Epidemiology of Ankle Sprains and the Risk of Separation From Service in U.S. Army Soldiers.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To report the incidence rate of ankle sprains in active-duty soldiers and to examine if soldiers who sustain ankle sprain injuries are more likely to leave the Army than those who do not sustain an ankle sprain. BACKGROUND: Ankle sprains are one of the most common musculoskeletal injuries in physically active people and have been identified as the most common foot or ankle injury in active-duty Army personnel, with a rate of 103 sprains per 1000 soldiers per year. METHODS: Data were analyzed on the entire active-duty US Army population from 2000 to 2006 (n = 1 014 042). A semi-parametric Cox proportional hazard model was built. RESULTS: The overall incidence rate for ankle sprains was 45.14 per 1000 person-years. After controlling for length of service prior to the study period, soldiers who sustained a single ankle sprain were 27% less likely (relative risk ratio = 0.73; 95% confidence interval: 0.73, 0.75) to leave the service than soldiers who had no documented history of an ankle sprain. However, this trend toward increased service time no longer held true for those who sustained a recurrent sprain (risk ratio = 1.07; 95% confidence interval: 0.99, 1.15). CONCLUSION: It appears that individuals who sustain an incident ankle sprain have longer time in service in the Army than those who do not sustain this injury. However, this trend toward longer service time no longer held true for soldiers who sustained a recurrent. LEVEL OF EVIDENCE: Prognosis, level 2b.

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

BACKGROUND: 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. PURPOSE: To quantify the independent adjusted association of significant ADA STKI risk factors, 2000-2005. MATERIALS/METHODS: 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. RESULTS: 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). MAJOR CONCLUSION: Soldiers with a prior KI have nearly a 10-fold increased relative risk of developing a subsequent STKI.

Rates of knee injury in the U.S. Active Duty Army, 2000-2005.

We sought to summarize knee injuries (KI) in the U.S. Active Duty Army (ADA) in terms of absolute numbers, examine current rate trends, and identify ADA who were at increased risk for experiencing a KI. We used the Total Army Injury and Health Outcomes Database (TAIHOD) to compute unadjusted and adjusted rates of KI, categorized by the Barell Matrix, within the ADA for the years 2000-2005. During this period, 21 to 25 per 1,000 ADA suffered from KI. The highest yearly rates were observed for knee dislocation and sprains/strains (31 per 1,000 ADA). In ADA with a history of a KI (within 2 years), rates increased nearly tenfold. Elevated KI rates were also seen in ADA with prior upper or lower leg injuries, those > 30 years of age, and those with a category IV Armed Forces Qualification Test score (lowest admissible in Army). ADA KI rates remained fairly stable throughout the study period. Relative to other ADA Soldiers, those with prior knee, upper leg, or lower leg injuries are at increased risk for subsequent KI.

Does a simple bedside sonographic measurement of the inferior vena cava correlate to central venous pressure?

BACKGROUND: Bedside ultrasound has been suggested as a non-invasive modality to estimate central venous pressure (CVP). OBJECTIVE: Evaluate a simple bedside ultrasound technique to measure the diameter of the inferior vena cava (IVC) and correlate to simultaneously measured CVP. Secondary comparisons include anatomic location, probe orientation, and phase of respiration. METHODS: An unblinded prospective observation study was performed in an emergency department and critical care unit. Subjects were a convenience sample of adult patients with a central line at the superior venocaval-atrial junction. Ultrasound measured transverse and longitudinal diameters of the IVC at the subxiphoid, suprailiac, and mid-abdomen, each measured at end-inspiration and end-expiration. Correlation and regression analysis were used to relate CVP and IVC diameters. RESULTS: There were 72 subjects with a mean age of 67 years (range 21-94 years), 37 (53%) male, enrolled over 9 months. Seven subjects were excluded for tricuspid valvulopathy. Primary diagnoses were: respiratory failure 12 (18%), sepsis 11 (17%), and pancreatitis 3 (5%). There were 28 (43%) patients mechanically ventilated. Adequate measurements were obtainable in 57 (89%) using the subxiphoid, in 44 (68%) using the mid-abdomen, and in 28 (43%) using the suprailiac views. The correlation coefficients were statistically significant at 0.49 (95% confidence interval [CI] 0.26-0.66), 0.51 (95% CI 0.23-0.71), and 0.50 (95% CI 0.14-0.74) for end-inspiratory longitudinal subxiphoid, midpoint, and suprailiac views, respectively. Transverse values were statistically significant at 0.42 (95% CI 0.18-0.61), 0.38 (95% CI 0.09-0.61), and 0.67 (95% CI 0.40-0.84), respectively. End-expiratory measurements gave similar or slightly less significant values. CONCLUSION: The subxiphoid was the most reliably viewed of the three anatomic locations; however, the suprailiac view produced superior correlations to the CVP. Longitudinal views generally outperformed transverse views. A simple ultrasound measure of the IVC yields weak correlation to the CVP.