Being overweight or obese does not automatically disqualify you from getting a knee replacement. While there are risks associated with a knee replacement at 300 pounds or at any weight that is generally considered higher than a healthy weight, there are many factors to consider.
Knee replacement patients come in all shapes and sizes. Talk to your surgeon about your eligibility, any concerns, and what you can do to minimize risks, including a supported weight-loss plan.
What Is the Maximum Weight for Knee Replacement?
There is no official knee replacement weight limit or maximum body mass index (BMI). Determining who is a candidate for surgery is more complicated than a single measurement. However, many surgeons do have a cutoff point due to the increased surgical risks, slower recovery, and risks of implant failure. The typical limits are 300 pounds or a BMI of 40.
Your surgeon will evaluate all your risk factors and weigh those against the benefits before determining if you are a good candidate for the procedure. Other factors include your current pain and disability levels.
What is BMI? This simple tool explains BMI and helps you calculate yours. https://www.nhlbi.nih.gov/calculate-your-bmi
| BMI Surgical Category | Less Than 30: Generally Safe for Knee Replacement |
30 to 40: Borderline Risk for Knee Replacement |
40 and Higher: High Risk for Knee Replacement |
| Surgical Risks | Typical risks include infection, blood clots, bleeding, and nerve damage | Typical risks, plus risk of longer recovery, hospital stay, readmission, and implant failure | Significant risk of long recovery time, hospital stay, readmission, and implant failure |
| Reducing Risk | Stay healthy before surgery and follow your surgeon’s recommendations | Follow your surgeon’s recommendations for moderate weight loss | Work with your care team to lose enough weight for reduced surgical risks |
The Risks of Knee Replacement if You Are Obese
Although your weight does not automatically disqualify you from knee replacement, it is an important consideration. Excess weight increases your risk of serious complications during and after surgery.
These are some of the potential complications and issues to discuss with your surgeon if you are obese and are considering knee replacement surgery:
- Obese patients are more likely to need to stay overnight after surgery. A higher number of obese patients stay longer in the hospital or go to a rehabilitation facility instead of home after surgery, as compared to nonobese patients.
- Patients who are obese are more likely to have general surgical complications, including infections and slow-healing wounds. These lead to higher rates of being admitted back to the hospital.
- Obesity is often comorbid with other conditions, like diabetes or obstructive sleep apnea. These further increase the risk of surgical complications.
- Placing a joint implant can be more challenging in obese patients who have greater soft tissue depth at the knee. This can increase the risk of later complications with the joint.
In this short video, Dr. Bostian explains the risks in more detail and describes the personal approach all EmergeOrtho specialists take when planning treatments and preparing patients for surgery.
Should I Avoid Knee Replacement if I Am Obese?
Despite the added risks, the research indicates that being obese is not necessarily a reason to avoid joint replacement surgery. One study looked at patients who had undergone knee or hip replacement surgery.
The most obese patients in the study (25% of the total) had significant improvements in function after the surgery. Their functional gains were similar to nonobese patients. The obese patients had even greater reductions in pain after surgery.
The researchers concluded that weight alone should not be a disqualification for surgery. They still emphasized that patients and surgeons must consider the risks on an individual basis.
An even larger study from the U.K. evaluated knee replacement results in nearly 500,000 patients worldwide. These researchers found that outcomes were similar for both obese and nonobese patients. Few patients at any weight needed repeat surgery within 10 years. All groups had improved knee function and less pain.
Patient Story
Knee surgery can be life-changing. Hear Jimmy’s story of his knee revision performed by Dr. Bostian and how it improved his pain levels, mobility, and overall quality of life.
Safe Weight Loss Before Surgery: How To Reduce the Risks
Weight alone is not a disqualifying factor for knee replacement, but obesity still carries risks. Losing weight before the procedure can help you reduce them.
Your care team is available to help you meet a weight goal for surgery. Your plan may include using specific weight loss programs, physical therapy, and alternative treatments. Even small, incremental weight loss can significantly reduce surgical risks and improve your outcomes and recovery.
You can also reduce your surgery risks by improving your overall health. If you have chronic conditions, such as high blood pressure or diabetes, work with your doctor to manage them safely. Consider healthy lifestyle changes regardless of weight-loss efforts: quit smoking, reduce alcohol consumption, increase physical activity, and eat a healthy diet.
If you have knee pain significant enough to limit your mobility and impact your daily life, it might be time to consider a knee joint replacement. It is important to consider your weight and BMI for knee replacement, but do not assume you are not a good candidate. Contact us today to schedule an appointment with one of our EmergeOrtho-Foothills Region knee replacement specialists.
