ANTIBIOTIC-PROPHYLAXIS IN TOTAL HIP-ARTHROPLASTY - REVIEW OF 10 905 PRIMARY CEMENTED TOTAL HIP REPLACEMENTS REPORTED TO THE NORWEGIAN ARTHROPLASTY REGISTER, 1987 TO 1995

We have assessed the effect of different regimes of antibiotic prophyl axis on the survival of total hip implants, comparing antibiotics admi nistered both systemically and in the bone cement, systemically only, in the bone cement only and with no antibiotics given, We studied 1090 5 primary cemented total hip replacements, performed for osteoarthriti s of the hip and reported to the Norwegian arthroplasty register betwe en 1987 and 1995, Cox-estimated failure-rate ratios (FRR) are presente d with adjustment for gender, age, the brand of cement, the prosthesis , the type of operating theatre and the operating time. For revisions performed for infection (39 operations), the lowest rate of revision w as found among patients receiving antibiotic-containing cement plus sy stemic antibiotics (n = 5804). The revision rate for the 4586 patients receiving systemic antibiotics only was 4.3 times greater (95% CI 1.7 to 11.0, p = 0.001); in 239 with antibiotics in the bone cement only it was 6.3 times greater (CI 1.6 to 25.0, p = 0.003); and in the 276 w ho did not receive antibiotics it was by 11.5 times greater (CI 2.1 to 63.0, p = 0.002), Adjustment for the total amount of systemic antibio tic administered did not change the results, We also observed an incre ased revision rate for aseptic loosening (109 operations) comparing th e systemic-only (FRR = 1.8, CI 1.1 to 2.9, p = 0.01) and the cement-on ly regimes (FRR = 2.6, CI 1.2 to 5.9, p = 0.02) with the combined dosa ge. Our findings show that systemic antibiotics combined with antibiot ic-containing bone cement led to fewer revisions than the other method s.