8 • Donald J. Ortner 



Clinical diagnosis of orthopedic diseases relies heavily on 

 observations derived from radiology. Several conditions lim- 

 it the value of this perspective for research in skeletal pal- 

 eopathology. First, radiologists rarely take an x-ray film un- 

 less a patient has a complaint of some type. Clinical 

 orthopedic radiology is thus based on a human sample that 

 has a medical problem to begin with. In addition, the radiolo- 

 gist takes only the x-ray films needed to evaluate the com- 

 plaint of the patient. The implication of this is that the total 

 pattern of skeletal involvement in orthopedic diseases may 

 not be well known. 



Furthermore, most radiologists concede that a change in 

 bone density on the order of magnitude of forty percent is 

 necessary before a pathological change can be seen on a 

 clinical x-ray film. This means that many of the more subtle 

 changes apparent on a dry-bone specimen will not be part of 

 the experience of the radiologist and will thus not be part of 

 the radiological descriptive and classificatory system. The 

 overall pattern of various types of lesions in a skeleton is an 

 observation that is accessible to the paleopathologist (when 

 skeletal preservation is good) and is certainly of critical im- 

 portance in evaluating paleopathological specimens. To uti- 

 lize fully this type of observation will require thoughtful 

 feedback from clinical experience and additional research on 

 total patterns of skeletal disease in known cases. 



Another major problem in paleopathology is the lack of 

 comparability between reports on abnormal specimens, 

 which precludes meaningful comparison of data. There are 

 two major reasons for this: ( 1 ) the knowledge about skeletal 

 disease varies greatly between observers, and (2) there is no 

 consistent protocol for the types of data included in various 

 reports, so that different scholars observe different condi- 

 tions. If paleopathology is to address important questions 

 regarding, for example, the evolutionary significance of dis- 

 ease, we must improve the comparability for both content 

 and quality of our observations. 



Recently I was coauthor of an invited manuscript on hu- 

 man health and disease in the Mesolithic and Neolithic ages 

 (Ortner and Theobald 1987). The research for this manu- 

 script included a survey of published observations and data 

 on disease in archeological skeletons from sites dated to the 

 Mesolithic and Neolithic ages in the Near East, Eastern Med- 

 iterranean, Europe, and the USSR. In these geographical 

 areas, over 1 200 human skeletons dated to the Mesolithic and 

 more than 12,000 skeletons dated to the Neolithic Age have 

 been reported in the literature. 



One of the major problems in these published sources is 

 that most authors offer an opinion on diagnosis of pal- 

 eopathological specimens without carefully describing the 

 type and location of lesions. This effectively prohibits an 

 independent evaluation of these cases. This limits any state- 

 ments regarding variation in disease prevalence in antiquity 

 to highly speculative observations. The obvious strategy is to 

 develop and apply a descriptive methodology to the analysis 



and publication of pathological specimens that does not nec- 

 essarily preclude classification or diagnosis but, at the very 

 least, permits the reader to reach his or her own conclusion 

 regarding the nature of the pathology, without having to ac- 

 cept the diagnostic opinion of the author. 



To achieve this objective, a much greater emphasis is 

 needed in paleopathology on describing the abnormal condi- 

 tions seen in archeological human remains. There are two 

 dimensions of such a descriptive methodology. First, we 

 need a widely accepted method to describe the types of ab- 

 normal conditions that exist, using criteria that reflect the 

 underlying pathological processes. Second, we need to 

 show, in detail , the location of all abnormal conditions within 

 a paleopathological case. Application of a good descriptive 

 methodology, including the type and location of lesions, to 

 the analysis of archeological skeletal samples would be a 

 major step in providing descriptive data that would allow 

 independent evaluation of pathological conditions. 



Description of the type of lesion should be based on the 

 activity of the cells that produce the lesion. Three basic con- 

 ditions exist: (1) formation of abnormal mineralized tissue 

 (osteoblasts), (2) destruction of existing mineralized tissue 

 (osteoclasts), and (3) a combination of both processes either 

 in different parts of a lesion or different areas of the skeleton. 

 Any descriptive system should include, at least, this informa- 

 tion about skeletal lesions. There is, in addition, consider- 

 able variation in the amount and shape of the abnormal 

 mineralized tissue that is formed, which adds to our under- 

 standing of the pathological process. The rapidity of bone 

 loss in destructive lesions is indicated by the morphology of 

 lesion margins. This is a diagnostic feature that is apparent in 

 paleopathological specimens and can be linked with radi- 

 ological diagnostic criteria. There are also abnormalities in 

 the size and shape of bones as seen, for example, in the 

 dysplasias and rickets. 



Describing the type and location of abnormal conditions is 

 a far less complex problem than arriving at an accurate diag- 

 nosis. Furthermore, it is the type of data that can be trans- 

 ferred across disciplinary lines with relative ease, and pro- 

 vides an important basic step in the diagnostic process. It also 

 pennits reevaluation by other scholars who can arrive at a 

 different opinion on the diagnosis if their evaluation of the 

 data so warrants. 



Computer-aided design (CAD) software can be helpful in 

 such research. In my laboratory we have been exploring the 

 application of AutoCAD, a CAD software package devel- 

 oped by Autodesk, Inc., U.S.A., to research in skeletal pal- 

 eopathology (Figure 4). This software has many powerful 

 features. One is the ability to enlarge or reduce images. 

 Another feature is the potential of putting different types of 

 lesions on different layers of the CAD record for a pal- 

 eopathological specimen. One or more of these layers can be 

 turned on or off to clarify patterns and relationships between 

 different kinds of lesions. 



Zagreb Paleopathology Symp 1 9118 



