Impact of Functional Training on Injuries After Anterior Cruciate Ligament Reconstruction for Return-to-Duty Status in U.S. Naval Academy Midshipmen: A Retrospective Analysis.

INTRODUCTION

Acute anterior cruciate ligament (ACL) injuries can be disabling because of prolonged rehabilitation process following surgical reconstructions. Rates of ACL injuries among military service members are close to 10 times greater than the general civilian population, likely because of the operation tempo and the unique physical requirements. Studies debated functional testing requirements for return to sports, but no study investigated the impact of functional training and re-injury rates following ACL reconstruction and their association with functional testing outcomes and time to return to full duty in United States Naval Academy (USNA) Midshipmen. Therefore, the purpose of this study was to review all ACL reconstructions with and without meniscal injury at USNA, the functional training and testing, timing of return to military training, and associations with postoperative re-injury rates.

MATERIALS AND METHODS

A retrospective chart review of all Midshipmen who sustained ACL reconstructions between 2015 and 2019 was performed. Demographic variables, type of surgeries, functional training/testing outcomes, timing to return to full duty and postoperative re-injury rates were recorded up to January 1, 2022.

RESULTS

Of 204 ACL reconstructions, 87 were excluded, resulting in a sample size of 117 including 76 (65%) men and 41 (35%) women aged 20.4 ± 1.4 years. Fifty-one (44%) Midshipmen sustained a re-injury to the postoperative knee or complication. Thirty-three out of 76 (43%) men and 18 out of 41 (35%) women sustained complication or re-injury to the surgical knee. Of those re-injuries or complications, 12 Midshipmen (10%) sustained graft failures,12 (10%) anterior arthrofibrosis, 7 (6%) meniscus tears, 17 (15%) patella tendinopathy, and 3% other ligament injuries (MCL, PCL, etc.). Fifty participants (43%) followed a functional training program while 67 (57%) lacked documented functional training. There was a significant difference in Midshipmen who participated in functional training, displaying fewer postoperative anterior cruciate ligament reconstruction (ACLR) re-injuries or complications to the surgical knee as compared to those who did not (0.027). Nineteen Midshipmen (16%) performed functional testing while 98 did not. Of the 98 Midshipmen who did not perform functional testing, 57 (58%) had re-injury or complications to the surgical knee postoperatively compared to 9 (48%) who performed functional testing sustained a re-injury or complication. The average return to full duty was 37.1 ± 25.8 weeks versus 63.8 ± 35.8 weeks for Midshipmen who sustained postoperative injuries. Within 1 year of return to duty, 6 of 12 (50%) ACL graft failures occurred.

DISCUSSION-CONCLUSION: Postoperative injuries and complications following ACLR can delay the ability to return to duty by twice as long, consequently effecting military manpower capability. A functional training and testing program resembling both an athletic and military/operational environment can reduce re-injury and complication rates, resulting in faster return-to-duty rates. Future studies should assess the impact of military rehabilitation participation following ACLR and functional testing protocols to assess physical readiness of Midshipmen to return to full duty. Additionally, methods to assess psychological readiness to return to duty should be further investigated.