Unusual fractures associated with osteoporosis in premenopausal women.

Two premenopausal women (aged 40 and 34 years) and multiple undisplaced, often asymptomatic fractures of the femurs, ribs, metatarsals and other bones. The fractures, which appeared on roentgenograms as transverse radiolucent zones with variable callus formation, healed slowly or not at all despite treatment with calcium and vitamin D. They resembled pseudofractures (Looser's transformation zones) radiologically, but the biochemical and histologic findings were those of idiopathic osteoporosis rather than osteomalacia. Since neither patient had been subjected to unusual stress it was concluded that the fractures had resulted from normal activity in abnormal bone.     

Evaluation of cortical bone mass,thickness and density byz-scores in osteopenic conditions and in relation to menopause and estrogen treatment

Z-scores express differences from normals in standard deviation units, and are particularly useful for comparison of changes where normal values are age- and sex-dependent. We determinedz-scores for bone mineral mass, cortical thickness, and bone mineral density in the radius in various conditions and diseases in both sexes. In the males,z-scores were calculated for age, but in the femalesz-scores for menopausal status (years postmenopausal exclusive of years on estrogen treatment) were found to be more appropriate. With few exceptions, changes in a disease were of a similar order in both sexes. For bone mineral mass few meanz-scores were significantly increased, but diseases with significantly decreased meanz-scores were numerous. The usefulness ofz-scores in diagnosis and study of metabolic bone disease is discussed.     

Improved roentgenologic diagnosis of osteomalacia by microradioscopy of hand bones.

Microradioscopic study of metacarpals in 24 osteomalacic and 34 osteoporotic patients revealed excessive intracortical resorption (striations) in approximately 60 percent of patients suffering from osteomalacia, but in none of the osteoporotics. Phalangeal periosteal resorption was found less frequently in osteomalacia than metacarpal striations, and was absent in osteoporotics. On the other hand, quantitative evaluation of cortical thickness, percent cortical area, bone mineral mass, and density did not show any clear differences between the two study groups. It is concluded that the differential diagnosis between osteomalacia and osteoporosis may be considerably improved by microradioscopy of hand bones.     

The mode of progression of subperiosteal resorption in the hyperparathyroidism of chronic renal failure

Subperiosteal resorption in finger phalanges is usually thought to be the result of osteoclastic bone resorption on the periosteal surface of bone, progressive centripetally, with creation of the serrated appearances and “lace-like” patterns in periosteal cortical bone. Our longitudinal microradioscopic observations in patients with secondary hyperparathyroidism of chronic renal failure have revealed evidence of another pathogenetic mechanism: by the enlargement of intracortical juxtaperiosteal resorption spaces, the remaining thin layer of bone is broken down from inside the bone, i.e., a centrifugal rather than centripetal process.     

Treatment of renal osteodystrophy with 1,25-dihydroxycholecalciferol.

Nine patients with renal osteodystrophy were tested for 6.5 to 35 months with 1,25-dihydroxycholecalciferol (1,25-DHCC). A close biochemical follow-up was performed during the first 6 months of treatment, including biweekly determinations of serum calcium, phosphorus, magnesium, alkaline phosphatase and creatinine levels. A bone biopsy, radiologic investigations and determinations of plasma levels of immunoreactive parathyroid hormone (IPTH) and intestinal absorption of calcium 47 were performed before and after the 6 months. Although the five patients with osteitis fibrosa showed a significant improvement, the four with predominantly osteomalacic lesions showed no response to treatment. These four had a normal initial plasma iPTH level, higher serum calcium levels than the other five patients, extreme sensitivity to 1,25-DHCC, with frequent episodes of hypercalcemia, and only a slightly increased serum alkaline phosphatase level, which remained unchanged during treatment. All but one of the patients, irrespective of the histologic abnormality, showed a decrease in the uptake of radionuclide by bone after treatment. The renal function of one patient, a man with long-standing stable renal failure who had not undergone dialysis, deteriorated during treatment.     

Improved vertebral fracture threshold in postmenopausal osteoporosis by radiogrametric measurements: its usefulness in selection for preventive therapy

Measurements of the combined cortical thickness at the midshafts of the second metacarpal and the proximal radius, as well as their sums, were made from fine-grained radiographs in 107 normal premenopausal and 227 postmenopausal women and in 57 women with at least two spontaneous vertebral compressions. The -2 SD level of the premenopausal women was found to be an excellent vertebral fracture threshold for the radius measuring site and for the sums of metacarpal and radial measurements. Only 2 of 57 (4%) and 3 of 57 (5%), respectively, of values in the vertebral compression group fell at or above this level. At -3 SD a "secondary fracture threshold" was found for the sums in that only 7 of 57 (12%) of values in women with vertebral compressions were above this limit, but -3 SD was less satisfactory for the radius. We conclude that this method discriminates as well between nonfracture and fracture cases as other radiologic methods for measurement of bone mass or density. Because it is less costly it seems better suited for mass screening in selecting postmenopausal women for preventive therapy than the less widely available high-technology methods.     

A roentgenologic study of cortical bone resorption in chronic renal failure

Periosteal, intracortical, and endosteal resorptive changes were evaluated in both hands and the proximal radius in 161 chronic renal-failure patients by microradioscopy, radiographic morphometry, and photodensitometry. These changes were compared to abnormalities found in skeletal surveys. A combination of microradioscopy and morphometry of hand bones was sufficiently sensitive for early detection of bone loss in renal osteodystrophy in 61% of the patients. Intracortical resorption in metacarpals appeared to be a sign of more advanced renal osteodystrophy than subperiosteal resorption in phalanges. Photodensitometric findings in the radius generally agreed with microradioscopic and morphometric findings in hand bones.