Incidence and Risk Factors Associated with Meniscal Injuries Among Active-Duty US Military Service Members
Jones JC, Burks R, Owens BD, Sturdivant RX, Svoboda SJ, & Cameron KL. Journal of Athletic Training. 2012; 47: 67-73.
Injuries to the meniscus are relatively common in the physically active population and can cause limitations in activity levels, possible surgical intervention, as well as long-term complications due to early-onset osteoarthritis. Despite population-based estimates for the risk of meniscal injuries that require surgery there is limited information about incidence rates and risk factors for meniscal injuries in a young, physically active population; particularly among military service members. The purpose of this retrospective study was to investigate the meniscal injury rate among active-duty US military population between the years of 1998 through 2006. Injury data was collected utilizing diagnosis codes (ICD-9) for lateral, medial, or unspecified meniscal injury from the Defense Medical Surveillance System, which gathers all medical encounter information for the 4 branches of the military. During the 9 year period of interest, there was an overall acute meniscal injury incidence rate of 8.27 per 1000 person-years (number of meniscal injuries divided by the total number of service members during study time period), with approximately 11,100 acute meniscal injuries occurring per year. Approximately 50% of the meniscal injuries occurred to the medial meniscus, while approximately 22% occurred to the lateral and 27% were unspecified to medial or lateral. Demographic and occupational factors of sex, age, race, branch of service, and rank were all found to be associated with meniscal injury. Being male, of greater age, black or white, in the Army or Marine Corps, or a junior-enlisted ranking were all independently associated with higher meniscal injury rates.
This study confirmed clinical findings that medial meniscal injuries occur more often than lateral meniscal injuries, and that increased age is associated with higher rates of meniscal injuries. An interesting and novel finding of this study was that those who were in the Army or Marine Corp in addition to those with a rank of junior enlisted service member had higher meniscal injury incidence rates than the other branches or ranks. Junior enlisted members had higher rates than senior enlisted members, which seems to contradict the fact that older age was found to be an increased risk factor. Could it be that junior enlisted members may have different activity levels or demands such as cutting/pivoting in comparison to senior members? It would be interesting to collect information regarding the mechanism of knee injury, as well as any concomitant injuries, across these demographic and occupational factors to determine if there are differences in activities. In regards to the association of branches, it is possible that the training activities that the Army or Marine Corps were involved in seem to be leading to higher incidence rates. Since this study was a retrospective study, the authors did not collect outcomes post-injury, but it may be extremely interesting to see surgical rates, drop-out rates, performance effects, as well as onset of early osteoarthritis. This is a population, who has a higher incidence of meniscal injuries compared to the general US population, is also at a higher risk for long-term complications (e.g., osteoarthritis; Cameron et al. 2011). This would be an ideal population to test and implement preventative programs, investigate long-term complications, or intervention efficacy. Lastly, this study seemed to find an association between meniscal injury rates and gender/race. This may not be a good sampling of population due to the lower number of members classified with gender of women or race category of “other.” There were no differences found between African Americans and Caucasians. While this study is primarily applicable to military service member, it is possible that clinicians working with the college level athletes may see similar patterns of gender, race, and age influencing the risk of meniscal injuries. Has anyone seen anything clinically or in other literature to support the findings that that men experience meniscal injury at a much higher rate than women?
Written by: Nicole Cattano
Reviewed by: Jeffrey Driban
Jones JC, Burks R, Owens BD, Sturdivant RX, Svoboda SJ, & Cameron KL (2012). Incidence and Risk Factors Associated with Meniscal Injuries Among Active-Duty US Military Service Members. Journal of Athletic Training, 47 (1), 67-73 PMID: 22488232