Dealing with Difficult Total Knee Arthroplasties

Total knee arthroplasties (TKAs) are considered highly successful operations and yet approximately 20% or more of these patients report dissatisfaction with the procedure. Therefore, there is a constant effort to improve upon clinical outcomes aswell as to decrease complication rates.With this in mind, this Special Section comprises a series of reports with new information aimed at improving upon the results of these procedures. In the report by Chen et al, “DressingManagement During Total Knee Arthroplasty: A Systematic Review and MetaAnalysis,” the authors studied themanagement of this aspect of wound closure. They examined 16 reports on infection risk, re-operation risk, and length of time until change was needed for adhesives and mesh dressings, silver-impregnated dressings, and vacuum closures. Their results suggested superior outcomes when using adhesive and mesh dressings for total knee arthroplasties. These closures were found to have lower wound complication risks leading to fewer reoperations as well as readmissions. Monárrez et al report on the long-term follow-up of new implants designed to address the problem of bone loss during revision TKAs in “Two-Year Survivorship and Outcomes of a Three-Dimensional Printed Metaphyseal Cone in the Setting of Revision Total Knee Arthroplasty.” In an investigation of 62 patients who received these implants, the authors found that they provided excellent infection-free and all-cause revision-free survivorship at 2 years. Two reports investigated the effects of prior procedures on subsequent TKAs. Bains et al, investigated the temporal relationship between intra-articular knee injections and TKAs and the effect on manipulation under anesthesia, surgical site infections, and periprosthetic joint infections (PJIs) in “Delaying Total Knee Arthroplasty more than Four Weeks after Intra-articular Knee Injection Does Not Further Decrease Risk of Septic Revision.” They found that intraarticular knee injections less than 4 weeks before TKA increased the risk for PJI, but greater than 4 weeks did not confer increased infection risk. In “Knee Arthroscopy Prior to Total Knee Arthroplasty: Temporal Relationship to Surgical Complications” by Sax et al, the authors studied patients undergoing TKAs who had a past surgical history of knee arthroscopy to determine the optimal timing between operations. They found that delaying a TKAby 24weeks after knee arthroscopy is not associated with a decreased risk of septic revisions, though there was still an increased risk of manipulations under anesthesia. In the report by Kahan et al titled “Unicompartmental Knee Arthroplasty Has Lower Infection, Conversion, and Complication Rates Compared to High Tibial Osteotomy,” the complication rates between unicompartmental knee arthroplasties (UKAs) and high tibial osteotomies were compared. Their results suggest that UKAs may have lower infection, dislocation, and periprosthetic fracture rates, as well as fewer conversions to TKA. “Robust Randomized Controlled Data is Lacking in Total Joint Arthroplasty” by Chen et al focused onTKA randomized controlled trials (RCTs). They found that only a few RCTs focused on prosthetic designs and most had small sample sizes, with a substantial amount being follow-up studies. Therefore, the authors believe that other study designs, such as randomized database, or registry analyses, are also appropriate in this rapidly advancing field of joint arthroplasty for the continuous evaluation and approval of new prostheses and techniques. As the challenges of total knee arthroplasties evolve, we need to continue to reassess this procedure to optimize safety and outcomes. Therefore, this Special Section provides readers various current analyses of a certain subsets of routine and difficult total knee arthroplasties.