If you have been diagnosed with osteoarthritis in the hip or knee, you have likely been told by your doctor you may need a joint replacement now or in the future. You may have either already seen a surgeon about getting a joint replacement or already had a joint replacement. It is possible that at some point during the process the topic of your body weight may have come up. Maybe your family doctor suggested weight loss to help you manage your osteoarthritis. Or maybe the surgeon asked that you lose some weight before surgery. This may leave you wondering, “what does my weight have to do with my osteoarthritis and joint replacement?” This is a great question, and the truth is that your body weight has a lot to do with your hip and knee joint health!

The body mass index (BMI) is a way of estimating body fat by dividing a person’s body mass in kilograms by their height in metres squared. BMI is not a perfect measure but research shows that it does a good job of predicting body fat and a number of health risks.[10] The question is, do you need to lower your BMI before hip replacement or knee replacement surgery?

  1. If your BMI is between 30-40 you may be more likely to develop osteoarthritis or need a hip or knee replacement. A higher weight will also make you more likely to develop these conditions at a younger age.
  2. If your BMI is between 30-40 you likely do not have to lose weight before surgery as outcomes and risks are similar to lower BMI individuals.
  3. A BMI above 40 increases the risk of complications and infection increases and may require weight loss to increase safety for a hip or knee replacement.

Watch Zacharie answer the question "Do I need to lose weight before my hip or knee replacement?" in the video below.

Read the full blog that discusses weight loss before knee or hip replacement

Read all 8 of Zacharie's blogs here!

Regardless of your BMI, if you get a hip replacement or knee replacement Curovate can help you. The Curovate mobile app has rehabilitation protocols for both hip replacement and knee replacement surgeries, to help you have the best possible outcome. Curovate also provides daily video guided strengthening exercises, the ability to measure range of motion, in-app chat with a physical therapist to answer your surgery and recovery questions, and educational blogs and webinars.

If you need further customized assistance during your ACL recovery check out our Virtual Physical Therapy page to book your 1-on-1 video session with a physical therapist.

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Other Blogs Related to Joint Replacement


1. Abdulla, I., Mahdavi, S., Khong, H., Gill, R., Powell, J., Johnston, K. D., & Sharma, R. (2020). Does body mass index affect the rate of adverse outcomes in total hip and knee arthroplasty? A retrospective review of a total joint replacement database. Canadian Journal of Surgery, 63(2), E142.

2. Gandhi, R., Wasserstein, D., Razak, F., Davey, J. R., & Mahomed, N. N. (2010). BMI independently predicts younger age at hip and knee replacement. Obesity, 18(12), 2362-2366.

3. Guo, H., Xu, C., & Chen, J. (2020). Risk factors for periprosthetic joint infection after primary artificial hip and knee joint replacements. The Journal of Infection in Developing Countries, 14(06), 565-571.

4. Horan, F. (2006). Obesity and joint replacement. The Journal of Bone and Joint Surgery. British Volume, 88-B(10), 1269–1271.

5. Kulkarni, A., Jameson, S. S., James, P., Woodcock, S., Muller, S., & Reed, M. R. (2011). Does bariatric surgery prior to lower limb joint replacement reduce complications?. The Surgeon, 9(1), 18-21.

6. Li, W., Ayers, D. C., Lewis, C. G., Bowen, T. R., Allison, J. J., & Franklin, P. D. (2017). Functional gain and pain relief after total joint replacement according to obesity status. The Journal of bone and joint surgery. American volume, 99(14), 1183.

7. Liljensøe, A., Laursen, J. O., Bliddal, H., Søballe, K., & Mechlenburg, I. (2021). Weight loss intervention before total knee replacement: a 12-month randomized controlled trial. Scandinavian Journal of Surgery, 110(1), 3-12.

8. Liu, B., Balkwill, A., Banks, E., Cooper, C., Green, J., & Beral, V. (2007). Relationship of height, weight and body mass index to the risk of hip and knee replacements in middle-aged women. Rheumatology, 46(5), 861-867.

9. Roth, K. C., & Bessems, G. J. (2006). Sorry, but you will have to lose weight before receiving your knee replacement. Pain, 124, 126-33.

10. Stevens-Lapsley, J. E., Petterson, S. C., Mizner, R. L., & Snyder-Mackler, L. (2010). Impact of body mass index on functional performance after total knee arthroplasty. The Journal of arthroplasty, 25(7), 1104-1109.

11. Wendelboe, A. M., Hegmann, K. T., Biggs, J. J., Cox, C. M., Portmann, A. J., Gildea, J. H., ... & Lyon, J. L. (2003). Relationships between body mass indices and surgical replacements of knee and hip joints. American journal of preventive medicine, 25(4), 290-295.