[Histomorphometric study of nonpagetic bone in Paget patients. Results before and after diphosphonates]

An histomorphometric study with double tetracycline labelling was carried out on iliac biopsies taken from patients suffering from Paget's bone disease; 64 of the cases revealed non-pagetic bone in radiology, and 72 revealed a pagetic incidence. The purpose was to better compare non-pagetic bone with pagetic bone. 5 biopsies performed in a radiologically non-pagetic area were shown to be histologically pagetic. An histomorphometric profile of non-pagetic bone in a patient suffering from Paget's disease was established: increase in the reabsorption surfaces, of the periosteocytic uneven surfaces, of the volume and of the osteoid surfaces in the women; decrease in the osteoid thickness indicator and in the speed of normal calcification. These signs of hyperremodelling were, for the authors, connected with a hyperparathyroid condition which was secondary to calcium needs in the pagetic areas. The effects of diphosphonates on non-pagetic bone in the patients suffering from Paget's disease are clarified. This therapy has a beneficial action on the bone volume of non-pagetic bone, when the initial bony trabecular column is small.