W Winkelmann, S Fuchs-Winkelmann (Munster, Allemagne)
The reconstruction of large bone defects in complex cases of revision of aseptic loosened or infected knee or hip prostheses or in cases of revision of tumor prostheses remains a challenging surgical procedure.
In this study we examined 64 patients. 24 pts. of them have had multiple previous revisions for a loosened (6 pts.) or infected (4 pts.) hip prostheses or lossened (8 pts.) or infected (6 pts.) knee prostheses and 40 pts. have had a revision for a loosened (26 pts.) or infected (14 pts.) tumor prostheses.
For the aseptic loosened prostheses we use a special designed cementless revision system which is completely compatibel with the Münster-MUTARS tumor prostheses system. All of the infected cases have had a two stage revision, if ever possible we used for the final reconstruction silver coated spacer or complete silver coated tumor prostheses. In the non-infected cases we use for soft reconstruction in 18 pts. a Trevira material.
The follow-up time was at least two years. We did as well clinical, radiological and blood examination as bone scans.
Out of the 24 pts. with an infected prostheses we had 3 re-infections, in one patient an above kee amputation finally was necessary. All infected cases in which we implanted a silver coated prostheses heald. The clinical results were good in 40 pts., moderate in 16 pts. and poore in 8 pts.. The clinical results of the infected cases were less good as in the non-infected cases. There were 6 cases of loosening detected radiological and by bone scans, 4 of them needed another revision.
Conclusion
For the reconstruction of large bone defects in cases of non-infected revisions we recommend cementless anchorage of the stems of the modular prostheses. For infected cases we recommend a two stage procedure. The coating of the surfaces of the prostheses with antimicrobial agents is very helpfull. Our experience with the silver coating show very good results in tumor cases as well in revision cases. But as our animal experiments show up to know there is no possibility for silver coating of the cementless stems of the prostheses.