BIOMECHANICAL CHARACTERISTICS OF DIFFERENT ARTIFICIAL SUBSTITUTES FOR RABBIT MEDIAL MENISCUS AND EFFECT OF PROSTHESIS SIZE ON KNEE CARTILAGE

Large and small Dacron prostheses were implanted as substitute for the medial rabbit meniscus to investigate whether prosthesis size influences the biomechanical and clinical results. Both prostheses had a higher compression compliance and higher energy storage than the normal meniscus. Knees with sham-operation and meniscus resection were used as controls. Both prostheses led to similar osteophyte formation and synovitis after a 3-month implantation period. Ingrowth to the periphery of the prostheses was found in all cases. Knees with prostheses, no matter what size, had a higher compression compliance than sham-operated knees, but energy storage was similar to normal. Knees with prostheses had a similar cartilage status to sham-operated knees, and had less cartilage degeneration on the tibia than knees with resected menisci. Overall, prosthesis size had no influence on the outcome. Three new prostheses made of coated and uncoated Teflon and Dacron were developed to find a substitute with properties closer to the normal meniscus. Only the uncoated Teflon prosthesis showed similar compression compliance to normal, and had energy storage closer to normal than the other prostheses. These material properties could lead to improved results after implantation.