What is renal osteodystrophy?
The term renal osteodystrophy, which was introduced by Liu and Chu in 1943, refers to the full spectrum of musculoskeletal disorders associated with renal failure. It is also called chronic kidney disease-metabolic bone disease. Because the kidney plays a critical role in the overall regulation of mineral homeostasis, the development of renal failure has widespread consequences for the skeleton. The four principal types of renal osteodystrophy are:
- • Osteitis fibrosa: bony lesions caused by accelerated bone turnover as a result of secondary hyperparathyroidism. Hallmark lesion on bone biopsy is peritrabecular fibrosis in the setting of accelerated bone resorption and formation.
- • Osteomalacia: reduced rate of bone turnover with increased osteoid volume and defective mineralization often associated with aluminum toxicity.
- • Adynamic bone disease: bone turnover is markedly decreased as a result of excessive suppression of PTH. Unlike osteomalacia, there is no increase in osteoid volume.
- • Mixed disease: combined osteitis fibrosa and osteomalacia with marrow fibrosis.
The only way to separate these and definitively establish a diagnosis is by a dual-labeled bone biopsy.
