The results of investigation on the radiographic density in distal end of the human radius from the young up to the old the previous reports made on the lumbar vertebrae, the femoral neck and especially on cases of its fracture (the femoral neck: 23 cases, compression fracture: 59 cases) were comparatively examined.
The subjects studied were 215 cases of healthy persons ranging from 18 to 89 years of age (Male 89, Female 126), and 27 cases of Colles' fracture were also comparatively examined.
It seems almost to agree with the results of measurement reported before that with advancing years the density becomes higher regardless of sex, and that the female tends to show suddenly a relatively high density from her fifties.
A comparative study of the degree of density by age group in each region mentioned above and of that between the fractured and non-fractured groups revealed that in both cases of fracture and non-fracture, both sexes show a high density with increasing age in order of the forearm, the femoral neck and the lumbar vertebrae, and that in females this tendency is conspicuous. In cases of over fifty years of age, the fractured group presents a considerably high density.
On the other hand, since fracture occures in the majority of cases of over fifty years of age showing an abrupt increase in density, that is, in 96 out of 109 cases (87.2%), the density in cases of non-fracture, fracture and a combined fracture of the forearm and other regions developed within year after fracture was examined. As the result it was found that the fractured group presented a high density in both sexes in order of the forearm, the femoral neck and the lumbar vertebrae. A statistic investigation on the significant difference in the case of fracture and a combined fracture disclosed that in the forearm there is a significant difference with a risk of 1 per cent and in the femoral neck and the lumbar vertebrae with a risk of 5 per cent.
