Three‐dimensional anatomy of the cancellous structures within the proximal femur from computed tomography data

Abstract

Quantitative computed tomography was used to investigate the three-dimensional architecture and the density distribution of the cancellous structures of the proximal femur. We examined 10 femora from the cadavera of 10 individuals, 47-83 years old at the time of death. Three anatomic elements could be distinguished: the epiphysis, the epiphyseal scar, and the metaphysis. Although these elements constitute a functional unit, their individual cancellous patterns revealed significant structural differences. The epiphyseal segment had a more reticulate cancellous appearance, whereas the metaphysis demonstrated a more longitudinally oriented trabecular distribution. The three-dimensional reconstruction of the densest epiphyseal trabecular groups showed two different patterns: a dumbbell type (found in eight bones) and a hemispheric type (found in two bones). The epiphyseal scar was a clearly recognizable high-density structure found in all 10 bones. The epiphyseal scar-diaphysis angle was 13-26 degrees higher than the center column-diaphysis angle. The scar appeared as a tray supporting the epiphyseal cancellous structures, supported itself by the metaphyseal intersection of the main compressive and the arcuate trabecular systems. This intersection always occurred in a relatively small band-shaped zone under the central third of the epiphyseal scar. These three discrete anatomical segments within the proximal femur may reflect developmental and functional adaptations determined by joint incongruity or eccentric muscular activity. The present data will serve as a reference for future studies in which the cancellous patterns are used to help with the early diagnosis of states of disease.

Three-dimensional deformation mapping of Mode I interlaminar crack extension in particle-toughened interlayers

“…Image correlation of volumetric datasets was first implemented to determine continuum-level displacement and strain fields in trabecular bone [10], [11] and helped validate FE models [7], [13]. With CT resolutions now routinely reaching below the micro-meter range, 3D volumes of internal micro-architecture can now be generated with ultra-high resolution micro-focus CT systems [14], [15] and via SRCT [6], [16]. DVC uses the naturally occurring texture in the material to track 3D displacements of a small sub-volume of interest between two load steps, which can be translated into local strain measurements [11].…”

Function-Orientated Structural Analysis of the Proximal Human Femur

“…the medial trabecular system), is a structural consequence of the body weight acting on the femoral head. Hence, this structure represents a compression load [Singh et al, 1970;Osborne et al, 1980;Martens et al, 1983;Elke et al, 1995;Cody et al, 1996;Birnbaum et al, 2004;Stiehl et al, 2007]. According to the results presented here, this medial trabecular system is orientated approximately perpendicular to both the arcuate trabecular system (mean angle 90.7°) and the epiphyseal plate of the femoral head (mean angle 94.7°).…”

“…Although necessary for the definition of cranial and caudal sections, this provided a potential source of bias. Within the femoral head, the arcuate system does not exceed the epiphyseal plate [Elke et al, 1995]. Consequently, the cranial outline presented slightly distally to the epiphyseal plate of the femoral head and simultaneously in the range of the apophyseal plate of the greater trochanter.…”

“…However, in the majority of cases, the morphology is only roughly described, exact measurements of single trabeculae are not performed. The trabeculae are summed up in trabecular systems, which are equal to our assumed trabecular systems, albeit the trochanteric trabecular system included in our analysis has never been further addressed to our knowledge [Singh et al, 1970;Osborne et al, 1980;Martens et al, 1983;Elke et al, 1995;Stiehl et al, 2007]. All femora were suitable according to the method applied: all specimens were of comparable size exhibiting centrum-collum-diaphysis angles adequate to age without signs of pathological changes.…”

“…Surely, examiner dependence might be a limitation of the study using the method applied, but it provides the vital advantage that each step of the trabecular analysis can be critically controlled. Other trabecular analysis methods described in the literature either do not provide the possibility to examine each single trabecula of the trabecular systems [Elke et al, 1995;Uchiyama et al, 1999;Stiehl et al, 2007], are predominantly developed for mechanical analyses with limited suitability for structural examinations [Mullender et al, 1998;Homminga et al, 2002;Van Rietbergen et al, 2003], or would have ensued immense complexity and costs [Brismar et al, 1999]. The method used in this study is a simple, innovative technique for the investigation of the trabecular structure in the cancellous bone; the results can serve as a basis for the reasonable and specific application of more complex and costly procedures.…”