Bone microstructure and cement-bone interfacial biomechanics of tibial plateau of osteoarthritis and rheu-matoid arthritis / 医学研究生学报

ABSTRACT

Objective Bone cement joint prosthetic aseptic loosening always occurs in the bone cement-bone interface, while the mechanical strength of the interface mainly depends on the microstructure and adhesive strength.The aim of this study was to ex-plore the bone microstructure and the cement bone interfacial biomechanics of osteoarthritis(OA) and rheumatoid arthritis(RA), and also discuss the correlation. Methods Twenty trabecular bone specimens of tibial plateaus were taken from OA and RA patients who underwent total knee arthroplasty( TKA) .The microstructural parameters of the trabecular bone specimens were measured by Skyscan1176 microcomputed tomography.The bone specimens were made into cementbone models, which were tested by INSTRON strength tester.The association of bone microstructure and interfacial shear stress was analyzed subsequently. Results ①Bone volume fraction ( BV/TV) ( r=-0.313) , trabecular thickness ( Tb.Th) ( r=-0.340) ,trabecular spacing ( Tb.Sp) ( r=0.345) of OA had obvious correlation to shear strength (P<0.05).The cement-bone interfacial strength of medial tibial plateaus[(87.45±52.50)N] was lower than lateral tibial plat-eaus[(177.25±71.11)N] of OA (P<0.05).②Bone volume fraction (BV/TV)(r=0.343), trabecular number (Tb.N)(r=0.391) of RA had obvious correlation to shear strength (P<0.001).The cement-bone interfacial strength of lateral tibial plateaus[(62.23±46.22) N] was lower than medial tibial plateaus[(79.20±56.37N)] of RA (P<0.05).③The interfacial strength of OA[(132.35±76.64)N] was higher than RA[(71.05±51.55)N] (P<0.05). Conclusion There are differences of microstructure between OA and RA, which lead to the distinction of strength of cement -bone interface.And it has a certain guiding role of analyzing the biomechanics in TKA.