Risk factors for soft tissue knee injuries in active duty U.S. Army soldiers, 2000-2005

There is a scarcity of analytic research on active duty Army (ADA) knee injuries (KI), such as soft tissue knee injuries (STKI), which are the predominant ADA KI pattern.

To quantify the independent adjusted association of significant ADA STKI risk factors, 2000-2005.

Using the Total Army Injury and Health Outcomes Database, we (1) captured absolute STKI numbers and rates (N = 83,323) and (2) developed regression models to determine significant STKI risk factors. Models included STKI overall and subcategories: meniscus, patella, anterior/posterior cruciate ligament, and medial/lateral cruciate ligament.

Eight risk factors significantly increased STKI. They are: (1) prior KI (within 2 years) (odds ratio [OR] 9.83, 95% confidence interval [CI] 9.67-10.00); (2) increasing length of service (OR 1.83, 95% CI 1.76-1.90); (3) increasing age (OR 1.57, 95% CI 1.50-1.65); (4) prior deployment (OR 1.39, 95% CI 1.36-1.41); (5) prior ankle injury (OR 1.16, 95% CI 1.14-1.19); (6) Infantry occupation (OR 1.12, 95% CI 1.04-1.21); (7) marital status (OR 1.10, 95% CI 1.08-1.12); (8) and prior hip injury (OR 1.08, 95% CI 1.03-1.12).

Soldiers with a prior KI have nearly a 10-fold increased relative risk of developing a subsequent STKI.