Spectrum of renal osteodystrophy in dialysis patients at a tertiary hospital, riyadh, saudi arabia.

To evaluate renal osteodystrophy (ROD), bone biopsies were performed in 57 patients with end-stage renal failure (ESRF) on dialysis, 46 on hemodialysis (HD) and 11 on peritoneal dialysis (PD). There were 29 males (mean age of 42 years) and 28 females (mean age of 39 years). Relevant presenting clinical features were pruritus in 46 cases, bone pains in 32, acute pseudogout in three, bone deformities in two, conjunctiva! calcification in two, cutaneous calcification in two, and corneal calcification in one. The mean value of predialysis blood investigations were as follows: urea 33.9 mmol/L, creatinine 913 umol/L, bicarbonate 18 mmol/L, calcium 2.36 mmol/L, albumin 40 g/L, phosphorus 1.69 mmol/L, alkaline phosphatase 178 U/L, parathyroid hormone 543 pmol/L, magnesium 1.06 mmol/L and aluminum 1.81 mmol/L. Skeletal survey showed no changes in 24 patients (42%), hyperparathyroid cystic changes of bones in seven, osteoporosis as the predominant features in seven, mixed picture of ROD in 12, subperiosteal resorption of the metacarpals in two, osteosclerosis (Rugger Jersey Spine) in two and osteomalacia in two patients. Bone mineral density (BMD) was measured by dual x-ray absorptiometry in the lumbar spine (LS) and femoral neck (FN). All patients had low BMD (both LS and FN). Bone biopsy (BBX) revealed mixed picture in 30 cases, predominantly secondary hyperparathyroid changes in 10, mild hyperparathyroid changes in five, predominant osteoporosis in three, osteomalacia in four, aplastic (adynamic) bone in four, and aluminum deposition in one. All of the patients who showed evidence of bone involvement on BBX had abnormal BMD suggesting that BMD is a good non-invasive screening test for ROD but indiscriminative for the type of bone disease. BBX still remains the diagnostic tool to differentiate and classify different types of bone disease.