Evaluation of postoperative osteomyelitis of the sternum comparing CT and dual Tc-99m MDP bone and In-111 WBC SPECT

This article reports on a retrospective study of 32 patients who underwent CT and combined Tc-99m MDP and in-111 WBC SPECT between 1988 and 1991 for post-operative sternal osteomyelitis. Of these 32 patients, 7 patients (Group 1) underwent evaluation for possible sternal osteomyelitis due to persistent fevers, leukocytosis, or changes in the sternal incision; 12 patients (Group 2) had surgically proven osteomyelitis, and in 13 patients (Group 3) there was definite clinical evidence of sternal wound infection (however, surgical specimens of the sternum were not submitted). There was considerable overlap between the CT findings in the soft tissues adjacent to the sternum in Group 1 and Group 2 patients. Severe demineralization was seen in two patients, and erosion of the sternum was seen in five patients with proven osteomyelitis. Combined Tc-99m MDP bone and in-111 WBC SPECT was positive for osteomyelitis in 11 of 12 patients in Group 2. One patient with osteomyelitis had negative scintigraphy; however, this patient had a four-week course of IV antibiotic therapy prior to the study. All seven patients in Group 1 had negative SPECT scans and were treated successfully with oral antibiotics and minimal soft tissue debridement. Three patients in Group 3 had negative SPECT scans and were treated successfully with antibiotics and limited debridement. Ten patients with positive SPECT scans were treated with a combination of antibiotics and aggressive surgical intervention. In conclusion, CT findings in the soft tissues offer little specificity in distinguishing soft tissue inflammation from osteomyelitis of the sternum.(ABSTRACT TRUNCATED AT 250 WORDS)