[Primary hyperparathyroidism--bone turnover and osteitis fibrosa assessed by x-ray (author's transl)]

1. In primary hyperparathyroidism an increased bone turnover is seen, accompanied by osteitis fibrosa (= fibroosteoclasia, FO) in severe forms of the disease. Both types of bone reaction may be detected by microradioscopy X-rays of the hand, extensive striation of metacarpal cortical bone indicating increased bone turnover and subperiosteal resorption of phalanges pointing to FO. 2. In the present study 65 patients with proven PHPT were evaluated before and 39 after operation. Microradioscopy was combined with biochemical assessment of hyperparathyroidism including alkaline serum phosphatase (aPh) as an index of osteoblastic activity, hydroxyprolin excretion (HyPro) reflecting bone turnover, immunoreactive parathyroid hormone levels (PTH), serum calcium (SCa), urinary calcium (UCa), serum inorganic phosphorus (SP) and clearance of phosphate (Cp). A comparison was made with the incidence of renal stone disease and the degrees of metacarpal striation (StG) and subperiosteal resorption (UG) were followed after operation. 3. Preoperative X-rays of 60% of the PHPT subjects showed increased StG and/or UG, and in 41,5% the diagnosis of PHPT was possible from the X-ray findings only. There existed a significant correlation between StG and UG on one hand and aPh, HyPro and PTH on the other. No correlation, either positive or negative, was seen between FO and the incidence of renal stones. After surgery, subperiosteal bone lesions disappeared in all patients, while intracortical striations persisted in half of the subjects despite the normalised bone turnover. Thus, primary hyperparathyroidism may not only lead to endosteal bone loss but to an irreversible intracortical bone deficit as well.