Morphological properties of bone cement mixed with antibiotics

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Orthopedic Surgery

Background:

• Poly(methyl methacrylate) (PMMA) bone cement is widely used in orthopedic surgery.
• Antibiotic incorporation into bone cement is crucial for preventing surgical site infections.
• Understanding the morphological impact of antibiotics on PMMA cement is essential for optimizing clinical performance.

Purpose of the Study:

• To investigate the morphological changes in manually loaded PMMA bone cement with meropenem and vancomycin.
• To analyze the interaction between antibiotic particles and the PMMA matrix.
• To assess structural alterations during cement aging and incubation.

Main Methods:

• Scanning electron microscopy (SEM) was used to examine PMMA bone cement samples.
• Samples included manual mixtures of SmartSet Endurance™ MV bone cement with meropenem, vancomycin, or both.
• Microstructural analysis was performed after 24 hours and 28 days of incubation in Ringer's solution.

Main Results:

• Manually prepared PMMA bone cement exhibited microporosity up to 65 μm with a homogenous structure.
• Incubation for 28 days did not significantly alter the polymer structure but induced cracking under stress.
• Vancomycin addition increased cement porosity and pore irregularity, interfering with polymer formation.
• After 28 days, antibiotic particles were largely released from the surface, with higher meropenem release than vancomycin.

Conclusions:

• Vancomycin significantly affects PMMA bone cement morphology, increasing porosity and irregularity.
• Cement aging leads to substantial antibiotic particle release, particularly meropenem.
• The findings highlight the need to consider antibiotic-induced morphological changes for improved bone cement formulations.