Does intrawound application of vancomycin influence bone healing in spinal surgery?

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Cell Biology

Background:

• Surgical site infections are a significant complication in spinal surgery.
• Local application of lyophilized vancomycin is effective in reducing infection rates.
• High local vancomycin concentrations may pose risks to local tissue.

Purpose of the Study:

• To investigate the potential toxic effects of intrawound vancomycin on osteoblasts.
• To evaluate the impact of varying vancomycin concentrations on osteoblast migration, proliferation, viability, and differentiation.
• To determine safe dosage limits for intrawound vancomycin in spinal surgery.

Main Methods:

• Primary osteoblast cell cultures were established from patient bone samples.
• Cells were exposed to vancomycin concentrations of 3, 6, and 12 mg/cm².
• Analysis included pH changes, cell migration, proliferation, viability, alkaline phosphatase synthesis, and mineralization.

Main Results:

• Vancomycin concentrations above 3 mg/cm² decreased pH and significantly inhibited osteoblast migration and proliferation.
• Cell death was observed at concentrations exceeding 6 mg/cm².
• Alkaline phosphatase synthesis and mineralization were reduced across all tested dosages, with significant decreases above 3 mg/cm².

Conclusions:

• High-dose intrawound vancomycin may impede bone healing by affecting osteoblast function, potentially increasing non-union risk.
• Further in vivo studies are needed to establish optimal vancomycin concentrations balancing infection prevention and bone healing.
• Careful consideration of vancomycin dosage is crucial to avoid compromising spinal fusion outcomes.