Is fluoroscopy-guided percutaneous bone biopsy of diabetic foot with suspected osteomyelitis worthwhile? A retrospective study.

Background: Diabetic foot infection, particularly osteomyelitis, is a major risk factor of amputation in persons with diabetes. Bone biopsy with microbial examination is considered the gold standard of diagnosis of osteomyelitis, providing information about the offending pathogens as well as their antibiotics susceptibility. This allows targeting of these pathogens with narrow spectrum antibiotics, potentially reducing emergence of antimicrobial resistance. Percutaneous fluoroscopy guided bone biopsy allows accurate and safe targeting of the affected bone.

Methods: In a single tertiary medical institution and over 9 year period, we performed 170 percutaneous bone biopsies. We retrosepctively reviewed the medical record of these patients including patients' demographics, imaging and biopsy microbiology and pathollogic results.

Results: Microbiological cultures of 80 samples (47.1%) were positive with 53.8% of the positive culture showed monomicrobial growth and the remaining were polymicrobial. Of the positive bone samples 71.3% grew Gram-positive bacteria. Staphylococcus aureus was the most frequently isolated pathogen from positive bone cultures with almost one third showing methicillin resistence. Enterococcus species were the most frequently isolated pathogens from polymicrobial samples. Enterobacteriaceae species were the most common Gram-negative pathogens and were more common in polymicrobial samples.

Conclusions: Percutaneous image-guided bone biopsy is a low-risk, minimally invasive procedure that can provide valuable information about microbial pathogens and therefore enable targeting these pathogens with narrow spectrum antibiotics.