Abstract
Introduction: One of the most important factors, to improve the primary prosthesis stability is the bearing surface between the femoral head and the cup. The connection metal-metal and ceramic-ceramic seems to be one of the best to reduce the loosening rate. The purpose of the study is to evaluate the long-term results of uncemented total hip replacement using the ceramic Mittelmeier enoprosthesis (ceramic cup – ceramic head).
Material and Methods: In the last twenty years, 258 primary ceramic, Mittelmeier type hip endoprosthesis were implanted in our Institution. This surgery was performed in 222 patients (116 women and 106 men), at the average age at the surgery of 45,6 years (range from 18 years to 70 years). In 36 patients the surgery was performed on both hips. The means follow-up was 10,2 years ( range from 4 years to 18,6 years). The most frequent indication for surgery was: in 105 cases idiopathic, in 81 dyspalstic and in 25 posttraumatic coxarthrosis. All patients were evaluated clinically and radiological. For clinical evaluation the classification system proposed by Merle d’Aubigne and Postel with Charnley modification was used. For radiological evaluation the classification system proposed by De Lee and Charnley ( steam) and system by Gruen and Moreland (cup) was used.
Results: Based on above mentioned criteria in 87 hips (33,7%) the final result was graded as very good, in 96 cases (37,3%) as good, in 47 hips (18,2%) as satisfactory and in the remaining 28 cases (10,9%) the final result was poor. The very good and good results were noted in patients older than 50 years with idiopathic coxarthrosis. The poor results were observed in young patients with dysplastic coxarthrosis, especially in cases with poor developed hip joint after the previous hip surgery in the childhood, because of DDH (type III and IV according to Crowe at all. classification system). Only 13 hips (5%) required revision procedures. In 2 cases (0,8%) revision was directed only to the cup, in 6 hips (2,3%) to the steam and in 5 cases (1,9%) it was necessary to exchange both elements.
Conclusion: The long term results and our experience with ceramic uncemented hip endoprosthesis type Mittelmeier are promising. This type of hip prosthesis should be indicated in young patients with idiopathic or posttraumatic coxarthrosis. This indication could give long lasting good clinical and functional results.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
