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*Email: hoonishi@zf6.so-net.ne.jp[INTRODUCTION] :We have conducted interface bioactive bone cement method (IBBC) intotal hip arthoplasty (THA) to prevent generation of connective tissue and osteolysis for thelongevity of cemented THA since 1985, in which non-resorbable crystalline osteoconductivehydroxyapatite (HA) granules were interposed on the interface between bone and bone cement.To prevent the patients from infection, we use HA granules impregnated with antibiotics.However, there have been no reports on the loading and release of antibiotics from fine granulesof HA. Here, we have investigated the loading of antibiotics on HA and their release in vitro.[MATERIALS AND METHODS] :HA was impregnated with antibiotics such as flomoxefsodium (F), vancomycin hydrochloride (V) cefotiam dihydrochloride (C) and cefozopranhydrochloride (CE) under normal or reduced pressure. After washing with PBS three times, HAloaded with the antibiotic was placed in PBS. An aliquot of solution was sampled at appropriatetime intervals and the amount of the released antibiotic was estimated based on the antibacterialactivity.[RESULTS AND DISCUSSION] : When drug loading was done by dropping antibioticsolution to HA granules, the amount of antibiotic released from 20 mg of HA was 16 μg for F,0 μg for V, 13 μg for C and 65 μg for CE. The release of F continued for 48 hrs and that of Vand CE completed within 24 hrs. On the other hand, when antibiotics loading were conductedunder reduced pressure, the amount of released antibiotic was 14 μg for F, 0 μg for V, 0 μg forC and 1670 μg for CE. The burst release was observed for CE and F, and the release of themcompleted in 24 hrs. Then, the release of C and CE was observed in 0.025 M EDTA solutionafter the antibiotic was loaded under pressure. Observation was done for 19 days, at which onethird of HA was dissolved. After 40 μg of burst release, the release of C continued for 19 days,at which the total amount of C released was 122 μg. Meanwhile, the release of CE continuedover 19 days, during which 3350μg of CE was released after the burst release of 3280 μg. Thus,CE seemed the most suitable antibiotic for our purpose. The burst release of CE absorbed inHA following the issue of CE surrounding the HA granules on the interface of bone and bonecement is very effective for the protection of early infection after joint replacement.[REFERENCES] :Oonishi H. et al: THA with hydroxyapatite granules at cement-boneinterface, 15-to 20-year result. Clin Ortho Relat Res. 2008; 466:373-379.Friday, October 8, 2010, 14:00-14:50Session A14: Complication ManagementAnchor Like Sutures for Prophylaxis Against Patellar Ligament RuptureDuring Total Knee Arthroplasty*Wael Osman - University - Cairo, Egypt*Email: waelbehairy@yahoo.comBackground: Patellar ligament rupture is an uncommon but devastating complication of totalknee arthroplasty. Many predisposing factors may lead to rupture of the ligament during orshortly after surgery. The most common predisposing factor is extensive release of the ligamentfile:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]