Wear debris from two different alumina-on-alumina total hip arthroplasties

Abstract

We compared wear particles from two different designs of total hip arthroplasty with polycrystalline alumina-ceramic bearings of different production periods (group 1, before ISO 6474: group 2, according to ISO 6474). The neocapsules and interfacial connective tissue membranes were retrieved after mean implantation times of 131 months and 38 months, respectively. Specimen blocks were freed from embedding media, either methylmethacrylate or paraffin and digested in concentrated nitric acid. Particles were then counted and their sizes and composition determined by SEM and energy-dispersive x-ray analysis (EDXA). The mean numbers and sizes of most alumina wear particles did not differ for both production periods, but the larger sizes of particle in group 1 point to more severe surface destruction. The increased metal wear in group 2 was apparently due to alumina-induced abrasion of the stems. In this study the concentrations of particles in the periprosthetic tissues were 2 to 22 times lower than those observed previously with polyethylene and alumina/polyethylene wear couples.

Ceramic-on-ceramic THA Implants in Patients Younger Than 20 Years

“…In our study, osteolysis could not be detected on AP radiographs in any patient at final followup. The limited occurrence of osteolytic lesions observed with ceramic-on-ceramic bearing couples is thought to be attributable to a lower concentration of wear particles in the periprosthetic tissue around the bearing [4].…”

How Have New Bearing Surfaces Altered the Local Biological Reactions to Byproducts of Wear and Modularity?

“…However, neutrophils were not reported in several other studies of tissue around failed ceramic-on-ceramic implants [4,15,36,44,46], and in one other study, neutrophils were only associated with other features of infection [38]. Several reports have described the clinical difficulty distinguishing infection from other causes of failure of metal-on-metal implants [1,18], and occasional metal-on-metal cases with slightly increased neutrophils but without other features of infection have been noted [37], but most cases of failed metal-on-metal implants lack significant neutrophils.…”

“…(3) Are some types of debris more or less likely to be associated with histologic features suggestive of an immune reaction? (4) Are there sources of metal debris in nonmetal-on-metal implants that might be implicated in an immune reaction? (5) Are there types of debris that induce acute inflammation (neutrophils), thereby resembling the histologic appearance of a periprosthetic infection?…”

Alumina Inlay Failure in Cemented Polyethylene-backed Total Hip Arthroplasty

“…These advantages of alumina materials are related to its distinctive tribologic properties resulting from high scratch resistance and wettability of the material, both of which reduce third-body and adhesive wear. There are three other advantages of alumina: lower linear wear rate than metalon-polyethylene articulation [10]; lower concentration of wear particles in the periprosthetic tissue around the bearing than metal-on-polyethylene articulation [5]; and less release of TNF-a, which is one of the main factors inducing osteolysis, than by polyethylene particles [23]. These advantages are related to avoidance of the acetabular osteolysis observed with alumina-on-alumina THA [13].…”