THE ECONOMIC-IMPACT OF FAILURES IN TOTAL HIP-REPLACEMENT SURGERY - 28,997 CASES FROM THE NORWEGIAN ARTHROPLASTY REGISTER, 1987-1993

The Norwegian Arthroplasty Register was established in 1987. Until Jan uary 1994, approximately 200 different implant combinations had been u sed in total hip replacements (THR) in Norway. About 5,500 THR were pe rformed each year in this period with a total cost of 70 million USD p er year. We analyzed the economic consequences related to the use of s ome inferior primary hip arthroplasties in this period. As the referen ce arthroplasty, we chose the most commonly used prosthesis in Norway, i.e., the Charnley prosthesis fixed with high viscosity cement contai ning antibiotic and with systemic antibiotic prophylaxis (n 4,970). We compared this reference group to all other primary THR registered in the same time period (n 24,027), and to the following sub-groups of pr imary THR: 1) uncemented Ti-Fit/Bio-Fit (acetabulum/femur) combination (n 173), 2) uncemented Coxa/Femora combination (n 153), 3) THR with l ow-viscosity cement (n 1,807) and 4) THR with Boneloc cement (n 1,250) . We estimated the number of additional revisions compared to the refe rence arthroplasty after a follow-up of 3-5 years in the different gro ups, with adjustment for age, sex and diagnosis. The direct extra revi sion costs were calculated. Compared to the reference arthroplasty, th e group of all other primary THR gave an extra revision cost estimated at about 1.7 million USD per year. About 1,000 uncemented Bio-Fit fem oral prostheses have been applied in Norway, including those implanted before the registration started (1985-1987). The extra revision costs the first postoperative years for these 1,000 prostheses amount to ab out 0.7 million USD per year. Corresponding figures in the Coxa/Femora group were 0.08 million USD, in the group with low-viscosity cement, 0.3 million USD and in the Boneloc group, 0.4 million USD per year.