Detection of occult infection following total joint arthroplasty using sequential technetium-99m HDP bone scintigraphy and indium-111 WBC imaging.

Preoperative exclusion or confirmation of periprosthetic infection is essential for correct surgical management of patients with suspected infected joint prostheses. The sensitivity and specificity of [111In]WBC imaging in the diagnosis of infected total joint prostheses was examined in 28 patients and compared with sequential [99mTc]HDP/[111In]WBC scintigraphy and aspiration arthrography. The sensitivity of preoperative aspiration cultures was 12%, with a specificity of 81% and an accuracy of 58%. The sensitivity of [111In]WBC imaging alone was 100%, with a specificity of 50% and an accuracy of 65%. When correlated with the bone scintigraphy and read as sequential [99mTc]HDP/[111In]WBC imaging, the sensitivity was 88%, specificity 95%, and accuracy 93%. This study demonstrates that [111In]WBC imaging is an extremely sensitive imaging modality for the detection of occult infection of joint prostheses. It also demonstrates the necessity of correlating [111In]WBC images with [99mTc]HDP skeletal scintigraphy in the detection of occult periprosthetic infection.