The Importance of Weight Loss in Morbidly Obese Patients Before Knee Surgery

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Obesity is undoubtedly one of the biggest epidemics sweeping the United States today. The Centers for Disease Control and Prevention reported that “as of 2016 the prevalence of obesity was 39.8% and affected about 93.3 million US adults.”1 There is often an important connection between morbid obesity and osteoarthritis which frequently leads to the need for a total knee arthroplasty. According to the Arthritis Foundation “Being overweight puts additional pressure on hips and knees. Many years of carrying extra pounds can cause the cartilage that cushions joints to break down faster. Research has shown there is a link between being overweight and having an increased risk of osteoarthritis in the hands. These studies suggest that excess fat tissue produces inflammatory chemicals that can damage the joints.”2 Encouraging weight loss before a total knee surgery has been found to be beneficial for patients during their recovery.

Important research has found that weight loss in morbidly obese patients before the surgery improves outcomes. Orthopedic Design & Technology notes that “morbidly obese patients who lost at least 20 pounds prior to a total knee arthroplasty had shorter hospital stays and lower odds of having to go to a nursing facility even if they remained morbidly or severely obese, according to a study presented at the 2019 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS).”3 Understanding how weight is connected with recovery after a total knee surgery is beneficial to healthcare providers who can then adjust pre and post-operative planning to improve recovery outcomes.

Dr.Kenney conducted the study, “How Much Preoperative Weight Do Morbidly Obese Patients Undergoing Total Knee Arthroplasty Need to Lose to Meaningfully Improve Outcomes,” to find how much weight loss was necessary to improve operative time, length of stay, discharge to a facility and physical function improvement. The results found that morbidly obese patients who lost 20 pounds before their total knee arthroplasty resulted in a shorter length of stay and lower odds of facility discharge. The results are important because “length of stay and facility discharge are primary drivers of cost, quality of life, and satisfaction, this has immense implications,” said Dr. Keeney. “If you lose at least 20 pounds before surgery, your outcomes are going to be much better, even if you are still a physically large patient at the time of surgery. This is a concrete goal instead of telling patients we won’t operate on you unless you get below a BMI of 40, which for some patients, can be 50 or 100 pounds.”3 The study gives healthcare providers and patients a reasonable benchmark to aim for in order to help improve the outcome after a total knee replacement surgery.

Fortunately, new technology like TracPatch can be a great tool for healthcare providers looking to foster patient compliance while monitoring them remotely both pre and post-operatively. The two-piece TracPatch wearable device, which adheres to the patient’s leg above and below the knee following a total knee surgery, is useful because it continuously collects activity data including range of motion (ROM), exercise compliance, wound site temperature trends and ambulation, through a centralized app. The data is then sent to The Cloud and shared with the patient’s healthcare provider who can review and track patient progress.

Step tracking is an important feature of the TracPatch technology. Recently, step count has been linked with weight loss. Five miles a day, or 10,000 steps, is the most common target recommended to lose weight. “The average person burns about 100 calories for every mile walked. That means you’d burn roughly 500 calories each day and 3,500 calories in a week – the equivalent of one pound of fat. That’s ideal, since it’s generally considered safe to lose one to two pounds per week.” 4 Although there are other factors like calorie intake which play a role in weight loss, TracPatch makes it easy for a patient to track steps and their healthcare provider to review the activity data. This could be incredibly useful when it comes to healthcare providers working with morbidly obese patients to lose weight before a total knee surgery. For more information about TracPatch contact us today.


  1. Adult Obesity Facts | Overweight & Obesity | CDC. Retrieved July 16, 2019, from
  2. Osteoarthritis Causes. Retrieved July 16, 2019, from
  3. AAOS News: Weight Loss Before Knee Surgery Improves Outcomes for Morbidly Obese Patients. Retrieved July 16, 2019, from
  4. Fitzpatrick, C. (2019, January 28). Here’s How Much Weight You Could Lose If You Actually Logged 10,000 Steps a Day. Retrieved July 29, 2019, from
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