Bacterial growth on articulating spacers: an in vitro study

Area of Science:

• Biomaterials Science
• Infectious Disease Research
• Orthopedic Surgery

Background:

• Antibiotic-loaded bone cement spacers are crucial for treating orthopedic implant infections.
• The incorporation of materials like polyethylene and titanium into spacers warrants investigation for potential effects on bacterial viability.

Purpose of the Study:

• To evaluate whether embedding polyethylene and titanium into antibiotic-loaded cement spacers influences bacterial survival.
• To assess the efficacy of antibiotic-loaded spacers against common orthopedic pathogens.

Main Methods:

• Cement disk-shaped spacer models were created using antibiotic-loaded Palacos.
• Half of the models were embedded with polyethylene and titanium.
• Models were inoculated with methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S aureus (MRSA), or Staphylococcus epidermidis and cultured in nutrient broth.

Main Results:

• No MSSA or MRSA survived beyond 48 hours in the antibiotic bath, irrespective of embedded materials.
• After 96 hours, 86.6% of antibiotic cement-only models showed viable Staphylococcus epidermidis.
• 80% of models with antibiotic cement, polyethylene, and titanium also had viable Staphylococcus epidermidis.

Conclusions:

• The addition of polyethylene and titanium to antibiotic-loaded cement spacers does not enhance bacterial survival.
• Antibiotic-loaded cement spacers remain effective in reducing bacterial load, even with embedded biomaterials.