¿Pueden las mediciones 3D derivadas de la DXA lumbar predecir fracturas en las vértebras dorsales? / Can 3D measurements obtained by lumbar DXA predict fractures in the dorsal vertebrae?

OBJETIVO: Valorar la asociación de las mediciones tridimensionales (3D) derivadas de la absorciometría de rayos X de energía dual (DXA) lumbar con las fracturas osteoporóticas en las vértebras dorsales. MATERIAL Y MÉTODOS: Analizamos retrospectivamente 32 mujeres postmenopáusicas: 16 con fracturas incidentes en las vértebras dorsales y 16 controles sin ningún tipo de fractura. Las DXA lumbares se adquirieron en la visita inicial (es decir, antes del evento de fractura) y se midió la densidad mineral ósea de área (DMOa) en las vértebras L1 a L4. Las mediciones 3D derivadas de la DXA se evaluaron utilizando un software de modelado 3D (3D-SHAPER). La densidad mineral ósea volumétrica (DMOv) se calculó en el hueso trabecular, cortical e integral. También se midió el grosor cortical y la DMO superficial (DMOs) cortical. Las diferencias en las mediciones derivadas de la DXA entre los grupos de fracturados y controles se evaluaron utilizando una prueba t de Student no pareada. También se calculó la razón de probabilidades (OR) y el área bajo la curva característica operativa del receptor (AUC). RESULTADOS: En el presente estudio caso-control ajustado por edad no se encontraron diferencias significativas entre los grupos de fracturados y controles en términos de peso (ρ = 0,44), altura (ρ = 0,25) y DMOa (ρ = 0,11). Sin embargo, sí se encontraron diferencias significativas (ρ < 0,05) en la DMOv integral y trabecular y en la DMOs cortical. La DMOv trabecular en el cuerpo vertebral fue la medida que mejor discriminó entre ambos grupos, con un AUC de 0,733, respecto a 0,682 para la DMOa. CONCLUSIÓN: Este estudio muestra la capacidad de los modelos 3D derivados de la DXA lumbar para discriminar entre sujetos con fracturas incidentes en las vértebras dorsales y controles. Es necesario analizar cohortes mayores para determinar si estas mediciones podrían mejorar la predicción del riesgo de fractura en la práctica clínica

OBJECTIVE: To assess the relation between three-dimensional (3D) measurements obtained by lumbar dual energy X-ray absorptiometry (DXA) and osteoporotic fractures in dorsal vertebrae. MATERIAL AND METHODS: We analysed retrospectively 32 postmenopausal women, allocated to two groups: 16 women in the experimental group, who presented incident fractures of the dorsal vertebrae, and 16 women in the control group, who did not show any type of fracture. Measurements of the (aBMD) of vertebrae L1 through L4 were taken at the initial visit (i.e., prior to the fracture event) by lumbar dual-energy x-ray absorptiometries (DXA). 3D measurements obtained by DXA were evaluated using 3D modelling software (3D-SHAPER). Volumetric bone mineral density (vBMD) was calculated in the trabecular, cortical and integral bone. Cortical thickness and cortical surface BMD (sBMD) were also measured. Differences in measurements derived from the DXA between the experimental and control groups were assessed using an unpaired Student t-test. The odds ratio (OR) and the area under the receiver operating characteristic curve (AUC) were also determined. RESULTS: In the present age-adjusted case-control study, no significant differences were found between the experimental and control groups in terms of weight (ρ = 0.44), height (ρ = 0.25) and aBMD (ρ = 0.11). However, significant differences (ρ < 0.05) were found in the integral and trabecular vBMD and in the cortical sBMD. Trabecular vBMD in the vertebral body was the measure that best discriminated between both groups, with an AUC of 0.733, compared to 0.682 of the aBMD. CONCLUSION: This study shows the ability of 3D models resultant from lumbar DXAs to discern between subjects with incident fractures in the dorsal vertebrae and control subjects. It is necessary to analyse larger cohorts to establish if these measurements could improve the prediction of fracture risk in clinical practice

Discrimination of osteoporosis-related vertebral fractures by DXA-derived 3D measurements: a retrospective case-control study.

A retrospective case-control study assessing the association of DXA-derived 3D measurements with osteoporosis-related vertebral fractures was performed. Trabecular volumetric bone mineral density was the measurement that best discriminates between fracture and control groups. INTRODUCTION: The aim of the present study was to evaluate the association of DXA-derived 3D measurements at the lumbar spine with osteoporosis-related vertebral fractures. METHODS: We retrospectively analyzed a database of 74 postmenopausal women: 37 subjects with incident vertebral fractures and 37 age-matched controls without any type of fracture. DXA scans at the lumbar spine were acquired at baseline (i.e., before the fracture event for subjects in the fracture group), and areal bone mineral density (aBMD) was measured. DXA-derived 3D measurements, such as volumetric BMD (vBMD), were assessed using a DXA-based 3D modeling software (3D-SHAPER). vBMD was computed at the trabecular, cortical, and integral bone. Cortical thickness and cortical surface BMD were also measured. Differences in DXA-derived measurements between fracture and control groups were evaluated using unpaired t test. Odds ratio (OR) and area under the receiver operating curve (AUC) were also computed. Subgroup analyses according to fractured vertebra were performed. RESULTS: aBMD of fracture group was 9.3% lower compared with control group (p < 0.01); a higher difference was found for trabecular vBMD in the vertebral body (- 16.1%, p < 0.001). Trabecular vBMD was the measurement that best discriminates between fracture and control groups, with an AUC of 0.733, against 0.682 for aBMD. Overall, similar findings were observed within the subgroup analyses. The L1 vertebral fractures subgroup had the highest AUC at trabecular vBMD (0.827), against aBMD (0.758). CONCLUSION: This study showed the ability of cortical and trabecular measurements from DXA-derived 3D models to discriminate between fracture and control groups. Large cohorts need to be analyzed to determine if these measurements could improve fracture risk prediction in clinical practice.