Osseous complications of renal transplantation

Osseous complications are an important long term cause of morbidity in renal transplant recipients. The major clinical sequelae are persistent hyperparathyroidism, osteopenia and osteonecrosis. Persistent hyperparathyroidism leads to disordered calcium and phosphate metabolism in the posttransplant period, osteopenia predisposes to pathologic fractures and osteonecrosis causes debilitating joint disease often requiring surgical intervention. The etiology of these problems is multifactorial and includes uremic-mediated abnormalities in calcium homeostasis that persist post-transplant as well as acquired defects in mineral metabolism from immunosuppressant medications used to promote engraftment (1). Though current epidemiologic data defining the prevalence of these entities are lacking, the general consensus is that the incidence of these skeletal complications may be decreasing with the advent of low dose immunosuppression and better management of renal osteodystrophy. As one-year graft survival continues to improve, however, more patients are reaching the late post-transplant period when osteopenia and osteonecrosis become clinically manifest. Therefore, the total number of patients affected by these complications is likely to remain high.