[Implant-associated infections - Diagnostics].

Area of Science:

• Orthopedics
• Infectious Diseases
• Medical Diagnostics

Background:

• Implant-associated infections present diagnostic challenges due to subtle clinical manifestations of chronic low-grade infections.
• Accurate diagnosis relies on a combination of clinical assessment, patient history, imaging, histopathology, and microbiology.

Purpose of the Study:

• To outline the diagnostic cornerstones for implant-associated infections.
• To highlight key clinical signs and diagnostic modalities for timely identification of infections.
• To emphasize the importance of avoiding preoperative antibiotics and the role of specific tests in different infection types.

Main Methods:

• Clinical evaluation, patient history, and physical examination to identify suspicious symptoms like pain, local signs, and prosthesis loosening.
• Imaging techniques (X-ray, CT, MRI) to detect signs of infection, non-union, osteolysis, and prosthesis stability.
• Laboratory tests including C-reactive protein (CRP) levels, joint aspiration for leukocyte count, microbiological examination of tissue/fluid samples, and sonication of explanted implants.

Main Results:

• Subtle symptoms like new onset pain or prosthesis loosening warrant further investigation.
• Certain signs like sinus tracts or purulent discharge are definitive indicators of infection.
• Elevated CRP levels support infection but lack specificity; preoperative antibiotics interfere with diagnosis.
• Joint aspiration and microbiological analysis are critical for periprosthetic joint infections.
• Imaging is key for osteosynthesis infections, while blood cultures are vital for hematogenous spread.

Conclusions:

• A multi-faceted diagnostic strategy integrating clinical, imaging, and microbiological data is essential for implant-associated infections.
• Timely and accurate diagnosis, guided by specific clinical signs and appropriate investigations, improves patient outcomes.
• Understanding the nuances of diagnosis for different types of implant infections (e.g., periprosthetic, osteosynthesis) is crucial for effective management.