Weight loss before Total Knee Arthroplasty improves outcomes: JAMA

A new study published in the Journal of American Medical Association shows that weight loss after bariatric surgery reduced the risk of total knee arthroplasty (TKA) problems in persons with a BMI equal to or greater to 35.

Persons with significant obesity who have a total knee arthroplasty for osteoarthritis (OA) are at a greater risk of short- and long-term problems than people with a BMI of 30. It is unknown whether losing weight before TKA reduces this risk. As a result, Michelle M. Dowsey and colleagues undertook this trial to see if having bariatric surgery before TKA improves outcomes in persons with a BMI more than or equal to 35 and end-stage OA.

This assessor-blinded, parallel-group, randomized clinical study was undertaken between May 2012 and June 2020, with a 12-month minimum follow-up following TKA. TKA was done in a university-affiliated tertiary referral public hospital, while bariatric surgery was conducted at a private hospital facility and a university-affiliated private practice. From February through July 2021, data was analyzed. The main intervention strategy of this trial was bariatric surgery vs conventional weight management guidance (treatment as usual [TAU]) in persons scheduled for TKA.

The key findings of this study were as follow:

1. Eighty-two patients awaiting TKA were randomly assigned to either TAU or bariatric surgery.

2. The average (SD) age of the 82 participants was 57.8 (4.9) years, and the average (SD) BMI was 43.8. (5.5).

3. Thirty-nine (95.1%) patients in the intervention group received laparoscopic adjustable gastric banding, and 29 (70.7%) later underwent TKA.

4. TKA was performed on 39 patients (95.1%) in the TAU group.

5. The main result was experienced by six patients (14.6%) in the intervention group vs 15 (36.6%) in the TAU group.

6. At 12 months, the difference in BMI between groups was 6.32 in favor of the intervention group.

7. TKA was dropped by 12 people (29.3%) in the intervention group due to symptom improvement, whereas TKA was declined by 2 participants (4.9%) in the TAU group.

In conclusion, the results of this randomized controlled trial show that losing weight before TKA reduced the incidence of problems following TKA in individuals with a BMI greater than 35 with OA. It also appears to cause a significant number of patients to postpone TKA surgery.

Reference:

Dowsey, M. M., Brown, W. A., Cochrane, A., Burton, P. R., Liew, D., & Choong, P. F. (2022). Effect of Bariatric Surgery on Risk of Complications After Total Knee Arthroplasty. In JAMA Network Open (Vol. 5, Issue 4, p. e226722). American Medical Association (AMA). https://doi.org/10.1001/jamanetworkopen.2022.6722