Tissue distribution of antibiotics in the intervertebral disc.

STUDY DESIGN

This study analyzed the distribution of antibiotics within the intervertebral disc of rabbits. Specimens were tested with specific antibodies against antibiotics using an immunofluorescent technique.

OBJECTIVES

The results were correlated to provide a rationale for perioperative prophylaxis of infection.

SUMMARY OF BACKGROUND DATA

Several groups of investigators and the recent data from our laboratory showed quantitative changes in penetration of antibiotics into intervertebral disc. No previous study has assessed antibiotic distribution in anulus fibrosus and nucleus pulposus.

METHODS

Discs were obtained from rabbits after intravenous injection of penicillin or gentamicin. Antibiotics were localized in tissue sections using specific antibodies with a immunofluorescent method.

RESULTS

Penicillin (negatively charged) and gentamicin (positively charged) penetrated the neutrally charged anulus fibrosus, but penicillin had less ability than gentamicin to penetrate into the negatively charged nucleus pulposus.

CONCLUSION

Our data suggest that penetration and distribution of antibiotics into avascular intervertebral disc is significantly influenced by the charge of antibiotics.