How Does Obesity Impact Pediatric Anterior Cruciate Ligament Reconstruction?

Purpose: To assess the relationship of elevated body mass index (BMI) on postoperative outcomes, including graft rupture, contralateral anterior cruciate ligament (ACL) tear, new meniscus injuries, isokinetic strength testing, and range of motion (ROM) in a large group of pediatric patients. We also sought to calculate the risk of graft rupture in overweight patients with small femoral or tibial tunnels. The secondary objective was to evaluate the association between BMI and concurrent meniscus tears and the need for meniscectomy at the time of primary ACL reconstruction. Methods: We retrospectively reviewed all pediatric patients undergoing primary ACL reconstruction at our institution. BMI percentile for age was used to categorize children as having normal BMI or being overweight or obese per Centers for Disease Control and Prevention guidelines. Demographic data, intraoperative findings and techniques, postoperative complications (including graft rupture, contralateral ACL tear, and meniscus injuries), ROM, and isokinetic strength testing were recorded. Univariate analysis was followed by stepwise, logistic regression to control for confounders. Results: Of the 1,056 patients included, 535 (50.7%) were male and 521 were (49.3%) female, with a mean age of 15.1 ± 2.4 years. The average BMI was 23.1 ± 4.7. There were 675 (63.9%) children with normal BMI, 228 (21.6%) who were overweight, and 153 (14.5%) who were obese. In multivariate analysis, children with elevated BMI had a higher rate of concurrent meniscus tears compared with those with normal BMI (76.3% vs 70.2%; P = .02) and 1.6 times higher odds of requiring a meniscectomy (95% confidence interval, 1.2-2.2; P < .01). The 723 patients included in the analysis of postoperative complications had a mean follow-up duration of 26.2 ± 3.3 months Postoperatively, BMI did not impact the rate of graft rupture, contralateral ACL injury, or new meniscus tears. There was no increased risk of graft failure in overweight children with smaller graft size (≤8 mm). There was no clinically relevant difference in postoperative ROM or isokinetic strength testing. Conclusions: After ACL rupture, overweight and obese children sustained more overall meniscus tears and more irreparable meniscus tears than those with normal BMI. Graft size did not impact the risk of early graft failure in overweight patients. With an appropriate rehabilitation protocol, there was no increased risk of graft rupture, contralateral ACL injury, or new meniscus tear in early follow-up. Level of Evidence: Level III, retrospective comparative study.