Weight loss prior to TKA fails to modify postoperative complication rate: Study

A recent study published in The Journal of Arthroplasty found that reducing body mass index (BMI) before undergoing total knee arthroplasty (TKA) does not significantly affect postoperative complication rates in morbidly obese patients. The study could influence future surgical guidelines by suggesting that delaying surgery to achieve weight loss may not be beneficial and could potentially be harmful.

Total knee arthroplasty the commonly known knee replacement surgery is aimed to relieve pain and restore function in patients with severe knee arthritis. Traditionally, morbidly obese patients who are at high risk for complications have been encouraged to lose weight before undergoing surgery. It was believed that a lower BMI could reduce the risk of postoperative issues.

The study involved a total of 1,270 patients with a preoperative BMI of over 40. These individuals were categorized into three groups based on their BMI changes in the year preceding their surgeries. The groups included patients who decreased their BMI by 5% or more, those whose BMI increased by at least 5% and those whose BMI remained stable.

These findings revealed no significant difference in the 90-day postoperative complication rates among patients who lowered their BMI when compared to the individuals whose BMI did not change. The complication rates were similar across these groups by highlighting that a preoperative reduction in BMI did not confer expected benefits.

The study illuminated a concerning trend where nearly one-fourth of the patients underwent a significant increase in BMI during the pre-surgery period. This group showed a elevated risk of complications when compared to the individuals with stable BMI that indicates the weight gain while waiting for surgery could indeed be detrimental.

These results suggest that the strategy of delaying knee replacement surgery to achieve weight loss should be reevaluated and these findings support the need for more inclusive surgical criteria that do not necessarily cling on BMI reduction for morbidly obese patients.

Also, the patient-reported outcome measures (PROMs) that assess recovery and satisfaction levels from the patient’s perspective showed no significant differences between the groups after six weeks. This further supports the point that immediate surgical intervention without mandatory BMI reduction may be justified in this high-risk population.

Source:

LaValva, S. M., Grubel, J., Ong, J., Chiu, Y.-F., Lyman, S., Mandl, L. A., Cushner, F. D., Della Valle, A. G., & Parks, M. L. (2024). Substantial Weight Loss May Not Improve Early Outcomes of Total Knee Arthroplasty in the Morbidly Obese. In The Journal of Arthroplasty. Elsevier BV. https://doi.org/10.1016/j.arth.2024.04.015