FUNCTIONAL ENDOPROSTHESIS FOR THE KNEE (KEIO TYPE)

Since 1972, many prosthesis for the knee joint have been reported. They are, however, designed only for hinge and rolling functions neglecting the screw-home function. Surgical damage by massive bone resection would not permit secondary operation even if it is required and only osteosynthesis or hinge prosthesis are indicated thereafter. Musculo-tendinous stability being absolutely required on surgery, ligamentous transfer is often accompanyed in those prosthesis.In view of the above, we deviced a new functional endoprosthesis for the knee joint which satisfies all three functional phases of knee motion and maintains sufficient stability.The functional endoprosthesis (Keio type) is indicated for osteoarthritis, rheumatoid arthritis and some type of condylar fracture. Operative damage by this endoprosthesis is fairly less and secondly reconstruction using any type of similar prosthesis may still remain the treatment of second choice.