Risk Factors for Anterior Cruciate Ligament Injury The Association of the Menstrual Cycle with the Laxity of the Anterior Cruciate Ligament in Adolescent Female Athletes Risk Factors Associated with Noncontact Injury of the Anterior Cruciate Ligament Hormonal therapy: ACL and ankle injury. Neuromuscular control training programs and noncontact anterior cruciate ligament injury rates in female athletes: a numbers-needed-to-treat analysis. Relationship of the menstrual cycle phase to anterior cruciate ligament injuries in teenaged female athletes
Context : Injuries to the anterior cruciate ligament ( ACL ) of the knee are immediately debilitating and can cause long-term consequences , including the early onset of osteoarthritis . It is important to have a comprehensive underst and ing of all possible risk factors for ACL injury to identify individuals who are at risk for future injuries and to provide an appropriate level of counseling and programs for prevention . Objective : This review , part 1 of a 2-part series , highlights what is known and still unknown regarding anatomic and neuromuscular risk factors for injury to the ACL from the current peer- review ed literature . Data Sources : Studies were identified from MEDLINE ( 1951–March 2011 ) using the MeSH terms anterior cruciate ligament , knee injury , and risk factors . The bibliographies of relevant articles and review s were cross-referenced to complete the search . Study Selection : Prognostic studies that utilized the case-control and prospect i ve cohort study design s to evaluate risk factors for ACL injury were included in this review . Results : A total of 50 case-control and prospect i ve cohort articles were included in the review , and 30 of these studies focused on neuromuscular and anatomic risk factors . Conclusions : Several anatomic and neuromuscular risk factors are associated with increased risk of suffering ACL injury — such as female sex and specific measures of bony geometry of the knee joint , including decreased intercondylar femoral notch size , decreased depth of concavity of the medial tibial plateau , increased slope of the tibial plateaus , and increased anterior-posterior knee laxity . These risk factors most likely act in combination to influence the risk of ACL injury ; however , multivariate risk models that consider all the aforementioned risk factors in combination have not been established to explore this interaction Objective To identify a significant change in the laxity of the anterior cruciate ligament ( ACL ) in the competitive adolescent female athlete throughout the different phases of the menstrual cycle . Design Prospect i ve , single-blinded 8-week study set during a winter sports season . Setting Suburban Ohio Division I high school . Participants 26 members of gymnastics , soccer , track , tennis , and basketball teams . All participants were screened for normal menstrual cycles ( 26–30 days , menses 4–7 days long ) . Main Outcome Measures  KT-1000 arthrometer  was used to measure laxity by performing repeated measures throughout an 8-week period . Measurements were taken before the athletes ' workouts . The athlete charted the menstrual periods on a monthly calendar . The measurements were then grouped into the three phases of the menstrual cycle ( follicular , ovulatory , and luteal ) and averaged . Results Right knee laxity measured 4.98 mm follicular phase , 5.24 mm ovulatory , and 5.09 mm luteal . Left knee laxity measured 4.51 mm follicular , 4.43 mm ovulatory , and 4.62 mm luteal . There was no statistical difference among the three phases in the left ( p = 0.9 ) and right ( p = 0.7977 ) . Additionally , left ACL laxity was significantly less in all three phases . We found no statistically significant variability in laxity among the five sports sample d ( p > 0.63 to 0.10 ) and different ages ( p = 0.404 ) Conclusions We found an insignificant change in ACL laxity from follicular to luteal phases of the menstrual cycle . This indicates that no single phase of the menstrual cycle clinical ly affects the ACL more than the next . Although the presence of sex hormones — particularly estrogen — may indeed predispose females to higher ACL injury rates , we did not find any evidence that hormonal level changes equate with significant ACL laxity changes . We conclude that the menstrual cycle does not significantly affect ACL laxity in the competitive adolescent female athlete Background : The causes of noncontact anterior cruciate ligament injury remain an enigma . Purpose : To prospect ively evaluate risk factors for noncontact anterior cruciate ligament injuries in a large population of young athletic people . Study Design : Prospect i ve cohort study . Methods : In 1995 , 1198 new United States Military Academy cadets underwent detailed testing and many parameters were documented . During their 4-year tenure , all anterior cruciate ligament injuries that occurred were identified . Statistical analyses were used to identify the factors that may have predisposed the cadets to noncontact anterior cruciate ligament injuries . Results : Among the 895 cadets who completed the entire 4-year study , there were 24 noncontact anterior cruciate ligament tears ( 16 in men , 8 in women ) . Significant risk factors included small femoral notch width , generalized joint laxity , and , in women , higher than normal body mass index and KT-2000 arthrometer values that were 1 st and ard deviation or more above the mean . The presence of more than one of these risk factors greatly increased the relative risk of injury . All female cadets who had some combination of risk factors sustained noncontact anterior cruciate ligament injuries , indicating that some combinations of factors are especially perilous to the female knee . Conclusion : Several risk factors may predispose young athletes to noncontact anterior cruciate ligament injury BACKGROUND No definitive explanation for the difference in rate of male and female noncontact ACL injury has been found . The hormonal environment , known to be different in men and women has been hypothesized as a possible source for this difference in injury rate . PURPOSE To confirm earlier work looking at periodicity of noncontact ACL injury . To increase sample size by adding ankle sprains . To determine the rate of  noncontact ACL injury and ankle sprains in collegiate basketball and soccer . To determine if the use of oral contraceptives affects the rate of noncontact ACL injury and ankle sprains . METHODS Data was collected from a sample of NCAA schools over the 2000 - 2001 basketball and the 2001 - 2002 basketball and soccer seasons . RESULTS Recall and prospect i ve data collection of length of menstrual cycle did not produce equivalent results . Periodicity was present only in the recall group of " off pill " users . The rate of noncontact ACL injury and noncontact ankle sprains was twice as high in basketball as in soccer . There was no difference in rate of injuries between those athletes using  hormonal therapy and those athletes not using hormonal therapy . CONCLUSIONS Noncontact ACL injuries and ankle sprains occurred at significantly higher rates in basketball than in soccer but this rate difference was not linked to hormonal therapy usage . The overall rate of noncontact ACL injury and ankle sprain to women 's collegiate basketball and soccer players is very low OBJECTIVE To determine the numbers needed to treat ( NNT ) and relative risk reduction ( RRR ) associated with neuromuscular training programs aim ed at preventing noncontact anterior cruciate ligament ( ACL ) injuries in female athletes . DATA SOURCES We search ed PubMed , MEDLINE , SPORT Discus , CINAHL , and Web of Science from 1966 through 2005 using the terms knee , injury , anterior cruciate ligament , ACL , prevention , plyometric , and neuromuscular training . STUDY SELECTION Selected articles were from peer- review ed journals written in English that described original research studies comparing neuromuscular training programs with control programs to determine the number of noncontact ACL injuries per event exposure or hours of playing time . Five studies met the inclusion criteria and were independently rated by 3 review ers using the Physiotherapy Evidence Data base ( PEDro ) scale . Consensus PEDro scores ranged from 4 to 7 out of 10 . DATA EXTRACTION We used numbers of subjects , ACL injuries , and injury exposure rates to calculate NNT and RRR for each study . The NNT calculations from all studies were based on the number of players across 1 competitive season and were described as NNT benefit or NNT harm . DATA SYNTHESIS All 5 studies demonstrated a prophylactic effect due to the neuromuscular training programs . The pooled NNT estimates showed that 89 individuals ( 95 % confidence interval : 66 to 136 ) would need to participate in the prophylactic training program to prevent 1 ACL injury over the course of 1 competitive season . Pooled RRR was 70 % ( 95 % confidence interval : 54 % to 80 % ) among individuals who participated in the intervention program . One high- quality r and omized control trial and 4 medium- quality prospect i ve cohort studies showed mostly consistent findings . Thus , a Strength of Recommendation Taxonomy level of evidence of 1 with a grade B recommendation supports the use of neuromuscular training programs in the prevention of noncontact ACL injuries in female athletes Introduction Anterior cruciate ligament ( ACL ) injuries are more common among female athletes compared to male athletes . Several studies have been reported to explain the gender difference in ACL injury rates and several risk factors underlying gender disparity are believed to exist . Hormonal effects are considered to be one of the etiological factors for female non-contact ACL injuries . The objectives of this study were to determine if ACL injuries occurred r and omly or correlated with a specific phase of the female menstrual cycle in teenaged female athletes and then to determine if pre-menstrual and menstrual dysfunctions influenced these ACL injuries . Material s and methods Eighteen of 37 consecutive female athletes , with ACL injuries , met the study criteria : teenage , with regular menstrual cycle , and non-contact injury . The menstrual history , athletic activity , and injury history were collected . Results Seventy-two percent of the subjects had premenstrual symptoms and 83 % had  menstrual symptoms . The subjective activity level at the follicular phase was significantly lowest between the phases . A significant statistical association was found between the phase of the menstrual cycle and ACL injuries ( P = 0.0002 ) . There were more injuries in the ovulatory phase than expected , and fewer injuries occurred in the other phases . Conclusion The results showed a significant increase in non-contact ACL injuries in teenage female athletes during the ovulatory phase of the menstrual cycle and the subjective activity level and the premenstrual and menstrual symptoms might not affect the likelihood of the injuries . These findings suggest that sex hormones might play a role in the incidence of female non-contact ACL injuries
Conclusion : The literature suggests an association between hormonal fluctuations and ACL injury .
Recent studies have suggested that oral contraceptives may offer up to a 20 % reduction in risk of injury .
Background : Women are at substantially greater risk for anterior cruciate ligament ( ACL ) injuries than are men .
Purpose : To conduct a systematic review and meta- analysis of the literature to clarify the effect of the menstrual cycle and contraceptives on the laxity of and noncontact injuries to the ACL .