Just a little more info for your doctor visit....Cefdinir, a third-generation cephalosporin, is not typically recommended as a first-line treatment for PJI due to several limitations:
Spectrum of Activity:
Cefdinir is effective against some PJI pathogens like methicillin-sensitive S. aureus (MSSA) and certain streptococci.

However, it is ineffective against MRSA, methicillin-resistant coagulase-negative staphylococci, and Pseudomonas aeruginosa, which are common in PJI.

It has variable activity against Gram-negative bacteria and is not reliable for biofilm-associated infections.

Biofilm Penetration:
PJIs often involve bacterial biofilms, which are notoriously difficult to treat. Cefdinir has poor biofilm penetration, reducing its efficacy in eradicating infections on prosthetic surfaces.

Guidelines and Evidence:
Per the Infectious Diseases Society of America (IDSA) and other guidelines, PJI treatment typically involves antibiotics with better activity against resistant organisms and biofilms, such as vancomycin, daptomycin, or rifampin (often in combination).

Cefdinir is not mentioned in standard PJI treatment protocols due to its limited role in deep-seated or hardware-associated infections.