Vertebral Scheuermann's disease in Europe: prevalence, geographic variation and radiological correlates in men and women aged 50 and over.

UNLABELLED: In 27 centres across Europe, the prevalence of deforming spinal Scheuermann's disease in age-stratified population-based samples of over 10,000 men and women aged 50+ averaged 8% in each sex, but was highly variable between centres. Low DXA BMD was un-associated with Scheuermann's, helping the differential diagnosis from osteoporosis. INTRODUCTION: This study aims to assess the prevalence of Scheuermann's disease of the spine across Europe in men and women over 50 years of age, to quantitate its association with bone mineral density (BMD) and to assess its role as a confounder for the radiographic diagnosis of osteoporotic fracture. METHODS: In 27 centres participating in the population-based European Vertebral Osteoporosis Study (EVOS), standardised lateral radiographs of the lumbar and of the thoracic spine from T4 to L4 were assessed in all those of adequate quality. The presence of Scheuermann's disease, a confounder for prevalent fracture in later life, was defined by the presence of at least one Schmorl's node or irregular endplate together with kyphosis (sagittal Cobb angle >40° between T4 and T12) or a wedged-shaped vertebral body. Alternatively, the (rare) Edgren-Vaino sign was taken as diagnostic. The 6-point-per-vertebral-body (13 vertebrae) method was used to assess osteoporotic vertebral shape and fracture caseness. DXA BMD of the L2-L4 and femoral neck regions was measured in subsets. We also assessed the presence of Scheuermann's by alternative published algorithms when these used the radiographic signs we assessed. RESULTS: Vertebral radiographic images from 4486 men and 5655 women passed all quality checks. Prevalence of Scheuermann's varied considerably between centres, and based on random effect modelling, the overall European prevalence using our method was 8% with no significant difference between sexes. The highest prevalences were seen in Germany, Sweden, the UK and France and low prevalences were seen in Hungary, Poland and Slovakia. Centre-level prevalences in men and women were highly correlated. Scheuermann's was not associated with BMD of the spine or hip. CONCLUSIONS: Since most of the variation in population impact of Scheuermann's was unaccounted for by the radiological and anthropometric data, the search for new genetic and environmental determinants of this disease is encouraged.

Determinants of the size of incident vertebral deformities in European men and women in the sixth to ninth decades of age: the European Prospective Osteoporosis Study (EPOS).

UNLABELLED: More severe vertebral fractures have more personal impact. In the European Prospective Osteoporosis Study, more severe vertebral collapse was predictable from prior fracture characteristics. Subjects with bi-concave or crush fractures at baseline had a 2-fold increase in incident fracture size and thus increased risk of a disabling future fracture. INTRODUCTION: According to Euler's buckling theory, loss of horizontal trabeculae in vertebrae increases the risk of fracture and suggests that the extent of vertebral collapse will be increased in proportion. We tested the hypothesis that the characteristics of a baseline deformity would influence the size of a subsequent deformity. METHODS: In 207 subjects participating in the European Prospective Osteoporosis Study who suffered an incident spine fracture in a previously normal vertebra, we estimated loss of volume (fracture size) from plane film images of all vertebral bodies that were classified as having a new fracture. The sum of the three vertebral heights (anterior, mid-body, and posterior) obtained at follow-up was subtracted from the sum of the same measures at baseline. Each of the summed height loss for vertebrae with a McCloskey-Kanis deformity on the second film was expressed as a percentage. RESULTS AND CONCLUSIONS: In univariate models, the numbers of baseline deformities and the clinical category of the most severe baseline deformity were each significantly associated with the size of the most severe incident fracture and with the cumulated sum of all vertebral height losses. In multivariate modeling, age and the clinical category of the baseline deformity (crush > bi-concave > uni-concave > wedge) were the strongest determinants of both more severe and cumulative height loss. Baseline biconcave and crush fractures were associated at follow-up with new fractures that were approximately twice as large as those seen with other types of deformity or who previously had undeformed spines. In conclusion, the characteristics of a baseline vertebral deformity determines statistically the magnitude of vertebral body volume lost when a subsequent fracture occurs. Because severity of fracture and number of fractures are determinants of impact, the results should improve prediction of the future personal impact of osteoporosis once a baseline prevalent deformity has been identified.

Incidence of vertebral fracture in europe: results from the European Prospective Osteoporosis Study (EPOS).

Vertebral fracture is one of the major adverse clinical consequences of osteoporosis; however, there are few data concerning the incidence of vertebral fracture in population samples of men and women. The aim of this study was to determine the incidence of vertebral fracture in European men and women. A total of 14,011 men and women aged 50 years and over were recruited from population-based registers in 29 European centers and had an interviewer-administered questionnaire and lateral spinal radiographs performed. The response rate for participation in the study was approximately 50%. Repeat spinal radiographs were performed a mean of 3.8 years following the baseline film. All films were evaluated morphometrically. The definition of a morphometric fracture was a vertebra in which there was evidence of a 20% (+4 mm) or more reduction in anterior, middle, or posterior vertebral height between films--plus the additional requirement that a vertebra satisfy criteria for a prevalent deformity (using the McCloskey-Kanis method) in the follow-up film. There were 3174 men, mean age 63.1 years, and 3,614 women, mean age 62.2 years, with paired duplicate spinal radiographs (48% of those originally recruited to the baseline survey). The age standardized incidence of morphometric fracture was 10.7/1,000 person years (pyr) in women and 5.7/1,000 pyr in men. The age-standardized incidence of vertebral fracture as assessed qualitatively by the radiologist was broadly similar-12.1/1,000 pyr and 6.8/1,000 pyr, respectively. The incidence increased markedly with age in both men and women. There was some evidence of geographic variation in fracture occurrence; rates were higher in Sweden than elsewhere in Europe. This is the first large population-based study to ascertain the incidence of vertebral fracture in men and women over 50 years of age across Europe. The data confirm the frequent occurrence of the disorder in men as well as in women and the rise in incidence with age.

Falls explain between-center differences in the incidence of limb fracture across Europe.

There is important geographic variation in the occurrence of the major osteoporotic fractures across Europe. The aim of this study was to determine whether between-center variation in limb fracture rates across Europe could be explained by variation in the incidence of falls. Men and women, aged 50-79 years, were recruited from population-based registers in 30 European centers. Subjects were followed by postal questionnaire to ascertain the occurrence of incident fractures, and were also asked about the occurrence and number of recent falls. Self-reported fractures were confirmed, where possible, by review of the radiographs, medical record, or subject interview. The age- and gender-adjusted incidence of falls was calculated by center using Poisson regression. Poisson regression was also used to assess the extent to which between-center differences in the incidence of limb fractures could be explained by differences in the age- and gender-adjusted incidence of falls at those centers. In all, 6302 men (mean age 63.9 years) and 6761 women (mean age 63.1 years) completed at least one questionnaire concerning fractures and falls. During a median follow-up time of 3 years, 3647 falls were reported by men and 4783 by women. After adjusting for age and gender, there was evidence of significant between-center differences in the occurrence of falls. There was also between-center variation in the occurrence of upper limb, lower limb, and distal forearm fractures. Variation in the age- and gender-adjusted center-specific fall rates explained 24%, 14%, and 6% of the between-center variation in incidence of distal forearm and upper and lower limb fractures, respectively. Given the constraints inherent in such an analysis, in men and women aged 50-79 years, variation in fall rates could explain a significant proportion of the between-center variation in the incidence of limb fracture across Europe.

Imaging of hamate bone fractures in conventional X-rays and high-resolution computed tomography. An in vitro study.

RATIONALE AND OBJECTIVES: To examine the ability to image fractures of the body and hook of the hamate bone in conventional X-rays and high-resolution computed tomography (HR-CT). MATERIALS AND METHODS: In an in vitro experiment using 18 cadaver hands, the hamate bone was fractured at different places. Before and after fracture, conventional X-rays were taken in different planes (anteroposterior, lateral, oblique, and carpal tunnel), and HR-CT was performed with 2-mm layer thickness in the axial, sagittal, and coronal plane. RESULTS: Taking into account all the conventional X-ray projections applied, the in vivo experiment revealed a sensitivity of 72.2%, a specificity of 88.8%, and an accuracy of 80.5%. For the HR-CT, the sensitivity was 100%, the specificity was 94.4%, and the accuracy was 97.2%. CONCLUSIONS: Fractures of the body and hook of the hamate cannot always be detected with certainty in the conventional X-ray image, even if different projectional planes are used. The HR-CT is the imaging procedure of choice for further clarification, and an axial or sagittal plane should be selected.

Computerized analysis of gray-value profiles in spongy and cortical bone. Clinical experience.

RATIONALE AND OBJECTIVES: Osteoporosis is characterized by a loss of bone mineral density and deterioration of structure. The authors present a structural parameter for the quantitative assessment of osteoporotic changes in vertebral bone. METHODS: In 40 patients without or with known osteoporotic fractures, spongiosa and cortical bone mineral density was measured in lumbar vertebrae 1 to 3 by quantitative CT. Additional axial high-resolution CT slices were obtained for the structural analysis. In the spongiosa, the gray-value profile along a horizontal line in the CT slice was used, whereas in the cortical shell a profile was obtained from the cortical ridge. Both profiles were intersected with a horizontal line of variable position, and the maximum number of intersections was determined. RESULTS: The maximum number of intersections is significantly higher in cases with fractures (spongiosa 48.6, cortical shell 77.3) than in cases without fractures (spongiosa 42.1, cortical shell 62.4). It also correlates with bone mineral density and age. CONCLUSIONS: The presented method shows significantly different numeric results for patients with and without osteoporotic fractures. The analysis is easy to perform and provides additional information on the bone structure that may be used in combination with bone mineral density measurements.

CT determination of bone mineral density and structural investigations on the axial skeleton for estimating the osteoporosis-related fracture risk by means of a risk score.

In addition to the pure measurement of bone mineral density (BMD) in osteodensitometry, the investigation of bone structure is becoming increasingly important for estimating fracture risk. In a clinical study, a risk score was proposed which separately assesses BMD and structural parameters for spongious and cortical bone and aggregates them into a single diagnostic parameter. In 120 lumbar vertebrae from 40 patients, BMD was determined separately for spongious and cortical bone by means of quantitative CT using a single energy procedure (SE-QCT/85 kV). In addition, structural parameters based on high resolution CT were calculated for the spongiosa and cortical bone. For all patients the number of osteoporosis-related fractures was determined on the entire skeletal system. According to WHO criteria, the patients were subdivided into four groups: 1, normal; 2, osteopenic; 3, osteoporotic without fractures; 4, severely osteoporotic. Weighting factors were determined by means of multivariate least-squares analysis and used to calculate a risk score of all parameters. The ability of the individual parameters and of the sum of discriminate between the individual groups was tested. If one considers the individual parameters (BMD and the fractal structural values for spongious and cortical bone), they allow a statistically significant separation of the four groups, although there is overlapping in the value ranges. In patients with fractures, there was a significant reduction in the cortical mineral density, accompanied by a deterioration in structural properties. The following individual values were obtained (minimum-mean-maximum): spongiosa BMD (mg ml-1), unfractured: 62-112-163, fractured: 9-48-77; cortical BMD (mg ml-1), unfractured: 190-287-405, fractured: 133-191-269; spongiosa structural parameter, unfractured: 0.35-0.73-1.01, fractured: 0.95-1.24-1.58; cortical structural parameter, unfractured: 18-31-65, fractured: 21-44-66. Above 77 mg ml-1 CaHA in the spongiosa and 270 mg ml-1 CaHA in cortical bone, no fractures were observed. By appropriately selecting the weighting factors, the score is free of overlapping between the groups with and without fractures (values: unfractured 1-9-15, fractured 16-21-29). With higher score values, the fracture risk is increasing.

Issues of threshold selection when determining the fractal dimension in HRCT slices of lumbar vertebrae.

The box counting dimension is a frequently applied tool for the classification of trabecular bone structure. The algorithm requires a binarization of the gray value data, for example that acquired by high resolution CT (HRCT). We recently proposed a method to eliminate bone mineral density (BMD) by applying a linear normalization scheme. Further consideration has shown that full BMD independence has not been achieved, and the structural parameter proposed was therefore difficult to interpret. In this study we present an alternative approach to obtain a structural parameter that is independent of BMD. HRCT volume data was acquired on 21 lumbar vertebrae from five cadavers. In the segmented spongiosa, thresholding was based on different quantiles of the gray value histogram, yielding invariance over linear and non-linear transformations. Thresholding at high gray value levels (80% quantile) shows the highest level of significance when discriminating between osteoporotic and non-osteoporotic cases. As an addition to the measurement of BMD alone, the determination of structural properties allows an improvement of the assessment of the individual fracture risk.

Evaluation of the cortical structure in high resolution CT images of lumbar vertebrae by analysing low bone mineral density clusters and cortical profiles.

The structural classification of trabecular bone is of considerable clinical importance for the diagnosis of osteoporosis. Assessment of the cortical bone mineral density (BMD) and analysis of cortical structure is necessary because the cortex is also affected by osteoporosis. We describe a method for the automatic classification of the cortex from its structure on high resolution (HR) CT images. The method is based on the distribution of areas with low BMD in the cortex. Two different approaches are presented; one uses the grey scale profile of the cortical ridge, and the other one evaluates the distribution of connected regions (clusters) of low BMD. i.e. areas that lie below a certain threshold value. In HRCT images from 22 lumbar vertebrae, the number of intersections of the cortical intensity profile with a horizontal line was determined at various positions of this threshold line. At a certain position, there was a local maximum in the number of intersections which was 38% higher in the osteoporotic cases. The maximum shows a moderate correlation with the cortical BMD of rni = -0.72 (p < 0.0001). The number nc of connected regions (clusters) with pixel values below a certain threshold value was determined in relation to the threshold value T. The resulting function nc(T) shows a relative maximum slightly below the average grey scale value of the respective image. The curve depends on the degree of osteoporosis: the height of the maximum (i.e. the maximal number of clusters ncmax) allows distinction to be made between different degrees of osteoporosis, and ncmax shows a correlation with the cortical BMD of rnc = -0.84 (p < 0.0001).

Assessing the degree of osteoporosis in the axial skeleton using the dependence of the fractal dimension on the grey level threshold.

Combining the measurement of bone mineral density (BMD) and the classification of the trabecular structure in cancellous bone improves the estimation of the degree of osteoporosis. A fractal method for the automatic quantitative classification of the trabecular structure in midvertebral slices of lumbar vertebrae is introduced. This method is based on the computation of the fractal dimension (box counting method) for varying binarization thresholds. Radiographic images from 30 lumbar vertebrae and CT images from an additional 16 lumbar vertebrae were analysed by calculating the dimension D in dependency of the threshold value T. The function D(T) was normalized by the average image grey value, eliminating the bone mineral density from the computations. The results show that the images of the lumbar vertebrae have fractal properties, and the function D(T) has a typical behaviour that allows the discrimination of the degree of osteoporosis. With two parameters extracted from the function D(T) the correlation coefficients with BMD were both -79% for the radiographic images, and -93% and -91% for the CT data, respectively.

[Digital subtraction angiography. Visualization of aortocoronary venous bypass]. / Digitale Subtraktionsangiographie (DSA). Darstellung von aortokoronaren Venenbypässen.

Following venous injection of radiopaque contrast material, digital subtraction angiography was employed to examine coronary bypass grafts in ten patients. In LAO projection 18 of 24 grafts could be identified. This result shows the ability to assess patency of bypass grafts using computerized fluoroscopy.

[Angiographic diagnosis of vascular impotence]. / Angiographische Diagnostik der vaskulär bedingten Impotentia coeundi.

Twelve patients (average age 40 +/- 15 years) with impotentia coeundi were angiographically examined under suspicion of a vasculogenic impotence. Overview angiographies of the pelvis and selective iliaca interna injections were performed. The normal anatomy of the pudendal artery and the penile branches is shown. Ten patients were suffering from a stenosis or total occlusion of the dorsal pudendal artery, the dorsal penile artery or the profound penile artery with or without filling of a peripheral segment. The role of arteriography in surgical treatment is discussed.

[A new method for measuring rotation of a vertebral scoliosis (author's transl)]. / Eine neue Methode zur Messung des Rotationswinkels der Wirbelskoliose.

A new radiologic method for measuring the rotation of a scoliosis from CT pictures is described. Normal deviation from the 0 position at the level of the first lumbar vertebra in 50 patients without clinically demonstrable scoliosis when accurately positioned, was M = 0.06 degrees +/- 2.95 SD. Direct measurements of the rotation of the spine and of the displacement of the sternum permit serial observation of the progress of the scoliosis and of the consequent thoracic deformity, as well as the result of treatment.

[Dynamic computer tomographic for tumours of the facial skeleton (author's transl)]. / Dynamische Computertomographie bei Gesichtsschädeltumoren.

Serial computer tomography after intravenous bolus injection of contrast provides information concerning the vascularity of tumours in the facial skeleton. In addition the relationship of the tumour to the major vessels and their displacement or compression can be demonstrated. This provides information additional to the ordinary computer tomogram, so that neoplasms of the facial skeleton can be shown at various stages and their extent determined. A requirement for the use of serial CT is a scanner with a short scan time and scan interval.

[Possibility of error and difficulties in the computerized tomographic diagnosis of lumbar intervertebral disk prolapse]. / Irrtumsmöglichkeiten und Schwierigkeiten in der computertomographischen Diagnostik lumbaler Bandscheibenvorfälle.

In 310 computed axial tomograms of the lumbar spine which were studied retrospectively a number of pitfall situations were encountered. These in part were related to technical limitations, in part to degenerative joint disease and to postoperative hypertrophic scar formation. It became evident that the position of the disc within the intervertebral space may vary to a certain degree, a phenomenon not to be mistaken for disc protrusion.

[Quantitative mineral estimations in vertebral bodies by computer tomography (author's transl)]. / Quantitative Mineralsalzbestimmung im Wirbelkörper mittels Computertomographie.

The accuracy of computer tomographic bone density measurements in the axial skeleton was tested by comparing results obtained from the first lumbar body in abdominal phantoms. An almost linear relationship (r = 0.998) was found between increasing concentrations of a calcium chloride solution and CT absorption values. The sum of the CT values of sections through the vertebral body correlated well with their ash content (r = 0.90) as well as with the hydroxyl apatite values obtained by I125-absorption densitometry (r = 0.88). Reproducibility of CT measurements on the phantom was good (coefficient of variation = 1.2% in the spongiosa). Average CT values of separate measurements of the spongiosa and cortex could be correlated with the total spongiosa by a special programme (r = 0.95). In the practical application of this technique, possible sources of error must be considered, such as the effect of high energy polychromatic radiation, inhomogeneity of the object being investigated and difficulties in positioning the patients

[The quantitative determination of bone mineral content--a system comparison of similarly built computed tomographs]. / Quantitative Knochenmineralgehaltsbestimmung (QCT)--Systemvergleich baugleicher Computertomographen.

An intercomparison of 4 CT scanners of the same manufacturer was performed. The bone mineral content of 11 lumbar vertebral columns removed directly post mortem was determined in a specially constructed lucite-water phantom. Even devices of the same construction were shown to yield a variation in the quantitative evaluation markedly exceeding the annual physiological mineral loss. As long as scanner adjustment by physical calibration phantoms has not yet been established, a course assessment and therapy control of bone mineral content should always be carried out on the same QCT scanner.

[Intravenous digital subtraction angiography (DSA). Experience in 600 cases]. / Intravenöse digitale Subtraktionsangiographie (DSA). Erfahrungen in 600 Fällen.

Intravenous digital subtraction angiography has been employed to examine arteries in 600 patients. Conventional angiography was used in 41 cases where insufficient DSA was made, or as definitive preoperative investigation. In 88% the digital subtraction angiogram is diagnostic, and conventional angiography then shows little more additional information.

[Quantitative computerized tomographic determination of bone mineral content]. / Quantitative computertomographische Knochenmineralgehaltsbestimmung.

Quantitative computed tomography (QCT) for measuring bone mineral content of lumbar vertebrae is increasingly used internationally. The effect of using conventional CT (single energy CT, SE-CT) and dual energy CT (DE-CT) on reproducibility has been examined. We defined a standard measurement protocol, which automatically evaluates a calibration phantom. This should ensure an in vivo reproducibility of 1 to 2%. Reference data, which has been obtained with this protocol from 113 normal subjects, using SE-CT and DE-CT, are presented.

[The imaging of hamate fractures in the conventional X-ray and CT: experimental results and clinical experiences]. / Darstellung von Os hamatum-Frakturen im konventionellen Röntgenbild und CT: experimentelle Ergebnisse sowie klinische Erfahrungen.

PURPOSE: Examination of the ability to image fractures of the body and hook of the hamate bone in conventional X-rays and HR-CT. MATERIAL AND METHODS: In an in vitro experiment on 18 cadaver hands, the hamate bone was fractured at different localisations. Before and after fracture, conventional x-rays were taken in different projectional planes: a.-p., lateral, oblique and carpal tunnel view, as well as an HR-CT with 2 mm layer thickness in the axial, sagittal and coronal plane. In addition, 15 clinically verified hamate bone fractures (two body and 13 hook of hamate fractures) were reviewed retrospectively to assess the value of the imaging procedures that led to diagnosis. RESULTS: Taking into account all conventional x-ray projections applied, the in vitro experiment yielded a sensitivity of 72.2%, a specificity of 88.8% and an accuracy of 80.5%. For CT, the sensitivity was 100%, the specificity 94.4% and the accuracy 97.2%. In retrospective clinical evaluation, 60% of the existing fractures were identified in the conventional x-ray images. The remaining fractures were detected by additional procedures like scintigraphy, conventional tomography and CT. CONCLUSION: For the diagnosis of fractures of the body and hook of the hamate HR-CT is the imaging procedure of choice, in which case an axial or sagittal plane should be chosen.