Bone fracture and osteodensitometry with dual energy X-ray absorptiometry in kidney transplant recipients.

Kidney transplant recipients have multiple factors leading to osteoporosis. The purpose of this study was to determine the fracture rate after kidney transplantation and the significance of osteodensitometry with dual energy x-ray absorptiometry (DXA) in identifying the risk patients. Bone mineral density (BMD) was measured with DXA in 100 graft recipients (mean interval 63 +/- 53 months after transplantation) and correlated with the incidence of fractures. Fracture rate of peripheral bones increased from 0.009 before transplantation and 0.012 on hemodialysis to 0.032 fractures per patient and year after transplantation. Seventeen fractures of peripheral bones occurred in 11% of the patients within a mean of 103 +/- 59 months after transplantation. Three additional patients had fractures of the lumbar spine. Patients with fractures were characterized by low or low-normal BMD (0.93 +/- 0.23 versus 1.04 +/- 0.17 g/cm2 at lumbar spine), a frequent history of parathyroidectomy (21% versus 6%), and a longer transplant interval (103 +/- 59 versus 57 +/- 49 months). Fractures occurred in patients with low and normal BMD. DXA at the femoral neck proved to be of no value to define patients at risk of fractures. DXA at the lumbar spine also proved to be of limited value for this question. Therefore, alternatively, more sensitive methods of BMD and of bone architecture measurements are necessary for identifying the kidney transplant recipients at risk of fracture.