Quantitative metacarpal bone measurements before and after renal transplantation.

The outer (D) and inner diameter (d) of the second metacarpal bone, the combined cortical thickness (D-d), cortical area (D2-d2) and bone mass [D2d2)/D2) were measured in 74 renal transplant (RT) recipients at the time of renal transplantation and in a prospective analysis of 60 recipients after transplantation. The RT patient group was made up of recipients who after renal transplantation developed osteonecrosis or spontaneous fractures (RT-ON/SF) and an age- and sex-matched renal control group of subjects who did not develop these complications (RT-C). At the time of renal transplantation, in renal transplant recipient men and women, significantly reduced values in D, D-d and D2-d2 was noticed. These findings could be explained by a higher ratio of bone resorption than formation at the periosteal surface. Following renal transplantation, significant increases in d were seen with significant decreases in D-d, D2-d2 and (D2-d2)/D2, probably due to endosteal bone resorption, whereas D was unchanged compared with normal control persons. In the total group and in RT-ON/SF women, D decreased significantly and in ON/SF, increased significantly with significant decrease in bone mass compared with normal women whereas no significant changes in the parameters were seen in RT-C women. These findings indicate that bone loss after transplantation continues at the periosteal surface in women. The bone loss was most markedly demonstrated in women, who subsequently develop osteonecrosis or spontaneous fractures, probably due to a combined periosteal and endosteal resorption of calcified bony tissue.