[A study using nondecalcified bone biopsy of the incidence and presentation forms of renal osteodystrophy].
BACKGROUND: Renal osteodystrophy (ROD) is a common complication of chronic renal failure. Fibrous osteitis and, to a lesser extent, osteomalacia are the predominant lesions. The aim of the present study was to evaluate the prevalence of the different forms of ROD. METHODS: Nondecalcified bone biopsies were evaluated in 100 patients with end-stage renal disease (57 in pre-dialysis and 43 on hemodialysis) in whom biochemical (calcium, phosphorus, alkaline phosphatase, parathyroid hormone) and histomorphometric studies were carried out. Bone biopsies were classified in four histological groups: mild, fibrous osteitis (FO), osteomalacia (OM) and mixed type (FO + OM). RESULTS: 96% of patients had histological findings of ROD with the following distribution: 41% mild; 30% FO; 14% OM; and 11% mixed. The most advanced types of ROD were seen in interstitial renal diseases. Pre-dialysis OM was associated with metabolic acidosis, a low phosphocalcic product and relative hypophosphoremia. Chronic aluminium poisoning was uncommon (7%) and was basically associated with OM. No instance of aluminium poisoning with osteodystrophy and bone fractures was seen. CONCLUSIONS: The most severe histological forms of OM were found in hemodialysis patients with persistent hypophosphoremia and associated with osteosclerosis.