The Impact of Time to Anterior Cruciate Ligament Reconstruction on Return to Duty Among Active Duty Military Personnel
Authors: Burt Brandon A , Lopez Preston E , Chardon Marie L , Sakai Joshua , Evans John T 
Published: September 2024

ABSTRACT

Introduction
After an anterior cruciate ligament (ACL) injury, service members often undergo ACL reconstruction (ACLR) to restore knee stability, which is critical for performing physically demanding and unconventional military-specific tasks. Despite advancements in surgical techniques and rehabilitation protocols, a large portion of service members will not fully return to duty (RTD) post-ACLR and will receive a permanent profile restriction (PP) or undergo a medical evaluation board (MEB). The timing of ACLR is a modifiable factor that can potentially impact RTD and remains underexplored in this population. This study aimed to assess the relationship between the timing of ACLR and its impact on RTD and meniscal procedures performed at index ACLR.

Methods
This retrospective observational study was conducted among active duty military personnel who underwent primary ACLR at Madigan Army Medical Center between October 1, 2016, and December 31, 2022. The primary outcome was the number of RTD, PP, or MEB outcomes. Secondary outcomes included the incidence and type of meniscal procedure performed at index ACLR. Kruskal-Wallis analyses were employed to assess the relationships between time to ACLR and RTD, as well as the incidence and type of meniscal procedure performed. After separating time to ACLR into four distinct time-based groups (0-3 months, 3-6 months, 6-12 months, and &gt;12 months), a chi-squared test with post hoc analysis via Dunn’s test with Bonferroni correction was conducted to identify a time interval from injury to ACLR that impacted RTD.

Results
Initial analysis to assess the relationship between time to ACLR and outcome (RTD, PP, or MEB) were significant (P = .02). Subsequent analyses performed between 4 distinct time-based groups (0-3 months, 3-6 months, 6-12 months, and &gt;12 months) were also significant (P = .03). Pairwise comparisons revealed an 80% rate of RTD in the 0-3 month group compared to a 53% RTD rate in 3-6 month group (P = .006). However, comparisons between the 3-6 month and 6-12 month group (P = .68) and between the 6-12 month and greater than 12 month groups were not significant (P = .80).
Additionally, time to ACLR significantly differed between service members who did not undergo any concurrent meniscal procedure to those who had a meniscal debridement (P = .002), and to those who underwent meniscal repair (P = .02). There was no significant difference in time to ACLR between those who underwent debridement versus repair (P = .22). Patients without any meniscal procedure had an average surgery time of 175 days, compared to 240 days for those undergoing meniscal repair and 295 days for those with meniscal debridement.

Conclusion
The findings from this novel study suggest that ACLR within 3 months after injury can improve the likelihood of RTD without limitations. The timing of ACLR can also impact the incidence and type of meniscal procedures, as patients who did not undergo any concomitant meniscal procedures underwent ACLR within 6 months after injury. This study offers valuable insight into the importance of earlier ACLR among service members to improve RTD rates and decrease additional concomitant meniscal procedures.