Total Hip Arthroplasty Among Superobese Patients: Proceed With Caution

Morbid obesity, defined as body mass index (BMI) ≥40 kg/m², increases perioperative risk following total hip arthroplasty (THA). However, limited contemporary data exists on outcomes of superobese patients (BMI ≥50 kg/m²) following primary THA. Using a large modern cohort, this study seeks to quantify the risk of infection and surgical, medical, and thromboembolic complications among superobese THA patients.

The Premier Healthcare Database was queried to identify all primary elective THA patients between 2016 and 2021. All superobese patients were compared to a normal BMI cohort (BMI 18.5-24.9 kg/m²). Univariate analysis and multivariable regression were utilized to assess differences in primary outcomes, including 90-day infectious, surgical, medical, and thromboembolic complications.

Twenty-one thousand, thirty-five THA patients were identified; 888 patients (4.2%) had a BMI ≥50 kg/m², while 20,147 patients (95.8%) had a BMI 18.5-24.9 kg/m². On multivariable analysis, superobese patients demonstrated an increased risk of infectious and surgical complications, including periprosthetic joint infection (adjusted odds ratio [aOR]: 7.23, 95% confidence interval (CI): 3.95-13.24, P < .001), sepsis (aOR: 4.24, 95% CI: 2.19-9.23, P < .001), and wound dehiscence (aOR 7.61, 95% CI: 3.90-14.85, P < .001). The risk of pulmonary embolism (aOR 4.32, 95% CI: 1.75-10.64, P = .001), acute respiratory failure (aOR: 2.31, 95% CI: 1.32-4.05, P = .003), acute renal failure (aOR: 3.15, 95% CI: 2.19-4.52, P < .001), and hospital readmission (aOR: 2.31, 95% CI: 1.75-3.07, P < .001) were similarly elevated within the superobese cohort.

Superobese patients face markedly increased risk for infection and surgical, medical, and thromboembolic complications following primary THA. Our findings emphasize the importance of preoperative risk stratification, optimization, and patient counseling in this high-risk cohort.