Papers by Keyword: Clinical Results

Abstract: In the late 1970s, we started the clinical use of total knee prostheses (TKPs) composed of alumina ceramic. In this study, we investigated the long-term clinical performance of ceramic TKPs. First-generation ceramic TKPs were used between 1981 and 1985; second-generation TKPs, between 1990 and 1996 and third-generation TKPs, between 1993 and 1998. We examined the findings of clinical radiographic observation. A total of 137 first-generation ceramic TKPs were followed up for 20–23 years after implantation. All the rates of loosening, sinking and revision were higher with cementless fixation than with cemented fixation. In the second- and third-generation TKPs, all the components were implanted using bone cement. In 249 joints that were followed up for 6–14 years, neither loosening nor sinking was observed. No osteolysis was observed in any case. We compared the wear of metal TKPs and ceramic TKPs that were retrieved after long-term use. Metal TKPs exhibited a higher wear rate than ceramic TKPs, and they also exhibited scratched surface damages. The lower wear rate and considerably less surface damage observed in our previous study suggest the long-term durability and performance of ceramic TKPs.

Abstract: In total hip prosthesis (THP), we have been using alumina ceramic femoral heads to reduce polyethylene debris and the modified cementing technique, which was named “interface bioactive bone cement (IBBC)” method to improve implant fixation. In this study, we investigated the long-term clinical performance of THPs with an alumina ceramic head and IBBC method. From 1986 to 1988, 285 joints (215 patients) were operated on by a senior surgeon, and 265 joints (192 patients) could be followed up. The presence of radiolucent lines, loosening, osteolysis and ultrahigh-molecular-weight polyethylene (UHMWPE) socket wear were observed. In IBBC, a radiolucent line appeared as a ’space’, and loosening appeared as a ’separation’ between the HA layer and the cement. A ‘space’ appeared in 3 joints (1.4%) on the acetabulum and in 4 joints (1.8%) on the femur, while a ‘separation’ appeared in 3 joints (1.4%) on the acetabulum. Osteolysis was noted in 1 joint (0.5%) on the acetabulum and in 2 joints (0.9%) on the femur. No revision surgery was required. In our previous study, we reported that the thickness of the socket affected its clinical wear rate and that the wear rate of sockets with an alumina ceramic head was 20% lower than that of sockets with a metal head. By reducing wear debris through the use of ceramic heads, osteolysis could be reduced. Long-term fixation of THPs to the bone has been achieved by using IBBC. Thus, the long-term clinical results of THPs with an alumina head that were fixed using IBBC were excellent.

Abstract: Improved cement technique by interposing less than two layers of hydroxyapatite (HA) granules between bone and bone cement at the cementing (Interface Bioactive Bone Cement : IBBC) have been performed in total knee arthroplasty (TKA). 140 knees (120 patients) could be followed up clinically and radiologically. As a control, clinical results of TKA with conventional cementing (Non-IBBC) were used. In IBBC cases, the appearance rate of the radiolucent lines on the tibial components and the periprosthetic osteolysis of the tibial components were significantly low. In IBBC, bone cement bound to HA mechanically immediately after surgery and HA granules bound to the bone physicochemically after bone ingrowth into the spaces around the HA granules. Thus, we believe that IBBC is a method combining the advantage of cementless HA coating and bone cement.