Bone histomorphometry is still the golden standard for diagnosing renal osteodystrophy

The clinical picture of renal osteodystrophy (RO) is very uncharacteristic. The diagnosis is made by means of biochemical indicators, intact parathormone (iPTH) concentration, bone X-rays, bone densitometry and particularly bone histomorphometry. The aim of our study was to establish whether a combination of non-invasive methods can bring us closer to the diagnosis as to avoid bone biopsy.

We chose 30 patients treated by chronic hemodialysis. Only 4 of them had no symptoms of RO. Biochemical parameters (Ca, P) and iPTH concentrations were determined. bone X-rays were taken (the parathyroid series), bone mineral density was measured by quantitative digital radiography (QDR), and bone biopsy specimens were taken for bone histomorphometry. The data were analyzed by the Statistica by StatSoft and SPSS computer programs.

With respect to bone histomorphometry, 10 patients had osteitis fibrosa (OF), 15 had mixed osteodystrophy (MO), 5 adynamic bone disease (ABD). There was a good correlation of iPTH and alkaline phosphatase (AP) concentrations with histomorphometric parameters. There was also a correlation between radiological changes and histomorphometric parameters. After the analysis of discrimination using the SPSS computer program, taking only iPTH into consideration, 36.6% of patients were correctly classified according to their diagnosis. Considering iPTH and densitometry, 46.6% were classified correctly. Considering iPTH and radiological changes, 60% of patients were classified correctly.

To diagnose 73.3% of patients correctly, it was necessary to consider the above mentioned non-invasive parameters, as well as AP, P, concentrations and the patient age. Histomorphometry remains the "golden standard" for diagnosing RO.