INSUFFICIENCY FRACTURES OF THE SACRUM - A CAUSE OF LOW-BACK-PAIN AFTER LUNG TRANSPLANTATION

Insufficiency fractures of the sacrum were diagnosed during the first year after successful transplantation in four (5.6%) of 71 lung and he art-lung transplant recipients. Each patient had development of low ba ck pain after minor or no trauma; all had osteoporosis. In each instan ce, plain radiographs failed to demonstrate the fracture, and the diag nosis was established by radionuclide bone scanning that demonstrated the characteristic ''butterfly'' (bilateral sacral fracture) or ''half -butterfly'' appearance (unilateral sacral fracture). Sacral insuffici ency fractures, a significant cause of low back pain in lung transplan t recipients, may be underdiagnosed in this population because routine radiographs do not usually reveal the fracture; bone scanning is the preferred diagnostic modality.