Clinical application of ceramics in knee arthroplasty was first reported by Langer in 1972, when a non-bone cement alumina ceramic tibial plateau was used.The first total knee replacement system with non-bone cement fixed alumina ceramics combined with ULTRA high molecular weight polyethylene (UHMWPE) appeared in Japan.Later, the system was designed and improved for bone cement fixation (KOM-1, 2, 3).Other UHMWPE combined alumina ceramic TKA systems, such as KC-1, TSD, NCU, LFA-i and YMCK, have also found clinical applications in Japan.A metallic femoral condyle with an alumina ceramic articular surface was also designed to avoid direct contact between the ceramic and the bone.Zirconia ceramic femoral condyles have also been used in Japan (Bi-surface, KU).The Multigen knee system based on cobalt-chromium femoral condyle has also begun to introduce AMC (Biolox@delta) femur prosthetics without changing the design.After 12 months of follow-up, the Clinical score of Biolox@delta Ceramic femoral condyle (Multigen Plus) was good, and no loosening was observed.
Image from: BIOLOX®
In TKA, it is difficult to compare the wear rates of different interfaces. The prosthesis design has a great impact on wear, so relevant data can only be obtained from the same design and in vitro wear studies of different interface materials.For example, on the Shore-Western knee simulator, the wear of the BI-Surface system (Kyocera, Corp, Kyoto, Japan), the zirconium femoral condyle, and the cobalt-chromium femoral condyle of the same design were compared for UHMWPE.The results showed that the UHMWPE wear rate of the zirconia prosthetics was 4 times lower on average, while the surface roughness (Ra) of the cobalt-chromium femoral condyle was 5 times higher than that of the zirconia femoral condyle.In addition, the wear rate is related to the radiation in UHMWPE radiation disinfection.
In another study with different methods of UHMWPE disinfection, knee simulator type and measurement parameters, the wear rates of the FEMORAL condyle of alumina, zirconia and cobalt-chromium alloy in bi-Surface knee system on UHMWPE were compared.The results were still similar. The wear rate of the ceramic component decreased by 5 times on average, while the wear rate of the alumina ceramic component was lower than that of the zirconia ceramic.Damage was observed on the surface of the cobalt-chromium prosthesis, but not on the ceramic prosthesis.In addition, 5 million cycles were performed on knee simulators to compare the performance of co-Cr alloy and AMC femoral condyles against trisomal wear of uHMWPE knee systems.Compared with the cobalt-chromium femoral condyle, the surface of ceramic assembly was not damaged, and the wear of UHMWPE pad was less.
In clinical application, the first-generation TKA ceramic prosthesis has a high loosening rate due to the lack of non-bone cement fixation and bone integration.However, a few well fixed alumina ceramic and zirconia ceramic prosthesis performed well clinically.A variety of designed alumina and cobalt-chromium alloy femoral condyle extractor prostheses (6 to 23 years in the human body) were studied to analyze wear and surface damage.It was found that the surface of the femoral condyle was more damaged and the roughness was higher, which was consistent with the results of in vitro experiments.The UHMWPE pad that forms the joint with the ceramic femoral condyle wears out less.
