[Revision of infected total hip prostheses by ablation reimplantation of an uncemented prosthesis. 57 case reports].

PURPOSE OF THE STUDY: 57 cases of infected total hip prosthesis treated by removal of the implant and implantation of unncemented prosthesis, were studied to evaluate functional and sepsis results.

MATERIAL AND METHODS: 57 patients treated by reimplantation of an uncemented total hip prosthesis after removal of the infected prosthesis were observed. 16 patients underwent a single-stage exchange, 41 a two-stage reimplantation. 46 cases were analysed for infection findings (clinical, radiological and biological assessment) and only 34 cases for functional evaluation (PMA scale, Harris score) with a mean follow-up of 6.6 years. The antibiotic therapy was adapted to each patient but generally, the treatment was prolonged.

RESULTS: At follow-up time (which might be too short in time), only 2 patients had a recurrence of infection. One had a single-stage exchange (reoperated by two stage exchange with a good final result at 6 years follow-up), the other a two-stage exchange. In both cases we found that postoperative antibiotic therapy was inadequate. Functional results were better with PMA scale (23 good results of 34) than with Harris score (14 excellent or good results only). 5 patients were reoperated for mechanical implant failure.

DISCUSSION: Since 1991, we adopted a standardized procedure to treat chronic infected total hip prosthesis including: routine preoperative aspiration of symptomatic prosthesis; removal of the implant and around debridement followed at a later date (6 weeks) by reimplantation using uncemented implants (hydroxyapatite coated implant). Postoperative antibiotic therapy has to be massive (parenteral bitherapy for at least 21 days after each operative stage) and has to last 6 months after reimplantation. This procedure seems reliable and corroborate the validity of two-stage treatment. The using of uncemented implants allows a good bone reconstruction and does not seem to increase the risk of septic recurrence.

CONCLUSION: It is quite difficult to find a hard and fast rule in infected prosthesis treatment, because many factors can influence results. The proposed procedure seems reliable, even if antibiotherapy is long and hard, but requires a strong collaboration between bacteriologist infectiologist and surgeon.