Body mass prediction from femoral volume and sixteen other femoral variables in the elderly: BMI and adipose tissue effects.

OBJECTIVES: The frequently used prediction equations of body mass do not seem appropriate for elderly individuals. Here, we establish the relationship between femoral dimensions and known body mass in elderly individuals in order to develop prediction formulas and identify the factors affecting their accuracy. MATERIALS AND METHODS: The body mass linear least-squares regression is based on 17 femoral dimensions, including femoral volume, and 66 individuals. Body proportion and composition effects on accuracy are analyzed by means of the body mass index (BMI) and on a subset sample (n = 25), by means of the masses of adipose, bone and muscle tissues. RESULTS: Most variables significantly reflect body mass. Among them, six dimensions (e.g., biepicondylar breadth, femoral volume, and head femoral diameter) present percent standard errors of estimate ranging from 9.5 to 11% (r = 0.72-0.81) in normal BMI samples. Correlations are clearly lower in samples with normal and abnormal BMI [r = 0.38-0.58; % of standard error of estimate (SEE) = 17.3-19.6%] and not significantly correlated in females (femoral volume) who present high proportions of abnormal BMI and adipose tissue. In the subset, femoral volume is well correlated with bone mass (r = 0.88; %SEE = 7.9%) and lean body mass (r = 0.67; %SEE = 17.2%). DISCUSSION: Our body mass estimation equations for elderly individuals are relevant since relatively low correlations are recurrent in studies using younger individuals of known body mass. However, age, sex, lifestyle, and skeleton considerations of studied populations can provide information about the relevance of the body mass estimation, which is dependent on the BMI classification and the proportion of adipose tissue. Our general considerations can be used for studies of younger individuals.

Comparison of Several White Matter Tracts in Feline and Canine Brain by Using Magnetic Resonance Diffusion Tensor Imaging.

Recently, we published a first anatomical diffusion tensor imaging (DTI) atlas regarding white matter tracts in the canine brain. The purpose of this study was to show the significance of DTI in the revelation of the white matter fibres in the feline brain (i.e., to obtain an anatomical DTI atlas of images) and to descriptively compare these to previously obtained white matter fibre images of the canine brain. DTI MR Images of four cats euthanized for reasons other than neurological disorders were obtained with a 3 T system. Combined fractional anisotropic (FA) and directional maps were obtained within the hour after death. An experienced anatomist tracked white matter tracts of clinical relevance using the scanner software. After validation of these tracts, we compared relevant neurological connections between the cat and the dog. Comparison of cerebral structures between different species is easier when the three dimensional anatomy is visualized by using DTI. 3D rendered DTI images clearly show major differences in neurological architecture between cats and dogs for example, the more important space occupying role of the limbic system, and the less diffuse, less nodular, less pronounced and thinner fibre bundles in the feline brain compared to the canine brain (except for the cerebellum different parts connecting fibres passing through the brainstem which are pronouncedly developed). Anat Rec, 300:1270-1289, 2017. © 2017 Wiley Periodicals, Inc.

Predicting appendicular lean and fat mass with bioelectrical impedance analysis in older adults with physical function decline - The PROVIDE study.

BACKGROUND & AIMS: No generalizable formulas exist that are derived from bioelectrical impedance analysis (BIA) for predicting appendicular lean mass (ALM) and fat mass (AFM) in sarcopenic older adults. Since precision of regional body composition (BC) data in multicentre trials is essential, this study aimed to: 1) develop and cross-validate soft tissue BIA equations with GE Lunar and Hologic DXA systems as their reference 2) to compare our new ALM equation to two previously published models and 3) to assess the agreement between BIA- and DXA-derived soft tissue ratios as indicators of limb tissue quality. METHODS: Two-hundred and ninety-one participants with functional limitations (SPPB-score 4-9; sarcopenia class I or II, measured by BIA) were recruited from 18 study centres in six European countries. BIA equations, using DXA-derived ALM and AFM as the dependent variable, and age, gender, weight, impedance index and reactance as independent variables, were developed using a stepwise multiple linear regression approach. RESULTS: Cross-validation gave rise to 4 equations using the whole sample: ALMLUNAR (kg) = 1.821 + (0.168*height2/resistance) + (0.132*weight) + (0.017*reactance) - (1.931*sex) [R2 = 0.86 and SEE = 1.37 kg] AFMLUNAR (kg) = -6.553 - (0.093* height2/resistance) + (0.272*weight) + (4.295*sex) [R2 = 0.70 and SEE = 1.53 kg] ALMHOLOGIC (kg) = 4.957 + (0.196* height2/resistance) + (0.060*weight) - (2.554*sex) [R2 = 0.90 and SEE = 1.28 kg] AFMHOLOGIC (kg) = -4.716 - (0.142* height2/resistance) + (0.316*weight) + (4.453*sex) - (0.040*reactance) [R2 = 0.73 and SEE = 1.54 kg] Both previously published models significantly overestimated ALM in our sample with biases of -0.36 kg to -1.05 kg. For the ratio of ALM to AFM, a strong correlation (r = 0.82, P < 0.0001) was found between the mean estimate from BIA and the DXA models without significant difference (estimated bias of 0.02 and 95% LOA -0.62, 0.65). CONCLUSION: We propose new BIA equations allowing the estimation of appendicular lean and fat mass. Our equations allow to accurately estimate the appendicular lean/fat ratio which might provide information regarding limb tissue quality, in clinical settings. Furthermore, these BIA equations can be applied to characterize sarcopenia with Hologic and Lunar reference values for BC. Previously published BIA-based models tend to overestimate ALM in sarcopenic older adults. Users of both GE Lunar and Hologic may now benefit from these equations in field research.

The accuracy of body mass prediction for elderly specimens: Implications for paleoanthropology and legal medicine.

Different practices in paleoanthropology and legal medicine raise questions concerning the robustness of body mass (BM) prediction. Integrating personal identification from body mass estimation with skeleton is not a classic approach in legal medicine. The originality of our study is the use of an elderly sample in order to push prediction methods to their limits and to discuss about implications in paleoanthropology and legal medicine. The aim is to observe the accuracy of BM prediction in relation to the body mass index (BMI, index of classification) using five femoral head (FH) methods and one shaft (FSH) method. The sample is composed of 41 dry femurs obtained from dissection where age (c. 82 years) and gender are known, and weight (c. 59.5 kg) and height are measured upon admission to the body leg service. We show that the estimation of the mean BM of the elderly sample is not significantly different to the real mean BM when the appropriate formula is used for the femoral head diameter. In fact, the best prediction is obtained with the McHenry formula (1992), which was based on a sample with an equivalent average mass to that of our sample. In comparison, external shaft diameters, which are known to be more influenced by mechanical stimuli than femoral head diameters, yield less satisfactory results with the McHenry formula (1992) for shaft diameters. Based on all the methods used and the distinctive selected sample, overestimation (always observed with the different femoral head methods) can be restricted to 1.1%. The observed overestimation with the shaft method can be restricted to 7%. However, the estimation of individual BM is much less reliable. The BMI has a strong impact on the accuracy of individual BM prediction, and is unquestionably more reliable for individuals with normal BMI (9.6% vs 16.7% for the best prediction error). In this case, the FH method is also the better predictive method but not if we integrate the total sample (i.e., the FSH method is better with more varied BMI). Finally, the estimation of the mean BM of a sample can be used with more confidence compared to the estimation of individual BM. The former is very useful in an evolutionary perspective whereas the latter should be used in keeping with the information gathered on the studied specimen in order to reduce prediction errors. Finally, the BM estimation can be a parameter to consider for personal identification.

Ultrasound follow-up of posttraumatic injuries of the sagittal band of the dorsal hood treated by a conservative approach.

Traumatic dislocation of the extensor tendon over the metacarpophalangeal (MCP) joint is a rare problem in patients without rheumatoid disorders. The common extensor tendon is stabilized on the metacarpal head by components of the dorsal hood (DH). A tear in the sagittal bands, allows (sub)luxation of the tendon. To ensure appropriate treatment, the identification of the damaged structures is essential. Ultrasound (US) is a valuable method in the evaluation of DH injuries and in the follow-up for evaluation of healing or lack of healing of the lesions. We report three cases with partial rupture of the sagittal band of the DH: two cases in the index finger and one case in the long finger, which caused pain and swelling and was diagnosed with US. The patients were treated conservatively and the pain resolved after 9 months in case 1, 3 months in case 2 and 6 months in case 3. The follow-up at one year revealed painless full range of motion and no residual subluxation during the dynamic ultrasound.

Use of anthropometry for the prediction of regional body tissue distribution in adults: benefits and limitations in clinical practice.

Regional body composition changes with aging. Some of the changes in composition are considered major risk factors for developing obesity related chronic diseases which in turn may lead to increased mortality in adults. The role of anthropometry is well recognized in the screening, diagnosis and follow-up of adults for risk classification, regardless of age. Regional body composition is influenced by a number of intrinsic and extrinsic factors. Therapeutic measures recommended to lower cardiovascular disease risk include lifestyle changes. The aim of this review is to systematically summarize studies that assessed the relationships between anthropometry and regional body composition. The potential benefits and limitations of anthropometry for use in clinical practice are presented and suggestions for future research given.

Assessment of regional adipose tissue depots: a DXA and CT comparison in cadavers of elderly persons.

OBJECTIVE: Since dual energy X-ray absorptiometry (DXA) cannot distinguish between different adipose tissue (AT) deposits, it remains unclear how DXA-derived body composition variables relate to anatomical tissue (sub)compartments. The aim of the present study was to compare and relate regional DXA variables with absolute tissue masses obtained by computer tomography (CT) scanning of the lower limbs in elderly persons. METHODS: Eleven well-preserved white Caucasian adults (seven male and four female cadavers) with a median age of 79.0 years (ranging from 68 to 96 years) were fully scanned with DXA and CT. Separate densities of skin tissue, AT, muscle tissue and bone were obtained by hydrostatic weighing. RESULTS: The leg DXA-variables were significantly related (rho-values between 0.60 and 0.98, P < 0.01) to CT-derived tissue counterparts, but showed significant systematic differences except for subcutaneous AT mass (P = 0.773). After controlling for other AT depots, fat as measured by DXA (fat(DXA)) related only to intermuscular AT (rho = 0.82, P < 0.01) in males and to subcutaneous AT (rho = 0.84, P < 0.05) in females. CONCLUSION: Although significantly interrelated, DXA and CT variables should not be used interchangeably since they have different quantitative and physiological significance. Our results suggest that fat(DXA) represents different parts of AT depots in elderly men and women. Since DXA is not appropriate for assessing tissue variability cautious clinical interpretation is warranted.

Diffusion tensor imaging of white matter tracts in the dog brain.

Diffusion weighted imaging sequences are now widely available on Magnetic Resonance Imaging (MRI) scanners. Diffusion Tensor Imaging (DTI) of the brain is able to show white matter tracts and is now commonly used in human medicine to study brain anatomy, tumors, structural pathways,… The purpose of this study was to show the interest of DTI to reveal the white matter fibers in the dogs' brain. DTI MR Images for this study were obtained with a 3 T system of 4 dogs euthanized for other reasons than neurological disorders. Combined fractional anisotropic (FA) and directional maps were obtained in the first 2 hours after death. The heads were amputated immediately after scanning and stored in 10% formalin until preparation for dissection. An experienced anatomist tracked white matter tracts with clinical relevance using the scanner software. The selected tracts were REFVIDume rendered and correlated with gross dissection. Using DTI we were able to track relevant neurological connections, such as the corticospinal tract, the optic and the cerebellar tract. The three dimensional anatomy is better presented using modern visualization techniques. DTI seems to be a valuable tool in order to present clinically relevant white matter tracts to neurological clinicians and researchers.

Accuracy and concordance of anthropometry for measuring regional fat distribution in adults aged 20-55 years.

OBJECTIVES: This study aimed to assess the accuracy and concordance of anthropometrically derived prediction equations for the estimation of regional fat mass (FM) distribution. METHODS: Sixty-two white males and 50 females with a large range of age (20-55 years) and BMI (16.6-33.4 kg/m(2)) were included. Whole body dual energy X-ray absorptiometry (DXA) scans were acquired and anthropometric prediction equations for regional FM were developed and cross-validated. On the basis of the total sample two anthropometrically derived indices of FM distribution [Formula: see text] ratio and [Formula: see text] ratio were compared with their DXA analogues. RESULTS: In both sexes multiple linear regression models predicted the regional DXA fat masses with good accuracy (P < 0.001). In men mean bias (limits of agreement) were: -6.8 g (-535,364) for FM(arms), 65 g (-1921,2052) for FM(trunk), -21 g (-1374,1332) for FM(legs), -0.2% (-5.0,4.7) for %FM(trunk) and -0.5% (-6.8,5.8) for %FM(legs). In women mean difference (limits of agreement) were: -86 g (-463,450) for FM(arms), 30 g (-1784,1844) for FM(trunk), -278 g (-1782,1227) for FM(legs), 0.4% (-5.5,6.3) for %FM(trunk), and 0.3% (-8.3,8.9) for %FM(legs). No systematic (constant and proportional) differences between methods for the determination of FM distribution ratios were found, suggesting method interchangeability. The concordance for subject classification based on t-scores according to the National Health and Nutrition Examination Survey (NHANES) was significant (P < 0.001), with substantial agreement for [Formula: see text] ratio (κ(w) = 0.80) and [Formula: see text] ratio (κ(w) = 0.75). CONCLUSION: Anthropometric variables offer promise to the development of simple, noninvasive, and inexpensive screening to identify individuals with abnormal FM distribution. The anthropometrically derived indices of FM distribution demonstrate sufficient accuracy for clinical use. Am. J. Hum. Biol., 2013. © 2012 Wiley Periodicals, Inc.

Cross-sectional content analysis of clinically applied circumferences.

BACKGROUND: The contours of a human body are determined by the volumes of the underlying tissues [adipose tissue (AT), muscle, bone and viscera]. Conceptually, they are assumed to be used as a concentric set of cylinders. Determination of these clinically applied circumferences in terms of relative tissue proportions has led to conflicting results. As it remains unclear what a circumference really measures or represents and how it relates to body composition (BC), the aim of this study was to determine the content of the circumferences and whether these perimeters can be used to assess segmental or whole body tissue components. DESIGN: Subsequent to an anthropometric protocol, the five white Caucasian cadavers were fractionated into slices of 3 cm and segmental and whole BC was determined at the anatomical tissue-system level by direct dissection. RESULTS: Only two circumferences correlated significantly with their dominating component [upper arm circumference (r = 0·98; P < 0·01) and waist circumference (WC) (r = 0·90; P < 0·05) with AT]. Two circumferences were related to a segmental tissue component [WC (r = 1·00; P < 0·001) with muscle mass of the trunk and wrist circumference (WrC) (r = 0·90; P < 0·05) with bone mass of the upper limb]. Two circumferences were related to a whole body tissue component [chest circumference (r = 0·90; P < 0·05) with whole body AT mass and WrC (r = 0·90; P < 0·05) with whole body bone mass]. CONCLUSION: The clinically applied circumferences do not measure what they pretend to measure. Of all the studied circumferences, only 2 circumferences (WC and WrC) can be used to assess segmental or whole body tissue components.

Reproducibility, accuracy and concordance of Accutrend Plus for measuring circulating lipid concentration in adults.

INTRODUCTION: The determination of lipid biomarkers by capillary sampling may be useful in the screening, diagnosis and/or personal management of hyperlipidemia and cardiovascular risk. It remains unclear whether the use of the Accutrend Plus system is appropriate. This study aimed to assess its reproducibility, accuracy and concordance for blood lipid profiling in adults. MATERIALS AND METHODS: Fasting capillary total cholesterol (TC) and triglyceride (TG) concentration on Accutrend Plus were compared with their venous analogues obtained by a laboratory reference method in sixty-one adults (27 men and 34 women, aged 33.0 years). Supplementary capillary sampling was performed at two consecutive days taking into account macro-nutrient intake. RESULTS: The day-to-day reproducibility of the Accutrend Plus system proved to be high for TC (ICC = 0.85, P < 0.001), but moderate for TG (ICC = 0.68, P < 0.001). Strong correlations (r > or = 0.80, P < 0.001) with the reference method were found for TC and TG. Mean difference (limits of agreement) were: 0.26 mmol/L (-0.95, 1.47) for TC, and -0.16 mmol/L (-1.29, 0.98) for TG. The concordance for subject classification according to the National Cholesterol Education Program (NCEP) guidelines was significant (P < 0.001), with substantial agreement for TC (K(w) = 0.67), and moderate agreement for TG (K(w) = 0.50). CONCLUSIONS: Day-to-day reproducibility of the Accutrend Plus device for TC and TG is not optimal and lacks accuracy when compared to the reference laboratory method. The concordance between both methods for classifying subjects according to the NCEP is inadequate. Accutrend Plus device should not be interchangeably used as a substitution for the standard laboratory methods in the diagnosis of hyperlipidemia.

Prediction of segmental lean mass using anthropometric variables in young adults.

The aim of the present study was to develop and cross-validate anthropometrical prediction equations for segmental lean tissue mass (SLM). One hundred and seventeen young healthy Caucasians (67 men and 50 women; mean age: 31.9 ± 10.0 years; Body Mass Index: 24.3 ± 3.2 kg · m(-2)) were included. Body mass (BM), stretch stature (SS), 14 circumferences (CC), 13 skinfolds (SF) and 4 bone breadths (BB) were used as anthropometric measurements. Segmental lean mass of both arms, trunk and both legs were measured by dual energy X-ray absorptiometry as the criterion method. Three prediction equations for SLM were developed as follows: arms = 40.394(BM) + 169.836(CCarm-tensed) + 399.162(CCwrist) - 85.414(SFtriceps) - 39.790(SFbiceps) - 7289.190, where Adj.R (2) = 0.97, P < 0.001, and standard error of estimate (SEE) = 355 g;trunk = 181.530(BM) + 155.037(SS) + 534.818(CCneck) + 175.638(CCchest) - 88.359(SFchest) - 147.232(SFsupraspinale) - 46522.165, where Adj.R(2) = 0.97, P < 0.001, and SEE = 1077g; and legs = 55.838(BM) + 88.356(SS) + 235.579(CCmid-thigh) + 278.595(CCcalf) + 288.984(CCankle) - 84.954(SFfront-thigh) - 53.009(SFmedial calf) - 28522.241, where Adj.R (2) = 0.96, P < 0.001, and SEE = 724 g. Cross-validation statistics showed no significant differences (P < 0.05) between observed and predicted SLM. Root mean squared errors were smallest for arms (362 g), followed by legs (820 g) and trunk (1477 g). These new prediction equations allow an accurate estimation of segmental lean mass in groups of young adults, but estimation errors of 8 to 14% can occur in certain individuals.

Comparison of frequently used, unexplored and newly designed indices for the assessment of segmental and whole body constituents.

Many constitutional indices, used as screening parameters in public health, have been explored (in-vivo) and applied for many years, but as yet there is no consensus on a universal index. This reflects confusion, or at least lack of agreement, about what a constitutional index should represent. The aim of this study was to explore the direct relationship of frequently used, unexplored and newly designed indices with adipose tissue masses and trunk adipose tissue distribution, on an anatomical 5-component model. Whole body and trunk composition, of 28 white Caucasian cadavers (aged 78.4±6.9 years), were determined at the anatomical tissue-system level by direct dissection. In the male group, the body mass index, the height/3body volume index and the weight/height-waist circumference-depth index showed good to excellent significant correlations with all adipose tissue masses (r-values between 0.75 and 0.92) and with the internal adipose tissue/adipose tissue ratio (r-values between 0.59 and 0.78). In the female group, the body mass index, the height/3body volume index and the weight/height-waist circumference index showed moderate to excellent significant correlations with all adipose tissue masses (r-values between 0.58 and 0.87) and with the internal adipose tissue/adipose tissue ratio (r-values between 0.52 and 0.80) and the internal adipose tissue/subcutaneous adipose tissue ratio (r-values between 0.48 and 0.78). The findings suggest that the newly designed indices (e.g. weight to height-waist circumference-depth index in males and weight to height-waist circumference index in females) are better correlates of whole body adipose tissue masses and trunk adipose tissue distribution than the frequently used indices.

The musculus pterygoïdeus proprius: an in-vivo approach with magnetic resonance imaging.

There is a limited understanding of the normal function of the pterygoïdeus proprius muscle and the role that this muscle may have in temporomandibular disorders. Despite a well-described anatomical in-vitro approach to this muscle, there are still difficulties in investigating the fossa pterygopalatina. This study reveals an alternative in-vivo approach by magnetic resonance imaging to visualise the muscle in the fossa pterygopalatina on 78 head halves, describe the connections with the musculus temporalis and pterygoïdeus lateralis as well as report the incidence without dealing with the known inconveniences of the dissection approach. The results show an incidence of 12.82% for the musculus pterygoïdeus proprius equally divided between both genders. Two different types of bridging between the musculus temporalis and musculus pterygoïdeus lateralis were also found: (i) 'O' shape (6.41%) and (ii) 'Y' shape (6.41%). This study suggests the use of magnetic resonance imaging to investigate the different connections between vascular and muscular structures in the fossa pterygopalatina. Further research with this approach to link the appearance of the muscle with neurovascular entrapment syndromes is warranted.

Accuracy of peripheral quantitative computed tomography and magnetic resonance imaging in assessing cortical bone cross-sectional area: a cadaver study.

OBJECTIVE: The present study aimed to assess the accuracy of peripheral quantitative computed tomography (pQCT) and magnetic resonance imaging (MRI) in assessing the cortical cross-sectional area (CCSA) at the level of the tibia. METHODS: Nine human whole-leg specimens were scanned with pQCT and MRI (T1-weighted and ultrashort echo-time [UTE] images) at 2 diaphyseal levels, 1 distal and the other 1 proximal. Subsequently, the bones were cut, and the CCSA was measured using digitized planimetry on the transverse sections. The correlation between CCSAs assessed via pQCT and MRI (T1 and UTE images) and assessed via planimetry, taken as a criterion standard, was evaluated using the Spearman rank correlation method. RESULTS: The mean (SD) CCSA with pQCT was 237.3 (54.3) mm2; T1-MRI, 228.8 (63.2) mm2; UTE-MRI, 178.5 (54.8) mm2; and planimetry, 250.17 (59.3) mm2. The CCSA measured with pQCT and T1-MRI was highly correlated with the planimetric CCSA (rho = 0.868 and rho = 0.880, respectively, P < 0.001). The correlation involving UTE-MRI was somewhat weaker (rho = 0.664, P = 0.003). CONCLUSIONS: Peripheral quantitative computed tomography and MRI (T1-weighted images) are accurate for the assessment of the CCSA at the tibial shaft.

Reproducibility of global three-dimensional motion during manual atlanto-axial rotation mobilization: an in vitro study.

The reproducibility of the three-dimensional (3D) kinematic aspects of motion coupling patterns during manual mobilizing techniques is still a debatable matter. The present in vitro study analysed segmental 3D motion of the atlanto-axial joint during manual axial rotation mobilization. Twenty fresh frozen human cervical specimens were studied in a test-retest situation with two examiners. The specimens were manually mobilized using three different techniques: (1) a regional mobilization technique of the cervical spine; (2) a segmental mobilization technique of the atlas with manual fixation of the axis; and (3) a segmental mobilization of the atlas on the axis applying a locking technique. Segmental atlanto-axial kinematics was registered with a Zebris CMS-20 ultrasound-based tracking system. The Euclidian norm was used as a representation of overall 3D motion. The results indicated good reproducibility (mean intraclass correlation coefficient, ICC: 0.87). Intraobserver reproducibility was slightly higher (mean ICC: 0.91; range: 0.76-0.99) than interobserver reproducibility (mean ICC: 0.85; range: 0.56-0.98) (P < 0.05). The total range of motion expressed as the Euclidean norm of 3D motion components was a parameter with good reproducibility in the study of segmental kinematics of manual atlanto-axial mobilization. Although previous studies have demonstrated poor inter-rater reliability of manual examination and mobilization of segmental motion components, the results of the present study shed a new and more positive light on the reproducibility of techniques for manual mobilization of the upper cervical spine.

Quality control, accuracy, and prediction capacity of dual energy X-ray absorptiometry variables and data acquisition.

The acquisition of soft tissue measurements, fat (chemical) or adipose tissue (morphological) quantities, is essential in clinical research and nutritional status and its associated health risks. This has led to a proliferation of methods for the in-vivo determination of body composition. None of the indirect in-vivo approaches to estimate body adipose tissue has been validated against direct dissection data except for the skinfold.Since the development of DEXA as a measurement tool of bone density and mineral content for the detection of osteoporosis, it became a tool for measuring regional and whole body masses, lean tissue, and fat. A number of validation attempts have been made, however mostly against other indirect in-vivo techniques. The purpose of this study was to conduct an in-vitro validation and quality control of the data acquisition of DEXA using dissection as the criterion method. Fourteen porcine hind legs were scanned with DEXA, weighed in air and water and dissected into skin, adipose tissue, muscle and bone. Normal distribution, means, standard deviations, paired student t-test, Pearson correlation coefficients, interclass correlations test, and a Bland-Altman plot were used. The results show systematically good to excellent correlations between DEXA and dissection data acquisition (r(2)=0.75 to 0.99), but absolute indirect DEXA and direct dissection values are significantly different (p<0.05). DEXA overestimates total weight, lean mass, and fat free mass and underestimates both mass and % adipose tissue. DEXA provides erroneous values for bone density. Data produced by DEXA are morphological, not chemical values, as claimed by the manufacturer. This 'pilot' study indicates that a 'simple' combination of skin, adipose tissue, muscle, and bone from hind legs may give an incomplete picture of reality as one needs to measure viscera, connective tissue, and air pockets of the body. Validation studies with intact bodies are advised.

In vitro three dimensional morphometry of the lateral atlantoaxial articular surfaces.

STUDY DESIGN: The present study verifies the 3-dimensional anatomic features of the lateral atlantoaxial joints with reference to a local reference frame using a direct in vitro approach. OBJECTIVE: To study the concordance between the axial and atlantal articular surfaces. SUMMARY OF BACKGROUND DATA: Detailed information of joint-configurations is imperative for understanding the complex kinematics of the upper cervical joint. Data on the quantitative morphology of the human spinal facet joints has been published, but did not include the atlanto-occipital and atlantoaxial joints. METHODS: In 20 fresh spine specimens, metal markers were implanted on the cranium, the atlas, and the axis. After registration of the intact specimens, the bony segments were separated and markers and anatomic landmarks were digitized. The size, shape, and orientation relative to the local reference frame of the axis were derived from the relative position data of the joint surface landmarks. RESULTS: The diameters and surface areas of the inferior articular surfaces of the atlas are slightly smaller than the corresponding surfaces on the superior aspects of the axis (17.7 mm and 235 mm vs. 17.0 and 212 mm). In this sample of older-aged specimens, the curvature of the articulating surfaces is nearly flat. The absolute angle between the left and right surface areas is about 130 degrees and corresponds well between axis and atlas. The orientation of the joint surfaces of axis and atlas with respect to the sagittal plane of the axis indicates a good congruency. CONCLUSION: There seems to be a strong relationship between the anatomic features of the lateral articulating surfaces of atlas and axis. Differences in the orientation of joint surfaces to the frontal plane may be related to deviations from the neutral position. This issue raises the problem of the definition of three-dimensional-neutral joint positions.

In vivo 3D arthrokinematics of the proximal and distal radioulnar joints during active pronation and supination.

BACKGROUND: Pronation and supination of the forearm are important motions with major impact of impairment on daily activities. Despite this, the migration of contact of the articular surfaces of the proximal and distal radioulnar joints during active pronation has not been evaluated in vivo. METHOD: Helical CT-data in elbow positions of full active supination, mid position and full pronation with the elbow in extension were acquired from three female subjects and processed in 3D skeletal reconstructions. From the sets of skeletal landmarks relative radioulnar finite helical axes were estimated. The migration of the articular contact was evaluated in the planes perpendicularly reconstructed on these finite helical axes. FINDINGS: The center of the radial head translated 1.96 (SD 0.24) mm from a posterior location on the ulna in supination to a centered location in mid-position and an anterior location in pronation. For the distal radioulnar joint, the center of rotation remained relatively fixed about the center of the curvature of the articular surface of the ulna. RELEVANCE: The motion of the radial head on the ulnar surface consists of an anterior spinning with anterior gliding which contrasts with the concave-convex rule as used in manual therapy i.e. posterior gliding of the caput radii on the ulna with pronation. As such, the findings have major therapeutic implications for manual therapy.