Plate-like Trabeculae Research Articles

Glenoid bone architecture

This article describes regional variations in trabecular bone architecture in terms of density and orientation within six glenoid specimens. The mean donor age was 56 years and ranged from 31 to 72 years. An automated imaging technique based on 3-dimensional serial sectioning was used for the direct examination of the glenoid cancellous bone structures. Subchondral plate thickness was on average 1.9 mm and ranged from 1.2 mm to 2.9 mm. The volume fraction of trabecular bone varied from 11% to 45% with peak values at the posterior glenoid vault. On graphic 3-dimensional reconstructions, the glenoid appeared as platelike trabeculae, radially oriented perpendicular to the subchondral plate and interconnected by thin rods. These views also displayed regional variations throughout the glenoid, reflecting differences in the macroscopic appearance. Quantitative structural analysis revealed different degrees of anisotropy at the glenoid cancellous region, predominantly transverse isotropy. Resemblance to direct weight-bearing cancellous bone such as the proximal tibia was evident.

Cancellous Bone Structure in the Growing and Aging Lumbar Spine in a Historic Nubian Population

There is abundant data on cancellous bone in the aging human spine, but little relating to the growing vertebral cancellous bone in childhood an adolescence. The purpose of this study was to map vertebral cancellous bone in a growth and age series of historic skeletal samples and to make comparisons with data published on recent material. Lumbar vertebral bodies were collected from 65 skeletons (0-60 years) from a medieval Nubian population. Ethnohistoric information was collected to interpret conditions that might have influenced bone structure and metabolism. The cancellous bone was studied three dimensionally, using stereophotography and scanning electron microscopy and morphometrically by performing a semiautomatic structural analysis on digitized backscattered electron images of polymethacrylate-embedded material. The cancellous bone structure in the children consisted mainly of a densely packed, uniform network of small rodlike trabeculae. The greatest bone volume fraction with small, more platelike trabeculae was observed during adolescence. In young adults, larger platelike trabeculae were present in the central zone and smaller trabeculae in the superior and inferior zones, as described for modern skeletal material. Structural changes associated with aging were observed much sooner than in modern man. by the estimated age of approximately 50-60 years, the predominant architectural elements were slender rarified rods in both sexes. The ethnohistorical data suggest that this was essentially a black African population of physically active peasants, not likely to suffer Vitamin D insufficiency or deficient calcium intake. Thus an earlier onset of the biological age changes in cancellous bone found in modern populations was probably relevant.

Distribution and orientation of bone in the human lumbar vertebral centrum.

This article describes regional variations in cancellous bone morphology within the human lumbar spine of a 60-year-old woman. An automated imaging technique, based upon the method of directed secants, was used to quantify variations in bone porosity and trabecular size, distribution, and orientation within serial transverse histological sections of the L1 and L2 vertebral centrum. Several morphologically distinct levels of organization were observed along the axis of the centrum. The superior and inferior sections of the centrum were made up of an open-celled network of trabeculae, while the translational and middle sections consisted primarily of plate-like trabeculae forming a closed-cell structure. The densest and most oriented bone was found in the superior and inferior sections of the posterior-lateral centrum, whereas least dense and least oriented bone was found in the central third of the anterior centrum. Average trabecular thickness did not vary appreciably from level to level, but varied considerably within a given level, particularly in the inferior sections of the centrum. The number of trabeculae was lowest in the central sections of the centrum, where plate-like trabeculae were most prevalent. The topological architecture of different levels within the centrum exhibited a remarkable degree of organization, which suggests that the spine, like other skeletal structures, has adapted to functional stresses produced during daily activities. Detailed morphological data are tabulated and should be of use to investigators interested in modeling the three-dimensional structural and physical properties of the lumbar spine.