Abstract
Aim: to define main clinical and diagnostical problems related to osteoporosis and osteomalacia. Literature data showed that not only osteoporosis but osteomalacia may be the reason for decreasing of mechanical properties of skeleton with risk of low-energy fractures. The solution of associated medical and social problems is difficult because DEXA does not allow to differentiate between osteoporosis and osteomalacia that leads to misdiagnosis and unnecessary prescription of antiosteoporotic drugs. This approach is pathogenetically unproved and even may be harmful for the patient. Osteoporosis and osteomalacia does not exclude each other so bone mass reducing in one cohort of patient may be due to osteoporosis, other - osteomalacia and some of them - combinations of both. Another point is that results of controlled clinical trials that evaluated efficacy of antiosteoporotic drugs without differentiative histology tests for osteoporosis and osteomalacia are of doubtful value. As the bone biopsy that is necessary for osteomalacia diagnosis is invasive procedure there is need in definition of clear criteria when it has to be done in patient with reduced bone mass.