Bone scan demonstration of progression of sacral insufficiency stress fracture.

This case documents the progression of a sacral insufficiency stress fracture, initially involving the lateral left ala and later extending across the body of the sacrum to the right ala. The 'H' shaped distribution of increased uptake on radionuclide bone scanning is characteristic of this type of fracture, although variations of this pattern are also seen according to the severity of the sacral trauma. While the differing bone scan patterns of this particular fracture type are well established, it is unusual to document the progression of this fracture on bone scan in any one patient.