Does Your Patient Need to Lose Weight? Weight Change Before and After Total Hip Arthroplasty Does Not Affect Healthcare Utilization and Achievement of the Minimal Clinically Important Difference.

BACKGROUND: Despite the potential negative impact of preoperative obesity on THA outcomes, the association between preoperative and postoperative weight change and outcomes is much less understood. Therefore, this study aimed to determine the impact of pre- and postoperative weight change and preoperative body mass index (BMI) on healthcare utilization, satisfaction, and achievement of minimal clinically important difference (MCID) for Hip disability and Osteoarthritis Outcome Score Physical Function Short-Form (HOOS PS) and HOOS Pain.

METHODS: Patients who underwent primary elective unilateral THA between January 2016 and December 2019 were included (N = 2,868). Multivariable logistic regression assessed the association between BMI and pre- and postoperative weight change on outcomes while controlling for demographic characteristics.

RESULTS: There was no association between preoperative weight change and prolonged length of stay (LOS >3 days), 90-day readmission, non-home discharge, patient dissatisfaction at 1-year, or achievement of HOOS Pain or HOOS PS MCID. Postoperative weight loss was an independent risk factor for patient dissatisfaction at 1-year but was not associated with achievement of either HOOS Pain or HOOS PS MCID at 1-year postoperative. Preoperative obesity Classes I to III were independent risk factors for non-home discharge. Nevertheless, preoperative obesity Class I and Class II were associated with an increased probability of reaching HOOS Pain MCID. Preoperative BMI was not associated with an increased risk of patient dissatisfaction.

CONCLUSION: Preoperative weight change does not appear to influence healthcare utilization, satisfaction, or achievement of MCID in pain and function following THA. Postoperative weight loss may play a role as a risk factor for dissatisfaction following THA. Additionally, patients who had a higher baseline BMI may be more likely to see improvement in pain following THA. Therefore, when counseling obese patients for THA, surgeons must balance the risk of perioperative complications with the expectation of greater improvements in pain.