How to Improve TKR in Obese Patients

Obesity affects 35% of the adult population in the U.S. A new literature review published in the Journal of the American Academy of Orthopaedic Surgeons (JAAOS) identifies strategies to improve total knee replacement (TKR) outcomes in patients with obesity. The work, entitled, “Morbid Obesity and Total Knee Arthroplasty: A Growing Problem,” appears in the March 2017 edition.

“Until recently, little was known about the outcomes of patients with obesity undergoing TKR,” said lead study author and orthopedic hip and knee surgeon J. Ryan Martin, M.D., in the March 1, 2017 news release. “We sought to review what information is known and what areas need further investigation.”

As indicated in the news release, “Researchers also found that excess soft tissue in patients with obesity can obstruct visibility in the treatment site during surgery. This lack of visibility can result in difficulty achieving proper alignment and implant fixation as well as longer surgical time. Techniques such as computer-assisted alignment may expedite surgery, and minimize complications.”

Dr. Martin told OTW, “Initially, I became interested in the topic of obesity and TKA during a research project I was working on to evaluate the outcomes of obese patients that underwent bariatric surgery prior to total knee arthroplasty. I found in this study, that compared to patients that were obese that did not undergo bariatric surgery prior to TKA, the bariatric patients did worse even with a lower body mass index. This project demonstrated to me that obesity is a complex issue and further research is necessary to improve outcomes in this patient population undergoing primary TKA.”

“This study compiles the latest research on obesity into a single article. It demonstrates the strengths and weakness of our current understanding of obesity and total knee replacement. The majority of the articles reviewed were published within the last five years.”

“Preoperatively, nutritional optimization appears to be a limitation of many of the current studies available. This may improve patient outcomes but further investigation is necessary before recommendations can be made. Intraoperatively, utilizing exposure techniques that improve visualization may decrease intraoperative complications. Additionally, the use of a stemmed tibial component may decrease the risk of aseptic tibial loosening in this patient population. Postoperatively, obese patients may have multiple medical comorbidities including diabetes, coronary artery disease, etc. These comorbidities should be closely monitored as they may impact patient outcomes.”

“Performing a TKA in an obese patient is not a routine TKA. Careful perioperative planning can lead to significantly improved results in this patient population. Nutritional and medical optimization appear to be two key factors in improving outcomes.”