Return to military duty following anterior cruciate ligament reconstruction is associated with preoperative Body Mass Index and postoperative physiotherapy

Purpose To determine the rate and time of return to duty following anterior cruciate ligament reconstruction (ACLR) in military members, and to determine whether their outcomes are influenced by patient characteristics or surgical parameters. Methods We prospectively assessed 280 military members that underwent ACLR. 27 were excluded due to multi-ligamentous injuries or revision surgery, two did not provide informed consent and 62 were lost to follow-up. Patient demographics, pre-injury physical workload, complications and whether/when patients resumed duty and sports were noted, as well as clinical outcomes at a minimum follow-up of one year, including Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee score (IKDC), Lysholm, and Tegner scale. Results The final cohort of 189 military members (82% men) had mean age of 25.5 ± 3.4 (range,19–38) at ACLR. At 3.3 ± 1.6 years (range, 1.0–6.3), the Tegner score was 6.1 ± 2.0, Lysholm was 87.0 ± 13.7, IKDC was 80.1 ± 15.7, and KOOS was 81.1 ± 14.8. Only 144 patients (76%) resumed duty, at 9.5 ± 5.3 months (range,1–28), and 141 patients (75%) resumed sport, at 10.2 ± 6.2 months (range,1–35). Multivariable analysis revealed that return to duty was less likely in patients with higher BMI (OR,0.89; p = 0.025), but more likely in patients that followed military physiotherapy (OR,2.76; p = 0.017) and with higher pre-injury physical workload (OR,3.93; p = 0.010). Conclusion At a follow-up of 3.3 ± 1.6 years, 76% returned to duty at 9.5 ± 5.3 months, and 75% returned to their main sport at 10.2 ± 6.2 months. Patients with higher BMI are significantly less likely to resume military duty and sports; those that followed military physiotherapy were most likely to resume duty, while those that had greater pre-injury physical workload were more likely to both resume duty and sport.