Particular fragility cruciate ligament in women during sports exercise: reasons and therapeutic attitudes

Introduction

The last 30 years, there has been a significant increase sport participation of women in all fields and at all levels including State-united after the adoption of Amendment No. IX on Education in 1972 ( 1) eliminating female discrimination in sport at school.

Sport participation of men in secondary education has increased by less than 3% (from 3.7 to 3.8 million) since 1972, while participation of women increased by more than 9 times, doubling every 10 (0.3 to 2.8 million) (2). With this increase in sports participation, exposure to trauma and thus to injuries also increased. The women involved in pivotal sports, have a risk of ACL injury largest men. Many studies have shown a risk 4-7 times higher than ACL for the female population than for men in the same sporting level (3-6)

Most ACL injuries in female athletes occur during a non-contact pivot accidents, usually during deceleration, a pivot (change of direction), or landing from a jump. The definition of a non-contact pivot accident was established by Marshall (7.8) as “a force applied to the knee at the time of the accident, contactless movement of an athlete with another athlete or object “” Forces Applied to the knee at the time of injury resulted from the athlete’s own movements and Did not Involve touch with Reviews another athlete or object. ”

Several theories attempt to explain this difference in sex ratio.

One of them would be an anatomical theory, but that alone can not explain the difference. Other authors reported that the higher frequency of rupture of anterior cruciate ligament in women is linked to neuromuscular control imbalances. Lastly, changes in sex hormones of the menstrual cycle may have some responsibility.

Epidemiology

The rupture of the anterior cruciate ligament is one of the most common sports injuries. The frequency of ACL injuries in the United States is 250,000 per year LCA (9). The cost of the damage to public health is very important since it is 17 000 per ligament in the USA (10).

In the Netherlands, more than 5,000 ligamentoplasties were performed in 2008, a torn ACL in 3200 residents. In France, 35,000 ACL tears were made in 2007, an ACL tear for 1900 inhabitants (11). In Switzerland, there are about 81 ACL injuries per 100 000 individuals per year (10 to 64).

In Germany, 70 ACL injuries per 100 000 individuals per year (12).

Finally, the frequency of ACL tears in Norway (register) is 85 ACL injuries per 100 000 individuals per year (16 to 39) with a larger number of girls in the age 15/19 years ( 13).

Sports practiced

We know that ACL injuries are more common in women with a risk 4-6 times higher, and the difference is variable depending on the practiced sports and athletics.

The incidence of ACL injury in handball is 0.82 ACL for 1,000 hours of hand in women, against 0.31 ACL for 1,000 hours of hand in men (relative risk 2.65). More the risk increases with the competition: 2.29 ACL injuries per 1000 match hours in women (relative risk 2.8) (6.14).

Parkkari studied the incidence and risk factors for rupture of the cruciate ligament in adolescents and young adults. The study population of 46,472 individuals. Between 1987 and 1997 were included in this study 21432 boys and 25099 girls aged 14 to 18 years. This population was followed for an average period of 9 years (4-14 years) the average age of the population at the end of the study was 30 years for adolescents in 1987 and included 21 years for those in 1997. this study was made from public health records with Finland as inclusion criteria, all patients hospitalized with a diagnosis of lesion of the anterior or posterior cruciate ligament. During this period there were 265 ruptures cruciate ligament in 46,472 individuals. The incidence in this population was 61 ACL injuries per 100 000 individuals per year with 96 ACL injuries per 100 000 males per year and 30 ACL injuries per 100 000 women per year. The average age at time of injury was 22.6 years for males and 22.2 years for girls. However, taking into account the socio-economic context, health, sports activity of this mixed population, the relative risk was twice as high for girls having a sport 4 times a week than boys ( RR 8.5 versus 4.3). There was no difference in a sport less than 3 times a week (15).

Prodromos also studied the distribution of the frequency of ACL tears in various sports. Basketball is one of the most risky sports for girls with a failure rate of 0.29 per 1000 exposures LCA girls and 0.08 per 1000 exposures LCA boys, the sex ratio is 3.6 in this population of student athletes. In professional basketball, the sex ratio is close to 1 (0.20 per 1000 exposures LCA girls and 0.21 per 1000 exposures LCA boys). The risk for football is 0.32 ACL injuries per 1000 exposures for girls and 0.12 ACL injuries per 1000 exposures for boys, the sex ratio is 2.77. Handball has a rate of 0.56 ACL injuries per 1000 exposures for girls and 0.11 ACL injuries per 1000 exposures boys. Combat sports have a rate of 0.77 ACL injuries per 1000 exposures for girls and 0.19 ACL injuries per 1000 exposures for boys, the sex ratio is 4.05. In this study there was no difference between the sexes in the secondary failures due to skiing accidents. However the risk is much lower among ski professionals (monitor, tracker, guide) than in the general population, respectively 0.02 ACL injuries per 1000 exposures and 0.63 ACL injuries per 1000 exposures (14). However, Johnson more breaks in women sex ratio ski racing F / M 2.5 (16). Finally Pasanen shows that 70% of ACL tears are secondary to a contact pivot without trauma among women (17).

Risk factors

Various factors attempt to explain this difference in sex ratio. It is the extrinsic and intrinsic factors.

Extrinsic factors:

1.    Competition versus training.

We know little about the risk of rupture during the competition, Myklebust reported that male and female athletes are at a higher risk of ACL injury during a handball match that during training (18). Johnson more breaks in women sex ratio ski racing F / M 2.5 (16). But no study provides an explanation on this extrinsic risk factor.

2.    Surface and ground

The increase in the coefficient of friction between the sneakers and playing surfaces has improved the power and athletic performance but also increases the risk of ACL injury. Lambson found that the risk of ACL injury is greater for footballers whose shoes have a larger number of studs and when the games interface is more adherent (19). Olsen reported that the risk of ACL injury is higher in female handball teams playing on artificial soils (with a higher adhesion) on wooden floors. This relationship did not exist for male athletes (20).

3.    Equipment and knee

The knee protection seem to overcome the shortcomings of LCA among alpine skiers. Kocher actually studied professional skiers with ACL fragility. He found a greater risk of knee injury among those not wearing functional splint compared to others. (Relative risk 6.4) (58). However, McDevitt found no difference among young soldiers made a ligament of the knee, the number of re-rupture was the same with or without knee brace (21).

4.    Meteorology

For sports on natural or artificial turf, the mechanical interface between the foot and the playing surface is highly dependent on weather conditions. However, very little is known about the effect of this variable in ACL injuries. Orchard was reported that ACL tears (contactless pivot) of Australian football teams are more frequent during periods of low rainfall and high evaporation. This work hypothesizes that weather conditions affect the adhesion mechanism between the shoe and playing surface, and thus the risk of ACL (22).

5.    History of knee sprain

Myer’s study shows that female athletes carried a torn anterior cruciate ligament had a knee sprain history (without ACL injury) in 37% of cases versus 29% in a sporting control group with no history and same level (23).

6.    Other

Specific factors such as sports, playing rules, referees or coaches have not been studied. Other factors could also be involved, such as age, sports skills, the psychological profile of the athlete.

Intrinsic factor:

1.    anatomical factors

a.    hyperlaxity

Many studies indicate that hypermobility is more common among adolescents than among their male counterparts (24,25,26). Ramesh found that ACL injuries are more common in patients with an overall laxity of the joints, especially the knees (27). Myer has prospectively studied the laxity of girls in order to assess the risk of ACL injuries in female athletes. Its purpose was to determine whether female athletes with greater laxity of joints and especially the knees are more prone to ACL injuries. This biomechanical and epidemiological prospective study to verify this hypothesis (23). Huston reported greater knee laxity in sports adult women compared to men (24), while Cheng showed no difference in children prepubescent (28).

b.    Anatomy of the indentation

The anatomy of the inter condylar cut is different in women and in men. Indeed, Griffin has shown that the notch is narrower and the LCA is smaller in women (29).

c.    Slope posterior tibial

A highly significant correlation was found between the lower posterior tibial slope and anterior tibial translation (29). But the causal relationship between the posterior slope of the tibial plateau and the risk of ACL rupture remains to be seen.

2.    Biomechanical factor : kinematics and kinetics

We know that almost 70 to 80% of ACL rupture mechanisms are non-contact pivot activities. These injuries often occur during a reception after a jump, change direction or deceleration.

Olsen think a valgus axis tibialis associated with an external or internal rotation of the knee is the cause sprains ACL (30). secondly Boden, hypothesized that a strong eccentric contraction of the quadriceps is the main cause (31). Recent studies have shown consistently that the predominant forces influencing the tension of the ACL are earlier forces on the tibia, or by external mechanisms such as a fall or a reception on the lower limb, either by mechanisms internal as the dominant quadriceps contraction with the knee near extension. The combination of anterior tibial translation and valgus are probably the most important cause of the mechanism of injury among athletes. body of studies have shown that it is the anterior drawer force that creates the most tension on the ACL with effect increased varus, valgus or internal and external rotation (32). However, an isolated external rotation applied to the knee increases the relatively low voltage of the ACL. Isolated forced valgus causes tension on the ACL just after a major injury to the medial collateral ligament. Those cadaver studies serve to highlight the importance of anterior shear forces in the ACL injury. The knee close to full extension, quadriceps contraction and the resultant force developed in the patellar tendon causes anterior drawer on the proximal tibia with tensioning ACL. Hewett studied the risk of valgus jump reception in female athletes. The system included motion analysis in jump landing with 8 digital cameras, a computer data collection and the markers placed on the subject. The analysis of the angles of knee flexion-extension with the valgus -varus was quantified for each subject in a series of jumps vertically from a high pedestal 31 cm with the feet positioned at 35 cm distance. The subjects were instructed to jump to the ground by a vertical jump and raising both arms as if they were jumping to launch a basketball. This study showed that at-risk subjects had a significant increase in the jump reception valgus compared to the control group. These results indicate that athletes should be encouraged to change their jump reception technology (without valgus) to reduce the risk of knee injury (33).

3.    Neuromuscular factors: muscle strength and muscle activation

Neuromuscular imbalance may partially explain the mechanism of injury: women are more ” quadriceps dominant ” in their body schema than men. Recruitment hamstring is significantly higher in men than in women. The report hamstring / quadriceps maximum tends to be higher in men than in women. Now we saw that a strong eccentric contraction of the quadriceps is a major cause of ACL tear.

4.    hormonal factors

We know that there are hormonorecepteurs on LCA, estrogen receptor, progesterone, testosterone and relaxin. These receptors certainly have an effect on the metabolism and mechanical properties of ACL but we do not know today what are really the effects (34,35,36,37). A review of the literature shows that ACL injuries are not constant during the menstrual cycle. There are significantly more frequent breaks during the preovulatory phase in the post-ovulatory phase. The working Wojtys is one of the first published on the subject. He used data on menstrual status of women at the time of the injury by questioning the patient. It showed significantly greater prevalence of ACL tears (without contact pin) female athletes during the pre-ovulatory phase of the menstrual cycle (38). In a subsequent study, he studied the levels of estrogen, progesterone and luteinizing hormone in urine to characterize the menstrual status of women at the time of the accident. This confirmed a higher frequency of ACL ruptures between the 9 ^{th and 14 th day}the 28-day cycle. There were fewer injuries during the post-ovulatory phase (defined as the 15 ^th to the end of the cycle) (39)

Arendt also found that female athletes were more likely to have an ACL tear during the pre-ovulatory phase of their menstrual cycle
that during the post-ovulatory phase (40). Slauterbeck reported a disproportionately higher number of ACL injuries during the pre-ovulatory phase of the menstrual cycle, with fewer injuries occur at the end of cycle (41). More recently, Beynnon assayed in serum progesterone and estradiol for dating the period of the menstrual cycle at the time of the sprain. He studied recreational skiers. Serious breaches of the pre-ovulatory phase were significantly larger than those in the post-ovulatory phase (relative risk 3.22). During the pre-ovulatory phase of the menstrual cycle, there is an increased concentration of estradiol and a lesser concentration of progesterone.

Analysis of hormonal blood levels found a serum estradiol similar between patients with ACL tear and control groupOn average, levels of oestradiol were 112.4 pg / mL vs. 109.6 pg / ml serum. In contrast, serum progesterone concentrations are higher in healthy individuals in the control group compared to the group ACL tear. Progesterone mean concentrations were 5.31 ng / ml serum (0.1-26.2 ng / ml) versus 3.15 ng / ml (0.3-17.5 ng / ml). It is important to emphasize that it remains unclear whether estradiol and progesterone act directly on the ACL and whether this increases the risk of ACL injury. It is possible that these hormones act on the structures other than the ACL.

For example, they could have an effect on muscle contraction and neuromuscular control (42). In this study as in that of Wojtys, about 74% of women had an ACL injury during the pre-ovulatory phase of their menstrual cycle and 26% in the post-ovulatory phase. Furthermore 72.5% of women not taking oral contraceptives. However, the stabilizing effect of oral contraceptives in women is yet to be defined. It is important to distinguish the different oral contraceptives (alone or combined estrogen progesterone progesterone) as well as changes in dosage. There is no conclusive evidence on the protective effect of oral contraceptives in the ACL.

Prevention

Faced with all its rupture risk factors for ACL in women, a number of prevention and education programs have been proposed.

a.    Education

Ettlinger used a relatively simple prevention of ACL injuries among skiers approach and tried to change high-risk behavior through increased education and awareness. In this non-randomized prospective study, 4,000 professional skiers downhill skiing (instructors and patrollers in 20 ski areas) have done their training during the ski season 1993 1994. In their training, they watched 19 minutes of video showing 10 accidents with ACL tear at skiers of different levels. The video used allowed the skiers to view high-risk behavior and study these situations to reduce themselves to the risk of ACL injury. During the season, following training, a reduction of 62% of ACL injuries was recorded (43).

b.    Prevention

Although a number of ACL injury risk factors has been enunciated, only biomechanical risk factors have been sufficiently analyzed to provide an ACL ruptures prevention program. Most prevention programs will try to change the dynamic loading of the knee joint by a neuromuscular control and proprioceptive work. The studies to date, based on the biomechanical changes, resulted in the reduction of knee injuries in athletes, particularly among women (44). The technical and neuromuscular preparations jump reception in training and in particular the correction of valgus knee forces to receiving the jump considerably reduce ACL injury rates in female athletes (45).The effectiveness of prevention programs based on a number of common elements. Most include one or more of the following:

• Simple stretching
• muscle building
• Awareness of risk positions
• technical change
• Aerobics
• plyometrics
• proprioception
• Training in balance

Current data show that a work of active range of motion and / or passive is against-indicated in ACL ruptures prevention program. A recent meta-analysis and review of the literature indicates that joints easing work does not provide protective effects against injury, as has been alleged previously in the literature. In addition, other studies show that stretching just before a sporting activity can decrease performance and do not reduce the risk of injury. (46-52)Female athletes should especially benefit from neuromuscular preparation because they have a decreased strength and power compared to their male counterparts. This preparation designed for young women increases their power, strength and neuromuscular control. The dynamic and neuromuscular training can reduce gender differences regarding the absorption of force, the active stabilization of the knee, muscle and biomechanical imbalances, while increasing the strength of bones, ligaments and tendons.

c.    Strengthening and conditioning

Cahill showed the effectiveness of preparedness and fitness before the sports season for high school teams from football for 4 years, he was a reduction of knee injuries and injuries requiring surgery (53 ). Caraffa conducted a study on 600 semi-professional football. Half had a specific proprioceptive preparation in addition to their regular training. 3 seasons there have been in the group prepared 0.15 ACL injuries / team / year versus 1.15 ACL injuries / team / season in the group with conventional preparation (54). Several groups have proposed a neuromuscular training program to prevent ACL tears. Henning has implemented a prevention program in Division I of the NCAA women’s basketball over the last 8 years in the US. He offered to change the trajectory of changes of direction in preferring the more rounded acute angle trajectories trajectories. He also advised to avoid sudden stops without deceleration step 3 preferring not quick stop. This program allowed a reduction of 89% of knee injuries (55). Hewett has studied the effect of this program on the incidence of knee injury in football, volleyball and basketball. 43 teams were compared (N = 1263 athletes), including 15 women’s teams (N = 366) who completed the program; 15 other (N = 463) who have not completed the program and 13 men’s teams (N = 434) did not follow the program. The program was conducted from video and manual. The program took place 3 days a week. Seventy percent (70%) athletes (248/366) completed training of 6 weeks and others have done at least 4 weeks of training. The incidence of serious knee injuries (N = 14) in the female group was unprepared 0.43 / 1000 exposures versus 0.12 / 1000 exhibitions in the group prepared and 0.09 / 1000 exhibitions in the unprepared male group ( 56).Myklebust conducted a non-randomized prospective study, with 900 female handball players during a period of 3 years in Norway. The control group consists of 60 teams (N = 942 players in 1998-1998) compared to 58 trained teams (N = 855 in 1999-2000) and 52 trained teams (N = 850 in the 2000-2001 season). There were 29 ACL injuries during the control season, 23 injuries during the first season and 17 injuries during the second season (57).

Preventing these injuries would allow tens of thousands of young female athletes to pursue their sporting activities in adulthood and to prevent long-term disability and osteoarthritis that occur with an estimate 10 times after rupture of knee ligaments

Conclusion :

t is now well known that the risk of ACL injuries in the athlete population is greater in female athletes compared to male athletes. Extrinsic and intrinsic factors involved in this difference.

Women have an ACL smaller, less rigid and less resistant to breakage. Women also have a greater joint laxity and decreased muscle stiffness.

Hormonal factors contribute to this difference. (Estrogen, relaxin, progesterone, testosterone).T he women are significantly more at risk of ACL injury during the pre-ovulatory period of the menstrual cycle and during the post-ovulatory period but few articles have focused on direct hormonal effects on the ACL.

The risk of rupture of the central pivot seems increased in the first phase of the cycle. Oral contraceptives may have a protective effect without the effect is well known. The collaboration of the two specialties (orthopedic sports doctor – gynecologist) is certainly desirable in the future to better understand its factors. The issue is significant in terms of prevention and public health.

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Doctor Nicolas LEFEVRE, Doctor Serge HERMAN, Doctor Yoann BOHU. – 24 décembre 2013.