Bone densitometry in patients with osteomalacia: is it valuable?

Abstract

Osteomalacia is a generalized bone disorder characterized by impairment of mineralization, leading to accumulation of unmineralized matrix or osteoid in the skeleton. The clinical features of osteomalacia include musculoskeletal vague pain and muscle weakness. In its mild and early stages, osteomalacia may be misdiagnosed with variety of musculoskeletal diseases including osteopenia and osteoporosis, and for early diagnosis high rate of suspicion of osteomalacia is necessary. Our purpose was to determine the amount of bone mineral density (BMD) in patients with osteomalacia and to evaluate the efficiency of bone densitometry in these patients. Diagnosis of our patients was based on history, physical, laboratory and radiological findings and in three patients with bone biopsy and histological approval. BMD (gm/cm(2)) at the lumbar vertebrae (L2-L4) and femoral neck were measured by dual X-ray absorptiometry in 20 patients with osteomalacia (16 females and 4 males, age range 20 to 60 years, mean 39 years) before treatment, comparing with 28 matched healthy individuals, and their T scores were evaluated according to WHO criteria for the diagnosis of osteopenia and osteoporosis. 14 patients with osteomalacia (70%) had BMD in amount of osteoporosis in the lumbar spine, and 12 patients with osteomalacia (60%) had BMD in amount of osteoporosis in their femoral neck. 50% of the patients had T≥ -3. We concluded that bone densitometry may detect osteoporosis in up to 70% of patients with osteomalacia. Middle aged individuals with significant osteoporosis should be evaluated for osteomalacia, beside other causes of secondary osteoporosis. Measurement of BMD in patients with osteomalacia is helpful for assessment of the severity of bone condition and following management.

Keywords: Vitamin D; bone mineral density; densitometry; osteomalacia; osteoporosis.