Nuclear medicine and the infected joint replacement.

Area of Science:

• Orthopedic Surgery
• Radiology
• Infectious Disease

Background:

• Hip and knee arthroplasties are common, but prosthetic joint failure necessitates accurate diagnosis.
• Differentiating aseptic loosening from infection is critical due to different treatment pathways.
• Clinical signs and basic laboratory tests are often insufficient for diagnosing prosthetic joint infection.

Purpose of the Study:

• To review diagnostic modalities for prosthetic joint infection.
• To compare the accuracy of various imaging techniques in identifying joint replacement failure due to infection.

Main Methods:

• Review of diagnostic tests including joint aspiration, plain radiographs, CT, MRI, and radionuclide imaging.
• Evaluation of bone scintigraphy, bone gallium imaging, and leukocyte/marrow imaging.
• Discussion of newer agents like (111)In-labeled immunoglobulin, (99m)Tc-ciprofloxacin, and (18)F-FDG PET.

Main Results:

• Joint aspiration has high specificity but variable sensitivity for infection.
• Plain radiographs and cross-sectional imaging are limited by artifacts.
• Radionuclide imaging is preferred due to hardware independence; bone scintigraphy has 50-70% accuracy.
• Combined leukocyte/marrow imaging demonstrates approximately 90% accuracy for prosthetic joint infection.

Conclusions:

• Combined leukocyte/marrow imaging is the current radionuclide imaging procedure of choice for prosthetic joint infection.
• While other radionuclide techniques show promise, their diagnostic value for prosthetic joint infection is still under investigation.
• Accurate diagnosis of prosthetic joint infection remains a challenge, requiring careful selection of imaging modalities.