Obesity, Weight Loss, and Joint Replacement Surgery
If you need total knee or total hip replacement surgery—and your weight is significantly higher than it should be—your doctor may advise you to lose weight before your procedure. Even though you may feel fit and healthy at your current weight, studies show that a patient with a BMI greater than 40 is more likely to experience serious complications both during and after surgery than a patient of normal weight. Your doctor wants you to be aware of these risks so that you can take steps to minimize them before your procedure.
BMI is a measure of body fat based on height and weight. Typically, the higher your BMI, the more body fat you have. Your doctor will use the following calculation to determine your BMI:
For an adult, the following BMI ranges apply:
BMI Ranges |
Weight Status |
18 to 24 |
Normal |
25 to 29 |
Overweight |
30 to 39 |
Obese |
40 to 49 |
Morbidly obese |
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Patients with obesity are more likely to have certain diseases and health conditions that increase the risks of surgery. These include:
- Cardiovascular disease, including high blood pressure
- Type 2 diabetes
- Obstructive sleep apnea
- Metabolic syndrome—a group of health conditions that increase your risk for developing cardiovascular disease and type 2 diabetes
It is important to be in the best health possible before your surgery. If you have one of these conditions, your doctor will work with you to ensure that it is managed and under control before your procedure.
There are risks associated with every surgery. However, some risks are greater for patients with obesity.
Complications During Surgery
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Anesthesia. It is more difficult to administer anesthesia to a patient with obesity. Complications may be due to the patient’s body shape and anatomy, or to health conditions that can affect breathing. Challenges for the anesthesiologist include:
- Locating veins to administer general anesthesia and necessary medications
- Ensuring that oxygen and airflow are sufficient
- Properly positioning the needle when delivering spinal and epidural nerve blocks and other types of regional anesthesia
Operative times. There are technical challenges associated with performing surgery on a patient with obesity, so operative times are often longer. In general, the longer you are in surgery, the greater your risk of experiencing complications.
Complications After Surgery
Compared with a patient of normal weight, a patient with obesity is more likely to experience the following complications after surgery:
- Infection
- Poor wound healing
- Difficulty breathing
- Blood clots
- Pulmonary embolism—a blood clot in the lungs
Joint replacement will help relieve your pain and enable you to live a fuller, more active life. However, if you have obesity, you may never achieve the increased mobility and range of motion experienced by a patient of normal weight.
You may also experience more implant and prosthesis complications after surgery, including:
- Component loosening and failure
- Dislocation of the replacement joint, especially in the hip
In some cases, a second “revision” surgery may be necessary to remove failed implants and replace them with new ones.
In most cases, total hip and total knee replacement are elective procedures. For this reason, your doctor may recommend that you try nonsurgical treatments—such as medications and physical therapy—in order to delay your joint replacement surgery. This will give you time to lose weight and reduce your BMI before your procedure.
Losing Weight
The key elements to losing weight are diet and exercise. In general, you should try to make the following lifestyle changes:
- Reduce your fat and calorie intake. Try to eat meals that are full of fruits, vegetables and whole grains, lean meats, and low-fat dairy. Drink plenty of water and avoid sugary drinks that are high in calories.
- Get more physical activity and exercise. If you have constant hip or knee pain, you may not be as active as you were before. Low-impact activities—such as swimming, biking, or using an elliptical machine—will put less strain on your joints than strenuous exercise and will still be effective in helping you lose weight.
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Patients who need joint replacement surgery often intend to lose weight after their procedure—when their relief from pain will enable them to be more physically active.
In reality, however, studies show that just a small percentage of patients with obesity actually lose weight after joint replacement—the majority of patients maintain the same BMI after surgery.
Rather than waiting, there is great value in establishing a healthier lifestyle now—before your joint replacement surgery. Losing weight and reducing your BMI will decrease your risk for complications and increase the likelihood of a successful surgical outcome. In some cases, it may also decrease your pain to the point where joint replacement may no longer be needed—or can be put off for a number of years.
Although reaching and staying at a healthy weight can be a long-term challenge, the payoff is significant. If you need help losing weight and lowering your BMI before joint replacement surgery, talk to your primary care doctor. He or she can recommend specific low-impact exercises and activities and help you choose a commercial weight-loss plan that fits your needs and lifestyle.
Cited from: http://orthoinfo.aaos.org/topic.cfm?topic=A00745
January 21, 2016
Bariatric surgery prior to total knee replacement may reduce complications and costs for patients with morbid obesity
ROSEMONT, Ill. (Jan. 21, 2016)—Previous research studies have linked obesity to adverse outcomes and increased costs following total knee replacement surgery (TKR). A new, computer model-based evaluation appearing in the Journal of Bone and Joint Surgery, supports bariatric surgery in morbidly obese patients with end-stage osteoarthritis (loss of cartilage and joint pain, caused by aging and use) prior to TKR.
Approximately 30 percent of Americans are obese (a body mass index (BMI) ≥30 kg/m2) and obesity is a known risk factor for osteoarthritis. While TKR is a typical treatment for end-stage osteoarthritis, obesity places patients at an increased risk for complications, including delayed wound healing, infection, the need for revision surgery, and lower functional outcomes.
In the evaluation, researchers used a computer model to analyze previously published data on obesity, bariatric surgery and TKR. The evaluation compared the costs and outcomes of two treatment options for patients with morbid obesity (a BMI ≥35 kg/m2) and end-stage knee osteoarthritis: The first, TKR without prior weight loss; and the second, TKR two years after bariatric surgery.
“We know that bariatric surgery can be an effective treatment for morbid obesity, reducing a patient’s excess weight. In addition, the surgery also reduces the burden of co-morbidities, like diabetes and high blood pressure, and may extend a patient’s life span,” said orthopaedic surgeon and lead article author Alexander McLawhorn, MD, MBA. “What we didn’t know was whether or not it is cost effective to recommend bariatric surgery to achieve weight loss and improve preoperative health prior to joint replacement.”
The model predicts that patients with morbid obesity who undergo bariatric surgery two years prior to TKR are more likely to enjoy improved quality-of-life, measured in quality-adjusted life years (QALYs), than patients undergoing TKR without prior weight loss surgery. In addition, the cost necessary for this level of improvement was $13,910 per QALY, which is below the amount society and health care payers, like insurers and the government, are typically willing to pay.
“We found that successful bariatric surgery performed two years before TKR could be a cost-effective treatment strategy for morbidly obese patients with end-stage arthritis,” said Dr. McLawhorn. “While there remains some uncertainty in terms of the precise effects of bariatric surgery on knee osteoarthritis and total knee replacement, our model summarizes what is known about the clinical effects and costs of obesity, bariatric surgery and total knee replacement.
“The results of this study may help surgeons in counseling morbidly obese patients with knee osteoarthritis, and trying to come up with an individualized treatment plan that includes optimization of overall health, nutrition and weight prior to knee replacement,” said Dr. McLawhorn.
cited from: http://newsroom.aaos.org/media-resources/news/bariatric-surgery-prior-to-total-knee-replacement-may-reduce-complications-and-costs-for-patients-with-morbid-obesity.htm