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Female Athletes: Unique Challenges Facing Women Warriors
Since Title IX passed in 1972, women have become exponentially more involved in competitive sports, from high school to professional levels. With more women engaging in serious athletics, the specific challenges they face have come to the forefront of sports medicine. These problems include the female athlete triad, concussions, exercise safety in pregnancy, anterior cruciate ligament (ACL) injuries, and continued sex discrimination and social injustice. Orthopedists treating female athletes should be aware of these problems, each of which is discussed in this review.
1. Female athlete triad
In 1992, the term female athlete triad was coined to describe 3 problems that often coexist in high-intensity female athletes.1 Since then, the definition has evolved, but the problem has remained essentially the same. The modern definition incorporates menstrual abnormalities, low energy availability with or without disordered eating, and decreased bone mineral density (BMD).2
With intense exercise and weight loss comes a variety of menstrual disturbances.3 In affected athletes, the hypothalamus is underactivated, and changes in gonadotropin-releasing hormone and luteinizing hormone lead to decreased estrogen production. Research suggests abnormal menses result from having inadequate energy and insufficient caloric intake to support extensive exercise.1 This phenomenon can occur in athletes in any sport but is most prevalent in lean-body sports, such as swimming, gymnastics, and ballet. The incidence of abnormal menses is as high as 79% in ballet dancers but only 5% in the general population.3 Menstrual abnormalities indicate hormonal abnormalities that can interfere with growth and maturation in young athletes.
Although full-blown eating disorders are uncommon among female athletes, disordered eating patterns are often found among women in competitive sports. Disordered eating can involve a spectrum of inadequate caloric intake and purging behavior, such as vomiting or laxative abuse, and has been reported in up to 25% of collegiate female athletes.4 Physicians must recognize these conditions and initiate counseling and treatment when appropriate. Women with disordered eating are at risk for developing electrolyte imbalances, malnutrition syndromes, and osteopenia.
Although careful evaluation and counseling are important, physicians must note that, in most cases, athletics participation may also protect against disordered eating and body image difficulties. A study of 146 college-age women found better body satisfaction among athletes than among nonathletes.5 Lean-sport athletes (eg, swimmers, gymnasts) were at higher risk for disordered eating and body image problems than other athletes were. Similarly, other studies have found that a majority of athletes have healthy eating habits.4
For poorly nourished and hormonally imbalanced female athletes, decreased BMD poses substantial risk. One study found a significant difference in BMD between athletes with amenorrhea and athletes with normal menses.6 In a cohort of female Navy recruits, those with amenorrhea were at 91% higher risk for stress fractures; calcium and vitamin D supplementation reduced risk by 20%.7 Osteopenia may be a special problem for prepubescent athletes. Girls who engage in intense exercise and have delayed menarche may have a low estrogen state, predisposing them to low BMD.3 Osteopenia and osteoporosis are difficult to reverse and can put these athletes at risk for stress fractures the rest of their lives. If unrecognized, stress fractures can end an athlete’s career.
Recommendations for dual-energy X-ray absorptiometry (DXA) include testing female athletes who have a diagnosed eating disorder, body mass index under 17.5, history of delayed menarche, oligomenorrhea, 2 prior stress fractures, or prior abnormal DXA scan. Complete testing recommendations appear in the 2014 consensus statement on the female athlete triad and return to sport.2,8
Orthopedists performing physical examinations for sports participation can screen for the female athlete triad through thoughtful questioning about menstrual history, nutrition habits, and stress fracture symptoms. Best treatment for a diagnosed case of the triad is multidisciplinary care with strong social support. When abnormal menses are an issue, referral to a gynecologist or endocrinologist and consideration of estrogen replacement should be discussed. Some cases require a psychiatrist’s assistance in treating disordered eating. Athletic trainers, coaches, and parents should be involved over the treatment course.1 Orthopedists must counsel women with osteopenia and osteoporosis about decreasing exercise to a safe level, improving nutritional intake, and supplementing with calcium (1200-1500 mg/d) and vitamin D (600-800 IU/d).3,7
2. Concussions
Increasing awareness of males’ sport-related concussions, particularly of concussions that occur during National Football League practice and games, has made physicians and researchers more aware of the rate of concussion in female athletes. That rate has increased, and, according to some reports, the risk for sport-related injury is higher for female athletes.9 A study of high school athletes found that the rate of concussion in girl’s soccer was second only to that in football.10
Concussions are categorized as mild traumatic brain injuries, and manifestations of the diagnosis are divided into physical, emotional, cognitive, and observed symptoms. The spectrum of symptoms is wide, ranging from difficulty concentrating and thinking clearly to headaches and dizziness.11 Compared with male athletes who sustain a concussion, female athletes report more of these concussive symptoms and have worse visual memory scores.12
Efforts to change sports at the player level have been resisted. Helmets have been proposed for field hockey and lacrosse but have not passed stringent concussion testing. In soccer, which has a high rate of concussion, a reform to eliminate heading the ball has been considered. Resistance to these suggestions stems from the thought that changes could alter the traditions of the games. Some individuals have indicated that helmets may give players a false sense of security and thereby cause them to play more aggressively.
Orthopedic surgeons must be aware of concussion symptoms. Multiple concussions may have a cumulative effect on functional ability and emotional well-being and may lead to chronic traumatic encephalopathy.13 Concern about the long-term effects of concussion has led to the implementation of universal “return to play” laws. These laws vary by state but have 3 steps in common: Educate coaches, players, and athletes; remove athletes from play; and obtain health care professionals’ permission to return to play.14 These guidelines set up an action plan for treating an athlete who has sustained a concussion.
Encouraging results of educating coaches have been noted. Coaches who were given Centers for Disease Control and Prevention–sponsored material on preventing, recognizing, and responding to concussions were able to effectively address concussions; 6 months later, 63% were better able to appreciate the severity of concussions.15 Continued education of athletic communities should help bring this injury to the attention of those treating female athletes.
3. Exercise safety in pregnancy
Women in sports can continue their athletic regimens during pregnancy. It is important to address challenges to the pregnant woman and to the fetus when assessing the risks of exercise.
The physiologic changes that occur during pregnancy may affect how a pregnant athlete responds to stress. Plasma volume, red blood cell volume, and cardiac function and output all increase during normal pregnancy.3,16 Abnormal heart rate during pregnancy can adversely affect the fetus. During and after exercise, fetal bradycardia can occur. Therefore, recommendations should include not exceeding pre-pregnancy activity levels.3 Careful monitoring of exercise intensity is recommended by the American College of Obstetrics and Gynecology; the guideline is to maintain less than 70% of maximal heart rate.17,18
The negative effects of exercise on the pregnant athlete are limited, but it is important to educate patients and to consider preventive strategies. One physiologic change that occurs during pregnancy is ligamentous laxity, which is caused by the hormone relaxin.16 Ligamentous laxity has the potential to put pregnant athletes at risk for soft-tissue and bony injury during impact sports. However, the positive effects of exercise during pregnancy include improved appetite, sleep, and emotional health.19 Aerobic exercise during pregnancy may reverse insulin resistance as demonstrated in animal studies; though this outcome has not been demonstrated in human studies,20 women should be reassured that moderate exercise has overall beneficial effects.
Some research suggests that exercise may expose the fetus to hyperthermia, blood sugar changes, physical injury, and premature labor.16 Typically, fetal heat is dissipated from the mother. After intense exercise, maternal body temperature rises and leads to some degree of fetal hyperthermia.16 Animal model studies have suggested that hyperthermia may result in a slightly higher rate of congenital abnormalities. Pregnant women should keep their exercise routines to less than 60 minutes, should exercise in a thermally regulated environment, and should keep themselves hydrated to avoid fetal hyperthermia.18
Reduced blood flow, accompanied by a deficit of oxygen to the uterus and the developing fetus, is another concern for pregnant athletes. During exercise, when more blood is flowing to the muscles, less is flowing to the uterus.16 Furthermore, during the third trimester, women should avoid supine exercise, as venous outflow is poor with the body in that position.21
Elite athletes who continue training during pregnancy should be carefully counseled about adjusting their training regimens. Because of increased cardiac output and blood volume, the heart rate will be lower than usual, demanding an adjustment in interpretation. Blood cell counts do not increase as much as plasma volume does—often leading to relative anemia. For elite athletes, this means iron supplementation is crucial.22 Thermal regulation may be more difficult, as training regimens may demand prolonged exercise. Physicians should recommend adequate hydration for these athletes.18
Although continued exercise is generally safe for a pregnant athlete and her fetus, caution is required when there is increased risk for premature delivery, or other special conditions exist. Multiple gestation, placenta previa, history of early labor or premature births, and incompetent cervix all contraindicate aerobic exercise during pregnancy.18 With these exceptions in mind, physicians can safely counsel pregnant women to do moderate exercise 30 minutes every day.17,18 Other recommendations are listed at the American College of Obstetricians and Gynecologists website.23
4. Anterior cruciate ligament injuries
ACL injuries affect a staggering number of athletes. In the United States, approximately 100,000 people sustain these injuries annually.24 As they occur up to 8 times more often in women than in men, ACL injuries are a top concern for physicians treating female athletes.
This disproportionate injury rate is influenced by differences between male and female anatomy. The width and shape of the femoral intercondylar notch have been studied as potential variables influencing the risk for ACL injury. Analysis of notch-view radiographs revealed a significant inverse relationship between notch width and ACL injury.25 A-shaped notches, notches with a significantly larger base and a narrowed roof, were more prevalent in women but did not correlate with increased risk for ACL injury. Studies have shown that female athletes with a noncontact ACL injury have a higher lateral tibial plateau posterior slope; this slope is associated with increased peak anteromedial ACL strain, which may contribute to injury.26 An analysis of magnetic resonance imaging scans in patients with and without ACL injury revealed that, for female patients, decreased femoral intercondylar notch width at the anterior outlet combined with increased lateral compartment posterior slope correlated best with risk for ACL injury.27
Although static anatomical factors contribute to ACL injuries in female athletes, dynamic neuromuscular influences are potential opportunities for intervention. Female athletes with high relative quadriceps strength and weak hamstring strength may be at increased risk for ACL injury.28 This “quadriceps dominance” becomes important in sports involving high-risk activities, such as running, cutting, pivoting, and jumping. In addition, compared with male athletes, female athletes demonstrate increased lateral trunk motion and knee valgus torque while landing during noncontact ACL tears, making core stability a factor in ACL injury.29
The collaborative efforts of physicians, physical therapists, athletic trainers, and coaches have yielded multifactorial neuromuscular training programs for the prevention of noncontact ACL injuries. Ideal ACL prevention protocols involve sessions that last for at least 10 minutes and take place 3 times a week. At these sessions, exercises are focused on strengthening, balance, and proprioceptive training.30 The programs last about 8 weeks, but sustained benefits require maintenance after the program has been completed and during the off-season. Program adherence must be encouraged and can be facilitated by varying workouts and raising risk awareness. The most effective programs have reduced the relative risk of noncontact ACL injuries by 75% to 100%.31 These promising results have led to increased focus on program implementation in an effort to prevent ACL injury.
5. Continued sex discrimination and social injustice
In 1972, Title IX was passed as part of the Education Amendments Act. Title IX states, “No person in the United States shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or be subjected to discrimination under any educational program or activity receiving Federal financial assistance.” Passage of this law, which has implications outside of athletic participation, marked an important turning point in women’s ability to participate equally in college sports.32,33 The Civil Rights Restoration Act, passed in 1988, strengthened Title IX and made it applicable to all institutions receiving federal funding.34 Before the 1970s, women typically were restricted to club sports, and funding and participation opportunities were weighted heavily toward men. Over the past 40 years, women’s participation in high school, college, and professional sports has taken a huge leap forward.32 For example, the number of women participating in high school sports increased from 294,000 (7.4% of all athletes) in 1972 to 3.4 million (>41% of all athletes) in 2014.
Despite advances in women’s civil rights, examples of inequality in US schools remain, particularly in the distribution of funding, which still strongly favors men’s football.32 Men’s sports receive 90% of media coverage.33 In 2002, women represented 55% of college students but only 42% of varsity athletes.34 The schools that have complied the least with Title IX are schools in the Midwest and the South and those with football teams.34 Women are underrepresented as coaches, and funding continues to be disproportionately spent on men’s sports.
For women, the benefits of participating in sports are far-reaching and significant. These benefits include improvements in academic success, mental health, and responsible behavior.33 Women’s gaining acceptance and respect throughout the athletic world seems to have carried over elsewhere. Although many institutions remain noncompliant with Title IX, efforts continue to have a strongly positive effect on gender equality in the United States.
1. Nattiv A, Loucks AB, Manore MM, Sanborn CF, Sundgot-Borgen J, Warren MP; American College of Sports Medicine. American College of Sports Medicine position stand. The female athlete triad. Med Sci Sports Exerc. 2007;39(10):1867-1882.
2. De Souza MJ, Nattiv A, Joy E, et al; Expert Panel. 2014 Female Athlete Triad Coalition consensus statement on treatment and return to play of the female athlete triad: 1st international conference held in San Francisco, California, May 2012 and 2nd international conference held in Indianapolis, Indiana, May 2013. Br J Sports Med. 2014;48(4):289.
3. Warren MP, Shantha S. The female athlete. Baillieres Best Pract Res Clin Endocrinol Metab. 2000;14(1):37-53.
4. Greenleaf C, Petrie TA, Carter J, Reel JJ. Female collegiate athletes: prevalence of eating disorders and disordered eating behaviors. J Am Coll Health. 2009;57(5):489-495.
5. Reinking MF, Alexander LE. Prevalence of disordered-eating behaviors in undergraduate female collegiate athletes and nonathletes. J Athl Train. 2005;40(1):47-51.
6. Rencken ML, Chesnut CH 3rd, Drinkwater BL. Bone density at multiple skeletal sites in amenorrheic athletes. JAMA. 1996;276(3):238-240.
7. Lappe J, Cullen D, Haynatzki G, Recker R, Ahlf R, Thompson K. Calcium and vitamin D supplementation decreases incidence of stress fractures in female Navy recruits. J Bone Miner Res. 2008;23(5):741-749.
8. De Souza MJ. 2014 Female athlete triad consensus statement on guidelines for treatment and return to play. National Collegiate Athletic Association (NCAA) website. http://www.ncaa.org/health-and-safety/nutrition-and-performance/2014-female-athlete-triad-consensus-statement-guidelines. Accessed November 24, 2015.
9. Preiss-Farzanegan SJ, Chapman B, Wong TM, Wu J, Bazarian JJ. The relationship between gender and postconcussion symptoms after sport-related mild traumatic brain injury. PM R. 2009;1(3):245-253.
10. Marar M, McIlvain NM, Fields SK, Comstock RD. Epidemiology of concussions among United States high school athletes in 20 sports. Am J Sports Med. 2012;40(4):747-755.
11. Uhl RL, Rosenbaum AJ, Czajka C, Mulligan M, King C. Minor traumatic brain injury: a primer for the orthopaedic surgeon. J Am Acad Orthop Surg. 2013;21(10):624-631.
12. Covassin T, Elbin RJ, Harris W, Parker T, Kontos A. The role of age and sex in symptoms, neurocognitive performance, and postural stability in athletes after concussion. Am J Sports Med. 2012;40(6):1303-1312.
13. Covassin T, Moran R, Wilhelm K. Concussion symptoms and neurocognitive performance of high school and college athletes who incur multiple concussions. Am J Sports Med. 2013;41(12):2885-2889.
14. Sports concussion policies and laws: information for parents, coaches, and school & sports professionals. Centers for Disease Control and Prevention website. http://www.cdc.gov/headsup/policy/index.html. Updated February 16, 2015. Accessed November 24, 2015.
15. Covassin T, Elbin RJ, Sarmiento K. Educating coaches about concussion in sports: evaluation of the CDC’s “Heads Up: concussion in youth sports” initiative. J Sch Health. 2012;82(5):233-238.
16. Lumbers ER. Exercise in pregnancy: physiological basis of exercise prescription for the pregnant woman. J Sci Med Sport. 2002;5(1):20-31.
17. ACOG Committee Obstetric Practice. ACOG Committee opinion. Number 267, January 2002: exercise during pregnancy and the postpartum period. Obstet Gynecol. 2002;99(1):171-173.
18. Artal R, O’Toole M. Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period. Br J Sports Med. 2003;37(1):6-12.
19. Kramer MS. Regular aerobic exercise during pregnancy. Cochrane Database Syst Rev. 2000;(2):CD000180. Update in: Cochrane Database Syst Rev. 2002;(2):CD000180.
20. Stafne SN, Salvesen KA, Romundstad PR, Stuge B, Morkved S. Does regular exercise during pregnancy influence lumbopelvic pain? A randomized controlled trial. Acta Obstet Gynecol Scand. 2012;91(5):552-559.
21. Nascimento SL, Surita FG, Cecatti JG. Physical exercise during pregnancy: a systematic review. Curr Opin Obstet Gynecol. 2012;24(6):387-394.
22. Hale RW, Milne L. The elite athlete and exercise in pregnancy. Semin Perinatol. 1996;20(4):277-284.
23. Exercise during pregnancy. American College of Obstetricians and Gynecologists website. http://www.acog.org/Patients/FAQs/Exercise-During-Pregnancy. Published August 2011. Accessed November 24, 2015.
24. Giugliano DN, Solomon JL. ACL tears in female athletes. Phys Med Rehabil Clin North Am. 2007;18(3):417-438, viii.
25. Ireland ML, Ballantyne BT, Little K, McClay IS. A radiographic analysis of the relationship between the size and shape of the intercondylar notch and anterior cruciate ligament injury. Knee Surg Sports Traumatol Arthrosc. 2001;9(4):200-205.
26. Lipps DB, Oh YK, Ashton-Miller JA, Wojtys EM. Morphologic characteristics help explain the gender difference in peak anterior cruciate ligament strain during a simulated pivot landing. Am J Sports Med. 2012;40(1):32-40.
27. Sturnick DR, Vacek PM, DeSarno MJ, et al. Combined anatomic factors predicting risk of anterior cruciate ligament injury for males and females. Am J Sports Med. 2015;43(4):839-847.
28. Myer GD, Ford KR, Barber Foss KD, Liu C, Nick TG, Hewett TE. The relationship of hamstrings and quadriceps strength to anterior cruciate ligament injury in female athletes. Clin J Sport Med. 2009;19(1):3-8.
29. Hewett TE, Torg JS, Boden BP. Video analysis of trunk and knee motion during non-contact anterior cruciate ligament injury in female athletes: lateral trunk and knee abduction motion are combined components of the injury mechanism. Br J Sports Med. 2009;43(6):417-422.
30. Sutton KM, Bullock JM. Anterior cruciate ligament rupture: differences between males and females. J Am Acad Orthop Surg. 2013;21(1):41-50.
31. Noyes FR, Barber-Westin SD. Neuromuscular retraining intervention programs: do they reduce noncontact anterior cruciate ligament injury rates in adolescent female athletes? Arthroscopy. 2014;30(2):245-255.
32. Ladd AL. The sports bra, the ACL, and Title IX—the game in play. Clin Orthop Relat Res. 2014;472(6):1681-1684.
33. Lopiano DA. Modern history of women in sports. Twenty-five years of Title IX. Clin Sports Med. 2000;19(2):163-173, vii.
34. Anderson DJ, Cheslock JJ, Ehrenberg RG. Gender equity in intercollegiate athletics: determinants of Title IX compliance. J High Educ. 2006;77(2):225-250.
Since Title IX passed in 1972, women have become exponentially more involved in competitive sports, from high school to professional levels. With more women engaging in serious athletics, the specific challenges they face have come to the forefront of sports medicine. These problems include the female athlete triad, concussions, exercise safety in pregnancy, anterior cruciate ligament (ACL) injuries, and continued sex discrimination and social injustice. Orthopedists treating female athletes should be aware of these problems, each of which is discussed in this review.
1. Female athlete triad
In 1992, the term female athlete triad was coined to describe 3 problems that often coexist in high-intensity female athletes.1 Since then, the definition has evolved, but the problem has remained essentially the same. The modern definition incorporates menstrual abnormalities, low energy availability with or without disordered eating, and decreased bone mineral density (BMD).2
With intense exercise and weight loss comes a variety of menstrual disturbances.3 In affected athletes, the hypothalamus is underactivated, and changes in gonadotropin-releasing hormone and luteinizing hormone lead to decreased estrogen production. Research suggests abnormal menses result from having inadequate energy and insufficient caloric intake to support extensive exercise.1 This phenomenon can occur in athletes in any sport but is most prevalent in lean-body sports, such as swimming, gymnastics, and ballet. The incidence of abnormal menses is as high as 79% in ballet dancers but only 5% in the general population.3 Menstrual abnormalities indicate hormonal abnormalities that can interfere with growth and maturation in young athletes.
Although full-blown eating disorders are uncommon among female athletes, disordered eating patterns are often found among women in competitive sports. Disordered eating can involve a spectrum of inadequate caloric intake and purging behavior, such as vomiting or laxative abuse, and has been reported in up to 25% of collegiate female athletes.4 Physicians must recognize these conditions and initiate counseling and treatment when appropriate. Women with disordered eating are at risk for developing electrolyte imbalances, malnutrition syndromes, and osteopenia.
Although careful evaluation and counseling are important, physicians must note that, in most cases, athletics participation may also protect against disordered eating and body image difficulties. A study of 146 college-age women found better body satisfaction among athletes than among nonathletes.5 Lean-sport athletes (eg, swimmers, gymnasts) were at higher risk for disordered eating and body image problems than other athletes were. Similarly, other studies have found that a majority of athletes have healthy eating habits.4
For poorly nourished and hormonally imbalanced female athletes, decreased BMD poses substantial risk. One study found a significant difference in BMD between athletes with amenorrhea and athletes with normal menses.6 In a cohort of female Navy recruits, those with amenorrhea were at 91% higher risk for stress fractures; calcium and vitamin D supplementation reduced risk by 20%.7 Osteopenia may be a special problem for prepubescent athletes. Girls who engage in intense exercise and have delayed menarche may have a low estrogen state, predisposing them to low BMD.3 Osteopenia and osteoporosis are difficult to reverse and can put these athletes at risk for stress fractures the rest of their lives. If unrecognized, stress fractures can end an athlete’s career.
Recommendations for dual-energy X-ray absorptiometry (DXA) include testing female athletes who have a diagnosed eating disorder, body mass index under 17.5, history of delayed menarche, oligomenorrhea, 2 prior stress fractures, or prior abnormal DXA scan. Complete testing recommendations appear in the 2014 consensus statement on the female athlete triad and return to sport.2,8
Orthopedists performing physical examinations for sports participation can screen for the female athlete triad through thoughtful questioning about menstrual history, nutrition habits, and stress fracture symptoms. Best treatment for a diagnosed case of the triad is multidisciplinary care with strong social support. When abnormal menses are an issue, referral to a gynecologist or endocrinologist and consideration of estrogen replacement should be discussed. Some cases require a psychiatrist’s assistance in treating disordered eating. Athletic trainers, coaches, and parents should be involved over the treatment course.1 Orthopedists must counsel women with osteopenia and osteoporosis about decreasing exercise to a safe level, improving nutritional intake, and supplementing with calcium (1200-1500 mg/d) and vitamin D (600-800 IU/d).3,7
2. Concussions
Increasing awareness of males’ sport-related concussions, particularly of concussions that occur during National Football League practice and games, has made physicians and researchers more aware of the rate of concussion in female athletes. That rate has increased, and, according to some reports, the risk for sport-related injury is higher for female athletes.9 A study of high school athletes found that the rate of concussion in girl’s soccer was second only to that in football.10
Concussions are categorized as mild traumatic brain injuries, and manifestations of the diagnosis are divided into physical, emotional, cognitive, and observed symptoms. The spectrum of symptoms is wide, ranging from difficulty concentrating and thinking clearly to headaches and dizziness.11 Compared with male athletes who sustain a concussion, female athletes report more of these concussive symptoms and have worse visual memory scores.12
Efforts to change sports at the player level have been resisted. Helmets have been proposed for field hockey and lacrosse but have not passed stringent concussion testing. In soccer, which has a high rate of concussion, a reform to eliminate heading the ball has been considered. Resistance to these suggestions stems from the thought that changes could alter the traditions of the games. Some individuals have indicated that helmets may give players a false sense of security and thereby cause them to play more aggressively.
Orthopedic surgeons must be aware of concussion symptoms. Multiple concussions may have a cumulative effect on functional ability and emotional well-being and may lead to chronic traumatic encephalopathy.13 Concern about the long-term effects of concussion has led to the implementation of universal “return to play” laws. These laws vary by state but have 3 steps in common: Educate coaches, players, and athletes; remove athletes from play; and obtain health care professionals’ permission to return to play.14 These guidelines set up an action plan for treating an athlete who has sustained a concussion.
Encouraging results of educating coaches have been noted. Coaches who were given Centers for Disease Control and Prevention–sponsored material on preventing, recognizing, and responding to concussions were able to effectively address concussions; 6 months later, 63% were better able to appreciate the severity of concussions.15 Continued education of athletic communities should help bring this injury to the attention of those treating female athletes.
3. Exercise safety in pregnancy
Women in sports can continue their athletic regimens during pregnancy. It is important to address challenges to the pregnant woman and to the fetus when assessing the risks of exercise.
The physiologic changes that occur during pregnancy may affect how a pregnant athlete responds to stress. Plasma volume, red blood cell volume, and cardiac function and output all increase during normal pregnancy.3,16 Abnormal heart rate during pregnancy can adversely affect the fetus. During and after exercise, fetal bradycardia can occur. Therefore, recommendations should include not exceeding pre-pregnancy activity levels.3 Careful monitoring of exercise intensity is recommended by the American College of Obstetrics and Gynecology; the guideline is to maintain less than 70% of maximal heart rate.17,18
The negative effects of exercise on the pregnant athlete are limited, but it is important to educate patients and to consider preventive strategies. One physiologic change that occurs during pregnancy is ligamentous laxity, which is caused by the hormone relaxin.16 Ligamentous laxity has the potential to put pregnant athletes at risk for soft-tissue and bony injury during impact sports. However, the positive effects of exercise during pregnancy include improved appetite, sleep, and emotional health.19 Aerobic exercise during pregnancy may reverse insulin resistance as demonstrated in animal studies; though this outcome has not been demonstrated in human studies,20 women should be reassured that moderate exercise has overall beneficial effects.
Some research suggests that exercise may expose the fetus to hyperthermia, blood sugar changes, physical injury, and premature labor.16 Typically, fetal heat is dissipated from the mother. After intense exercise, maternal body temperature rises and leads to some degree of fetal hyperthermia.16 Animal model studies have suggested that hyperthermia may result in a slightly higher rate of congenital abnormalities. Pregnant women should keep their exercise routines to less than 60 minutes, should exercise in a thermally regulated environment, and should keep themselves hydrated to avoid fetal hyperthermia.18
Reduced blood flow, accompanied by a deficit of oxygen to the uterus and the developing fetus, is another concern for pregnant athletes. During exercise, when more blood is flowing to the muscles, less is flowing to the uterus.16 Furthermore, during the third trimester, women should avoid supine exercise, as venous outflow is poor with the body in that position.21
Elite athletes who continue training during pregnancy should be carefully counseled about adjusting their training regimens. Because of increased cardiac output and blood volume, the heart rate will be lower than usual, demanding an adjustment in interpretation. Blood cell counts do not increase as much as plasma volume does—often leading to relative anemia. For elite athletes, this means iron supplementation is crucial.22 Thermal regulation may be more difficult, as training regimens may demand prolonged exercise. Physicians should recommend adequate hydration for these athletes.18
Although continued exercise is generally safe for a pregnant athlete and her fetus, caution is required when there is increased risk for premature delivery, or other special conditions exist. Multiple gestation, placenta previa, history of early labor or premature births, and incompetent cervix all contraindicate aerobic exercise during pregnancy.18 With these exceptions in mind, physicians can safely counsel pregnant women to do moderate exercise 30 minutes every day.17,18 Other recommendations are listed at the American College of Obstetricians and Gynecologists website.23
4. Anterior cruciate ligament injuries
ACL injuries affect a staggering number of athletes. In the United States, approximately 100,000 people sustain these injuries annually.24 As they occur up to 8 times more often in women than in men, ACL injuries are a top concern for physicians treating female athletes.
This disproportionate injury rate is influenced by differences between male and female anatomy. The width and shape of the femoral intercondylar notch have been studied as potential variables influencing the risk for ACL injury. Analysis of notch-view radiographs revealed a significant inverse relationship between notch width and ACL injury.25 A-shaped notches, notches with a significantly larger base and a narrowed roof, were more prevalent in women but did not correlate with increased risk for ACL injury. Studies have shown that female athletes with a noncontact ACL injury have a higher lateral tibial plateau posterior slope; this slope is associated with increased peak anteromedial ACL strain, which may contribute to injury.26 An analysis of magnetic resonance imaging scans in patients with and without ACL injury revealed that, for female patients, decreased femoral intercondylar notch width at the anterior outlet combined with increased lateral compartment posterior slope correlated best with risk for ACL injury.27
Although static anatomical factors contribute to ACL injuries in female athletes, dynamic neuromuscular influences are potential opportunities for intervention. Female athletes with high relative quadriceps strength and weak hamstring strength may be at increased risk for ACL injury.28 This “quadriceps dominance” becomes important in sports involving high-risk activities, such as running, cutting, pivoting, and jumping. In addition, compared with male athletes, female athletes demonstrate increased lateral trunk motion and knee valgus torque while landing during noncontact ACL tears, making core stability a factor in ACL injury.29
The collaborative efforts of physicians, physical therapists, athletic trainers, and coaches have yielded multifactorial neuromuscular training programs for the prevention of noncontact ACL injuries. Ideal ACL prevention protocols involve sessions that last for at least 10 minutes and take place 3 times a week. At these sessions, exercises are focused on strengthening, balance, and proprioceptive training.30 The programs last about 8 weeks, but sustained benefits require maintenance after the program has been completed and during the off-season. Program adherence must be encouraged and can be facilitated by varying workouts and raising risk awareness. The most effective programs have reduced the relative risk of noncontact ACL injuries by 75% to 100%.31 These promising results have led to increased focus on program implementation in an effort to prevent ACL injury.
5. Continued sex discrimination and social injustice
In 1972, Title IX was passed as part of the Education Amendments Act. Title IX states, “No person in the United States shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or be subjected to discrimination under any educational program or activity receiving Federal financial assistance.” Passage of this law, which has implications outside of athletic participation, marked an important turning point in women’s ability to participate equally in college sports.32,33 The Civil Rights Restoration Act, passed in 1988, strengthened Title IX and made it applicable to all institutions receiving federal funding.34 Before the 1970s, women typically were restricted to club sports, and funding and participation opportunities were weighted heavily toward men. Over the past 40 years, women’s participation in high school, college, and professional sports has taken a huge leap forward.32 For example, the number of women participating in high school sports increased from 294,000 (7.4% of all athletes) in 1972 to 3.4 million (>41% of all athletes) in 2014.
Despite advances in women’s civil rights, examples of inequality in US schools remain, particularly in the distribution of funding, which still strongly favors men’s football.32 Men’s sports receive 90% of media coverage.33 In 2002, women represented 55% of college students but only 42% of varsity athletes.34 The schools that have complied the least with Title IX are schools in the Midwest and the South and those with football teams.34 Women are underrepresented as coaches, and funding continues to be disproportionately spent on men’s sports.
For women, the benefits of participating in sports are far-reaching and significant. These benefits include improvements in academic success, mental health, and responsible behavior.33 Women’s gaining acceptance and respect throughout the athletic world seems to have carried over elsewhere. Although many institutions remain noncompliant with Title IX, efforts continue to have a strongly positive effect on gender equality in the United States.
Since Title IX passed in 1972, women have become exponentially more involved in competitive sports, from high school to professional levels. With more women engaging in serious athletics, the specific challenges they face have come to the forefront of sports medicine. These problems include the female athlete triad, concussions, exercise safety in pregnancy, anterior cruciate ligament (ACL) injuries, and continued sex discrimination and social injustice. Orthopedists treating female athletes should be aware of these problems, each of which is discussed in this review.
1. Female athlete triad
In 1992, the term female athlete triad was coined to describe 3 problems that often coexist in high-intensity female athletes.1 Since then, the definition has evolved, but the problem has remained essentially the same. The modern definition incorporates menstrual abnormalities, low energy availability with or without disordered eating, and decreased bone mineral density (BMD).2
With intense exercise and weight loss comes a variety of menstrual disturbances.3 In affected athletes, the hypothalamus is underactivated, and changes in gonadotropin-releasing hormone and luteinizing hormone lead to decreased estrogen production. Research suggests abnormal menses result from having inadequate energy and insufficient caloric intake to support extensive exercise.1 This phenomenon can occur in athletes in any sport but is most prevalent in lean-body sports, such as swimming, gymnastics, and ballet. The incidence of abnormal menses is as high as 79% in ballet dancers but only 5% in the general population.3 Menstrual abnormalities indicate hormonal abnormalities that can interfere with growth and maturation in young athletes.
Although full-blown eating disorders are uncommon among female athletes, disordered eating patterns are often found among women in competitive sports. Disordered eating can involve a spectrum of inadequate caloric intake and purging behavior, such as vomiting or laxative abuse, and has been reported in up to 25% of collegiate female athletes.4 Physicians must recognize these conditions and initiate counseling and treatment when appropriate. Women with disordered eating are at risk for developing electrolyte imbalances, malnutrition syndromes, and osteopenia.
Although careful evaluation and counseling are important, physicians must note that, in most cases, athletics participation may also protect against disordered eating and body image difficulties. A study of 146 college-age women found better body satisfaction among athletes than among nonathletes.5 Lean-sport athletes (eg, swimmers, gymnasts) were at higher risk for disordered eating and body image problems than other athletes were. Similarly, other studies have found that a majority of athletes have healthy eating habits.4
For poorly nourished and hormonally imbalanced female athletes, decreased BMD poses substantial risk. One study found a significant difference in BMD between athletes with amenorrhea and athletes with normal menses.6 In a cohort of female Navy recruits, those with amenorrhea were at 91% higher risk for stress fractures; calcium and vitamin D supplementation reduced risk by 20%.7 Osteopenia may be a special problem for prepubescent athletes. Girls who engage in intense exercise and have delayed menarche may have a low estrogen state, predisposing them to low BMD.3 Osteopenia and osteoporosis are difficult to reverse and can put these athletes at risk for stress fractures the rest of their lives. If unrecognized, stress fractures can end an athlete’s career.
Recommendations for dual-energy X-ray absorptiometry (DXA) include testing female athletes who have a diagnosed eating disorder, body mass index under 17.5, history of delayed menarche, oligomenorrhea, 2 prior stress fractures, or prior abnormal DXA scan. Complete testing recommendations appear in the 2014 consensus statement on the female athlete triad and return to sport.2,8
Orthopedists performing physical examinations for sports participation can screen for the female athlete triad through thoughtful questioning about menstrual history, nutrition habits, and stress fracture symptoms. Best treatment for a diagnosed case of the triad is multidisciplinary care with strong social support. When abnormal menses are an issue, referral to a gynecologist or endocrinologist and consideration of estrogen replacement should be discussed. Some cases require a psychiatrist’s assistance in treating disordered eating. Athletic trainers, coaches, and parents should be involved over the treatment course.1 Orthopedists must counsel women with osteopenia and osteoporosis about decreasing exercise to a safe level, improving nutritional intake, and supplementing with calcium (1200-1500 mg/d) and vitamin D (600-800 IU/d).3,7
2. Concussions
Increasing awareness of males’ sport-related concussions, particularly of concussions that occur during National Football League practice and games, has made physicians and researchers more aware of the rate of concussion in female athletes. That rate has increased, and, according to some reports, the risk for sport-related injury is higher for female athletes.9 A study of high school athletes found that the rate of concussion in girl’s soccer was second only to that in football.10
Concussions are categorized as mild traumatic brain injuries, and manifestations of the diagnosis are divided into physical, emotional, cognitive, and observed symptoms. The spectrum of symptoms is wide, ranging from difficulty concentrating and thinking clearly to headaches and dizziness.11 Compared with male athletes who sustain a concussion, female athletes report more of these concussive symptoms and have worse visual memory scores.12
Efforts to change sports at the player level have been resisted. Helmets have been proposed for field hockey and lacrosse but have not passed stringent concussion testing. In soccer, which has a high rate of concussion, a reform to eliminate heading the ball has been considered. Resistance to these suggestions stems from the thought that changes could alter the traditions of the games. Some individuals have indicated that helmets may give players a false sense of security and thereby cause them to play more aggressively.
Orthopedic surgeons must be aware of concussion symptoms. Multiple concussions may have a cumulative effect on functional ability and emotional well-being and may lead to chronic traumatic encephalopathy.13 Concern about the long-term effects of concussion has led to the implementation of universal “return to play” laws. These laws vary by state but have 3 steps in common: Educate coaches, players, and athletes; remove athletes from play; and obtain health care professionals’ permission to return to play.14 These guidelines set up an action plan for treating an athlete who has sustained a concussion.
Encouraging results of educating coaches have been noted. Coaches who were given Centers for Disease Control and Prevention–sponsored material on preventing, recognizing, and responding to concussions were able to effectively address concussions; 6 months later, 63% were better able to appreciate the severity of concussions.15 Continued education of athletic communities should help bring this injury to the attention of those treating female athletes.
3. Exercise safety in pregnancy
Women in sports can continue their athletic regimens during pregnancy. It is important to address challenges to the pregnant woman and to the fetus when assessing the risks of exercise.
The physiologic changes that occur during pregnancy may affect how a pregnant athlete responds to stress. Plasma volume, red blood cell volume, and cardiac function and output all increase during normal pregnancy.3,16 Abnormal heart rate during pregnancy can adversely affect the fetus. During and after exercise, fetal bradycardia can occur. Therefore, recommendations should include not exceeding pre-pregnancy activity levels.3 Careful monitoring of exercise intensity is recommended by the American College of Obstetrics and Gynecology; the guideline is to maintain less than 70% of maximal heart rate.17,18
The negative effects of exercise on the pregnant athlete are limited, but it is important to educate patients and to consider preventive strategies. One physiologic change that occurs during pregnancy is ligamentous laxity, which is caused by the hormone relaxin.16 Ligamentous laxity has the potential to put pregnant athletes at risk for soft-tissue and bony injury during impact sports. However, the positive effects of exercise during pregnancy include improved appetite, sleep, and emotional health.19 Aerobic exercise during pregnancy may reverse insulin resistance as demonstrated in animal studies; though this outcome has not been demonstrated in human studies,20 women should be reassured that moderate exercise has overall beneficial effects.
Some research suggests that exercise may expose the fetus to hyperthermia, blood sugar changes, physical injury, and premature labor.16 Typically, fetal heat is dissipated from the mother. After intense exercise, maternal body temperature rises and leads to some degree of fetal hyperthermia.16 Animal model studies have suggested that hyperthermia may result in a slightly higher rate of congenital abnormalities. Pregnant women should keep their exercise routines to less than 60 minutes, should exercise in a thermally regulated environment, and should keep themselves hydrated to avoid fetal hyperthermia.18
Reduced blood flow, accompanied by a deficit of oxygen to the uterus and the developing fetus, is another concern for pregnant athletes. During exercise, when more blood is flowing to the muscles, less is flowing to the uterus.16 Furthermore, during the third trimester, women should avoid supine exercise, as venous outflow is poor with the body in that position.21
Elite athletes who continue training during pregnancy should be carefully counseled about adjusting their training regimens. Because of increased cardiac output and blood volume, the heart rate will be lower than usual, demanding an adjustment in interpretation. Blood cell counts do not increase as much as plasma volume does—often leading to relative anemia. For elite athletes, this means iron supplementation is crucial.22 Thermal regulation may be more difficult, as training regimens may demand prolonged exercise. Physicians should recommend adequate hydration for these athletes.18
Although continued exercise is generally safe for a pregnant athlete and her fetus, caution is required when there is increased risk for premature delivery, or other special conditions exist. Multiple gestation, placenta previa, history of early labor or premature births, and incompetent cervix all contraindicate aerobic exercise during pregnancy.18 With these exceptions in mind, physicians can safely counsel pregnant women to do moderate exercise 30 minutes every day.17,18 Other recommendations are listed at the American College of Obstetricians and Gynecologists website.23
4. Anterior cruciate ligament injuries
ACL injuries affect a staggering number of athletes. In the United States, approximately 100,000 people sustain these injuries annually.24 As they occur up to 8 times more often in women than in men, ACL injuries are a top concern for physicians treating female athletes.
This disproportionate injury rate is influenced by differences between male and female anatomy. The width and shape of the femoral intercondylar notch have been studied as potential variables influencing the risk for ACL injury. Analysis of notch-view radiographs revealed a significant inverse relationship between notch width and ACL injury.25 A-shaped notches, notches with a significantly larger base and a narrowed roof, were more prevalent in women but did not correlate with increased risk for ACL injury. Studies have shown that female athletes with a noncontact ACL injury have a higher lateral tibial plateau posterior slope; this slope is associated with increased peak anteromedial ACL strain, which may contribute to injury.26 An analysis of magnetic resonance imaging scans in patients with and without ACL injury revealed that, for female patients, decreased femoral intercondylar notch width at the anterior outlet combined with increased lateral compartment posterior slope correlated best with risk for ACL injury.27
Although static anatomical factors contribute to ACL injuries in female athletes, dynamic neuromuscular influences are potential opportunities for intervention. Female athletes with high relative quadriceps strength and weak hamstring strength may be at increased risk for ACL injury.28 This “quadriceps dominance” becomes important in sports involving high-risk activities, such as running, cutting, pivoting, and jumping. In addition, compared with male athletes, female athletes demonstrate increased lateral trunk motion and knee valgus torque while landing during noncontact ACL tears, making core stability a factor in ACL injury.29
The collaborative efforts of physicians, physical therapists, athletic trainers, and coaches have yielded multifactorial neuromuscular training programs for the prevention of noncontact ACL injuries. Ideal ACL prevention protocols involve sessions that last for at least 10 minutes and take place 3 times a week. At these sessions, exercises are focused on strengthening, balance, and proprioceptive training.30 The programs last about 8 weeks, but sustained benefits require maintenance after the program has been completed and during the off-season. Program adherence must be encouraged and can be facilitated by varying workouts and raising risk awareness. The most effective programs have reduced the relative risk of noncontact ACL injuries by 75% to 100%.31 These promising results have led to increased focus on program implementation in an effort to prevent ACL injury.
5. Continued sex discrimination and social injustice
In 1972, Title IX was passed as part of the Education Amendments Act. Title IX states, “No person in the United States shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or be subjected to discrimination under any educational program or activity receiving Federal financial assistance.” Passage of this law, which has implications outside of athletic participation, marked an important turning point in women’s ability to participate equally in college sports.32,33 The Civil Rights Restoration Act, passed in 1988, strengthened Title IX and made it applicable to all institutions receiving federal funding.34 Before the 1970s, women typically were restricted to club sports, and funding and participation opportunities were weighted heavily toward men. Over the past 40 years, women’s participation in high school, college, and professional sports has taken a huge leap forward.32 For example, the number of women participating in high school sports increased from 294,000 (7.4% of all athletes) in 1972 to 3.4 million (>41% of all athletes) in 2014.
Despite advances in women’s civil rights, examples of inequality in US schools remain, particularly in the distribution of funding, which still strongly favors men’s football.32 Men’s sports receive 90% of media coverage.33 In 2002, women represented 55% of college students but only 42% of varsity athletes.34 The schools that have complied the least with Title IX are schools in the Midwest and the South and those with football teams.34 Women are underrepresented as coaches, and funding continues to be disproportionately spent on men’s sports.
For women, the benefits of participating in sports are far-reaching and significant. These benefits include improvements in academic success, mental health, and responsible behavior.33 Women’s gaining acceptance and respect throughout the athletic world seems to have carried over elsewhere. Although many institutions remain noncompliant with Title IX, efforts continue to have a strongly positive effect on gender equality in the United States.
1. Nattiv A, Loucks AB, Manore MM, Sanborn CF, Sundgot-Borgen J, Warren MP; American College of Sports Medicine. American College of Sports Medicine position stand. The female athlete triad. Med Sci Sports Exerc. 2007;39(10):1867-1882.
2. De Souza MJ, Nattiv A, Joy E, et al; Expert Panel. 2014 Female Athlete Triad Coalition consensus statement on treatment and return to play of the female athlete triad: 1st international conference held in San Francisco, California, May 2012 and 2nd international conference held in Indianapolis, Indiana, May 2013. Br J Sports Med. 2014;48(4):289.
3. Warren MP, Shantha S. The female athlete. Baillieres Best Pract Res Clin Endocrinol Metab. 2000;14(1):37-53.
4. Greenleaf C, Petrie TA, Carter J, Reel JJ. Female collegiate athletes: prevalence of eating disorders and disordered eating behaviors. J Am Coll Health. 2009;57(5):489-495.
5. Reinking MF, Alexander LE. Prevalence of disordered-eating behaviors in undergraduate female collegiate athletes and nonathletes. J Athl Train. 2005;40(1):47-51.
6. Rencken ML, Chesnut CH 3rd, Drinkwater BL. Bone density at multiple skeletal sites in amenorrheic athletes. JAMA. 1996;276(3):238-240.
7. Lappe J, Cullen D, Haynatzki G, Recker R, Ahlf R, Thompson K. Calcium and vitamin D supplementation decreases incidence of stress fractures in female Navy recruits. J Bone Miner Res. 2008;23(5):741-749.
8. De Souza MJ. 2014 Female athlete triad consensus statement on guidelines for treatment and return to play. National Collegiate Athletic Association (NCAA) website. http://www.ncaa.org/health-and-safety/nutrition-and-performance/2014-female-athlete-triad-consensus-statement-guidelines. Accessed November 24, 2015.
9. Preiss-Farzanegan SJ, Chapman B, Wong TM, Wu J, Bazarian JJ. The relationship between gender and postconcussion symptoms after sport-related mild traumatic brain injury. PM R. 2009;1(3):245-253.
10. Marar M, McIlvain NM, Fields SK, Comstock RD. Epidemiology of concussions among United States high school athletes in 20 sports. Am J Sports Med. 2012;40(4):747-755.
11. Uhl RL, Rosenbaum AJ, Czajka C, Mulligan M, King C. Minor traumatic brain injury: a primer for the orthopaedic surgeon. J Am Acad Orthop Surg. 2013;21(10):624-631.
12. Covassin T, Elbin RJ, Harris W, Parker T, Kontos A. The role of age and sex in symptoms, neurocognitive performance, and postural stability in athletes after concussion. Am J Sports Med. 2012;40(6):1303-1312.
13. Covassin T, Moran R, Wilhelm K. Concussion symptoms and neurocognitive performance of high school and college athletes who incur multiple concussions. Am J Sports Med. 2013;41(12):2885-2889.
14. Sports concussion policies and laws: information for parents, coaches, and school & sports professionals. Centers for Disease Control and Prevention website. http://www.cdc.gov/headsup/policy/index.html. Updated February 16, 2015. Accessed November 24, 2015.
15. Covassin T, Elbin RJ, Sarmiento K. Educating coaches about concussion in sports: evaluation of the CDC’s “Heads Up: concussion in youth sports” initiative. J Sch Health. 2012;82(5):233-238.
16. Lumbers ER. Exercise in pregnancy: physiological basis of exercise prescription for the pregnant woman. J Sci Med Sport. 2002;5(1):20-31.
17. ACOG Committee Obstetric Practice. ACOG Committee opinion. Number 267, January 2002: exercise during pregnancy and the postpartum period. Obstet Gynecol. 2002;99(1):171-173.
18. Artal R, O’Toole M. Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period. Br J Sports Med. 2003;37(1):6-12.
19. Kramer MS. Regular aerobic exercise during pregnancy. Cochrane Database Syst Rev. 2000;(2):CD000180. Update in: Cochrane Database Syst Rev. 2002;(2):CD000180.
20. Stafne SN, Salvesen KA, Romundstad PR, Stuge B, Morkved S. Does regular exercise during pregnancy influence lumbopelvic pain? A randomized controlled trial. Acta Obstet Gynecol Scand. 2012;91(5):552-559.
21. Nascimento SL, Surita FG, Cecatti JG. Physical exercise during pregnancy: a systematic review. Curr Opin Obstet Gynecol. 2012;24(6):387-394.
22. Hale RW, Milne L. The elite athlete and exercise in pregnancy. Semin Perinatol. 1996;20(4):277-284.
23. Exercise during pregnancy. American College of Obstetricians and Gynecologists website. http://www.acog.org/Patients/FAQs/Exercise-During-Pregnancy. Published August 2011. Accessed November 24, 2015.
24. Giugliano DN, Solomon JL. ACL tears in female athletes. Phys Med Rehabil Clin North Am. 2007;18(3):417-438, viii.
25. Ireland ML, Ballantyne BT, Little K, McClay IS. A radiographic analysis of the relationship between the size and shape of the intercondylar notch and anterior cruciate ligament injury. Knee Surg Sports Traumatol Arthrosc. 2001;9(4):200-205.
26. Lipps DB, Oh YK, Ashton-Miller JA, Wojtys EM. Morphologic characteristics help explain the gender difference in peak anterior cruciate ligament strain during a simulated pivot landing. Am J Sports Med. 2012;40(1):32-40.
27. Sturnick DR, Vacek PM, DeSarno MJ, et al. Combined anatomic factors predicting risk of anterior cruciate ligament injury for males and females. Am J Sports Med. 2015;43(4):839-847.
28. Myer GD, Ford KR, Barber Foss KD, Liu C, Nick TG, Hewett TE. The relationship of hamstrings and quadriceps strength to anterior cruciate ligament injury in female athletes. Clin J Sport Med. 2009;19(1):3-8.
29. Hewett TE, Torg JS, Boden BP. Video analysis of trunk and knee motion during non-contact anterior cruciate ligament injury in female athletes: lateral trunk and knee abduction motion are combined components of the injury mechanism. Br J Sports Med. 2009;43(6):417-422.
30. Sutton KM, Bullock JM. Anterior cruciate ligament rupture: differences between males and females. J Am Acad Orthop Surg. 2013;21(1):41-50.
31. Noyes FR, Barber-Westin SD. Neuromuscular retraining intervention programs: do they reduce noncontact anterior cruciate ligament injury rates in adolescent female athletes? Arthroscopy. 2014;30(2):245-255.
32. Ladd AL. The sports bra, the ACL, and Title IX—the game in play. Clin Orthop Relat Res. 2014;472(6):1681-1684.
33. Lopiano DA. Modern history of women in sports. Twenty-five years of Title IX. Clin Sports Med. 2000;19(2):163-173, vii.
34. Anderson DJ, Cheslock JJ, Ehrenberg RG. Gender equity in intercollegiate athletics: determinants of Title IX compliance. J High Educ. 2006;77(2):225-250.
1. Nattiv A, Loucks AB, Manore MM, Sanborn CF, Sundgot-Borgen J, Warren MP; American College of Sports Medicine. American College of Sports Medicine position stand. The female athlete triad. Med Sci Sports Exerc. 2007;39(10):1867-1882.
2. De Souza MJ, Nattiv A, Joy E, et al; Expert Panel. 2014 Female Athlete Triad Coalition consensus statement on treatment and return to play of the female athlete triad: 1st international conference held in San Francisco, California, May 2012 and 2nd international conference held in Indianapolis, Indiana, May 2013. Br J Sports Med. 2014;48(4):289.
3. Warren MP, Shantha S. The female athlete. Baillieres Best Pract Res Clin Endocrinol Metab. 2000;14(1):37-53.
4. Greenleaf C, Petrie TA, Carter J, Reel JJ. Female collegiate athletes: prevalence of eating disorders and disordered eating behaviors. J Am Coll Health. 2009;57(5):489-495.
5. Reinking MF, Alexander LE. Prevalence of disordered-eating behaviors in undergraduate female collegiate athletes and nonathletes. J Athl Train. 2005;40(1):47-51.
6. Rencken ML, Chesnut CH 3rd, Drinkwater BL. Bone density at multiple skeletal sites in amenorrheic athletes. JAMA. 1996;276(3):238-240.
7. Lappe J, Cullen D, Haynatzki G, Recker R, Ahlf R, Thompson K. Calcium and vitamin D supplementation decreases incidence of stress fractures in female Navy recruits. J Bone Miner Res. 2008;23(5):741-749.
8. De Souza MJ. 2014 Female athlete triad consensus statement on guidelines for treatment and return to play. National Collegiate Athletic Association (NCAA) website. http://www.ncaa.org/health-and-safety/nutrition-and-performance/2014-female-athlete-triad-consensus-statement-guidelines. Accessed November 24, 2015.
9. Preiss-Farzanegan SJ, Chapman B, Wong TM, Wu J, Bazarian JJ. The relationship between gender and postconcussion symptoms after sport-related mild traumatic brain injury. PM R. 2009;1(3):245-253.
10. Marar M, McIlvain NM, Fields SK, Comstock RD. Epidemiology of concussions among United States high school athletes in 20 sports. Am J Sports Med. 2012;40(4):747-755.
11. Uhl RL, Rosenbaum AJ, Czajka C, Mulligan M, King C. Minor traumatic brain injury: a primer for the orthopaedic surgeon. J Am Acad Orthop Surg. 2013;21(10):624-631.
12. Covassin T, Elbin RJ, Harris W, Parker T, Kontos A. The role of age and sex in symptoms, neurocognitive performance, and postural stability in athletes after concussion. Am J Sports Med. 2012;40(6):1303-1312.
13. Covassin T, Moran R, Wilhelm K. Concussion symptoms and neurocognitive performance of high school and college athletes who incur multiple concussions. Am J Sports Med. 2013;41(12):2885-2889.
14. Sports concussion policies and laws: information for parents, coaches, and school & sports professionals. Centers for Disease Control and Prevention website. http://www.cdc.gov/headsup/policy/index.html. Updated February 16, 2015. Accessed November 24, 2015.
15. Covassin T, Elbin RJ, Sarmiento K. Educating coaches about concussion in sports: evaluation of the CDC’s “Heads Up: concussion in youth sports” initiative. J Sch Health. 2012;82(5):233-238.
16. Lumbers ER. Exercise in pregnancy: physiological basis of exercise prescription for the pregnant woman. J Sci Med Sport. 2002;5(1):20-31.
17. ACOG Committee Obstetric Practice. ACOG Committee opinion. Number 267, January 2002: exercise during pregnancy and the postpartum period. Obstet Gynecol. 2002;99(1):171-173.
18. Artal R, O’Toole M. Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period. Br J Sports Med. 2003;37(1):6-12.
19. Kramer MS. Regular aerobic exercise during pregnancy. Cochrane Database Syst Rev. 2000;(2):CD000180. Update in: Cochrane Database Syst Rev. 2002;(2):CD000180.
20. Stafne SN, Salvesen KA, Romundstad PR, Stuge B, Morkved S. Does regular exercise during pregnancy influence lumbopelvic pain? A randomized controlled trial. Acta Obstet Gynecol Scand. 2012;91(5):552-559.
21. Nascimento SL, Surita FG, Cecatti JG. Physical exercise during pregnancy: a systematic review. Curr Opin Obstet Gynecol. 2012;24(6):387-394.
22. Hale RW, Milne L. The elite athlete and exercise in pregnancy. Semin Perinatol. 1996;20(4):277-284.
23. Exercise during pregnancy. American College of Obstetricians and Gynecologists website. http://www.acog.org/Patients/FAQs/Exercise-During-Pregnancy. Published August 2011. Accessed November 24, 2015.
24. Giugliano DN, Solomon JL. ACL tears in female athletes. Phys Med Rehabil Clin North Am. 2007;18(3):417-438, viii.
25. Ireland ML, Ballantyne BT, Little K, McClay IS. A radiographic analysis of the relationship between the size and shape of the intercondylar notch and anterior cruciate ligament injury. Knee Surg Sports Traumatol Arthrosc. 2001;9(4):200-205.
26. Lipps DB, Oh YK, Ashton-Miller JA, Wojtys EM. Morphologic characteristics help explain the gender difference in peak anterior cruciate ligament strain during a simulated pivot landing. Am J Sports Med. 2012;40(1):32-40.
27. Sturnick DR, Vacek PM, DeSarno MJ, et al. Combined anatomic factors predicting risk of anterior cruciate ligament injury for males and females. Am J Sports Med. 2015;43(4):839-847.
28. Myer GD, Ford KR, Barber Foss KD, Liu C, Nick TG, Hewett TE. The relationship of hamstrings and quadriceps strength to anterior cruciate ligament injury in female athletes. Clin J Sport Med. 2009;19(1):3-8.
29. Hewett TE, Torg JS, Boden BP. Video analysis of trunk and knee motion during non-contact anterior cruciate ligament injury in female athletes: lateral trunk and knee abduction motion are combined components of the injury mechanism. Br J Sports Med. 2009;43(6):417-422.
30. Sutton KM, Bullock JM. Anterior cruciate ligament rupture: differences between males and females. J Am Acad Orthop Surg. 2013;21(1):41-50.
31. Noyes FR, Barber-Westin SD. Neuromuscular retraining intervention programs: do they reduce noncontact anterior cruciate ligament injury rates in adolescent female athletes? Arthroscopy. 2014;30(2):245-255.
32. Ladd AL. The sports bra, the ACL, and Title IX—the game in play. Clin Orthop Relat Res. 2014;472(6):1681-1684.
33. Lopiano DA. Modern history of women in sports. Twenty-five years of Title IX. Clin Sports Med. 2000;19(2):163-173, vii.
34. Anderson DJ, Cheslock JJ, Ehrenberg RG. Gender equity in intercollegiate athletics: determinants of Title IX compliance. J High Educ. 2006;77(2):225-250.
The Importance of Sex of Patient in the Management of Femoroacetabular Impingement
Femoroacetabular impingement (FAI), a recently described hip condition in adolescents and young adults, results from abnormal physical contact between the proximal femur and the acetabulum.1 FAI is usually characterized by the site of the predominant morphologic abnormality—proximal femur (cam-type FAI), acetabulum (pincer-type FAI), or both (mixed impingement). Cam-type FAI is typified by the aspherical extension of the articular surface at the anterosuperior head–neck junction of the proximal femur with loss of the normal offset. With hip motion, especially in the maximal ranges of flexion and internal rotation, the aspherical proximal femur repeatedly contacts the anterosuperior acetabulum, damaging the chondrolabral junction and ultimately the labrum itself. In pincer-type impingement, femoral head overcoverage caused by acetabular retroversion and/or coxa profunda directly damages the anterior labrum when the acetabular rim contacts the proximal femur during physiologic motion. “Contrecoup” injury of the posterior-inferior acetabular cartilage may also occur. Over time, recurrent microtrauma to the acetabular cartilage and/or labrum may lead to degenerative changes of the hip and ultimately to premature osteoarthritis.1,2
Patients with FAI typically present with groin pain that may be activity-related or that may occur with prolonged sitting with the hip in a flexed position. Physical examination findings suggestive of FAI include decreased passive internal hip rotation and reproducible pain with adduction and internal rotation of the flexed hip—the impingement sign, or the flexion, adduction, and internal rotation (FADIR) test.3 Diagnostic imaging evaluation initially includes radiographs of the pelvis and hips. These radiographs may show a “pistol-grip” deformity and/or decreased head–neck offset (as determined by increased alpha angle) in the setting of cam-type impingement (Figure 1).4 Pincer-type impingement may be associated with a crossover sign, coxa profunda, and an increased center-edge angle (CEA). Advanced imaging studies, such as computed tomography (CT), magnetic resonance imaging (MRI) arthrogram, and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), are commonly used to better delineate bony deformity and concomitant injuries of the labrum and cartilage (Figure 2).
Treatment for FAI often consists initially of activity modification, use of anti-inflammatory medications, and physical therapy. Intra-articular corticosteroid injections may be used both diagnostically and therapeutically. When nonsurgical measures fail to adequately relieve symptoms, surgery may be warranted. Whether performed open or arthroscopically, surgery is directed first at correcting the underlying osseous abnormality—performing an osteoplasty of the proximal femur to remove the cam lesion, performing an acetabular osteoplasty (“rim-trimming”) to address a focal pincer lesion, and/or performing a periacetabular osteotomy to decrease global acetabular overcoverage (Figure 3).5
Sex-Based Differences in FAI Incidence
Traditionally, it was thought that cam-type impingement occurred predominantly in young, athletic males, whereas pincer-type impingement resulting from acetabular overcoverage occurred primarily in females during their fourth decade. However, our understanding of the sex-based differences in the incidence and presentation of FAI has evolved, and it is now clear that the interplay of sex, radiographic signs of impingement, and development of symptoms requiring treatment is more complex.
In recent large population-based studies, investigators have attempted to better characterize the sex-based differences in the incidence of osseous FAI deformity. Gosvig and colleagues2 examined radiographic and questionnaire outcomes of 3620 patients (age range, 21-90 years) and found that males were more likely than females to have a pistol-grip deformity of the hip (19.6% vs 5.2%); that deep acetabular sockets were common in both sexes (15.2% vs 19.4%); and that the presence of pistol-grip deformity or deep socket was significantly associated with development of osteoarthritis, independent of sex.
In a study of 2081 asymptomatic patients (mean age, 18.6 years), Laborie and colleagues4 reported similar radiographic findings. Males were significantly more likely than females to have a cam-type deformity, as evidenced by pistol-grip deformity, focal prominence of the femoral neck, and/or flattening of the lateral aspect of the femoral head. Males were also more likely than females to have a pincer deformity, though radiographic signs of pincer deformity—a crossover sign, excessive acetabular coverage (defined by increased CEA), and a posterior wall sign—were common in both sexes, occurring in 16.6% of females and 34.3% of males. Bilateral findings of FAI-associated deformity were also more common in males than in females, both for cam-type deformity (24.7% vs 6.3%) and pincer-type deformity (21.7% vs 9.7%).
Sex-Based Differences in FAI Presentation
In males and females, the clinical presentation of FAI is similar—insidious onset of deep groin pain, often exacerbated with activity, and physical examination findings of decreased hip motion (particularly internal rotation) and a positive impingement test.3 Nevertheless, the sexes’ clinical presentation differs in several ways. Specifically, in a study using 3-dimensional CT to assess bony deformity in both symptomatic and asymptomatic patients, Beaulé and colleagues6 reported that alpha angles were significantly higher in symptomatic males than in symptomatic females (73.3° vs 58.7°). Hetsroni and colleagues7 recently reported similar results in a study of 217 symptomatic young adults treated arthroscopically for hip pain. Preoperative CT showed that alpha angles were significantly larger in males than in females (63.6° vs 47.8°). The authors postulated that females may be more likely to be symptomatic in the setting of smaller cam lesions because of the increased peak hip flexion and frontal plane motion commonly demonstrated by females during drop landings in sport. The authors further hypothesized that sex differences in muscle mass (which contributes to dynamic hip stability) and ligamentous laxity (a component of static hip stability) may result in larger physiologic ranges of motion for many females. As a result, bony impingement may occur in the setting of smaller anatomical lesions in females. The authors further noted that, compared with their male counterparts, females being treated for symptomatic FAI had significantly more femoral and acetabular anteversion.
Another male–female presentation difference involves symptom bilaterality. Specifically, males are significantly more likely than females to have symptomatic FAI involving both hips. In a recent study of 646 patients who underwent hip arthroscopy for symptomatic FAI during a 2-year period, Klingenstein and colleagues8 found that females constituted 48.2% of unilateral arthroscopy patients but only 34.8% of bilateral arthroscopy patients. The odds ratio of males treated for both hips, compared with females, was 1.7 (95% confidence interval, 1.16–2.54).
Last, it has been reported that, on clinical presentation, hip function scores are significantly lower in females than in males. In a recent study of 612 cases of symptomatic FAI treated with hip arthroscopy, Malviya and colleagues9 found that females had significantly lower quality-of-life scores both before and after surgery. Hetsroni and colleagues7 reported similar findings, with females having significantly lower preoperative modified Harris Hip Scores and lower Hip Outcome Scores in the domains of Activities of Daily Living and Sports.
Sex-Based Differences in FAI Treatment
and Outcomes
Surgical treatment of FAI is focused on identifying the source of hip pain and dysfunction—be it osseous lesion, labral tearing, chondral injury, or iliopsoas tendonitis—and treating it accordingly, regardless of sex. Most studies of this approach find consistent improvement in the short-term and midterm outcome scores for a majority of patients. However, relatively few studies have focused specifically on sex in determining the percentage of patients who require surgical treatment, in deciding the type of surgery that should be performed, or in measuring surgical outcomes in patients with symptomatic FAI.
In their review of 23 studies of FAI surgery, Ng and colleagues10 found that, of 970 patients, 608 (62.7%) were male and 362 (37.3%) were female. Similarly higher rates for males were previously published.5,11 More recently, Clohisy and colleagues12 reported on the descriptive epidemiology of patients having surgery for FAI at 8 different medical centers in North America. Fifty-five percent of the hips surgically treated for symptomatic FAI were females’. The authors speculated that this unexpectedly high rate could have resulted from US and Canadian female athletes’ increasingly higher level of sports participation. The results of this study, one of the largest examining the rate of surgery for males and females with FAI, suggest that females are more likely to have surgery for symptomatic FAI despite being less likely to have radiographic evidence of impingement. Our understanding of this phenomenon continues to advance.
In a recent prospective study, Krych and colleagues13 evaluated the clinical outcomes of FAI surgeries (labral débridement, labral repair) in an all-female patient cohort. Female patients with symptomatic FAI were randomized to undergo either labral débridement or labral repair. There were clinical improvements in both groups, but, compared with labral débridement patients, labral repair patients had more significantly improved Hip Outcome Scores in the domains of Activities of Daily Living and Sports, as well as better subjective outcomes. Although the study did not compare female patients with male patients, it does provide evidence that female patients specifically may benefit more from labral repair than from labral débridement alone.
With respect to different surgical treatments for male and female patients, Hetsroni and colleagues7 introduced the idea of sex-specific treatment when they noted more hip anteversion in their study’s female patients than in its male patients. They suggested that, because the anterosuperior acetabulum is subjected to a high amount of stress during weight-bearing and gait, this area in females with suspected pincer lesions should be rim-trimmed judiciously to avoid increasing the stress and perhaps even hastening the development of degenerative disease. Last, though several authors have noted that hip function scores are lower in females than in males on presentation, it has also been reported that females demonstrate more improvement in functional scores after surgery.9 This may be important information to discuss during preoperative counseling about expected goals and outcomes.
Conclusion
Femoroacetabular impingement is a common clinical entity that affects both males and females. However, sexual dimorphism in FAI incidence, presentation, treatment, and outcomes has recently been described in the literature (Table). Being aware of these sex-based differences and tailoring patient evaluation and management accordingly will likely result in optimal outcomes for each person who presents with symptomatic FAI.
1. Ganz R, Parvizi J, Beck M, Leunig M, Notzli H, Siebenrock KA. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop. 2003;(417):112-120.
2. Gosvig KK, Jacobsen S, Sonne-Holm S, Palm H, Troelsen A. Prevalence of malformations of the hip joint and their relationship to sex, groin pain, and risk of osteoarthritis: a population-based survey. J Bone Joint Surg Am. 2010;92(5):1162-1169.
3. Philippon MJ, Maxwell RB, Johnston TL, Schenker M, Briggs KK. Clinical presentation of femoroacetabular impingement. Knee Surg Sports Traumatol Arthrosc. 2007;15(8):1041-1047.
4. Laborie LB, Lehmann TG, Engesaeter IO, Eastwood DM, Engesaeter LB, Rosendahl K. Prevalence of radiographic findings thought to be associated with femoroacetabular impingement in a population-based cohort of 2081 healthy young adults. Radiology. 2011;260(2):494-502.
5. Clohisy JC, St John LC, Schutz AL. Surgical treatment of femoroacetabular impingement: a systematic review of the literature. Clin Orthop. 2010;468(2):555-564.
6. Beaulé PE, Zaragoza E, Motamedi K, Copelan N, Dorey FJ. Three-dimensional computed tomography of the hip in the assessment of femoroacetabular impingement. J Orthop Res. 2005;23(6):1286-1292.
7. Hetsroni I, Dela Torre K, Duke G, Lyman S, Kelly BT. Sex differences of hip morphology in young adults with hip pain and labral tears. Arthroscopy. 2013;29(1):54-63.
8. Klingenstein GG, Zbeda RM, Bedi A, Magennis E, Kelly BT. Prevalence and preoperative demographic and radiographic predictors of bilateral femoroacetabular impingement. Am J Sports Med. 2013;41(4):762-768.
9. Malviya A, Stafford GH, Villar RN. Impact of arthroscopy of the hip for femoroacetabular impingement on quality of life at a mean follow-up of 3.2 years. J Bone Joint Surg Br. 2012;94(4):466-470.
10. Ng VY, Arora N, Best TM, Pan X, Ellis TJ. Efficacy of surgery for femoroacetabular impingement: a systematic review. Am J Sports Med. 2010;38(11):2337-2345.
11. Matsuda DK, Carlisle JC, Arthurs SC, Wierks CH, Philippon MJ. Comparative systematic review of the open dislocation, mini-open, and arthroscopic surgeries for femoroacetabular impingement. Arthroscopy. 2011;27(2):252-269.
12. Clohisy JC, Baca G, Beaule PE, et al. Descriptive epidemiology of femoroacetabular impingement: a North American cohort of patients undergoing surgery. Am J Sports Med. 2013;41(6):1348-1356.
13. Krych AJ, Thompson M, Knutson Z, Scoon J, Coleman SH. Arthroscopic labral repair versus selective labral debridement in female patients with femoroacetabular impingement: a prospective randomized study. Arthroscopy. 2013;29(1):46-53.
Femoroacetabular impingement (FAI), a recently described hip condition in adolescents and young adults, results from abnormal physical contact between the proximal femur and the acetabulum.1 FAI is usually characterized by the site of the predominant morphologic abnormality—proximal femur (cam-type FAI), acetabulum (pincer-type FAI), or both (mixed impingement). Cam-type FAI is typified by the aspherical extension of the articular surface at the anterosuperior head–neck junction of the proximal femur with loss of the normal offset. With hip motion, especially in the maximal ranges of flexion and internal rotation, the aspherical proximal femur repeatedly contacts the anterosuperior acetabulum, damaging the chondrolabral junction and ultimately the labrum itself. In pincer-type impingement, femoral head overcoverage caused by acetabular retroversion and/or coxa profunda directly damages the anterior labrum when the acetabular rim contacts the proximal femur during physiologic motion. “Contrecoup” injury of the posterior-inferior acetabular cartilage may also occur. Over time, recurrent microtrauma to the acetabular cartilage and/or labrum may lead to degenerative changes of the hip and ultimately to premature osteoarthritis.1,2
Patients with FAI typically present with groin pain that may be activity-related or that may occur with prolonged sitting with the hip in a flexed position. Physical examination findings suggestive of FAI include decreased passive internal hip rotation and reproducible pain with adduction and internal rotation of the flexed hip—the impingement sign, or the flexion, adduction, and internal rotation (FADIR) test.3 Diagnostic imaging evaluation initially includes radiographs of the pelvis and hips. These radiographs may show a “pistol-grip” deformity and/or decreased head–neck offset (as determined by increased alpha angle) in the setting of cam-type impingement (Figure 1).4 Pincer-type impingement may be associated with a crossover sign, coxa profunda, and an increased center-edge angle (CEA). Advanced imaging studies, such as computed tomography (CT), magnetic resonance imaging (MRI) arthrogram, and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), are commonly used to better delineate bony deformity and concomitant injuries of the labrum and cartilage (Figure 2).
Treatment for FAI often consists initially of activity modification, use of anti-inflammatory medications, and physical therapy. Intra-articular corticosteroid injections may be used both diagnostically and therapeutically. When nonsurgical measures fail to adequately relieve symptoms, surgery may be warranted. Whether performed open or arthroscopically, surgery is directed first at correcting the underlying osseous abnormality—performing an osteoplasty of the proximal femur to remove the cam lesion, performing an acetabular osteoplasty (“rim-trimming”) to address a focal pincer lesion, and/or performing a periacetabular osteotomy to decrease global acetabular overcoverage (Figure 3).5
Sex-Based Differences in FAI Incidence
Traditionally, it was thought that cam-type impingement occurred predominantly in young, athletic males, whereas pincer-type impingement resulting from acetabular overcoverage occurred primarily in females during their fourth decade. However, our understanding of the sex-based differences in the incidence and presentation of FAI has evolved, and it is now clear that the interplay of sex, radiographic signs of impingement, and development of symptoms requiring treatment is more complex.
In recent large population-based studies, investigators have attempted to better characterize the sex-based differences in the incidence of osseous FAI deformity. Gosvig and colleagues2 examined radiographic and questionnaire outcomes of 3620 patients (age range, 21-90 years) and found that males were more likely than females to have a pistol-grip deformity of the hip (19.6% vs 5.2%); that deep acetabular sockets were common in both sexes (15.2% vs 19.4%); and that the presence of pistol-grip deformity or deep socket was significantly associated with development of osteoarthritis, independent of sex.
In a study of 2081 asymptomatic patients (mean age, 18.6 years), Laborie and colleagues4 reported similar radiographic findings. Males were significantly more likely than females to have a cam-type deformity, as evidenced by pistol-grip deformity, focal prominence of the femoral neck, and/or flattening of the lateral aspect of the femoral head. Males were also more likely than females to have a pincer deformity, though radiographic signs of pincer deformity—a crossover sign, excessive acetabular coverage (defined by increased CEA), and a posterior wall sign—were common in both sexes, occurring in 16.6% of females and 34.3% of males. Bilateral findings of FAI-associated deformity were also more common in males than in females, both for cam-type deformity (24.7% vs 6.3%) and pincer-type deformity (21.7% vs 9.7%).
Sex-Based Differences in FAI Presentation
In males and females, the clinical presentation of FAI is similar—insidious onset of deep groin pain, often exacerbated with activity, and physical examination findings of decreased hip motion (particularly internal rotation) and a positive impingement test.3 Nevertheless, the sexes’ clinical presentation differs in several ways. Specifically, in a study using 3-dimensional CT to assess bony deformity in both symptomatic and asymptomatic patients, Beaulé and colleagues6 reported that alpha angles were significantly higher in symptomatic males than in symptomatic females (73.3° vs 58.7°). Hetsroni and colleagues7 recently reported similar results in a study of 217 symptomatic young adults treated arthroscopically for hip pain. Preoperative CT showed that alpha angles were significantly larger in males than in females (63.6° vs 47.8°). The authors postulated that females may be more likely to be symptomatic in the setting of smaller cam lesions because of the increased peak hip flexion and frontal plane motion commonly demonstrated by females during drop landings in sport. The authors further hypothesized that sex differences in muscle mass (which contributes to dynamic hip stability) and ligamentous laxity (a component of static hip stability) may result in larger physiologic ranges of motion for many females. As a result, bony impingement may occur in the setting of smaller anatomical lesions in females. The authors further noted that, compared with their male counterparts, females being treated for symptomatic FAI had significantly more femoral and acetabular anteversion.
Another male–female presentation difference involves symptom bilaterality. Specifically, males are significantly more likely than females to have symptomatic FAI involving both hips. In a recent study of 646 patients who underwent hip arthroscopy for symptomatic FAI during a 2-year period, Klingenstein and colleagues8 found that females constituted 48.2% of unilateral arthroscopy patients but only 34.8% of bilateral arthroscopy patients. The odds ratio of males treated for both hips, compared with females, was 1.7 (95% confidence interval, 1.16–2.54).
Last, it has been reported that, on clinical presentation, hip function scores are significantly lower in females than in males. In a recent study of 612 cases of symptomatic FAI treated with hip arthroscopy, Malviya and colleagues9 found that females had significantly lower quality-of-life scores both before and after surgery. Hetsroni and colleagues7 reported similar findings, with females having significantly lower preoperative modified Harris Hip Scores and lower Hip Outcome Scores in the domains of Activities of Daily Living and Sports.
Sex-Based Differences in FAI Treatment
and Outcomes
Surgical treatment of FAI is focused on identifying the source of hip pain and dysfunction—be it osseous lesion, labral tearing, chondral injury, or iliopsoas tendonitis—and treating it accordingly, regardless of sex. Most studies of this approach find consistent improvement in the short-term and midterm outcome scores for a majority of patients. However, relatively few studies have focused specifically on sex in determining the percentage of patients who require surgical treatment, in deciding the type of surgery that should be performed, or in measuring surgical outcomes in patients with symptomatic FAI.
In their review of 23 studies of FAI surgery, Ng and colleagues10 found that, of 970 patients, 608 (62.7%) were male and 362 (37.3%) were female. Similarly higher rates for males were previously published.5,11 More recently, Clohisy and colleagues12 reported on the descriptive epidemiology of patients having surgery for FAI at 8 different medical centers in North America. Fifty-five percent of the hips surgically treated for symptomatic FAI were females’. The authors speculated that this unexpectedly high rate could have resulted from US and Canadian female athletes’ increasingly higher level of sports participation. The results of this study, one of the largest examining the rate of surgery for males and females with FAI, suggest that females are more likely to have surgery for symptomatic FAI despite being less likely to have radiographic evidence of impingement. Our understanding of this phenomenon continues to advance.
In a recent prospective study, Krych and colleagues13 evaluated the clinical outcomes of FAI surgeries (labral débridement, labral repair) in an all-female patient cohort. Female patients with symptomatic FAI were randomized to undergo either labral débridement or labral repair. There were clinical improvements in both groups, but, compared with labral débridement patients, labral repair patients had more significantly improved Hip Outcome Scores in the domains of Activities of Daily Living and Sports, as well as better subjective outcomes. Although the study did not compare female patients with male patients, it does provide evidence that female patients specifically may benefit more from labral repair than from labral débridement alone.
With respect to different surgical treatments for male and female patients, Hetsroni and colleagues7 introduced the idea of sex-specific treatment when they noted more hip anteversion in their study’s female patients than in its male patients. They suggested that, because the anterosuperior acetabulum is subjected to a high amount of stress during weight-bearing and gait, this area in females with suspected pincer lesions should be rim-trimmed judiciously to avoid increasing the stress and perhaps even hastening the development of degenerative disease. Last, though several authors have noted that hip function scores are lower in females than in males on presentation, it has also been reported that females demonstrate more improvement in functional scores after surgery.9 This may be important information to discuss during preoperative counseling about expected goals and outcomes.
Conclusion
Femoroacetabular impingement is a common clinical entity that affects both males and females. However, sexual dimorphism in FAI incidence, presentation, treatment, and outcomes has recently been described in the literature (Table). Being aware of these sex-based differences and tailoring patient evaluation and management accordingly will likely result in optimal outcomes for each person who presents with symptomatic FAI.
Femoroacetabular impingement (FAI), a recently described hip condition in adolescents and young adults, results from abnormal physical contact between the proximal femur and the acetabulum.1 FAI is usually characterized by the site of the predominant morphologic abnormality—proximal femur (cam-type FAI), acetabulum (pincer-type FAI), or both (mixed impingement). Cam-type FAI is typified by the aspherical extension of the articular surface at the anterosuperior head–neck junction of the proximal femur with loss of the normal offset. With hip motion, especially in the maximal ranges of flexion and internal rotation, the aspherical proximal femur repeatedly contacts the anterosuperior acetabulum, damaging the chondrolabral junction and ultimately the labrum itself. In pincer-type impingement, femoral head overcoverage caused by acetabular retroversion and/or coxa profunda directly damages the anterior labrum when the acetabular rim contacts the proximal femur during physiologic motion. “Contrecoup” injury of the posterior-inferior acetabular cartilage may also occur. Over time, recurrent microtrauma to the acetabular cartilage and/or labrum may lead to degenerative changes of the hip and ultimately to premature osteoarthritis.1,2
Patients with FAI typically present with groin pain that may be activity-related or that may occur with prolonged sitting with the hip in a flexed position. Physical examination findings suggestive of FAI include decreased passive internal hip rotation and reproducible pain with adduction and internal rotation of the flexed hip—the impingement sign, or the flexion, adduction, and internal rotation (FADIR) test.3 Diagnostic imaging evaluation initially includes radiographs of the pelvis and hips. These radiographs may show a “pistol-grip” deformity and/or decreased head–neck offset (as determined by increased alpha angle) in the setting of cam-type impingement (Figure 1).4 Pincer-type impingement may be associated with a crossover sign, coxa profunda, and an increased center-edge angle (CEA). Advanced imaging studies, such as computed tomography (CT), magnetic resonance imaging (MRI) arthrogram, and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), are commonly used to better delineate bony deformity and concomitant injuries of the labrum and cartilage (Figure 2).
Treatment for FAI often consists initially of activity modification, use of anti-inflammatory medications, and physical therapy. Intra-articular corticosteroid injections may be used both diagnostically and therapeutically. When nonsurgical measures fail to adequately relieve symptoms, surgery may be warranted. Whether performed open or arthroscopically, surgery is directed first at correcting the underlying osseous abnormality—performing an osteoplasty of the proximal femur to remove the cam lesion, performing an acetabular osteoplasty (“rim-trimming”) to address a focal pincer lesion, and/or performing a periacetabular osteotomy to decrease global acetabular overcoverage (Figure 3).5
Sex-Based Differences in FAI Incidence
Traditionally, it was thought that cam-type impingement occurred predominantly in young, athletic males, whereas pincer-type impingement resulting from acetabular overcoverage occurred primarily in females during their fourth decade. However, our understanding of the sex-based differences in the incidence and presentation of FAI has evolved, and it is now clear that the interplay of sex, radiographic signs of impingement, and development of symptoms requiring treatment is more complex.
In recent large population-based studies, investigators have attempted to better characterize the sex-based differences in the incidence of osseous FAI deformity. Gosvig and colleagues2 examined radiographic and questionnaire outcomes of 3620 patients (age range, 21-90 years) and found that males were more likely than females to have a pistol-grip deformity of the hip (19.6% vs 5.2%); that deep acetabular sockets were common in both sexes (15.2% vs 19.4%); and that the presence of pistol-grip deformity or deep socket was significantly associated with development of osteoarthritis, independent of sex.
In a study of 2081 asymptomatic patients (mean age, 18.6 years), Laborie and colleagues4 reported similar radiographic findings. Males were significantly more likely than females to have a cam-type deformity, as evidenced by pistol-grip deformity, focal prominence of the femoral neck, and/or flattening of the lateral aspect of the femoral head. Males were also more likely than females to have a pincer deformity, though radiographic signs of pincer deformity—a crossover sign, excessive acetabular coverage (defined by increased CEA), and a posterior wall sign—were common in both sexes, occurring in 16.6% of females and 34.3% of males. Bilateral findings of FAI-associated deformity were also more common in males than in females, both for cam-type deformity (24.7% vs 6.3%) and pincer-type deformity (21.7% vs 9.7%).
Sex-Based Differences in FAI Presentation
In males and females, the clinical presentation of FAI is similar—insidious onset of deep groin pain, often exacerbated with activity, and physical examination findings of decreased hip motion (particularly internal rotation) and a positive impingement test.3 Nevertheless, the sexes’ clinical presentation differs in several ways. Specifically, in a study using 3-dimensional CT to assess bony deformity in both symptomatic and asymptomatic patients, Beaulé and colleagues6 reported that alpha angles were significantly higher in symptomatic males than in symptomatic females (73.3° vs 58.7°). Hetsroni and colleagues7 recently reported similar results in a study of 217 symptomatic young adults treated arthroscopically for hip pain. Preoperative CT showed that alpha angles were significantly larger in males than in females (63.6° vs 47.8°). The authors postulated that females may be more likely to be symptomatic in the setting of smaller cam lesions because of the increased peak hip flexion and frontal plane motion commonly demonstrated by females during drop landings in sport. The authors further hypothesized that sex differences in muscle mass (which contributes to dynamic hip stability) and ligamentous laxity (a component of static hip stability) may result in larger physiologic ranges of motion for many females. As a result, bony impingement may occur in the setting of smaller anatomical lesions in females. The authors further noted that, compared with their male counterparts, females being treated for symptomatic FAI had significantly more femoral and acetabular anteversion.
Another male–female presentation difference involves symptom bilaterality. Specifically, males are significantly more likely than females to have symptomatic FAI involving both hips. In a recent study of 646 patients who underwent hip arthroscopy for symptomatic FAI during a 2-year period, Klingenstein and colleagues8 found that females constituted 48.2% of unilateral arthroscopy patients but only 34.8% of bilateral arthroscopy patients. The odds ratio of males treated for both hips, compared with females, was 1.7 (95% confidence interval, 1.16–2.54).
Last, it has been reported that, on clinical presentation, hip function scores are significantly lower in females than in males. In a recent study of 612 cases of symptomatic FAI treated with hip arthroscopy, Malviya and colleagues9 found that females had significantly lower quality-of-life scores both before and after surgery. Hetsroni and colleagues7 reported similar findings, with females having significantly lower preoperative modified Harris Hip Scores and lower Hip Outcome Scores in the domains of Activities of Daily Living and Sports.
Sex-Based Differences in FAI Treatment
and Outcomes
Surgical treatment of FAI is focused on identifying the source of hip pain and dysfunction—be it osseous lesion, labral tearing, chondral injury, or iliopsoas tendonitis—and treating it accordingly, regardless of sex. Most studies of this approach find consistent improvement in the short-term and midterm outcome scores for a majority of patients. However, relatively few studies have focused specifically on sex in determining the percentage of patients who require surgical treatment, in deciding the type of surgery that should be performed, or in measuring surgical outcomes in patients with symptomatic FAI.
In their review of 23 studies of FAI surgery, Ng and colleagues10 found that, of 970 patients, 608 (62.7%) were male and 362 (37.3%) were female. Similarly higher rates for males were previously published.5,11 More recently, Clohisy and colleagues12 reported on the descriptive epidemiology of patients having surgery for FAI at 8 different medical centers in North America. Fifty-five percent of the hips surgically treated for symptomatic FAI were females’. The authors speculated that this unexpectedly high rate could have resulted from US and Canadian female athletes’ increasingly higher level of sports participation. The results of this study, one of the largest examining the rate of surgery for males and females with FAI, suggest that females are more likely to have surgery for symptomatic FAI despite being less likely to have radiographic evidence of impingement. Our understanding of this phenomenon continues to advance.
In a recent prospective study, Krych and colleagues13 evaluated the clinical outcomes of FAI surgeries (labral débridement, labral repair) in an all-female patient cohort. Female patients with symptomatic FAI were randomized to undergo either labral débridement or labral repair. There were clinical improvements in both groups, but, compared with labral débridement patients, labral repair patients had more significantly improved Hip Outcome Scores in the domains of Activities of Daily Living and Sports, as well as better subjective outcomes. Although the study did not compare female patients with male patients, it does provide evidence that female patients specifically may benefit more from labral repair than from labral débridement alone.
With respect to different surgical treatments for male and female patients, Hetsroni and colleagues7 introduced the idea of sex-specific treatment when they noted more hip anteversion in their study’s female patients than in its male patients. They suggested that, because the anterosuperior acetabulum is subjected to a high amount of stress during weight-bearing and gait, this area in females with suspected pincer lesions should be rim-trimmed judiciously to avoid increasing the stress and perhaps even hastening the development of degenerative disease. Last, though several authors have noted that hip function scores are lower in females than in males on presentation, it has also been reported that females demonstrate more improvement in functional scores after surgery.9 This may be important information to discuss during preoperative counseling about expected goals and outcomes.
Conclusion
Femoroacetabular impingement is a common clinical entity that affects both males and females. However, sexual dimorphism in FAI incidence, presentation, treatment, and outcomes has recently been described in the literature (Table). Being aware of these sex-based differences and tailoring patient evaluation and management accordingly will likely result in optimal outcomes for each person who presents with symptomatic FAI.
1. Ganz R, Parvizi J, Beck M, Leunig M, Notzli H, Siebenrock KA. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop. 2003;(417):112-120.
2. Gosvig KK, Jacobsen S, Sonne-Holm S, Palm H, Troelsen A. Prevalence of malformations of the hip joint and their relationship to sex, groin pain, and risk of osteoarthritis: a population-based survey. J Bone Joint Surg Am. 2010;92(5):1162-1169.
3. Philippon MJ, Maxwell RB, Johnston TL, Schenker M, Briggs KK. Clinical presentation of femoroacetabular impingement. Knee Surg Sports Traumatol Arthrosc. 2007;15(8):1041-1047.
4. Laborie LB, Lehmann TG, Engesaeter IO, Eastwood DM, Engesaeter LB, Rosendahl K. Prevalence of radiographic findings thought to be associated with femoroacetabular impingement in a population-based cohort of 2081 healthy young adults. Radiology. 2011;260(2):494-502.
5. Clohisy JC, St John LC, Schutz AL. Surgical treatment of femoroacetabular impingement: a systematic review of the literature. Clin Orthop. 2010;468(2):555-564.
6. Beaulé PE, Zaragoza E, Motamedi K, Copelan N, Dorey FJ. Three-dimensional computed tomography of the hip in the assessment of femoroacetabular impingement. J Orthop Res. 2005;23(6):1286-1292.
7. Hetsroni I, Dela Torre K, Duke G, Lyman S, Kelly BT. Sex differences of hip morphology in young adults with hip pain and labral tears. Arthroscopy. 2013;29(1):54-63.
8. Klingenstein GG, Zbeda RM, Bedi A, Magennis E, Kelly BT. Prevalence and preoperative demographic and radiographic predictors of bilateral femoroacetabular impingement. Am J Sports Med. 2013;41(4):762-768.
9. Malviya A, Stafford GH, Villar RN. Impact of arthroscopy of the hip for femoroacetabular impingement on quality of life at a mean follow-up of 3.2 years. J Bone Joint Surg Br. 2012;94(4):466-470.
10. Ng VY, Arora N, Best TM, Pan X, Ellis TJ. Efficacy of surgery for femoroacetabular impingement: a systematic review. Am J Sports Med. 2010;38(11):2337-2345.
11. Matsuda DK, Carlisle JC, Arthurs SC, Wierks CH, Philippon MJ. Comparative systematic review of the open dislocation, mini-open, and arthroscopic surgeries for femoroacetabular impingement. Arthroscopy. 2011;27(2):252-269.
12. Clohisy JC, Baca G, Beaule PE, et al. Descriptive epidemiology of femoroacetabular impingement: a North American cohort of patients undergoing surgery. Am J Sports Med. 2013;41(6):1348-1356.
13. Krych AJ, Thompson M, Knutson Z, Scoon J, Coleman SH. Arthroscopic labral repair versus selective labral debridement in female patients with femoroacetabular impingement: a prospective randomized study. Arthroscopy. 2013;29(1):46-53.
1. Ganz R, Parvizi J, Beck M, Leunig M, Notzli H, Siebenrock KA. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop. 2003;(417):112-120.
2. Gosvig KK, Jacobsen S, Sonne-Holm S, Palm H, Troelsen A. Prevalence of malformations of the hip joint and their relationship to sex, groin pain, and risk of osteoarthritis: a population-based survey. J Bone Joint Surg Am. 2010;92(5):1162-1169.
3. Philippon MJ, Maxwell RB, Johnston TL, Schenker M, Briggs KK. Clinical presentation of femoroacetabular impingement. Knee Surg Sports Traumatol Arthrosc. 2007;15(8):1041-1047.
4. Laborie LB, Lehmann TG, Engesaeter IO, Eastwood DM, Engesaeter LB, Rosendahl K. Prevalence of radiographic findings thought to be associated with femoroacetabular impingement in a population-based cohort of 2081 healthy young adults. Radiology. 2011;260(2):494-502.
5. Clohisy JC, St John LC, Schutz AL. Surgical treatment of femoroacetabular impingement: a systematic review of the literature. Clin Orthop. 2010;468(2):555-564.
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