[Total hip prosthesis in patients less than 50 years of age. Value of ceramic materials]

87 consecutive cases of sealed total hip prosthesis with an alumina/alumina friction couple, placed in 76 patients less than 50 years old, have been studied. The surveillance period ranged between 2 and 13 years for 74 of them. 51 have been followed over more than 5 years, 10 have been lost out of sight and 3 died. 5 failures are to be deplored, one by fracture of a 22 mm ceramic head, the normal size in this series being 32 mm; the 4 others occurred after 6, 6, 10 and 11 years and are the consequence of a cotyloid loosening. Compared to the other series in literature concerning young patients and therefore those considered to be "at risk", the results obtained are better, especially if the high number of cases re-operated upon in this series (18 prosthesis exchanges out of 87) is taken into account. The actuarial method of Kaplan Meier gives a probability of 94% of keeping the prosthesis for 8 years. It is undoubtedly the quality of the design of the titanium femoral stem and especially the small amount of erosion scraps produced by the alumina/alumina couple which explain this result. The hip replacement must however remain an exceptional indication in a young subject.