I. Gunal et al., IN-VITRO EVALUATION OF ANTIBIOTIC DIFFUSI ON FROM ANTIBIOTIC-IMPREGNATED XENOGRAFTS, Revue de chirurgie orthopedique et reparatrice de l'appareil moteur, 82(1), 1996, pp. 59-62
Purpose of the study The purpose of the study was to evaluate xenograf
ts as a slow release antibiotic delivery system, as xenografts also ha
ve excellent biocompatibility and osteogenesis-stimulating effect. Mat
erial Xenograft (Unilab Surgibone) blocks of 5 x 5 x 5 mm were used in
the study. Antibiotics used for impregnation were gentamicin sulphate
, ciprofloxacin and penicillin G. Methods In the pilot study, xenograf
t blocks impregnated with gentamicin sulphate solution and the contact
time was between 1/2 to 10 hours. Then the grafts were incubated and
the antibiotic concentration was measured in the elution fluid changed
every day. The minimum contact time to release the antibiotic 10 days
over 0.5 mu g/ml was 8 hours. The 8 hours contact time was used in th
e main study to evaluate gentamicin sulphate, ciprofloxacin and penici
llin G. The method was the same as in the pilot study. Results All ant
ibiotics showed similar release patterns reaching their peaks on the 5
th day and then gradually decreasing below the effective level (0.5 mu
g/ml) approximately on day 10. Discussion Although various materials
have been used to deliver antibiotics, they have some certain disadvan
tages especially reduced biocompatibility. The superiority of xenograf
ts over other materials, is not only biocompatibility but also to faci
litate osteogenesis. The only objection may be the relatively short du
ration of release (10 days) but the length of antibiotherapy is contro
versial and standard 6 weeks of administration has no documented super
iority over other time intervals. Conclusion Our delivery system is su
perior to others as its function is not only to deliver antibiotics bu
t has its place in orthopedic practice to fill defects and stimulate o
steogenesis. Also the preparation of this system is not time and skill
consuming.