ACTA ENDOCRINOLOGICA (BUC)

Introduction: During the past thirty years bone biopsy has been used as an invasive diagnostic and research investigation of bone structure and metabolism. Quantitative bone histomorphometry parameters offer information on both bone mass and bone quality.\r\nObjectives: This study aimed to establish the value of routine qualitative bone biopsy evaluation in subjects with unexplained primary osteoporosis. Patients in whom low bone mineral density was not adequately explained by risk factors or patients in whom therapy\r\nwas not followed by BMD changes according to evidence-based data on treatment of osteoporosis were referred to bone biopsy. One-hundred seventy patients (73 men and 97 women), aged 54.29?0.95 years, were included in the study. The diagnosis was based on clinical data, lumbar spine and hip dual X-ray absorptiometry (DXA) evaluation and routine laboratory measurements. Bone biopsy was performed by horizontal approach, using an electric drill. Qualitative bone biopsy evaluation was performed in one single department by trained pathologists. Quantitative bone histology assessment (histomorphometry) was not available.\r\nResults: Of the 170 bone samples, secondary causes of low bone mineral density were identified in 19 patients (mastocytosis, multiple myeloma, myeloproliferative syndrome, sarcoidosis and osteomalacia). In 21 subjects with osteoporosis as defined by WHO criteria qualitative histological evaluation found no pathological changes. Accelerated bone resorption as expressed by the daily urinary levels of deoxypyridinoline (D-Pyr) and longterm sodium fluoride therapy were associated with relevant osteoidosis as assessed by qualitative evaluation of bone samples. Bone biopsy changes were not related to serum thyroid hormone, parathyroid hormone or 25-hydroxyvitamin D3 levels.\r\nConclusions: Qualitative bone biopsy evaluation may offer valuable information in the diagnosis of metabolic bone diseases in subjects with unexplained causes of low bone mineral density or in non-responders to anti-fracture agents. Despite of lack of quantitative information on bone mass and the degree of mineralization of bone tissue, few patients with osteoporosis may benefit from this diagnostic routine procedure.