Directional Variation of Trabecular Bone in the Femoral Head, a μ-CT based Approach (original) (raw)
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Correlations between the mechanical properties, radiology and histomorphometry of human femoral bone
Clinical Biomechanics, 1992
Initial fixation of the femoral components of total hip replacements is related to the mechanica1 integrity of the bone within the proximal femur. This preliminary study examined the correlations between the mechanica1 properties, histomorphometry, and radiology of bone core specimens taken from the proximal femora of cadavers and of patients undergoing total hip replacement surgery. Measurements and subjective assessments of the femoral bone from radiographs were shown to have poor correlation with both compressive mechanica1 properties and bone volume measurements. However, the mechanica1 properties of the bone core specimens and the histomorphometric measurements correlated wel1 with the bone density measured by single-photon absorptiometry, indicating that this type of imaging technique may be of value in determining bone quality prior to surgery. Relevante The prediction of the mechanica1 properties of the proximal femur by preoperative imaging may have direct bearing on the type of femoral component to be used in total hip replacement. Preoperative assessment of bone quality would allow the surgeon to predict the likely fixation obtainable with different designs.
Osteoporosis International, 2010
We investigated age-and gender-related variation of both cortical and trabecular microstructure in human femoral neck. We found that age-related change of cortical porosity is more noticeable than that of trabecular parameter. Our data may help to gain more insight into the potential mechanism of osteoporotic femoral neck fractures. Introduction Variations in the microstructure of cortical and trabecular bone contribute to decreased bone strength. Ageand gender-related changes in cortical and trabecular microstructure of femoral neck is unclear. The aim of this study was to identify three-dimensional (3D) microstructural changes of both cortical and trabecular bone simultaneously in human femoral neck with age and gender, using microcomputed tomography (micro-CT). We hypothesized that there would be differences in age-related changes of cortical and trabecular bone for both women and men. Methods We used 56 femoral necks of 28 women and men (57-98 years of age) from a Japanese population. The subjects were chosen to give an even age and gender distribution. Both women and men were divided into three age groups: middle (57-68 years), old (72-82 years), and elderly (87-98 years) groups. We examined cortical bone specimen from the inferior sector of femoral neck and trabecular bone specimen from the middle of femoral neck using micro-CT and 3D bone analysis software. Results Cortical thickness (Ct.Th) decreased by 10-15%, cortical porosity (Ca.V/TV) almost doubled, and canal diameter (Ca.Dm) increased by 65-77% between the middle-aged and elderly groups for both women and men. The trabecular bone volume fraction (BV/TV) decreased by around 20%; trabecular thickness (Tb.Th), trabecular number (Tb.N), and connectivity density (Conn.D) decreased; and trabecular separation (Tb.Sp) and structure model index (SMI) increased with age for both women and men. As compared with women, men had higher Ct.Th and BV/TVand lower Ca.V/TVand Ca.Dm among three age groups. There was a significant inverse correlation between Ca.V.TV and BV/TV for both women and men. Conclusion Our findings indicate that Ct.Th and BV/TV decreased, and Ca.V/TV and Ca.Dm increased in femoral neck with age for both women and men. The most obvious age-related change is the increase of Ca.V/TV. The decrease of BV/TV with age is more noticeable than that of Ct.Th. This is the first study that has provided both cortical and trabecular microstructural data simultaneously in a Japanese sample. These data may help us to gain more insight into the potential mechanism of osteoporotic femoral neck fractures.
Medical Physics, 2006
Microcomputed tomography ͑CT͒ produces three-dimensional ͑3D͒ images of trabecular bone. We compared conventional CT ͑CCT͒ with a polychromatic x-ray cone beam to synchrotron radiation ͑SR͒ CT with a monochromatic parallel beam for assessing trabecular bone microarchitecture of 14 subchondral femoral head specimens from patients with osteoarthritis ͑n =10͒ or osteoporosis ͑n =4͒. SRCT images with a voxel size of 10.13 m were reconstructed from 900 2D radiographic projections ͑angular step, 0.2°͒. CCT images with a voxel size of 10.77 m were reconstructed from 205, 413, and 825 projections obtained using angular steps of 0.9°, 0.45°, and 0.23°, respectively. A single threshold was used to binarize the images. We computed bone volume/ tissue volume ͑BV/TV͒, bone surface/bone volume ͑BS/BV͒, trabecular number ͑Tb.N͒, trabecular thickness ͑Tb.Th and Tb. Th * ͒, trabecular spacing ͑Tb.Sp͒, degree of anisotropy ͑DA͒, and Euler density. With the 0.9°angular step, all CCT values were significantly different from SRCT values. With the 0.23°and 0.45°rotation steps, BV/TV, Tb.Th, and BS/BV by CCT differed significantly from the values by SRCT. The error due to slice matching ͑visual site matching ±10 slices͒ was within 1% for most parameters. Compared to SRCT, BV/TV, Tb.Sp, and Tb.Th by CCT were underestimated, whereas Tb.N and Tb. Th * were overestimated. A Bland and Altman plot showed no bias for Tb.N or DA. Bias was −0.8± 1.0%, +5.0± 1.1 m, −5.9± 6.3 m, and −5.7± 29.1 m for BV/TV, Tb. Th * , Tb.Th, and Tb.Sp, respectively, and the differences did not vary over the range of values. Although systematic differences were noted between SRCT and CCT values, correlations between the techniques were high and the differences would probably not change the discrimination between study groups. CCT provides a reliable 3D assessment of human defatted bone when working at the 0.23°or 0.45°rotation step; the 0.9°rotation step may be insufficiently accurate for morphological bone analysis.
Clinical Anatomy, 2019
The success of a total hip arthroplasty is directly related to the ability of the implant to match original femoral morphology. Given this critical relationship, we characterized normal proximal femoral morphology as it relates to sex, age, and symmetry. Sixty abdominopelvic computed tomography (CT) scans (30 male and 30 female, ages 20-85 years old) from patients without any osseous pathology or implants were utilized. Three-dimensional models were constructed from the CT scans using Mimics v19 (Materialize). Thirteen landmarks were placed on each femur model and yielded eight morphological measurements for each femur. Medullary cavity measurements were taken superior to, at the center of, and inferior to the lesser trochanter. Morphological measurements were analyzed by sex, age group, and left versus right. A significant difference was identified between males and females for femoral head height, inferior neck length, minimum neck diameter, neck shaft angle, mediolateral medullary cavity measurement superior to the lesser trochanter and the anteroposterior at the lesser trochanter (P < 0.05). Age was found to correlate with medullary cavity measurements. As previously identified in the literature, differences with respect to the right and left femur were not of practical significance. The results show that sex is critical in determining prosthesis fit with the examined morphological measurements of the proximal femur while age is more important with respect to the medullary cavity. It is also evident that the current practice of using one femur to approximate the opposite is a viable clinical assumption. Clin.
Journal of …, 2007
The aim of this study was to verify whether a misalignment between the testing direction and the trabecular main direction has a significant effect on the compressive behaviour of cancellous bone. Ten cylindrical specimens were extracted from femoral heads with a misalignment to the trabecular main direction of approximately 20 deg. Each specimen was paired with a specimen extracted aligned with the main direction of the trabeculae on the basis of the closest bone volume fraction, obtaining two groups, one ‘aligned’ and one ‘misaligned’. The average off-axis angle was 6.1 deg and 21.6 deg for the ‘aligned’ and ‘misaligned’ group, respectively. The specimens underwent micro-tomographic analysis, compressive testing, microindentation testing and ashing. No significant differences were found in histomorphometric parameters, hardness and ash density between the two groups, whereas significant differences were found in Young’s modulus and ultimate stress: both parameters, measured for the ‘misaligned’ group, were about 40% lower than those measured for the ‘aligned’ group. These results demonstrate a great effect of the angle between the testing direction and the main direction of the trabecular structure on the compressive behaviour of cancellous bone. This angle should be reduced as much as possible (in the present work the average value was 6.6 +- 3.3 deg), in any case measured, and always reported together with the mechanical parameters of cancellous bone.
Hip & Pelvis, 2021
We analyzed the microstructure and bone mineral density (BMD) of the trabecular bone in the femoral head of patients with osteoporosis. Materials and Methods: Sixteen femoral heads with osteoporotic femoral neck fractures underwent microcomputed tomography scanning. In each tip-apex distance (TAD) of 15, 20, and 25 mm, five regions of interest (ROIs) were extracted from the central, anterior, posterior, superior, and inferior sections. A total of 15 ROIs were extracted from TADs of 15, 20, and 25 mm. The measurement parameters included BMD, percent bone volume: bone volume/total volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), structural model index (SMI), and degree of anisotropy (DOA). Results: The lowest BMD and BV/TV values were observed in the inferior region and differed significantly from those in other regions (P<0.05). Lower Tb.Th and Tb.N values were observed in the inferior region compared with those in the central region (P<0.05). The highest SMI value was observed in the inferior region (P<0.05). With TAD of 15 and 20 mm, the DOA values in the inferior region were lower than those in the anterior region (P<0.05). Lower BMD and BV/TV values were observed in the anterior, central, and inferior regions of TAD of 15 mm compared with those in the corresponding regions of TAD of 25 mm (P<0.05). Conclusion: Positioning the lag screw between TAD of 20 to 25 mm and in the inferior region is recommended, and TAD of less than 15 mm is not recommended.
Structural and Radiological Parameters for the Nondestructive Characterization of Trabecular Bone
Annals of Biomedical Engineering, 2000
Trabecular bone is characterized by compositional and organizational factors. The former include porosity at microlevel and mineralization. The latter refer to the trabecular architecture. Both determine the mechanical properties of the trabecular bone. The aim of this study is to investigate the relationship between the mechanical properties and the local HU value, the bone mineral density, the in vitro histomorphometric properties assessed by means of microcomputed tomography, and the Young's modulus determined by ultrasound measurement. Also the correlation between local HU values based on CT data of the full bone and HU values based on CT data of excised trabecular bone cylinders is investigated. Therefore density and strength related parameters of 22 trabecular bone cylinders retrieved from a fresh cadaver femur were measured by using different techniques. The mean HU value of the excised bone samples is very highly correlated with the pQCT density (R 2 ϭ0.95) and the CT-based morphometric parameter BV/TV (R 2 ϭ0.95). The mean HU values, determined from the CT images of the planned and excised bone samples, are less highly correlated (R 2 ϭ0.75). The Young's modulus E US determined from the ultrasound measurement is highly correlated with the maximal stress max (R 2 ϭ0.88) but not with the mechanically determined Young's modulus E mech (R 2 ϭ0.67). The maximal stress max correlates well with the density parameters ͑R 2 varies between 0.76 and 0.86͒. On the contrary the mechanically determined Young's modulus E mech does not correlate well with the density parameters ͑R 2 varies between 0.52 and 0.56͒. The absorbed energy E abs during the deformation is only highly correlated with the maximal stress max (R 2 ϭ0.83). The inclusion of structural parameters besides a density related parameter did improve the prediction of the Young's modulus and the maximal stress. In conclusion, it seems that the HU value from clinical CT scanning is a good predictor of the local bone density and volume fraction. A combination of local density and a measure of the structural anisotropy is clearly needed to achieve good predictions of bone mechanics.
Morphological analysis of the proximal femur using quantitative computed tomography
International Orthopaedics, 2006
The anatomy of the proximal femur was studied in 35 specimens using quantitative computed tomography (QCT) and compared with anatomical sections studied by plane radiography and gross dissection. We found the primary supporting structure of the femoral head to be the primary compressive strut, which is a dense column of trabecular bone projecting from the pressure buttress of the medial femoral neck to the epiphyseal scar. Trabecular bone mushroomed from the epiphyseal scar and terminated at right angles to the cortex of the femoral head. We believe the primary compressive strut is the predominant loadbearing structure connecting the femoral head to the femoral neck, as many specimens lacked continuity of the head cortex to the femoral neck. Based on the CT number, the primary compressive strut had similar bone density to cortical structures such as the lesser trochanter, calcar femorale and posterior lateral femoral cortex. Ward's triangle lacked structural integrity in many cases, and we doubt the significance of tensile trabculae for sharing load. Surgical techniques such as femoral fracture fixation, resurfacing hip arthroplasty and allograft transplantation may benefit from this knowledge. Résumé L'anatomie de l'extrémité supérieure du fémur a été étudiée chez 35 sujets à partir d'études de type scanner et comparée avec des sections anatomiques, des radiographies et des dissections. Nous avons étudié les différentes structures qui supporte la tête fémorale. Les coupes scanner montrent que la densité osseuse de ces structures est identique à celle du trochanter et de la corticale de la face postérieure du fémur. Les techniques chirurgicales concernant l'extrémité supérieure du fémur, fixation de fractures, resurfaçage, arthroplastie de resurfaçage et al. logreffes doivent bénéficier de ce travail anatomique et radiologique.
Journal of Orthopaedic Surgery, 2017
Purpose: Osteopenia and osteoporosis are the two most common musculoskeletal disorders in the elderly population. We determined whether osteopenic and osteoporotic patients with fractures exhibit differences in trabecular morphology and biomechanical properties of bone. Methods: Fourteen osteopenic patients and 28 osteoporotic patients with hip fractures who underwent hemiarthroplasty for proximal femoral fractures caused by low-energy injury were included. Bone mineral density (BMD) measurements were performed. Compression tests and high-resolution micro-computed tomography were used to assess cancellous bone samples obtained from the principal compressive region of the femoral head. Results: The BMD values were lower in the osteoporotic patients than in the osteopenic patients ( p < 0.05). There was a significant difference in the yield stress values between the groups ( p < 0.05). However, no significant differences in the strain energy density, stiffness and Young’s modulu...
Journal of Clinical Orthopaedics and Trauma
Objective: Our objective is to analyze the normal radiological morphologic parameters of the adult hip joint of the Indian population and compare it with standard measurements and with other populations to assess the variations. Methods: A prospective analysis of the normal pelvis X-rays of 800 persons (1600 hips) was done. We have calculated the acetabular inclination, acetabular index, lateral center edge angle (LCEA) and neckshaft angle (NSA), sphericity of the femoral head, congruity of the joint, version of the acetabulum, depth of acetabulum, and lateralization of the femoral head in normal X-rays of the pelvis in adult persons. We used RadiAnt DICOM viewer version 4.6.5.18450 (64bit) for measurement. Statistical analysis and mean values were calculated using SPSS software. Results: There were 978 X-rays of the male hip and 622 female. The acetabular inclination varied from 1 to 9. The mean acetabular index was 26.5. The LCEA was between 20 and 50. The mean neck-shaft angle was 133. There were 35, hips with an aspherical head. 94.2% X-rays the hip joint was congruent. There was 2.9% of the retroversion of acetabulum, 3.3% lateralization. Conclusion: Most of the parameters were comparable to standard values the acetabular index was lower. LCEA and NSA were higher. The acetabular angle was lower. There were femoral head asphericity, joint incongruity, and lateralization of the femoral head in a small proportion of our general population.