[Material-specific wear of ceramic/ceramic sliding surfaces in revised hip endoprostheses--clinical and technological considerations]

Morphologic characteristics of periprosthetic tissues from hip prostheses with ceramic-ceramic couples: a comparative histologic investigation of 18 revision and 30 autopsy cases

Pseudocapsules and interface membranes from 18 revision cases having hip prostheses with ceramic-ceramic couples and 30 autopsy specimens (6 with ceramic-ceramic couples, 7 with ceramic-polyethylene combinations and 17 with metal-polyethylene combinations) were histomorphologically analyzed, including a semiquantitative grading of the wear particles and histologic changes. Unlike the revision cases, which usually showed ceramic wear particles in the adjacent tissues, only half of the autopsy cases revealed ceramic wear. As compared to the ceramic-polyethylene and metal-polyethylene couples, the alumina on alumina combinations showed a thinner synovial layer with reduced villous transformation and smaller infiltrates of macrophages and necroses, which can be explained by the absence of polyethylene wear. Metal-polyethylene couplings produced more than twice as many polyethylene wear particles with correspondingly more marked foreign body reaction than the ceramic-polyethylene couplings.

The ceramic cup type Lindenhof. Results 10-14 years after implantation

We followed up 10-14 years postoperatively the 106 ceramic cups type 'Lindenhof' that were implanted in the years 1978-1982. In that time, only 7 (6.6%) cups had to be changed due to aseptic loosening. Examination of 73 (68.9%) cups showed that only 4% of the patients were dissatisfied. Using the score of Merle d'Aubigne, we found 89% good and very good results. The high number of cup migrations reported by other authors could not be verified: we saw 35% in all. Most of them appeared in the early postoperative period, stabilized themselves and were not accompanied by pain. Our 10-year survival rate for this ceramic cup is 92%, including the septic changing of arthroplasties.