History of total knee replacement.

In the early 1970s, the condylar knee was developed independently in the United States and overseas. The concept of replacing the tibiofemoral condylar surfaces with cemented fixation, along with preservation of the cruciate ligaments, was developed and refined. To correct severe knee deformities, the condylar knee with posterior cruciate-sacrificing design was introduced, also in the early 1970s. By 1974, replacing the patellofemoral joint and either preserving or sacrificing the cruciate ligaments had become standard practice. Subsequently, condylar knee designs were improved to include modularity and noncemented fixation, with use of universal instrumentation. Today, over 19 companies in the United States distribute total knee implants of three different types: cruciate-preserving, cruciate-substituting, and TC-III. Six major companies are actively involved in designing mobile-bearing knees. Future developments, such as navigation-guided surgery, enhanced kinematics, and wear-resistant bearing surfaces with better fixation, promise a consistent evolution for the total knee replacement.