Renal osteodystrophy.

Renal osteodystrophy is a complex disorder which can be divided into five distinct bone histologic subtypes: mild bone disease, hyperparathyroid bone disease, mixed bone disease, osteomalacia, and low-turnover bone disease. Hyperparathyroidism develops in renal failure due to two principal abnormalities: 1,25(OH)2D3 deficiency and hyperphosphatemia. Treatment of these problems is important in order to prevent hyperparathyroidism. Most cases of osteomalacia, mixed bone disease, and low-turnover bone disease are influenced by aluminum status and parathyroid hormone. Aluminum-associated bone disease can be treated with termination of aluminum exposure and/or deferoxamine therapy. Numerous diagnostic pitfalls exist in the evaluation of renal osteodystrophy, and the bone biopsy is extremely important to avoid these problems and plan proper therapy.