrow lesions occur in regions under increased loading, and excess loading produces increased bone mineral density (BMD). The ratio of BMD in the medial tibial plateau compared with that in the lateral tibial plateau (M:L BMD ratio) reflects loading in the knee. Therefore, we hypothesized that a higher M:L BMD ratio would be associated with medial bone marrow lesions, and that lower ratios would be associated with lateral bone marrow lesions.

METHODS

Participants in the Framingham Osteoarthritis Study underwent magnetic resonance imaging (MRI), measurement of bone mineral density (BMD), and knee radiography between 2002 and 2004. MRI was used to define medial and lateral bone marrow lesions in the medial and lateral tibiofemoral compartments, respectively. We performed a logistic regression analysis with medial bone marrow lesions as the outcome, testing M:L BMD ratio groups as predictor variables. We adjusted for age, sex, body mass index, and systemic BMD, using generalized estimating equations to adjust for correlations between knees. An identical analysis evaluating lateral bone marrow lesions was performed.

RESULTS

Medial bone marrow lesions were strongly associated with a high M:L BMD ratio. The odds ratios (ORs) for prevalent medial bone marrow lesions, for the lowest to the highest quartile of M:L BMD ratios, were 1.0 (referent), 1.3, 5.0, and infinity (P for trend < 0.0001). Lateral bone marrow lesions were strongly associated with low M:L BMD ratios (the ORs for prevalent lateral bone marrow lesions, for the highest to the lowest quartile, were 1.0 [referent], 3.0, 26.8, and 54.0 [P for trend < 0.0001]).

CONCLUSION

Medial bone marrow lesions occur in knees with relatively higher local medial tibial bone density, and lateral bone marrow lesions occur in knees with relatively higher lateral tibial bone density, supporting the hypothesis that local BMD reflects loading within the knee. Our findings emphasize the importance of loading in the pathophysiology of OA.

Reduction in vertebral fracture risk in teriparatide-treated postmenopausal women as assessed by spinal deformity index

Teriparatide is the first bone-building drug available for the treatment of osteoporosis. We investigated the efficacy of this compound as assessed by spinal deformity index (SDI) using data from the Fracture Prevention Trial (FPT). The FPT was a randomized, double blind trial of placebo versus teriparatide 20 microg (TPTD20) versus teriparatide 40 microg (TPTD40) administered by daily self-injection. Patients included in the current analyses were those patients from the placebo (n = 398) and TPTD20 (the approved dose, n = 403) groups with baseline and follow-up radiographs and at least one vertebral fracture at baseline. For each vertebra, a visual semiquantitative grade of 0, 1, 2, or 3 was assigned for no fracture or mild, moderate, or severe fracture, respectively; the SDI was calculated by summing the fracture grades of all T4 to L4 vertebrae. The mean SDI increased in the placebo and TPTD20 groups by 0.485 and 0.134, respectively (P < 0.001). The proportions of patients with SDI increases >1, >2, and >3 were reduced by 85%, 80%, and 80%, respectively. In the placebo group, increasing baseline SDI was correlated with the mean increase in SDI during the trial (r = 0.080, P = 0.01), consistent with the progressive natural history of osteoporosis. However, in the TPTD20 group, increasing baseline SDI was not correlated with the mean increase in SDI during the trial (P = 0.297) indicating that teriparatide mitigated or eliminated the increased risk associated with increasing fracture burden. Increases in SDI during the trial were associated with increasing proportions of patients with new or worsening back pain and greater mean height loss (P < 0.0001), demonstrating an association with important clinical consequences. The results indicate that teriparatide greatly reduced the increase in fracture burden in the FPT and mitigated or eliminated the risk for future fractures imparted by increasing baseline fracture burden.

Prognostic utility of a semiquantitative spinal deformity index

The semiquantitative spinal deformity index (SDI) is a summary measure of the vertebral fracture status of the spine incorporating both the number and severity of vertebral fractures. For each vertebra, a visual semiquantitative grade of 0, 1, 2, or 3 is assigned for no fracture or mild, moderate, or severe fracture, respectively, and the SDI is calculated by summing the fracture grades of all vertebrae (T4 to L4). We investigated the effect of prevalent vertebral fracture number and severity, as integrated by the SDI, on 3-year vertebral fracture risk by performing logistic regression modeling with data from the MORE trial. There was a striking linear relationship between baseline SDI and the model-based vertebral fracture risk estimates, with a near-perfect correlation (r = 0.98, P < 0.001). However, the SDI may be overly simplistic, as a given SDI value can be attained through differing vertebral fracture scenarios (i.e., an SDI of 3 can be realized three ways), each corresponding to potentially different vertebral fracture risk. To address this issue, a second, more complex model was constructed that included individual predictor variables for number of mild, number of moderate, and number of severe prevalent vertebral fractures. The model-based risk estimates for vertebral fracture using the SDI and the more complex model were highly correlated (r = 0.91, P < 0.001), giving almost identical values up to an SDI of 5. Thus, for most clinical scenarios, it is not necessary to consider the particular fracture configuration that led to a given SDI score for predicting a patient's future vertebral fracture risk. These results validate the SDI as an accurate tool for assessing future vertebral fracture risk; patients with greater baseline SDI had greater future risk for vertebral fractures.

The effects of teriparatide on the incidence of back pain in postmenopausal women with osteoporosis

OBJECTIVES

Back pain is a major cause of suffering, disability, and cost. The risk of developing back pain was assessed following treatment with teriparatide [rh(PTH 1-34)] in postmenopausal women with osteoporosis.

RESEARCH DESIGN AND METHODS

A secondary analysis of back pain findings from the global, multi-site Fracture Prevention Trial was conducted where postmenopausal women with prevalent vertebral fractures were administered teriparatide 20 microg (n = 541) or placebo (n = 544) for a median of 19 months. Treatment-emergent back pain data were collected during adverse event monitoring, and spine radiographs were obtained at baseline and study endpoint.

MAIN OUTCOME MEASURES

The risk of back pain stratified by severity of new or worsening back pain and the risk of back pain associated with both number and severity of new vertebral fractures.

RESULTS

Women randomized to teriparatide 20 microg had a 31% reduced relative risk of moderate or severe back pain (16.5% vs. 11.5%, P = 0.016) and a 57% reduced risk of severe back pain (5.2% vs. 2.2%, P = 0.011). Compared with placebo, teriparatide-treated patients experienced reduced relative risk of developing back pain associated with findings of: one or more new vertebral fractures by 83% (6.5% vs. 1.1%, P < 0.001), two or more new vertebral fractures by 91% (2.5% vs. 0.20%, P = 0.004), and one or more new moderate or severe vertebral fractures by 100% (5.1% vs. 0.0%, P < 0.001).

CONCLUSIONS

Teriparatide-treated women had reduced risk for moderate or severe back pain, severe back pain, and back pain associated with vertebral fractures. The mechanism of the back pain reduction likely includes the reduction both in severity and number of new vertebral fractures.