O3472 OUTCOME OF THE CEMENTLESS BICHAT III HIP ENDOPROSTHESIS: VERY BAD RESULTS IN OUR HANDS

Abstract

Aim: The purpose of this report was to analyse the clinical and survivorship results and revision rates of Bichat III uncemented total hip arthroplasty in a community hospital setting. Poor results are rarely published what may have effect on the results of meta-analyses done on hip replacement surgery. At the time of selecting the prosthesis there were no reports published on this particular model. Methods: Between 1987 and 1990 þftyþve patients (57 hips) were operated using the Bichat III endoprosthesis. The prosthesis has a ßuted, anatomic and non-porous Ti femur, and a threaded nonporous acetabular cup. There were 25 male and 30 female patients. Mean age of the male patients was 62 (40–75) and that for the female 61 years (43–82). The indication for operation was primary arthrosis in 45, posttraumatic arthrosis in 5, LPC in 2 cases, and rheumatoid arthritis, AVN and CHD one each. All the operations were made using the Hardingen approach. For the survivorship analysis the patients were traced from the Finnish Arthroplasty Register and Kaplan-Meir survival was calculated for all the 57 patients with the 95% Cl. Those not revised until 31st December 2001 were called for clinical and radiological examination. The mean follow-up time was 12,7 years (11,4–14,2). Results: During the follow-up 16 patients died (28%), and revision was done on 21 patients (37%) after a mean follow-up time of 7,2 years (3,6–11,3). Seventeen patients arrived to the clinical follow-up; of those only 10 cases were without any radiological signs of loosening. For all the patients re-examined the Mayo Clinics Hip Score was 50.8 in average ((5–75), and that for those with radiological signs of loosening 46,3 (16–71). The survivorship calculated at ten years was 57,0% (95%Cl 42,5–71,6; 22 hips at risk). Typical features at revision were total loosening of both components, marked metallosis and breakage of the polyethylene liner. Conclusions: Our results are in accordance with other reports with uncemented, non-porous coated components, as well as with those of the screw þxed acetabular cups. Also the reports from other Nordic arthroplasty registers speak favour of the non-acceptable results with such concepts of THA. Publication of also the negative results of THA may decrease risk of sc. publication bias. We conclude that until now there is sufþcient evidence that porous coating on both components of hip endoprosthesis is crucial for reliable þxation of uncemented components. Prosthesis selection should be made on a well documented basis and trials should be made in arthroplasty centers and on a prospective and randomized basis.