[Midterm results and revisions of the thrust plate prosthesis (TPP)]

Abstract

Aim: Although already in use for 20 years, the concept of the metaphyseal anchored thrust plate prosthesis has not yet gained general acceptance. Clinical and radiological follow-up examinations were carried out 5 to 8 years after implantation of a TPP. We tried to answer the question if the metaphyseal anchorage of the cement-less TPP is equal to a diaphyseal anchorage of a cement-less stem prosthesis and to define the advantages of the TPP.

Methods: We included 170 of the patients from our clinic with an implanted TPP in this study. Furthermore we reviewed the results of 30 revision hip arthroplasties of the TPP. The clinical examination were carried out using the Harris hip score while the radiological examinations were performed on the basis of predefined criteria.

Results: We found good clinical results. The preoperative Harris score of 48.7 increased to 93.7 at 24 months postoperatively. Radiolucencies were detected and were of varying relevance in dependence on their localization. The Kaplan-Meier survival analysis at 8 years was 90.5 %. The clinical results after changing the TPP were also good to excellent. The mean Harris hip score was 87.3.

Conclusion: Our study suggests that in spite of a slightly higher aseptic loosening rate in comparison to the cement-less stem prosthesis, the thrust plate prosthesis proved to be worthwhile. On the basis of previous experience we assume that the TPP is a good alternative implant especially for young patients.