A Palaeopathological Study of the Vertebral Columns of the Japanese from Jomon to Edo Periods

Abstract

Though the pathological changes in bones of the early Japanese people have attracted attention of physical anthropologists for more than half a century, the descriptions of only a few pathological anomalies have been published in various independent reports.The present study deals with various kinds of pathological changes in vertebral columns. As shown in Table 1, 188 vertebral columns in total from Jomon to Edo periods were observed. Since the skeletal remains from Yayoi to Muromachi periods are in very poor condition, and as many skeletal remains of Edo period were found in group burials, skulls and post-cranial skeletons could not be identified with certainty.Spondylosis deformans which forms osteophytes in vertebrae was classified according to various types and grade as shown in Figure 1, The incidence of osteophytes in the male of Jomon and Edo periods are given in Table 2.Regarding the degree of osteophytes, significant statistical differnces were observed between Jomon and Edo people. The former have higher frequencies in grades II, III and N, than the latter. This seems to reflect the difference of the condition of subsistence especially of the intensity of physical working. The highest frequency of osteophytes was seen in the lower thoratic and the lumbal spines, especialy in L-2 and L-3. The degree of osteophytes (grade) changes from grade I to IQ and N with the advance of age.Lumbo-sacral transitional vertebrae, spina bifida occulta, and Schmorl's node were also observed. The incidences of each type of these malformations in both sexes are given in Tables 3, 4 and 5.Lumbo-sacral transitional vertebrae was classified into four types set forth by JINNAKA according to the process of articular formation as shown in Figure 2. Spina bifida occulta in the sacrum was classified into two types, complete type and imcomplete type. The former was not recog nized at all in every period. The incidences of the later range from 10% to 13%.Schmorl's node was found frequently on the lower thoratic and the lumbal vertebral bodies as it was the case with spondylosis deformans.Other interesting pathological changes in vertebrae diagnosed as spondylitis tuberculosa, spondylarthritis ankylopoetica, vertebral body fracture, congenital intravertebral ankylosis, congenital anomalies, etc., were described. As for the origin of tuberculosis in Japan, this infectious disease is supposed to have been imported from the Asian continent in Yayoi or Kof un period by immigrants who introduced continental culture to this country.