20 pound weight loss improves TKA outcomes in obese

Elizabeth Hofheinz, MPH, MEd. 

Morbidly obese patients who dropped at least 20 pounds before total knee arthroplasty had a shorter length of stay in the hospital and a reduced chance of having to go to a SNF.  Individuals who were morbidly obese and lost 20 pounds before TKA had lower odds of being discharged to a nursing facility, lower odds of an extended length of stay of at least four days and an absolute shorter length of stay compared to patients who did not lose 20 pounds. There  was no difference in the length of surgery or improvements in physical function. 


The study, "How Much Preoperative Weight Do Morbidly Obese Patients Undergoing TKA Need to Lose to Meaningfully Improve Outcomes?" was recently presented at the 2019 Meeting of the American Academy of Orthopaedic Surgeons. David Jevsevar, MD MBA, senior author and chair of Orthopaedics at Dartmouth-Hitchock Medical Center explained the study. They identified 203 patients who were morbidly obese at least 90 days before surgery and measured their BMI immediately before surgery. 41% lost at least 5 pounds before surgery, 29% lost at least 10 pounds and 14% lost at lease 20 pounds.  The study showed that even a relatively small amount of weight loss improved outcomes. Further prospective study is needed to define the causation for the improved outcomes that were observed.