The Impact of Preoperative Weight Loss Timing on Surgical Outcomes in Total Hip Arthroplasty

Abstract

Introduction

Elevated BMI (body mass index) increases surgical complications post-total hip arthroplasty (THA). However, the effects of rapid weight loss pre-THA remain unclear. This study evaluated patients who had initial BMIs between 40 and 50, and then achieved a BMI under 35 at various intervals before their THA. Comparisons were made with consistent obese and non-obese groups to understand potential complications.

Methods

Using a national database, we categorized THA patients based on initial BMI and weight loss timing before the surgery. These were contrasted with those maintaining a steady BMI of 20 to 30, or 40 to 50. We monitored outcomes like periprosthetic joint infections (PJI), surgical site infections (SSI), and non-infectious revisions for two years post-surgery, incorporating demographic considerations. Statistical analyses utilized Chi-square tests for categorical outcomes and Student's t-tests for continuous variables.

Results

Among patients who had a BMI of 45 to 50, weight loss 3 to 9 months pre-surgery increased PJI risks at 90 days (Odds Ratios [OR]: 2.15 to 5.22, P < 0.001). However, weight loss a year before the surgery lowered the PJI risk (OR: 0.14 to 0.27, P < 0.005). Constantly obese patients faced heightened PJI risks 1 to 2 years post-surgery (OR: 1.64 to 1.95, P < 0.015). Regarding SSI, risks increased with weight loss 3 to 9 months before surgery, but decreased when weight loss occurred a year earlier. In the BMI 40 to 45 group, weight loss 3 to 6 months pre-surgery showed higher PJI and SSI at 90 days (P < 0.001), with obese participants consistently at greater risk.

Conclusion

While high BMI poses THA risks, weight loss timing plays a crucial role in post-operative complications. Weight loss closer to the surgery (0 to 9 months) can heighten risks, but shedding weight a year in advance seems beneficial. Conversely, initiating weight loss approximately a year before surgery offers potential protective effects against post-operative issues. This highlights the importance of strategic weight management guidance for patients considering THA, ensuring optimal surgical results and reducing potential adverse outcomes.