Early diagnosis of septic arthritis of the sacroiliac joint by use of computed tomography.

Two cases of suspected septic arthritis of the sacroiliac joint with normal radiographs and nuclide scans were investigated by computed tomography. Bone and soft tissue abnormalities consistent with septic arthritis were found. Diagnosis was confirmed by needle aspiration of the sacroiliac joint. Computed tomography may be useful in the early diagnosis of the sacroiliac joint when plain radiographs and nuclide scans are normal.