Dialysate calcium levels, dialysis hours and the healing of osteitis fibrosa.

Unselected patients receiving intermittent haemodialysis at home were examined by hand radiographs to study the progression of osteitis fibrosa. Patients were using Kiil dialysers and Drake-Willock proportioning systems. The calcium phosphorus product was controlled by an adequate dialysis schedule supplemented by aluminum hydroxide gel. Dialysate calcium ranged between 5.7 and 7.3 mg/100 ml depending on the calcium content of local tap water. In 73 percent of patients the osteitis fibrosa improved radiologically and in most patients complete healing occurred. The rate of change was slow. Patients whose bones healed had significantly higher serum and tap water calcium levels than those whose bones deteriorated. There was no significant difference in the serum phosphorus levels in the two groups. Improvement of osteitis fibrosa requires both control of calcium phosphorus product and suppression of the parathyroid gland. Long dialysis hours with a positive calcium balance during dialysis were necessary to achieve the best results.