Improved mechanical long-term reliability of hip resurfacing prostheses by using silicon nitride

Abstract

Although ceramic prostheses have been successfully used in conventional total hip arthroplasty (THA) for many decades, ceramic materials have not yet been applied for hip resurfacing (HR) surgeries. The objective of this study is to investigate the mechanical reliability of silicon nitride as a new ceramic material in HR prostheses. A finite element analysis (FEA) was performed to study the effects of two different designs of prostheses on the stress distribution in the femur-neck area. A metallic (cobalt-chromium-alloy) Birmingham hip resurfacing (BHR) prosthesis and our newly designed ceramic (silicon nitride) HR prosthesis were hereby compared. The stresses induced by physiologically loading the femur bone with an implant were calculated and compared with the corresponding stresses for the healthy, intact femur bone. Here, we found stress distributions in the femur bone with the implanted silicon nitride HR prosthesis which were similar to those of healthy, intact femur bone. The lifetime predictions showed that silicon nitride is indeed mechanically reliable and, thus, is ideal for HR prostheses. Moreover, we conclude that the FEA and corresponded post-processing can help us to evaluate a new ceramic material and a specific new implant design with respect to the mechanical reliability before clinical application.

Bioceramics for Hip Joints: The Physical Chemistry Viewpoint

“…But, are things actually so simple? The need for high toughness and structural reliability would suggest driving our attention on Si 3 N 4 ceramics as a primary covalent-bonded candidate for arthroplastic joint applications [132,133,134,135]. Toughness of a commercially available Si 3 N 4 biomaterial (manufactured by Amedica Corporation, Salt Lake City, UT, USA) has been reported as two to three times higher than that of monolithic Al 2 O 3 and was also appreciably higher than that of the leading Al 2 O 3 -ZrO 2 composites (Composite A in the previous section), toughened by polymorphic transformation [136].…”

Evaluation of silicon nitride as a wear resistant and resorbable alternative for total hip joint replacement

“…The less detrimental biological response may give a reduced number of revisions as an end result. However, whereas the wear and tribofilm formation of Si 3 N 4 sliding against itself in water have been investigated, 10 , 11 , 14 , 15 , 21 there is a lack of knowledge on the wear and tribofilm formation in PBS and bovine serum and also regarding the solubility of the wear particles.…”

The Rationale for Silicon Nitride Bearings in Orthopaedic Applications

“…Laboratory investigations using finite element analyses support the use of silicon nitride in load-bearing hip resurfacing components; these differ from hip replacement in that the diseased femoral head is resurfaced with a prosthetic cap, rather than being cut out and replaced entirely. 32 Stress distributions in the proximal femur bone with implanted silicon nitride hip prostheses are similar to those of intact, healthy bone. Mazzocchi et al investigated silicon nitride ceramics for their potential use in orthopaedic implants, and validated several properties that are critical to biomedical applications, such as wetting behavior and wear performance that simulates conditions typical of a hip joint prosthesis.…”