Osteolysis and ceramic bearing surfaces

Failure analysis of alumina on alumina total hip arthroplasty with a layered acetabular component: minimum ten-year follow-up study

This prospective study reports the outcome of total hip arthroplasty (THA) performed in a consecutive series of patients using an alumina ceramic on a ceramic-layered component (Alumina-Bearing-Surface system). The cohort consisted of 270 hips in 229 patients. The study evaluated the clinical and radiological results over a mean follow-up of 11.4 years. Revision THA was performed on 58 hips, including alumina alternative failure in 50 hips, loosening in 4 hips, recurrent dislocation in 2 hips, stem neck fracture in 1 hip and hematoma in 1 hip. The survival rate was 68% with revision for any reason as the end point. The risk factors of implant failure are the preoperative range of motion of the hip joint and postoperative dislocation.

Concerns about ceramics in THA

Currently available ceramic materials are superior to those used originally in total hip arthroplasty, which should translate into a much lower complication rate than what has been reported previously. In spite of this, a number of concerns remain. The ceramic-on-ceramic articulation is not immune to wear and surface damage. Conditions associated with ceramic wear include vertical cup position, femoral neck impingement, and femoral head separation. A unique pattern of stripe wear has been described as something that results from microseparation during gait. Catastrophic failure, although rare, continues to be a concern, and not all fractures can be predicted by proof testing. Revisions needed because of ceramic fractures can be extensive, and the results of the revision procedures can be compromised by the presence of highly abrasive particulate debris that is retained. Other concerns include the generation of debris from modular interfaces, neck damage and debris generation from impingement of some designs, inability to use a ceramic head a second time on a metal trunnion, and the dramatic loss of head and liner options intraoperatively. Although ceramics show great promise as a lower wear articulation, manufacturing and design modifications and improvements will continue in an attempt to address the substantial concerns that persist.