Body Mass Index as a Predictor for Postoperative Complications Following Carpometacarpal Arthroplasty

Purpose: Carpometacarpal (CMC) arthroplasty is an effective surgical treatment to relieve pain and improve function for osteoarthritis of the CMC joint. The association between body mass index (BMI) and postoperative complications has been studied for other orthopedic procedures, including total knee arthroplasty, total hip arthroplasty, and total shoulder arthroplasty. However, BMI has not been studied as a risk factor for postoperative complications following CMC arthroplasty. The purpose of this study was to determine the postoperative complications associated with different categories of BMI following CMC arthroplasty. We hypothesized that increasing BMI is associated with more severe complications.

Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried for all patients who underwent CMC arthroplasty between 2015 and 2020. Patient demographics, comorbidities, surgical characteristics, and 30-day postoperative complication data were collected. Patients were stratified into cohorts based on BMI as follows: underweight (BMI < 18.5 kg/m²), normal/reference (18.5 kg/m² ≤ BMI < 30.0 kg/m²), obese (30.0 kg/m² ≤ BMI < 35.0 kg/m²), severely obese (35.0 kg/m² ≤ BMI < 40.0 kg/m²), and morbidly obese (BMI ≥ 40.0 kg/m²). Multivariate logistic regression was used to identify postoperative complications associated with each cohort.

Results: In total, 6,432 patients were included in this study: 3,622 (56.3%) patients were included in the normal/reference cohort, 77 (1.2%) patients were included in the underweight cohort, 1,479 (23.0%) patients were included in the obese cohort, 718 (11.2%) patients were included in the severely obese cohort, and 536 (8.3%) patients were included in the morbidly obese cohort. The obese cohort was independently associated with a higher rate of superficial incisional surgical-site infection (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.00-4.44; P = .050). The morbidly obese cohort was independently associated with readmission (OR, 3.35; 95% CI, 1.15-9.74; P = .026) and reoperation (OR, 3.40; 95% CI, 1.04-1.11; P = .043).

Conclusions: Morbid obesity is a clinically significant predictor for readmission and reoperation within 30 days following CMC arthroplasty. Obesity is a clinically significant predictor for superficial incisional surgical-site infection within 30 days following CMC arthroplasty.

Clinical relevance: A better understanding of BMI as a risk factor for postoperative complications may allow surgeons to improve preoperative risk stratification and patient counseling.

Type of study/level of evidence: Prognostic III.