The Roentgen Diagnosis of Osteoporosis and Its Limitations

THE importance of an early x-ray examination of the skeleton has been strongly suggested by recent studies on the influence of endocrine disorders on the metabolism of bone. The biochemist with his laboratory methods including all available chemical and metabolic tests, the clinician with a careful study of the case history and clinical methods, the radiologist with a thorough examination of the skeleton (in addition to the local region in question) must work together to arrive at a diagnosis as early as possible. The time may not be far distant when an x-ray examination of the skeleton will be as much a matter of routine in all affections of the endocrine system as the determination of the basal metabolic rate. This will apply to the adult and the growing organism. For the latter, the study of the appearance of the epiphysial centers and of their fusion with the diaphysis is, already at the present time, an important point of diagnosis. If we recognize the fact that bone is not an inert mass but takes part in all vital processes of the body, we must consider the skeleton as an organ which is responsive to physiological and pathological changes. Seen in this new light, x-ray examination of the skeleton gains new significance. If we see in the skeleton the calcium storehouse of the body, we can easily understand that it may be attacked in all endocrine and metabolic disorders in which we have a disturbance of Ca metabolism. The close connection between the parathyroids and calcium and phosphorus metabolism has been supported by the clinical finding of parathyroid tumors in cases of osteitis fibrosa cystica, by experimental production of similar bone changes by injection of parathyroid hormone, and by correction of the skeletal symptoms after removal of the parathyroids (Ballin). But the endocrinologist and the radiologist should never forget that in addition to the outstanding local skeletal changes in the form of cysts, fractures, and reactive deformities we nearly always have a general osteoporosis as an expression of the systemic affection. Sometimes, as Dresser and Ballin have shown, general decalcification is the only symptom of bony involvement in cases of parathyroid tumors. However, it is not as well known that in other endocrine and metabolic disorders we have a general osteoporosis as one of the most important clinical and diagnostic signs of the disease. A great percentage of cases of basophile adenoma of the pituitary gland show general decalcification of the skeleton (Cushing, Rutishauser, Ballin). Askanazy (quoted from Rutishauser) gives the disease the name “osteoporotic adiposity.” A number of observers have reported a pronounced generalized and homogeneous decalcification of the skeleton in hyperthyroidism (Kummer, Golden and Abbott). Erratum in: https://doi.org/10.1148/26.6.761d