The Evolution of Total Knee Replacements

Today’s total knee arthroplasty prostheses were built on the shoulders of titans in the field of arthroplasty including Michael Freeman, John Insall, and Chitranjan Ranawat. Many of the advances in prosthesis design took place in the early 1970s with differences between functional and anatomic approaches that still hold true today. The functional approach aimed to resect the posterior cruciate ligament (PCL) to allow for the greatest deformity correction. Advances were made to optimize mediolateral stability in the face of PCL resection. The anatomic approach aimed to preserve the PCL to allow for a more anatomic total knee replacement. Following the initial obstacles of total knee replacement stability, modular components were developed to allow for more complex joint reconstruction. Better understanding of anthropomorphic differences in knee anatomy as well as cultural requirements across communities led to the further development of gender specific and high-flexion designs. With each unique design developed, the advancements of all previous designs were carried forward.