Novel approaches to bone comorbidity in Cushing's disease: an update

Skeletal complications are frequent and clinically relevant findings in Cushing's disease (CD) since an uncoupled suppressed bone formation and enhanced bone resorption leads to a marked skeletal damage with a rapid increase of fracture risk. Reduced Bone Mineral Density (BMD) has been consistently reported and osteopenia or osteoporosis are typical findings in patients with CD. Vertebral Fractures (VFs) are frequently reported and may occur even in patients with an only mild reduction of BMD, representing nowadays a still under- or misdiagnosed comorbidity of these patients being frequently asymptomatic. A novel approach combining different available tools such as BMD evaluation and vertebral morphometry, in order to improve diagnosis, management, and follow-up of bone comorbidity in all patients affected by CD, is needed. This approach is foreseen to be a crucial part of management of patients with CD, particularly in Pituitary Tumor Center of Excellence since VFs, the landmark of the bone involvement, may occur early in the history of the disease and may represent a relevant risk factor for further fractures, reduced quality of life and survival and need for pharmacologic prevention and treatment.

A deep learning framework for vertebral morphometry and Cobb angle measurement with external validation

PURPOSE

To propose a fully automated deep learning (DL) framework for the vertebral morphometry and Cobb angle measurement from three-dimensional (3D) computed tomography (CT) images of the spine, and validate the proposed framework on an external database.

METHODS

The vertebrae were first localized and segmented in each 3D CT image using a DL architecture based on an ensemble of U-Nets, and then automated vertebral morphometry in the form of vertebral body (VB) and intervertebral disk (IVD) heights, and spinal curvature measurements in the form of coronal and sagittal Cobb angles (thoracic kyphosis and lumbar lordosis) were performed using dedicated machine learning techniques. The framework was trained on 1725 vertebrae from 160 CT images and validated on an external database of 157 vertebrae from 15 CT images.

RESULTS

The resulting mean absolute errors (± standard deviation) between the obtained DL and corresponding manual measurements were 1.17 ± 0.40 mm for VB heights, 0.54 ± 0.21 mm for IVD heights, and 3.42 ± 1.36° for coronal and sagittal Cobb angles, with respective maximal absolute errors of 2.51 mm, 1.64 mm, and 5.52°. Linear regression revealed excellent agreement, with Pearson's correlation coefficient of 0.943, 0.928, and 0.996, respectively.

CONCLUSION

The obtained results are within the range of values, obtained by existing DL approaches without external validation. The results therefore confirm the scalability of the proposed DL framework from the perspective of application to external data, and time and computational resource consumption required for framework training.

Inter-observer agreement of vertebral fracture assessment with dual-energy x-ray absorptiometry equipment

PURPOSE

To investigate the time and effort needed to perform vertebral morphometry, as well as inter-observer agreement for identification of vertebral fractures on vertebral fracture assessment (VFA) images.

METHODS

Ninety-six images were retrospectively selected, and three radiographers independently performed semi-automatic 6-point morphometry. Fractures were identified and graded using the Genant classification. Time needed to annotate each image was recorded, and reader fatigue was assessed using a modified Simulator Sickness Questionnaire (SSQ). Inter-observer agreement was assessed per-patient and per-vertebra for detecting fractures of all grades (grades 1-3) and for grade 2 and 3 fractures using the kappa statistic. Variability in measured vertebral height was evaluated using the intraclass correlation coefficient (ICC).

RESULTS

Per-patient agreement was 0.59 for grades 1-3 fracture detection, and 0.65 for grades 2-3 only. Agreement for per-vertebra fracture classification was 0.92. Vertebral height measurements had an ICC of 0.96. Time needed to annotate VFA images ranged between 91 and 540 s, with a mean annotation time of 259 s. Mean SSQ scores were significantly lower at the start of a reading session (1.29; 95% CI: 0.81-1.77) compared to the end of a session (3.25; 95% CI: 2.60-3.90; p < 0.001).

CONCLUSION

Agreement for detection of patients with vertebral fractures was only moderate, and vertebral morphometry requires substantial time investment. This indicates that there is a potential benefit for automating VFA, both in improving inter-observer agreement and in decreasing reading time and burden on readers.

The association between incident vertebral deformities, health-related quality of life and functional impairment: a 10.7-year cohort study

We aimed to describe longitudinal changes in health-related quality of life (HRQoL) measures associated with incident vertebral deformities (VDs) over 10.7 years. Incident VDs are associated with clinically significant functional impairment in men, and reduction in overall HRQoL in older women. Increasing severity and number of incident VDs are associated with clinically meaningful functional impairment in men, but not women.

INTRODUCTION

To describe associations between incident VD and changes in HRQoL and functional ability in older adults over 10.7 years.

METHODS

Participants (n = 780) underwent whole-body dual-energy X-ray absorptiometry (DXA) scans at baseline, 2.5, 5.1 and 10.7 years later. VD was defined as ≥ 25% reduction in anterior height relative to posterior height of vertebrae from T4 to L4. An incident VD was defined as a new VD at any follow-up visit. Assessment of Quality of Life (AQoL-4D) questionnaire and Health Assessment Questionnaire-Disability Index (HAQ-DI) were used to assess HRQoL and functional impairment. Changes in AQoL and HAQ-DI associated with incident VD were analysed using multilevel mixed-effects linear regression. Log binomial regression was used to examine clinically relevant changes and effects of severity and number of VD.

RESULTS

The incidence of VD was 37% over 10.7 years. In women, incident VDs were associated with annual reduction in AQoL utility score (β = -0.005, 95% CI -0.008 to -0.002). Men had increased risk of clinically significant reduction in HAQ-DI (IRR = 1.76, 95% CI 1.07-2.89). Men had increased risk of clinically important functional impairment with increasing severity (IRR 1.76, 95% CI 1.04-2.95 for mild vs IRR 1.98, 95% CI 1.13-3.47 for moderate to severe VD) as well as number of incident VD (IRR 1.85, 95% CI 1.17-2.93 for one vs IRR 1.88, 95% CI 0.94-3.78 for ≥ 2 VDs). Such associations were not observed in women.

CONCLUSIONS

Incident VDs are associated with clinically significant functional impairment in men, and reduction in overall HRQoL in older women. Increasing severity and number of incident VDs are associated with clinically meaningful functional impairment in men, but not women.

Morphometric measurements can improve prediction of progressive vertebral deformity following vertebral damage

PURPOSE

A damaged vertebral body can exhibit accelerated 'creep' under constant load, leading to progressive vertebral deformity. However, the risk of this happening is not easy to predict in clinical practice. The present cadaveric study aimed to identify morphometric measurements in a damaged vertebral body that can predict a susceptibility to accelerated creep.

METHODS

A total of 27 vertebral trabeculae samples cored from five cadaveric spines (3 male, 2 female, aged 36 to 73 (mean 57) years) were mechanically tested to establish the relationship between bone damage and residual strain. Compression testing of 28 human spinal motion segments (three vertebrae and intervening soft tissues) dissected from 14 cadaveric spines (10 male, 4 female, aged 67 to 92 (mean 80) years) showed how the rate of creep of a damaged vertebral body increases with increasing "damage intensity" in its trabecular bone. Damage intensity was calculated from vertebral body residual strain following initial compressive overload using the relationship established in the compression test of trabecular bone samples.

RESULTS

Calculations from trabecular bone samples showed a strong nonlinear relationship between residual strain and trabecular bone damage intensity (R² = 0.78, P < 0.001). In damaged vertebral bodies, damage intensity was then related to vertebral creep rate (R² = 0.39, P = 0.001). This procedure enabled accelerated vertebral body creep to be predicted from morphological changes (residual strains) in the damaged vertebra.

CONCLUSION

These findings suggest that morphometric measurements obtained from fractured vertebrae can be used to quantify vertebral damage and hence to predict progressive vertebral deformity.

Osteoporotic vertebral fractures: A diagnostic challenge in the 21ST century

Vertebral fractures are the most prevalent osteoporotic fractures and are paradoxically the most underdiagnosed. While only one-third of patients have acute pain, they can present other associated chronic complications. Vertrebal fractures are associated with the onset of new fractures, both vertebral and nonvertebral. Radiography of the dorsal-lumbar spine is a useful tool for detecting them but depends on the subjective interpretation of the physician conducting the assessment. New techniques, such as vertebral morphometry, have recently demonstrated greater efficacy in detecting v vertebral fractures and are performed concomitantly with bone densitometry. Knowing how to identify vertebral fractures is essential for the secondary prevention of new fractures and improving our patients' quality of life.

Vertebral fracture assessment (VFA) for monitoring vertebral reshaping in children and adolescents with osteogenesis imperfecta treated with intravenous neridronate

PURPOSE

The study was aimed at monitoring vertebral bodies changes with the use of Vertebral Fracture Assessment (VFA) in children and adolescents affected by osteogenesis imperfecta (OI) during treatment with intravenous neridronate.

METHODS

60 children and adolescents (35 males and 25 females; age 1-16 years) with OI type I, III and IV were included in the study. Intravenous neridronate was administered at the dose of 2 mg/kg every 3 months in all patients. Lumbar spine (LS) bone mineral density (BMD) and VFA by dual X-ray absorptiometry (DXA) were assessed every 6 months up to 24 months during treatment. VFA with vertebral morphometry (MXA) was used to calculate the three indices of vertebral deformity: wedging, concavity and crushing. Serum calcium, phosphate, parathyroid hormone (PTH), 25-hydroxy-vitamin D [25(OH)D], total alkaline phosphatase (ALP), bone alkaline phosphatase (BALP) and urinary C-terminal telopeptide of type 1 collagen (CTx) were measured at any time point.

RESULTS

Mean LS BMD values significantly increased at 24 months compared to baseline (p < 0.0001); the corresponding Z-score values were -1.28 ± 1.23 at 24 months vs -2.46 ± 1.25 at baseline; corresponding mean Bone Mineral Apparent Density (BMAD) values were 0.335 ± 0.206 vs 0.464 ± 0.216. Mean serum levels of ALP, BALP and CTx significantly decreased from baseline to 24 months. By MXA, we observed a significant 19.1% reduction of the mean wedging index of vertebral reshaping at 12 months, and 38.4% at 24 months (p < 0.0001) and of the mean concavity index (16.3% at 12 months and 35.9% at 24 months; p < 0.0001). Vertebral reshaping was achieved for 66/88 (75%) wedge fractures and 59/70 (84%) concave fractures, but there were 4 incident mild fractures. Finally, VF rate was reduced at 24 months compared to baseline: 37/710 (5.2%) vs 158/710 (22.2%).

CONCLUSION

Our study demonstrates the utility of VFA as a safe and alternative methodology in the follow-up of children and adolescents with OI.

Osteoporotic vertebral fractures: A diagnostic challenge in the 21st century

Vertebral fractures are the most prevalent osteoporotic fractures and are paradoxically the most underdiagnosed. While only one-third of patients have acute pain, they can present other associated chronic complications. Vertrebal fractures are associated with the onset of new fractures, both vertebral and nonvertebral. Radiography of the dorsal-lumbar spine is a useful tool for detecting them but depends on the subjective interpretation of the physician conducting the assessment. New techniques, such as vertebral morphometry, have recently demonstrated greater efficacy in detecting v vertebral fractures and are performed concomitantly with bone densitometry. Knowing how to identify vertebral fractures is essential for the secondary prevention of new fractures and improving our patients' quality of life.

Effects of zoledronic acid on vertebral shape of children and adolescents with osteogenesis imperfecta

Vertebral compression fracture (VCF) is a common and severe complication of osteogenesis imperfecta (OI). We prospectively observe the changes of vertebral shape during zoledronic acid (ZOL) treatment and assess influence factors of VCF in OI children. 32 children with VCF and 10 children without VCF (NVCF) were included and given ZOL treatment for 2 years, who were matched in age and gender. Control group included 17 treatment naïve OI patients with VCF who were matched in age, gender and clinical severity to 17 patients in VCF group received ZOL treatment for 1 year (as ZOL treated group). We performed quantitative vertebral morphometry and calculated concavity index (mh/ph), height-length ratio (ah/LL, mh/LL, ph/LL) and projection area (PA) of vertebrae from T4 to L4 before and after treatment. At baseline, patients in VCF group had significantly lower PA, mh/ph, ah/LL, mh/LL and ph/LL than patients in NVCF group (P < 0.01). PA, mh/ph, ah/LL, mh/ LL and ph/LL of patients with VCF were raised by (35.2 ± 19.5)%, (22.9 ± 15.1)%, (19.6 ± 13.9)%, (33.6 ± 25.5)%, and (8.1 ± 8.8)% (P < 0.01) after 1-year treatment of ZOL, and were increased by (71.8 ± 28.2)%, (42.8 ± 21.8)%, (35.1 ± 20.6)%, (65.4 ± 43.2)%, and (12.5 ± 11.4)% after 2-year treatment of ZOL (P < 0.01). Compared to control group, mh/ph, ah/LL and mh/LL were significantly higher (P < 0.01) in ZOL treated group. LS-BMD and its increase were positively correlated to vertebral height and PA at baseline and the improvement of vertebral height and PA after ZOL treatment, respectively. In conclusion, the compressive vertebrae of OI children could be effectively reshaped during ZOL treatment. Low LS-BMD was an independent risk factor for VCF and its increase was positively correlated to the improvement in vertebral shape after ZOL treatment.

Morphometric vertebral fractures in breast cancer patients treated with adjuvant aromatase inhibitor therapy: A cross-sectional study

BACKGROUND

The impact of long-term adjuvant therapy with aromatase inhibitors (AIs) on vertebral fracture (VF) risk is still unclear.

OBJECTIVE

In this cross-sectional study, we explored the prevalence and determinants of VFs in breast cancer (BC) patients before and during AI therapy. Each woman underwent a dual-energy X-ray absorptiometry (DXA) to evaluate bone mineral density (BMD) and identify VFs by a quantitative morphometric approach. Blood samples were collected to measure serum hormone and calcium levels.

RESULTS

We consecutively included 263 postmenopausal women with hormone receptor-positive early BC. One-hundred-sixty-nine women were AI-naïve, and 94 were AI-treated. AI-treated patients had lower BMD at total hip (p=0.01) and lumbar spine (p=0.03), higher serum vitamin D (p<0.001) and parathyroid hormone (p=0.006) values as compared to AI-naïve patients. The prevalence of VFs was 18.9% in AI-naïve patients, and 31.2% in those assessed during AI therapy (odds ratio 1.90, 95% CI 1.1-3.5, p=0.03). In AI-naïve patients, VFs were associated with older age (p=0.002) and lower BMD values at femoral neck (p=0.04) and total hip (p=0.007), whereas VFs occurred without association with any parameter analyzed in AI-treated patients. In AI-treated group, the prevalence of VFs was not significantly different between patients with osteoporosis and those with normal BMD (36.7% vs. 20.0%; p=0.31).

CONCLUSIONS

In women with early BC, AI therapy is associated with high prevalence of radiological VFs, which were shown to be independent of BMD values during the adjuvant treatment. These findings may be clinically relevant since they may lead to a change in management of AI-induced skeletal fragility. Specifically, the results of this study provide a rationale for performing a morphometric evaluation of VFs in all women undergoing treatment with AIs.

Vertebral body morphology is associated with incident lumbar vertebral fracture in postmenopausal women. The OFELY study

We investigate the predictive role of vertebral anterior cortical curvature and height heterogeneity in the occurrence of vertebral fractures in postmenopausal women. Women who will fracture had shorter vertebral height, greater heterogeneity of height than those who will not fracture, and their anterior vertebral body edge was less concave.

INTRODUCTION

Vertebral morphology has been demonstrated to be associated with further risk of fracture. The aim of this study was to analyze vertebral anterior cortical curvature (Ct.curv) and vertebral height heterogeneity in postmenopausal women before the occurrence of a vertebral fracture.

METHODS

This case-control study included 29 postmenopausal women who have underwent incident lumbar vertebral fractures (mean age 71 ± 9 years, mean time to fractures 9 ± 4 years), age-matched with 57 controls. From lateral X-rays of lumbar spine radiographs (T12 to L4), the following parameters were measured: (1) the posterior, middle, and anterior vertebral heights; (2) the heterogeneity of heights evaluated by the coefficient of variation of these three variables; (3) antero-posterior width, a 2D estimator of cross-sectional area; and (4) Ct.curv.

RESULTS

Mean vertebral heights were significantly lower among women who fractured than in controls (p < 0.05). The anterior and middle heights were significantly lower at L4 and L3 levels in fracture group (p = 0.02). The heterogeneity of vertebral height was significantly greater in the fracture group (p = 0.003). In addition, fractured patients had a significantly higher Ct.curv on L3 (p = 0.04). After adjustment for bone mineral density (BMD), only the heterogeneity of vertebral height remained significant (p = 0.005).

CONCLUSION

The current case-control study confirmed the association between vertebral height and occurrence of future vertebral fracture in postmenopausal women. The vertebrae with the smallest Ct.curv tended to fracture less often, and the heterogeneity of vertebral heights was associated with future fracture independently of BMD. An additional validation in a prospective study would be needed to confirm these initial results.

Diagnosis of vertebral fractures in children: is a simplified algorithm-based qualitative technique reliable?

BACKGROUND

Identification of osteoporotic vertebral fractures allows treatment opportunity reducing future risk. There is no agreed standardised method for diagnosing paediatric vertebral fractures.

OBJECTIVE

To evaluate the precision of a modified adult algorithm-based qualitative (ABQ) technique, applicable to children with primary or secondary osteoporosis.

MATERIALS AND METHODS

Three radiologists independently assessed lateral spine radiographs of 50 children with suspected reduction in bone mineral density using a modified ABQ scoring system and following simplification to include only clinically relevant parameters, a simplified ABQ score. A final consensus of all observers using simplified ABQ was performed as a reference standard for fracture characterisation. Kappa was calculated for interobserver agreement of the components of both scoring systems and intraobserver agreement of simplified ABQ based on a second read of 29 randomly selected images.

RESULTS

Interobserver Kappa for modified ABQ scoring for fracture detection, severity and shape ranged from 0.34 to 0.49 Kappa for abnormal endplate and position assessment was 0.27 to 0.38. Inter- and intraobserver Kappa for simplified ABQ scoring for fracture detection and grade ranged from 0.37 to 0.46 and 0.45 to 0.56, respectively. Inter- and intraobserver Kappa for affected endplate ranged from 0.31 to 0.41 and 0.45 to 0.51, respectively. Subjectively, observers' felt simplified ABQ was easier and less time-consuming.

CONCLUSION

Observer reliability of modified and simplified ABQ was similar, with slight to moderate agreement for fracture detection and grade/severity. Due to subjective preference for simplified ABQ, we suggest its use as a semi-objective measure of diagnosing paediatric vertebral fractures.