Trends in the Body Mass Index of Pediatric and Adult Patients Undergoing Anterior Cruciate Ligament Reconstruction

BACKGROUND: The body mass index (BMI) in the United States (US) is rising and may be contributing to increased anterior cruciate ligament reconstruction (ACLR) rates. It is currently unknown whether the BMI is increasing in patients who undergo ACLR. PURPOSE: To determine whether (1) the BMI changed in pediatric and adult patients who previously underwent ACLR or revision ACLR over a 10-year eligibility period, (2) the BMI changed at a greater rate in pediatric or adult patients, and (3) the percentage of overweight and obese patients in the ACLR population was different than that of the general overweight population. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A retrospective investigation of patients who underwent ACLR by 6 surgeons from June 3, 2005, to June 3, 2015, was conducted. Patients were divided into pediatric (<18 years) and adult (≥18 years) categories. BMI at the time of surgery was defined as underweight (<18.5 kg/m(2)), normal (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (≥30.0 kg/m(2)). Patients with an indeterminate BMI were excluded. Comparisons of overweight and obese patients were made with general population trends determined by the Centers for Disease Control and Prevention (CDC) in a single US state. Pearson (R) and Spearman (R (s)) correlations were used to determine correlations, Student t tests were used for 2-variable comparisons, analyses of variance were used for multivariable comparisons, and analyses of covariance were used for comparing linear relationships. RESULTS: There were 1305 patients (733 male, 572 female; 409 pediatric, 896 adult) included. Adults requiring surgical revision demonstrated a strong positive correlation with respect to BMI over time (R (s) = 0.906, P < .01). No other statistically significant trends in the BMI over time were found. The proportion of overweight pediatric patients undergoing ACLR was significantly greater than that of the general overweight pediatric population (P < .05), and the proportion of obese pediatric and adult patients in the general population was greater than that of the obese patients in the study cohort (P < .05). CONCLUSION: Between 2005 and 2015, the BMI for pediatric and adult patients who underwent ACLR did not demonstrate a significant change over time. However, there was a statistically significant strong positive correlation for increasing BMI in adult patients requiring revision, although the mean BMI in patients who underwent revision was less than that of the general population. In addition, the percentage of overweight pediatric patients undergoing ACLR was significantly greater than that of the general population of overweight patients in a single US state reported by the CDC.