The adolescent knee and risk for osteoarthritis - an opportunity or responsibility for sport medicine physicians?

Epidemiology of Knee Sprains in Youth, High School, and Collegiate American Football Players

CONTEXT

  Variations in knee-sprain incidence among competition levels are unclear but may help inform prevention strategies in American football players.

OBJECTIVE

  To describe the epidemiology of knee sprains in youth, high school, and collegiate football players.

DESIGN

  Descriptive epidemiology study.

SETTING

  Injury and athlete-exposure (AE) data were collected from 3 injury-surveillance programs at the youth, high school, and collegiate competition levels.

PATIENTS OR OTHER PARTICIPANTS

  Data from 310 youth, 184 high school, and 71 collegiate football team-seasons were collected during the 2012 through 2014 seasons.

MAIN OUTCOME MEASURE(S)

  Knee-sprain rates and risks were calculated for each competition level. Injury rate ratios (IRRs) and risk ratios (RRs) compared knee-sprain rates by competition level. Injury proportion ratios (IPRs) compared differences in surgery needs, recurrence, injury mechanism, and injury activity by competition level.

RESULTS

  Knee-sprain rates in youth, high school, and collegiate football were 0.16/1000 AEs, 0.25/1000 AEs, and 0.69/1000 AEs, respectively. Knee-sprain rates increased as the competition level increased (high school versus youth: IRR = 1.60; 95% confidence interval [CI] = 1.12, 2.30; collegiate versus high school: IRR = 2.73; 95% CI = 2.38, 3.96). Knee-sprain risk was highest in collegiate (4.3%), followed by high school (2.0%) and youth (0.5%) athletes. Knee-sprain risk increased as the competition level increased (high school versus youth: RR = 3.73; 95% CI = 2.60, 5.34; collegiate versus high school: RR = 2.14; 95% CI = 1.83, 2.51). Collegiate football had the lowest proportion of knee sprains that were noncontact injuries (collegiate versus youth: IPR = 0.54; 95% CI = 0.31, 0.95; collegiate versus high school: IPR = 0.59; 95% CI = 0.44, 0.79) and the lowest proportion that occurred while being tackled (collegiate versus youth: IPR = 0.44; 95% CI = 0.26, 0.76; collegiate versus high school: IPR = 0.71; 95% CI = 0.51, 0.98).

CONCLUSIONS

  Knee-sprain incidence was highest in collegiate football. However, level-specific variations in the distributions of knee sprains by injury activity may highlight the need to develop level-specific policies and prevention strategies that ensure safe sports play.

Anterior cruciate ligament injury: mechanisms of injury and strategies for injury prevention

Anterior cruciate ligament (ACL) injury is a common sports injury which can have severe negative consequences. Neuromuscular factors that increase risk, such as knee landing kinematics, may be ameliorated through training. Effective ACL injury prevention programs exist, although the ideal program is yet to be determined. It is recommended that athletes engaged in high-risk sports participate in an ACL injury prevention program to reduce the risk of sustaining this injury.

Injury initiates unfavourable weight gain and obesity markers in youth

OBJECTIVE

The purpose of this study was to examine the association of knee injuries with subsequent changes in body mass index and body composition during maturation in young females.

METHODS

A prospective longitudinal study design was employed to evaluate young females active in soccer or basketball (N=862). Participants who completed at least 1-year follow-up to provide consecutive annual measures of BMIZ and %fat were included in the study analysis to determine the effect of knee injuries on the trajectory of these obesity markers in youth.

RESULTS

Of the 71 reported knee injuries, 12 (17%) occurred in athletes at the prepubertal stage, 24 (34%) in athletes at the pubertal stage, and 35 (49%) in postpubertal athletes. Controlling for the effects of maturation, female athletes who reported knee injury demonstrated a greater yearly increase in BMIZ (LS means and 95% CI for the injured group=0.039 (-0.012 to 0.089), for the non-injured group=-0.019 (-0.066 to 0.029), and group difference=0.057 (0.005 to 0.11), p=0.03) and in %body fat (LS means and 95% CI for the injured group=1.05 (0.45 to 1.65), for the non-injured group=0.22 (-0.21 to 0.064), and group difference=0.83 (0.21 to 1.45), p=0.009), compared to those without knee injuries. This indicates that the athletes with knee injuries will increase their body mass index percentile by up to 5 units more than someone of the same age without an injury, and in body fat by up to 1.5%, compared to their non-injured peers.

CONCLUSIONS

The present findings indicate that knee injury during the growing years may be associated with unfavourable changes in body composition.