Histomorphometrische Analyse der Tangentiallamellenbucht (Endosteal Lamellar Pocket, ELP), Archäologische Bedeutung lokalisiert auftretender Variationen innerhalb der Compacta auf mikrostruktureller Ebene.
Zusammenfassung der Projektergebnisse
Because bones are a hard tissue, they grow very differently from other organs. A bone cannot grow from any necessary point in three dimensions; it grows only at its internal growth plate or along its inner or outer surfaces. The result is that long bone shafts can grow “sideways” in order to change their size, shape, and position relative to other bones through a process called bone modeling drift that is impossible to measure microscopically in humans due to invasiveness of available techniques. The current research program targeted this process, first described nearly one hundred years ago, and applies new techniques to permit its post mortem measurement and comparison (between regions on the same bone’s shaft, between different suspensory and non-suspensory bones, and between individuals of differing sexes, ages, and populations). This was accomplished by using a tell-tale meta-feature, called the endosteal lamellar pocket (ELP), left behind by modeling drift that informs on the history of growth in the crosssection. In this way, for the first time, it is possible to discuss not only what a bone’s shape is, but how that shape was achieved. This is important for medical research on musculoskeletal diseases and is also useful for bioarchaeological or forensic analyses where only human bony remains are left to learn from. The research program drew together expertise from Germany, the United States, and Mexico in order to generate this perspective and resulted in post-doctoral research offers, peer reviewed publications, invited and guest lectures, professional conference presentations and contributed to the work of Ph.D. students, volunteers, and technical professionals in bone biology, anthropology, and bioinformatics. New methods were created that can be used by other researchers interested in microstructural analyses of bone growth as well as custom software for counting large numbers of variables in histological investigations. In addition the research generated the first datasets useful for statistical comparisons of bone modeling processes. Across nearly all individuals analyzed in modern or archaeological contexts, the bone shaft was found to grow diametrically in an asymmetric fashion and presented a classical ELP (individuals missing one were nearly always older, above age 45). All along the shaft of the humerus it grows away from muscular forces of the shoulder, strengthening the bone posterio-medially to resist loading of the raising upper arm. In the femur the ELP indicates the net lateral drift that could assist the proper orientation of the femur above the knee, but is complicated by the typical net periosteal modeling that results in an anterio-posterior resistance to bending loads. The microstructural patterns associated with ELP formation take a lifetime to form and in some adults represents tissue that could be as much as 30 years younger than the bone most recently formed before death. Implications of a program of study such as this are multiple. It generates new understanding of primary bone biological form and function and offers techniques for quantifiable and statistical analysis of human modeling drift. It provides an explanation for surprisingly low statistical significance for some medical and bioarchaeological investigations into feature densities per cross-sectional region because two regions might look dissimilar simply due to being extremely different in their age of formation. The study also has ramifications for modern medical understanding of diseases such as arthritis or osteoporosis where it has been found that differences in development and physical activity levels early in life are major determinants of risk factors and prognosis in later years. Continued investigations into bone modeling variation should uncover means of measuring drift magnitude and comparing ELP variables with known markers of musculoskeletal stress associated with physical activity. In addition, more detailed investigation of the growing database on modeling variation will be used to answer specific questions regarding individuals and subpopulations in bioarchaeological contexts, permitting a clearer picture of human lifestyles and increasing our understanding of past human adaptation and accomplishment.
Projektbezogene Publikationen (Auswahl)
- (2011) Analyzing microscopic variation along the femoral and humeral diaphysis: A histological examination of the ELP as an indicator of long bone modelling drift. AAPA-Meeting (American Association of Physical Anthropologists), Minneapolis, Minnesota
Maggiano IS, Maggiano CM, Tiesler V, Stout S
- (2011) The Endosteal Lamellar Pocket as an indicator of childhood and adolescent modeling drift direction and magnitude during long bone growth. AAPA-Meeting, Minneapolis, Minnesota
Maggiano CM, Maggiano IS, Tiesler V, Stout S
- (2012) Analisis microscopico de la variacion en el desplazamiento (drift) por modelacion osea: una comparacion de las poblaciones yucatecas antiguas y modernas. In: Tiesler V: Métodos y aplicaciones de histomorfología en hueso descalcificado. Universidad Autónoma de Yucatán
Maggiano IS
- (2012) Quantitative histomorphometry of humeral and femoral diaphyses: A longitudinal comparison of osteon population density and primary bone deposition in eight anatomical regions of interest along the bone shaft. AAPA-Meeting, Portland, Oregon
Maggiano IS, Maggiano CM, Tiesler V, Stout S
