Worldwide prevalence and incidence of osteoporotic vertebral fractures

Three-material decomposition with dual-layer spectral CT compared to MRI for the detection of bone marrow edema in patients with acute vertebral fractures

OBJECTIVES

To assess whether bone marrow edema in patients with acute vertebral fractures can be accurately diagnosed based on three-material decomposition with dual-layer spectral CT (DLCT).

MATERIALS AND METHODS

Acute (n = 41) and chronic (n = 18) osteoporotic thoracolumbar vertebral fractures as diagnosed by MRI (hyperintense signal in STIR sequences) in 27 subjects (72 ± 11 years; 17 women) were assessed with DLCT. Spectral data were decomposed into hydroxyapatite, edema-equivalent, and fat-equivalent density maps using an in-house-developed algorithm. Two radiologists, blinded to clinical and MR findings, assessed DLCT and conventional CT independently, using a Likert scale (1 = no edema; 2 = likely no edema; 3 = likely edema; 4 = edema). For DLCT and conventional CT, accuracy, sensitivity, and specificity for identifying acute fractures (Likert scale, 3 and 4) were analyzed separately using MRI as standard of reference.

RESULTS

For the identification of acute fractures, conventional CT showed a sensitivity of 0.73-0.76 and specificity of 0.78-0.83, whereas the sensitivity (0.93-0.95) and specificity (0.89) of decomposed DLCT images were substantially higher. Accuracy increased from 0.76 for conventional CT to 0.92-0.93 using DLCT. Interreader agreement for fracture assessment was high in conventional CT (weighted κ [95% confidence interval]; 0.81 [0.70; 0.92]) and DLCT (0.96 [0.92; 1.00]).

CONCLUSIONS

Material decomposition of DLCT data substantially improved accuracy for the diagnosis of acute vertebral fractures, with a high interreader agreement. This may spare patients additional examinations and facilitate the diagnosis of vertebral fractures.

Bone mineral density measurements in vertebral specimens and phantoms using dual-layer spectral computed tomography

To assess whether phantomless calcium-hydroxyapatite (HA) specific bone mineral density (BMD) measurements with dual-layer spectral computed tomography are accurate in phantoms and vertebral specimens. Ex-vivo human vertebrae (n = 13) and a phantom containing different known HA concentrations were placed in a semi-anthropomorphic abdomen phantom with different extension rings simulating different degrees of obesity. Phantomless dual-layer spectral CT was performed at different tube current settings (500, 250, 125 and 50 mAs). HA-specific BMD was derived from spectral-based virtual monoenergetic images at 50 keV and 200 keV. Values were compared to the HA concentrations of the phantoms and conventional qCT measurements using a reference phantom, respectively. Above 125 mAs, errors for phantom measurements ranged between -1.3% to 4.8%, based on spectral information. In vertebral specimens, high correlations were found between BMD values assessed with spectral CT and conventional qCT (r ranging between 0.96 and 0.99; p < 0.001 for all) with different extension rings, and a high agreement was found in Bland Altman plots. Different degrees of obesity did not have a significant influence on measurements (P > 0.05 for all). These results suggest a high validity of HA-specific BMD measurements based on dual-layer spectral CT examinations in setups simulating different degrees of obesity without the need for a reference phantom, thus demonstrating their feasibility in clinical routine.

Evaluation of Percutaneous Vertebroplasty for Management of Symptomatic Osteoporotic Compression Fracture

INTRODUCTION

Osteoporotic vertebral compression fractures are a leading cause of disability and associated morbidities among Indian population. Worldwide, approximately 20% of elderly population above 70 years and 16% of postmenopausal women are suffering from it. Vertebral compression fractures should be aggressively treated with minimally invasive techniques such as Percutaneous Vertebroplasty (PVP) or Percutaneous Kyphoplasty (PKP) to minimize pain and disability associated with it.

AIM

To evaluate the PVP in terms of pain reduction and restoration of functional abilities among the patients suffering from symptomatic osteoporotic vertebral compression fracture.

MATERIALS AND METHODS

PVP using polymethyl methacrylate bone cement was performed between 2011 to 2013, on 25 patients admitted for symptomatic osteoporotic vertebral compression fracture in the Department of Orthopaedics, Institute of Post Graduate Medical Education and Research (IPGMER) and SSKM Hospital, Kolkata, West Bengal, India. All of them were followed up for one year. Pain and disability were evaluated with Visual Analogue Scale (VAS) and Oswestry Disability Questionnaire (ODQ) score respectively. Repeated measures ANOVA with Bonferroni post-hoc test was applied for significance testing.

RESULTS

Reduction in pain was reported by 56% of patients within 10 minutes of operation. Mean VAS score at presentation was 8.24 (±1.16). It reduced to 6.31 (±1.21) and 2.38 (±0.08) at immediate postoperative period and after 12 months respectively. There was significant reduction (p<0.05) in pain, as measured by VAS score, started at immediate postoperative period to end of follow up period up to one year. Disability, measured by ODQ score, significantly decrease (p<0.05) over time from one week to 12-month postoperatively. At presentation, ODQ score was 93.01 (±4.54). It reduced to 76.84 (±3.76), one week after operation and 16.23 (±1.17), one year after operation.

CONCLUSION

The PVP with polymethayl methacrylate bone cement is still a justified treatment procedure for osteoporotic vertebral compression fractures as it provides excellent pain relief, internal stability to the fractured vertebra thus preventing further collapse and progression of kyphosis, allowing the patients to regain normal activity at the earliest, and at a very reasonable cost with minimal complication.

Antiosteoporotic activity of Salvadora persica sticks extract in an estrogen deficient model of osteoporosis

Objectives

The effect of Salvadora persica sticks on prevention of tooth decay is well established, but the effect of S. persica stick extract (SPE) on the prevention/treatment of osteoporosis has not been studied. The purpose of this study is to provide baseline information of the effectiveness of SPE on ovariectomized (OVX) rat model of osteoporosis.

Methods

SPE was administered at 50, 150, and 300 mg/d orally to OVX rats for 16 weeks. Serum osteocalcin, alkaline phosphatase, calcium, and phosphorus, and urinary deoxypyridinoline, calcium, and phosphorus were measured. Bone mineral density (BMD), 3-point bending test, and histomorphometric characteristics of the femoral bone were also examined.

Results

SPE at doses of 150 and 300 mg/d, but not 50 mg/d, significantly prevented bone loss in OVX rats as proved by decreased biochemical markers of bone resorption and increased BMD and biomechanical indices of the femoral bone.

Conclusions

This study confirms a dose-dependent protective action of SPE on rat OVX model of osteoporosis. This effect needs further investigation at the molecular and clinical levels to provide a natural and cost-effective alternative for the management of postmenopausal osteoporosis.

Worldwide Fracture Prediction

The substantial increase in the burden of non-communicable diseases in general and osteoporosis in particular, necessitates the establishment of efficient and targeted diagnosis and treatment strategies. This chapter reviews and compares different tools for osteoporosis screening and diagnosis; it also provides an overview of different treatment guidelines adopted by countries worldwide. While access to dual-energy X-ray absorptiometry to measure bone mineral density (BMD) is limited in most areas in the world, the introduction of risk calculators that combine risk factors, with or without BMD, have resulted in a paradigm shift in osteoporosis screening and management. To-date, forty eight risk assessment tools that allow risk stratification of patients are available, however only few are externally validated and tested in a population-based setting. These include Osteoporosis Self-Assessment Tool; Osteoporosis Risk Assessment Instrument; Simple Calculated Osteoporosis Risk Estimation; Canadian Association of Radiologists and Osteoporosis Canada calculator; Fracture Risk Assessment Calculator (FRAX); Garvan; and QFracture. These tools vary in the number of risk factors incorporated. We present a detailed analysis of the development, characteristics, validation, performance, advantages and limitations of these tools. The World Health Organization proposes a dual-energy X-ray absorptiometry-BMD T-score ≤ -2.5 as an operational diagnostic threshold for osteoporosis, and many countries have also adopted this cut-off as an intervention threshold in their treatment guidelines. With the introduction of the new fracture assessment calculators, many countries chose to include fracture risk as one of the major criteria to initiate osteoporosis treatment. Of the 52 national guidelines identified in 36 countries, 30 included FRAX derived risk in their intervention threshold and 22 were non-FRAX based.  No universal tool or guideline approach will address the needs of all countries worldwide.  Osteoporosis screening and management guidelines are best tailored according to the needs and resources of individual counties. While few countries have succeeded in generating valuable epidemiological data on osteoporotic fractures, to validate their risk calculators and base their guidelines, many have yet to find the resources to assess variations and secular trends in fractures, the performance of various calculators, and ultimately adopt the most convenient care pathway algorithms.