Geometric total knee arthroplasty I. Conception, design, indications, and surgical technic

A hinged-type of metal artificial knee was developed by Walldius, ^1,2 and Shiers^3,4 and has been reasonably successful. The experience of many, however, has indicated that such a system tends to have certain faults, which include (1) a metal-to-metal articulation that accumulates metallic debris in the knee, (2) sometimes breakage or loosening of the linking bolt or hinge coupling, (3) a loosening of the stem components in the medullary cavities of the femur and tibia, and (4) a fairly high rate of delayed infection (Young HH: Personal communication). Biomechanically and anatomically, a rigidly hinged prosthetic knee does not allow for reasonable simulation of normal knee motions, including rotation. Thus, stresses are placed on all portions of the components, and fracture or loosening may occur in time.