Over the last 5 decades, total knee arthroplasty (TKA) has evolved to a very common and successful procedure. Currently, TKA is being performed through limited surgical approaches and innovative technology that include rapid recovery programs with early mobilization and return to normal daily activities. Despite all the successful advances achieved, it is estimated that 20% of patients are still not happy with their final outcome. In an effort to improve the clinical results in this group of patients, surgeons and engineers continue to design newer implants implanted with reproducible innovative technology. This current issue of Technique in Orthopedics focuses on these newer TKA designs and techniques.
Some of the new design changes pursue a more anatomic design with an emphasis on better size and shape, along with anatomic positioning of the components. Other newer designs place an emphasis on replicating knee kinematics with either retention of both cruciate ligaments or substituting for both cruciates with a dual cam—postdesign. Another approach to replicate knee kinematics is more conforming articular designs, such as the medial congruent knee or lateral pivot knee. A new look at mobile bearing designs is also presented, as it has been shown to be a clinically successful prosthesis.
Beyond the nuances of the various implant designs, 2 main issues remain significant factors to the long-term durability of TKA: polyethylene wear and component fixation. Improvements in polyethylene wear with antioxidation preparation have led to more wear resistance and potentially greater longevity. Although cement fixation has been considered the gold standard, the role of cementless fixation in TKA has been gaining interest.
Beyond designing new implants, the benefits of these new TKA designs have to be evaluated in the world of value-based medicine and alternate payment plans. Introducing new innovative technologies, such as robotic surgery, adds an additional cost to the procedure but has the potential to improve accuracy and impacting the ultimate outcome.
In closing, we have invited these authors, who have had an impact on TKA, to contribute to this issue of Techniques in Orthopedics and provide their thoughts as we search for the Holy Grail in TKA design. Hopefully, you will find this issue on TKA insightful.
Fred D. CushnerMD
Giles R. ScuderiMD [Black Square] [Black Square] [Black Square] [Black Square]