KNEE JOINT ENDOPROSTHESIS AND METHOD FOR MANUFACTURE OF CERAMIC KNEE JOINT ENDOPROSTHESIS Russian patent published in 1998 - IPC

FIELD: medicine. SUBSTANCE: knee joint endoprosthesis is manufactured from biologically compatible material and provided with antifriction surfaces. All-ceramic endoprosthesis has femoral and tibial components including pin for retaining in bone and platform with pivot joint. Pivot joint has closable mechanism defined by end of tibial component pin head and bottom of rectangular outlet opening leading into cylindrical cavity of pivot joint. End of tibial component pin head intersects bottom of rectangular opening at an angle of 45 deg. Smaller spaces between sides of rectangular opening and flats correspond to pin neck diameter. Intersection angle eliminates disconnection of tibial component. Method involves providing basic materials and preparing ceramic mass; forming billet by hot pressure casting; performing high-temperature drying and preroasting mechanical working; conducting roasting, thermal working and postroasting mechanical working. Preroasting mechanical working involves coarsening of rough surfaces, which are adapted for further engagement with bone tissue. Postroasting mechanical working involves polishing for finishing endoprosthesis to required sizes and grinding of toroidal pair friction surfaces. Method further involves providing two-staged thermal stabilization in vacuum and in atmospheric medium upon termination of thermal treatment. When ultimate postroasting mechanical working is terminated, repeated thermal stabilization process is conducted for eliminating internal stress, with material nominal stress value being controlled. EFFECT: increased efficiency and improved strength of prosthesis. 3 cl, 7 dwg