Is bone histomorphometry required for assessment of renal osteodystrophy in clinical practice?

We have read with great interest the article written by Jørgensen et al.1 We agree with the authors that a call for harmonization of renal osteodystrophy reference ranges of bone histomorphometry is required, although we would like to clarify some issues. Bone histomorphometry is a precise quantitative histologic assessment; however, it is entirely a research tool. Contemporary, qualitative histologic analysis of undecalcified bone biopsy specimens is merely used in evaluation of metabolic bone disease in clinical practice. Furthermore, Malluche et al.2 and Recker et al.3 evaluate bone turnover status not only based on bone formation rate/bone surface, but based on activation frequency, osteoblast and osteoclast number/bone length, erosion, and fibrosis surface/bone surface as well. Normal ranges were obtained from bone samples taken in healthy volunteers of comparable sex, race, and age ranges. These healthy participants did not exhibit any kidney dysfunction or evidence of metabolic bone disease.4