Keramik-Keramik-Gleitpaarungen in der primären Hüftendoprothetik

Abstract

The main reason for total hip arthroplasty (THA) revision is the wear-related aseptic loosening. Younger and active patients after total joint replacement create high demands, in particular, on the bearings. The progress, especially for alumina ceramic-on-ceramic bearings and mixed ceramics have solved many problems of the past and lead to good in vitro results. Modern ceramics (alumina or mixed ceramics containing alumina) are extremely hard, scratch-resistant, biocompatible, offer a low coefficient of friction, superior lubrication and have the lowest wear rates in comparison to all other bearings in THA. The disadvantage of ceramic is the risk of material failure, i.e., of ceramic fracture. The new generation of mixed ceramics (delta ceramic), has reduced the risk of head fractures to 0.03-0.05 %, but the risk for liner fractures remains unchanged at about 0.02 %. Assuming a non-impinging component implantation, ceramic-on-ceramic bearings have substantial advantages over all other bearings in THA. Due to the superior hardness, ceramic bearings produce less third body wear and are virtually impervious to damage from instruments during the implantation process. A specific complication for ceramic-on-ceramic bearings is "squeaking". The high rate of reported squeaking (0.45 to 10.7 %) highlights the importance of precise implant positioning and the stem and patient selection. With precise implant positioning this problem is rare with many implant designs and without clinical relevance. The improved tribology and the presumable resulting implant longevity make ceramic-on-ceramic the bearing of choice for young and active patients.

A Mid- to Long-Term Follow-Up Experience with a Specific Metal-on-Metal Total Hip Arthroplasty Design

“…Hard bearings such as COC and MoM couplings seemed to fulfil such characteristics. 26 27 28 29 30 However, first-generation implants failed due to aseptic loosening or other mechanical issues. 31 32 33 34 Particularly, the first MoM implants dramatically failed because of brittleness.…”

Komplikationen in der Hüftchirurgie beim Rheumatiker

“…Nachteilig bei dieser Materialkombination ist die sehr seltene Gefahr eines Bruches entweder des Keramikkopfes oder des Kera- mikinlays. Die neuen Deltakeramiken zeigen ein Frakturrisiko für den Kopf von 0,002 % und für das Inlay von 0,02 % [15].…”

“…Neu aufgetretene Gelenkgeräusche wie ein hochfrequentes Quietschen oder Reiben können ein Warnsignal für Probleme von Keramik-Keramik-Gleitpaarungen sein. Allerdings verursachen 0,45-10,7 % aller Keramik-Keramik-Gleitpaarungen Geräusche [15]. Die Bedeutung und Revisionsbedürftigkeit wird kontrovers diskutiert [32].…”