Bone histology and paleopathology: Methodological consi derations • 57 



calcium in the circulatory system is crucial for the mainte- 

 nance of cardiac and nervous system function (Marshall et al. 

 1976). 



In summary, diet, disease, and aging are all factors which 

 affect calcium metabolism and bone remodeling, and these 

 are especially valuable variables to track in prehistoric skele- 

 tal populations. This brief summary of bone dynamics serves 

 to highlight the complexity of bone as a tissue and, more 

 importantly, to suggest the ways in which the .skeletal system 

 responds to physiological disruption and the ways that this 

 response can be reconstructed from the histological proper- 

 ties. Skeletal remodeling provides a measure of skeletal 

 health as well as an indication of the health of the individual 

 as a whole. Of particular mterest to this research is that 

 skeletal remodeling presents an ideal form of evidence lead- 

 ing to an understanding of prehistoric health. By understand- 

 ing the physiological properties of skeletal remodeling, a 

 clearer and more realistic reconstruction of past health can be 

 made. 



Response to stress on a histological level 



Bone tissue is most affected by three factors: aging, disease, 

 and nutrition (Smogyi and Kodicek 1969). Of particular sig- 

 nificance to anthropological research is the fact that bone 

 microstructure is sensitive to these factors, and tissue at the 

 microstructural level is frequently preserved in archeological 

 specimens (Stout 1978). 



Bone reacts to stress in a limited number of ways. In 

 general, the skeletal response to physiological stress is one 

 (or a combination) of three phenomena: ( 1 ) reduced bone 

 mass, (2) increased bone mass, and (3) poorly mineralized or 

 abnormal bone quality (Meunieretal. 1979). It is the type of 

 response, the timing of onset, the degree of severity, the 

 pattern, and the frequency of abnormal histological proper- 

 ties which aid in the interpretation of remodeling. 



It is a well-documented fact that structural and physical 

 responses of bone to biological needs are affected by the 

 aging process (Kerley 1965). A knowledge of normal, age- 

 related processes in bone represents a factor critical to the 

 understanding of pathological or abnormal conditions. One 

 important distinction to be able to make when dealing with 

 bone loss is the one between loss due to old age and loss due 

 to other factors such as disease, malnutrition, or hormonal 

 imbalances. Clinical methods for delineating bone loss as a 

 function of age and other factors are outlined in Barzel 

 (1979), Fro.st (1973), Jaworski (1973), and Simmons and 

 Kunin(l979). 



Skeletal remodeling can also be significantly altered by 

 insufficient nutrients. Theeffectsof nutrient deficiencies can 

 be compounded not only by inadequacies in the diet, but by 

 further problems in malabsorption of nutrients in the system. 

 Experimental studies on animal models have shown the 

 effects of protein-caloric malnutrition to be systemic and 

 generalized (Steward 1975). During protein-calorie mal- 



Zagnb Paieopalhotogy Symp. 1988 



nutrition growth slows or ceases, remodeling rates increase, 

 and removal of bone exceeds deposition with mineralization 

 of existing bone greatly slowed (Dickerson and McCance 

 1961). 



Studies conducted on clinical populations experiencing 

 nutritional stress support the findings that a general sequence 

 of events are followed. These include ( 1 ) retardation in long 

 bone growth and delayed maturation for children, (2) slowed 

 formation of new bone for adults and children, and (3) exist- 

 ing bone loss by resorption with a net decrease in bone mass 

 (Gam 1970). 



While bone loss can be viewed as a pathological condition, 

 it is important to note that the loss can also be seen as an 

 adaptive response under certain circumstances such as nutri- 

 tional stress. In the face of protein-calorie malnutrition or 

 deficiencies in minerals, skeletal reserves can be used for 

 growth, repair or function. 



Rather than searching for a single diagnostic criterion, 

 patterns of bone growth and maintenance must be examined 

 with the emphasis on stress markers at the different stages of 

 skeletal activity throughout the life cycle. Remodeling ac- 

 tivities need to be carefully examined in conjunction with 

 other variables such as age, sex, and pathologic conditions in 

 order to interpret the nature and severity of nutritional stress. 



Use of histology in anthropological research 



As early as 1 849, researchers were looking at microstructure 

 of fossils, and in 1878 an extensive histological analysis of 

 fossil bone and teeth demonstrated that histological struc- 

 tures were preserved in archeological specimens (Stout and 

 Simmons 1979). Advances in technology led to a further 

 understanding of the extent to which skeletal histology is 

 preserved. Archeological specimens of varying age and from 

 differing soil types and differing degrees of moisture ex- 

 posure have been compared at the histological level for pres- 

 ervation. Race and co-workers (1968) found that the greatest 

 alteration in skeletal material due to weathering was chemi- 

 cal in nature (not structural), and that osteons were often 

 visible even in samples where severe chemical diagenesis 

 had occurred. 



During the early 1900s, attempts to detect abnormalities in 

 preserved skeletons increased along with the methods used to 

 assess pathological conditions (Brothwell and Sandison 

 1967). The development of radiographic techniques and the 

 application to prehistoric specimens by Moodie (1923) made 

 substantial progress in paleopathological research. Moodie 's 

 work often used histological sections, although analysis of 

 the sections was not based on quantifiable measures. In spite 

 of these early ob.servations of morphology, no systematic 

 analysis of histological structures was performed. Putschar 

 stated, "one should not. however, expect too much help from 

 the microscopic examination . . . since diagnostic micro- 

 scopic bone patterns arc rare" and he further emphasized that 

 "gross examination of the surface is more important" 



