Wear of 36-mm BIOLOX^® delta ceramic-on-ceramic bearing in total hip replacements under edge loading conditions

Abstract

Ceramic-on-ceramic bearings have become of great interest due to the substantial improvements in the manufacturing techniques and material properties and due to polyethylene wear debris-induced osteolysis and the issues with metal wear debris and ion release by metal-on-metal bearings. Edge loading conditions due to translational malpositioning (microseparation conditions) have been shown to replicate clinically relevant wear mechanisms and increase the wear of ceramic-on-ceramic bearings; thus, it was necessary to test new bearing materials and designs under these adverse conditions. The aim of this study was to assess the effect of increasing head size on the wear of BIOLOX(®) delta ceramic-on-ceramic bearings under edge loading conditions due to rotational (steep cup inclination angle) and translational (microseparation) malpositioning. In this study, six 36-mm ceramic-on-ceramic bearings (BIOLOX delta, CeramTec, Germany) were tested under standard and edge loading conditions using the Leeds II hip simulator and compared to the 28-mm bearings tested and published previously under identical conditions. The mean wear rate under standard gait conditions was below 0.1 mm(3)/million cycles for both the 28-mm and the 36-mm ceramic-on-ceramic bearings, and increasing the inclination angle did not affect the wear rates. The introduction of microseparation to the gait cycle increased the wear rate of ceramic-on-ceramic bearing and resulted in stripe wear on the femoral heads. Under microseparation conditions, the wear rate of size 36-mm bearings (0.22 mm(3)/million cycles) was significantly higher (p = 0.004) than that for size 28-mm bearings (0.13 mm(3)/million cycles). This was due to the larger contact area for the larger bearings and deprived lubrication under edge loading conditions. The wear rate of BIOLOX delta ceramic-on-ceramic bearings under microseparation conditions was still very low (<0.25 mm(3)/million cycles) compared to earlier generation ceramic-on-ceramic bearings (BIOLOX forte, 1.84 mm(3)/million cycles) and other bearing materials such as metal-on-metal bearings (2-8 mm(3)/million cycles).

Do Alumina Matrix Composite Bearings Decrease Hip Noises and Bearing Fractures at a Minimum of 5 Years After THA?

“…AMCs, also known as fourth-generation ceramics, provide superior strength with fracture toughness and allow manufacturing thinner liners with larger heads compared with earlier ceramic materials [1,4]. Although these material improvements would be expected to decrease clinical concerns associated with previous-generation alumina bearings such as ceramic fracture and squeaking, little is known about this new bearing material and intermediateterm effects are unclear [7,15,27].…”

“…These limitations of pure alumina characteristics required the development of improved ceramic materials. The alumina matrix composite (AMC) material, Delta ceramics (CeramTec 1 , Plochingen, Germany), has been reported to increase ceramic strength with fracture toughness over previous pure alumina in the laboratory setting and thus to allow manufacturing thinner acetabular liners and consequent larger heads [1,4]. Theoretically, these material improvements would be expected to decrease mentioned concerns associated with previousgeneration alumina bearings.…”

“…Therefore, we investigated: (1) What is the frequency of bearing-related complications (fracture, noise, and dissociation) with ceramic-on-ceramic AMC bearings in cementless THA? (2) What other complications arose in patients treated with these bearings?…”

Tribocorrosion of hard-on-hard total hip replacements with metal and ceramic counterfaces under standard and adverse loading conditions

“…This is F 11. This stripe pattern is typical of edge or rim loading and normally noted in Ceramic-onCeramic devices [35,36]. This action results in a more aggressive depassivation of the surface, as well as an increase in the generation of wear debris, resulting in a significantly higher rate of corrosion and therefore a higher rate of release of metallic ions directly at the bearing surface.…”

CORR Insights®: Do Alumina Matrix Composite Bearings Decrease Hip Noises and Bearing Fractures at a Minimum of 5 Years After THA?

“…The introduction of an alumina matrix composite material, Delta ceramics (CeramTec, Plochingen, Germany), could potentially reduce the risk of dislocation by allowing for a larger head and thinner liner [5]. This material, which includes embedded zirconia particles, is believed to provide an improved fracture resistance during the initial phase [1,2]. The zirconia particles in the alumina matrix composite bearing can stop a crack from spreading by changing its phase from tetragonal to monoclinic.…”