Osteomalacia and osteoporosis: evaluation of a diagnostic index.

Data from a retrospective study in 41 patients is used to suggest an index of bone disease. This is designed as a means of collating available results, clarifying the significance of each in diagnosing either osteomalacia or osteoporosis, and reducing the significance of a single abnormal finding--for example, a raised alkaline phosphatase activity or low serum 25 hydroxy vitamin D, when the overall index score is low. Index scores above 35% would be diagnostic of osteomalacia; scores below 15% if associated with collapsed vertebrae suggest osteoporosis. Scores between 15% and 35% would indicate the need for a bone biopsy to discriminate between osteoporosis and osteomalacia.