Current Controversies in Total Knee Arthroplasty—Part 2

This second of the two special focus section issues of The Journal of Knee Surgery continues to examine current controversies in TKA. Surgeons continue to push the envelope, with the goals being to improve patient satisfaction, improve clinical outcomes, and decrease revision surgery. We are fortunate to have leading experts in the field contributing to this special focus section issue, and the authors come from a wide range of clinical practices with a wealth of clinical experience that they are willing to share.

In the first article of this issue, Dr. Menighini and colleagues challenge the long- held belief that a cam and postmechanism is necessary when the posterior cruciate ligament is sacrificed. They discuss the current literature and their experience, with an anterior lipped and more conforming tibial liner, which obviates the need for a cam and postmechanism of a traditional posterior stabilized design. This can provide all the benefits of a posterior stabilized knee design without the drawbacks, thereby increasing operative efficiency, decreasing inventory, and improving patient outcomes.

The burden of revision TKA is increasing, and it will continue to do so as more primary TKA are being implanted. Current implant systems allow the surgeon to customize the prosthesis for each patient based on the existing deformity and amount of bone that remains. Successful revision surgery requires a stable foundation for the implants, and the use of stems continues to be a cornerstone tool for fixation by bypassing deficient or deformed bone and gaining stable fixation. The study by Dr. Driesman and his coauthors discusses the controversy regarding the use of cement for these stems, presenting the benefits and pitfalls of the two techniques. They, then, examine future questions that need to be addressed to help determine the best treatment options in various revision scenarios.

Initially, the tibial component was a monoblock polyethylene component. In the early 1980s, there was great enthusiasm for a metal backed acetabular component in total hip arthroplasty, and this belief was extended to the tibial component in TKA. The thought was that if the tibial tray was stiffer with less bending, this would lead to lower failure rates. Also, there was a perceived benefit to modularity. Over time, however, these benefits have not materialized, and while the cost of metal backed tibial component is three to four times the cost of an all-polyethylene component, the outcomes are similar. The article by Dr. White and colleagues reviews the literature on these two types of tibial implants, and it discusses the potential economic savings in these times of economic strain on the health care system and potential for cost savings for an increasingly popular procedure.

The use of a tourniquet has been the standard since the beginning, but recently its use has been called into question. Dr. Spangehl et al discuss the benefits and drawbacks of tourniquet use in TKA, and why this has become such an issue. They provide evidence-based guidelines on what surgeons should be doing in their practice. Finally, the issue of inpatient versus outpatient TKA is presented. Today, many centers across the United States are performing outpatient TKA, something that the Centers for Medicare and Medicaid Services, an agency of the U.S. Department of Health and Human Services, finally recognized in January of 2018. However, there has been much confusion and misconceptions, as to what this exactly means, and a great deal of misinformation has been propagated by supposed experts. Dr. Barnes and colleagues, who have significant expertise and experience in this area, present their rational and indications for outpatient TKA, and how one goes about setting up such a program.

Once again, I am deeply indebted to all the authors for their hard work and efforts that went into producing this special focus section issue. Without their commitment to excellent patient care and their interest in sharing their knowledge with orthopaedic surgeons, this would not have been possible. I strongly believe that the information presented in this issue will provide orthopaedic surgeons with the resources necessary to improve the care of their patients, leading to better outcomes and higher patient satisfaction.