A Study for a retrieved implant of ceramic-on-ceramic total hip arthroplasty

A Mittelmeier-type ceramic on ceramic total hip arthroplasty (THA) was retrieved because of aseptic loosening 17 years after implantation. The extent of wear was assessed by scanning electron microscopy. The synovial fluid and the tissue surrounding the implant were also examined. Scanning electron microscopy analysis of the ball head showed that the main wear zone had grade IV wear. The stripe wear zones showed grain pullout regions (grade 5 wear). Pathologically, chronic inflammation was observed in the surrounding tissue. The debris particles in the synovial fluid were polygonal and approximately 3 x 4 microm. Thus, the Mittelmeier-type THA proved excellent wear resistance. Further longevity of ceramic on ceramic THA may indeed become a reality with improvement of the design and quality of alumina.