Obesity-knee-replacement

Weight loss does not influence outcomes in joint replacement

In recent research, doctors give a puzzling assessment of whether or not it is a good idea for obese patients to lose weight before joint replacement surgery.

Here is what they said in the medical journal Systematic Reviews: Of the more than 104,000 patients who underwent elective total joint replacement surgery in 2012-2013 for hip and knee osteoarthritis 40 and 60 %, respectively, were obese.

Obesity is associated with increased risks for needing joint replacement, post-operative complications and delayed functional recovery.

In this study obese patients were put into a weight management program to lose weight prior to surgery.

As part of a larger project, a rapid review (of the medical literature) was conducted to examine the effects of short-term non-pharmacological and non-surgical weight loss interventions in adults in the year prior to total hip arthroplasty (THA) and total knee arthroplasty (TKA) on surgical and patient outcomes, and adverse events.

In the rapid review of the literature four studies were singled out:

In one of two high-quality retrospective cohort studies,

  • weight loss of 5 % or more of body weight in the year prior to joint replacement and maintained in the year after surgery was associated with a higher likelihood of deep surgical site infection in hip replacement patients and 90-day readmission in total knee replacement patients.
  • No significant differences were reported in incidence of superficial surgical site infections in hip replacement or total knee replacement patients who lost weight pre-operatively compared to those who maintained their weight in either study.

Conclusion: There is limited evidence to support the recommendation of weight loss in the year prior to joint replacement and to determine the effectiveness of short-term non-pharmacological, non-surgical weight management interventions on patient and surgical outcomes.1

So should hip and knee replacement candidates be told that weight loss does not matter?


Researchers say that one reason that patients can not lose weight is because they are in pain.

In patients where high rates of moderate and severe pain and back and arthritis pain were observed,  patients lost significantly less weight compared to those with either moderate or no pain.1

Doctors are debating whether or not obesity causes low back pain. One paper suggests that obesity had no direct influence in back pain, but it could prevent healing. 2

The body has tremendous regenerative capabilities but one must never forget the fact that many different factors affect connective tissue healing. Perhaps, the most overlooked factor in healing is nutritional and the health issue of obesity.


1. Lui M, Jones CA, Westby MD. Effect of non-surgical, non-pharmacological weight loss interventions in patients who are obese prior to hip and knee arthroplasty surgery: a rapid review. Syst Rev. 2015 Sep 27;4(1):121. [Pubmed]

2. Masheb RM, Lutes LD, Kim HM, et al. Weight loss outcomes in patients with pain.  Obesity (Silver Spring). 2015 Aug 3. doi: 10.1002/oby.21160.

3. Ibrahimi-Kaçuri et al. Low back pain and obesity. Med Arch. 2015 Apr;69(2):114-6. doi: 10.5455/medarh.2015.69.114-116. Epub 2015 Apr 6. [Pubmed]