Return to duty following combat-related multi-ligamentous knee injury

This retrospective cohort study characterized injury patterns, treatment practices, and identified the return to duty (RTD) rate following combat-related multi-ligament knee injuries (MLKI).

We evaluated injury characteristics and treatment methods of 46 military service members who had sustained a MLKI during combat activity. The primary clinical outcome measure was ability to return to active military duty. Secondary outcomes included subjective pain score, knee motion, knee instability, and use of ambulatory assistive device.

The RTD rate was 41% (19/46). High-energy mechanism, neurovascular injury, compartment syndrome, traumatic knee arthrotomy, and intra-articular femur fracture (Orthopedic Trauma Association Classification (OTA) 33-B/C) were all more prevalent in subjects who were unable to return to duty (p<0.05). Acute external fixator application and poor knee range of motion (ROM) were also associated with military separation (p=0.041 and p=0.016, respectively). The most common ligament injury pattern (n=9; 20%) was combined disruption of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), posterolateral corner (PLC), and medial collateral ligament (MCL). However, number of ligaments injured was not associated with RTD status.

MLKIs sustained in a combat setting have a high incidence of associated lower extremity injuries. Certain associated injuries, such as intra-articular femur fracture, knee arthrotomy, neurovascular injury, and compartment syndrome may be more important than the severity of the knee ligamentous injury in determining RTD outcome.