Ceramic History
Both cemented and non-cemented fixation in total hip arthroplasty have found broad clinical acceptance in the orthopaedic community. The weakest link in hip replacements has shifted from fixation issues to the wear debris generated by the articulating surfaces. When polyethylene is used as a bearing surface, polyethylene debris is generated in the sub-micron particle size range.1 This debris is widely accepted as a cause of osteolysis.2,3 The goal of eliminating poly wear debris has led to renewed interest in ceramic articulation.
Ceramic-on-ceramic articulation was first attempted in the 1970's and again in the early 1980's, each time resulting in limited clinical success.4,5 During the same time period, Sir John Charnley was experiencing good results with his metal on polyethylene system.6 These two factors, when combined with the orthopaedic community's focus on new press-fit implants during the 1980's, caused ceramic-on-ceramic articulation development to halt.
In 1977, Sedel began using a cemented titanium alloy stem with a Ceraver Osteal one piece alumina ceramic cup. These devices are shown in FIGURES 1 & 2. The series demonstrated a prosthesis life-expectancy of 97.8% at eight years. In an analysis of their failed prosthesis, the authors concluded that the failures were due to technique and not materials.7
FIGURE 1 | Ceraver Osteal Stem
FIGURE 2 | Ceraver Osteal Cup and Femoral Head that were sold as a matched pair.
In the United States, the AUTOPHOR™ ceramic prosthesis was introduced in the early 1980's. The prostheses consisted of a threaded cup and fenestrated stem design, as shown in FIGURES 3 & 4. Mahoney, et al, implanted 42 of these prostheses from 1982 to 1985. At an average of 51 months, there was a combined rate of failure for both the cup and stem of 35 per cent. The authors attribute the unsatisfactory results to inadequate cup performance and a poor quality of fit between the femoral stem and the femoral canal. In the end, the authors believed "that the ceramic articulation performed well and did not contribute to the unsatisfactory results."5
O'Leary et al had similar findings when using the AUTOPHOR™. The authors implanted 69 hips and had a 27% revision rate with an average time to revision of 26.2 months. The conclusions of the study were that the failure of the prosthesis could be "attributed to technical and prosthetic design considerations" and "failure seemed not to be to any factors pertaining to the ceramic-on-ceramic bearing."8
FIGURE 3 | The AUTOPHOR™ Cementless Stem. Symbols A, B, C were designated as zones on the stem for radiographic analysis.
