Concepts of the Modern Ceramic on Ceramic Total Hip Arthroplasty and Early Results

We reviewed the results of 70 total hip replacements utilizing a modern ceramic on ceramic total hip prosthesis in 60 patients. The age of the selected patients ranged from 25 to 76 years (mean, 46 years). The diagnoses at the time of implantation were osteoarthritis (33 patients), avascular necrosis (29 patients), developmental hip dysplasia (four patients), rheumatoid arthritis (one), and post-traumatic arthritis (three patients). All procedures were primary arthroplasties. The average time of follow-up was at least three years with the average being 39 months. Follow-up evaluation consisted of a physical examination, radiographs, a SF12 questionnaire and a Harris hip score rating at 6 weeks, 3 months, 6 months, and then 12 months post-operatively. Yearly evaluations were performed after the initial 12 month follow-up period. At the time of follow-up, no evidence of aseptic loosening was noted either clinically or radiographically. There were two dislocations, in which one required an immediate revision for anterior instability. Another revision was required for an acetabular cup migration in a patient with severe osteoporosis. There were no ceramic component fractures. Experience with this ceramic on ceramic total hip implant has been encouraging. Problems which had plagued older ceramicceramic articulating hip models have largely been eliminated by using state of the art hybrid hip arthroplasty designs and reliably high grade alumina quality. The use of alumina ceramics in total hip arthroplasty has dated back over 30 years ago in Europe. Boutin implanted the first ceramic-on-ceramic cemented hip replacement in France in 1970 [1]. During the next few years, early experience with ceramic couplings began to emerge from Germany. Biomechanical and biocompatibility testing confirmed alumina as being a safe wear and corrosion resistant material with a low coefficient of friction [2–6]. Griss [7] and Mittelmeier [8] began implanting both cementless and cemented versions of the alumina device with reasonable short-term outcomes. Despite improvements in taper technology, surface polishing, and ceramic grade, the earlier failures eroded confidence in these devices especially in light of Charnley’s early successes with the standard metalon-polyethylene prostheses. Later failures of the ceramic articulations were the result of loosening and not ceramic fractures. Most notable is the experience with the Autophor (Smith & Nephew Richards, Memphis, TN), which was the only ceramic-ceramic prosthesis marketed in the United States at the time. This implant had multiple design flaws not involving the ceramic bearings. These included a monoblock screw-in acetabular component without surface coating, a large skirt causing impingement, and a cementless femoral stem designed for macro-interlocking without any biological coating. Hence, the results were less than satisfactory [9]. Yoon et al. also reported their experience with this ceramic-on-ceramic total hip system. They found the prosthesis to have a high rate of loosening after 5 years from implantation. Failure was largely from the fixation of the acetabular component and the resulting osteolysis was documented [10]. Almost two decades ensued before the next generation of ceramic devices was reintroduced to the United States. Evidence began to implicate polyethylene as the cause of aseptic loosening of total hip replacements subsequently limiting their survival despite advancements in fixation, metallurgy and technique [11–14]. Polyethylene was also determined to be highly vulnerable to third body wear resulting in rapid accumulation of polyethylene debris and subsequent aseptic loosening. While the susceptibilities of polyethylene were being uncovered, advancements in both the fixation of implants and other bearing surface materials were being made. Efforts to identify alternate bearing materials intensified, and the redesigned and upgraded ceramic-on-ceramic coupling emerged as a potential solution. We present three-year results of our first 60 patients who were implanted with a modern ceramic-on-ceramic total hip replacement as part of the Food and Drug Administration approved Investigational Device Exemption protocol along with information for the general orthopaedic surgeon regarding the features of this device. Materials and Methods In 1997, the Food and Drug Administration granted an Investigational Device Exemption to Wright Medical Technology (Arlington, TN) for conducting a clinical research trial used the TranscendTM modern ceramic-on-ceramic total hip replacement (Fig. 1). As part of a larger multi-center study, the series presented include the first sixty patients in this clinical trial who were implanted with this device at our institution. All patients enrolled in this study signed a conDepartment of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA. Address correspondence to: Jonathan P. Garino, M.D., Department of Orthopaedic Surgery, Hospital of University of Pennsylvania, 3400 Spruce Street, Two Silverstein Pavillion, Philadelphia, PA 19104. The University of Pennsylvania Orthopaedic Journal 14: 1–4, 2001 © 2001 The University of Pennsylvania Orthopaedic Journal