ACL INJURIES IN THE FEMALE ATHLETE

Transcription

1 ACL INJURIES IN THE FEMALE ATHLETE Jeffrey L. Mikutis, D.O. Surgical Director, Sports Medicine Pediatric Orthopaedic Surgeon Orthopaedic Center for Spinal & Pediatric Care, Inc. Dayton Children s Hospital 1

2 Normal knee anatomy, front view Knee Injury Rates Ø Knee injuries are not infrequent in females participating in sports requiring pivoting, jumping, and changing direction such as soccer, basketball, and volleyball. Ø This is especially true in year round sports Ø Studies show the knee injury rate of per 1000 athletic exposures are predominately ACL tears 2

3 Knee Injury Rates Ø Recent studies show females are 2x-8x more likely to tear the ACL than male athletes Female-to-Male ACL Injury Ratio Soccer 2.67 Basketball 3.5 Wrestling 4.5 Sking 1.00 u The injury risk for all year round collegiate soccer and basketball players are 4.4-5% per year for females compared to 1.7% for males u Most ACL tears occur in the teenage years into the early 20 s. However, rates are increasing in younger athletes due to earlier exposure and more sustained athletic participation. u The annual ACL injury incidence rate is about 100, ,000 3

4 What does this all mean? u ACL tears lead to pain, prolonged rehab, lost productivity, lost competition and lost scholarship opportunities u Long term arthritic changes are a large concern as well Etiology 70% of ACL tears are from non-contact injuries How? u A sudden deceleration before a change of direction or landing u A plant-and-cut movement leading to forceful valgus rotation in the extended knee u Up to 30% of ACL contact injuries result from valgus injury to the extended knee 4

5 Risk Factors Extrinsic Risk Factors Ø Increased female participation in sports/ Title IV Ø Weather/playing conditions Ø Playing surface Ø Shoe/cleat design Ø Brace wear Risk Factors Factors Study Conclusions Weather, playing conditions Heidit et al (1996) Orchard et al (1997) Scranton et al (1997) Playing Surface Olsen et al (2003) Torg et al (1996) Meyers and Barnhill (2004) Cleat Design Lambson et al (1996) Robey et al (1971) Bracing Sitler et al (1990) Kocher et al (2003) Birmingham et al (2001) Teiz et al (1987) Risberg et al (1999) Higher rainfall and cooler temps were related to decreased ACL injury rates Increased rate of noncontact ACL injury in dry playing conditions Increased rate of ACL injury in synthetic vs. traditional floors 50% decrease in ACL injury in field or turf compared with natural grass Shoe design with more peripheral, longer cleats and more central, shorter cleats were associated with increased ACL injury Shorter cleats had a decrease rate of ACL injury when compared to longer cleats Prophylactic braces were effective in preventing injury Increased ACL re-injury in unbraced skiers vs. braced skiers Brace wear may improve mechanoreceptors which are disrupted in ACL-defiecient knees No benefit to brace wear; rates of knee injury increase with brace wear No benefits to brace wear following ACL reconstruction regarding overall function. Brace wear 1-2 years after reconstruction produced decrease quadriceps strength 5

6 Risk Factors Intrinsic Risk Factors Ø Anatomy Ø Increased Quadricep Angle (knee valgus + hip varus) leads to more laterally directed pull of the quads, putting the ACL at risk Ø Intercondylar Notch Ø Correlation between decreased notch width and ACL tears Ø Women have higher number of A shaped notches Ø Controversial Ø ACL Size Ø Females have smaller ACLs and mid-substance cross-rectinal area in some studies Risk Factors Intrinsic Risk Factors Ø Tibial Slope Ø BMI Ø Recent research is looking at increased posterior tibial slope (PTS) Ø Increased slope places the tibia more anterior relative to femur during quad contraction which may increase strain on the ACL Ø Greater medial tibial slope (MTS) in injured vs. uninjured Ø High correlation between increased BMI and incidence of ACL tears in a number of studies 6

7 Biomechanical and Neuromuscular Factors u Are the dynamic components that combine with previously mentioned static components u Neuromuscular factors most reliably related to ACL injury u Females have u Higher quadriceps to hamstring ratio u Higher ratio of quadriceps to hamstring recruition u Out of phase quadriceps-hamstring activation may lessen knee stiffness and reduce protective antagonistic effects of hamstrings Biomechanical and Neuromuscular Factors u Because quadriceps dominance in females is greater than males, they have smaller knee/hip flexion angles during athletics. u Highly trained female athletes correct this and surpass males in some cases u Decreased knee flexion angle and decreased hip flexion make the ACL vulnerable to injury 7

8 Biomechanical and Neuromuscular Factors u Females land with increased hip adduction and knee valgus leading to increased ground reaction force u Fatigue can increase the above factors, leading to increased injuries Biomechanical and Neuromuscular Factors 8

9 Sex Hormones Ø Estrogen and relaxin receptors on the ACL Ø These hormones decrease rate of collagen synthesis Ø Reports of increased laxity during menstrual cycle but findings are inconclusive regarding ACL tears Ø Some studies show greater prevalence of ACL tears during pre-ovulatory phase of menstrual cycle, negated by BCPs. Ø This has also been refuted by other studies. The data is insufficient to make any conclusive statements Genetics Ø Small study on twins shows increased incidence of ACL tears Ø This may be due to similar neuromuscular issues 9

10 ACL Prevention Strategies u Multiple literature supports a program of neuromuscular and proprioceptive training in young female athletes to lower the incidence of ACL tears u Successful intervention includes some of all of: u Plyometrics u Strength training u Stretching exercises u Balance and agility drills u Aerobic training u Body position awareness ACL Prevention Strategies 10

11 ACL Prevention Strategies Treatment of ACL Tears u Surgical treatment to reconstruct the torn ACL with a number of graft choices (hamstring, BTB, quadriceps) along with repair of intrarticular pathology (meniscal tears ) is recommended to return the cutting athletes to sports u ACL surgery in females is similar to males except: u May need to do a notchplasty u May need to augment hamstring tendons due to smaller size 11

12 Treatment of ACL Tears u Post-op rehab is necessary for 6-12 months before return to sports u Greater strength deficits found in females vs. males post-op u Females have greater incidence of ACL rupture of contralateral knee Conclusion u Young female athletes have greater incidence of ACL tears than young male athletes across the sports spectrum u Combination of anatomy, biomechanical, neuromuscular, genetic and hormonal factors predispose the female athlete to increased risk u Neuromuscular/proprioceptive programs have proven effective in reducing the incidence of ACL tears in the young female athlete u After ACL reconstruction, females may need rehab with attention to contralateral knee u Despite it all, they are still tougher than guys! 12

13 THANK YOU QUESTIONS? 13