Anterior cruciate ligament injuries in young females playing soccer at senior levels

The Effect of Primary ACL Reconstruction on Career Longevity in English Premier League and Championship Soccer Players Compared With Uninjured Controls: A Matched Cohort Analysis

BACKGROUND

Because of the multitude of variables that affect the retirement decisions of professional soccer players, it has proven difficult to isolate the effect of undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) on career longevity.

PURPOSE

To compare the career longevity of professional soccer players after a primary ACLR with that of an uninjured matched control cohort.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review of a consecutive series of primary ACLR was performed between 2008 and 2018 in professional male soccer players from the senior author's practice. Each athlete with ACLR was matched to 3 control athletes who had not undergone ACLR according to age, league, playing position, and preinjury game appearances/minutes played. Player career statistics-including league, game appearances, and game minutes-were compiled for each year until retirement or July 1, 2022.

RESULTS

A total of 82 soccer players in the English Premier League or Championship at the time of their primary ACLR were matched to 246 control athletes. The mean career length after ACLR was 6 ± 2.6 years, while that of the matched control athletes was 7.6 ± 2.8 years (P < .001). After primary ACLR, an athlete had a 2 times greater chance of retirement compared with the matched control athlete (hazard ratio, 2.19; P < .001). At 5 years after ACLR, 16% of athletes had retired from professional soccer, while 8.5% of the matched cohort were retired (P = .060). By 10 years, 72% of the ACLR cohort had retired compared with 43% of the matched cohort (P < .001). Forwards were more likely to have shortened careers compared with goalkeepers (P = .021); however, no significant differences were observed between midfielders, defenders, and forwards. Within the ACLR cohort, a contralateral ACL tear during the athlete's career caused a 2.30 times (P = .022) increased chance of retirement compared with athletes with only 1 ACL tear during their career. Mechanism of injury, meniscal pathology, graft rerupture, and chondral lesions did not affect career length.

CONCLUSION

Professional male soccer players who underwent ACLR had decreased career length by approximately 1.6 years compared with a matched player cohort.

Lifestyle characteristics in adolescent female football players: data from the Karolinska football Injury Cohort

BACKGROUND

Normative values of lifestyle characteristics in adolescent female football players may be used by clinicians and coaches to take actions because the potential important for well-being, performance on the pitch, and risk of injury. The aim was to report descriptive characteristics of lifestyle factors in adolescent female football players and potential changes over 1 year.

METHODS

We included 419 adolescent competitive female football players from 12 clubs and 27 teams (age 14 ± 1 years, range 12-17 years) and 286 were followed over 1 year. The players completed an extensive questionnaire regarding demographics, football-related factors, and lifestyle factors including tobacco consumption, alcohol use, medicine intake, eating and sleeping habits, well-being, stress, coping, and passion. Baseline data are presented for the total cohort and separately for 4 age groups (12, 13, 14, and 15-17 years).

RESULTS

12% skipped breakfast, 8% skipped lunch and 11% used protein supplements several days per week. 16% slept less than 8 h/night, 8% had impaired sleep with daytime consequences, and 22% stated that they were tired in daily activities several days per week. 32% experienced stress some or most days/week and 24% were classified as having psychological distress. Medicine intake (23% vs. 34%), skipping breakfast or lunch several days per week (10% vs. 47% and 20 vs. 33%), tiredness (20% vs. 27%), stress (26% vs. 40%), and psychological distress (27% vs. 37%) increased significantly (P = 0.031 to < 0.001) at the 1-year follow-up.

CONCLUSION

Many adolescent female football players skip breakfast and lunch, have insufficient sleep, experience stress and are classified as having psychological distress. These factors increased over 1 year.

Examining the Effects of Mirror Therapy on Psychological Readiness and Perception of Pain in ACL-Injured Female Football Players

Virtual reality-guided imagery (VRGI) and mirror therapy (MT) have been used in isolation to treat patients suffering from different injuries. However, no attempts have been made to understand the effects of combined VRGI and MT added to conventional physical therapy, and no information exists regarding perceptual responses to these rehabilitation strategies in female football players. Thus, this study aimed to examine the effect of MT added to conventional rehabilitation on psychological readiness and perception of pain in ACL-injured female football players. Thirty ACL-injured female football players competing in the 2nd and 3rd Italian tier who underwent an ACL rehabilitation program from the same clinic participated in this study. Players were randomly distributed in an MT group (n = 15) and a CON group (n = 15). All participants reported their perception of pain on a VAS before and after the interventions and their psychological readiness to return to sport after ACL injury and reconstruction surgery on the ACL-RSI scale after the intervention. An independent-sample t-test was performed to assess between-group differences in post-intervention ACL-RSI, and a further independent-sample t-test to assume non-significant differences between VAS values before the intervention. A two-way repeated-measures analysis of variance was used to test the null hypothesis of no different change in VAS over time between groups. After the intervention, the MT group perceived largely greater psychological readiness (p < 0.01). MT and CON groups experienced a large reduction in VAS after the intervention (p < 0.001). However, a small time × group interaction was observed (p = 0.023). MT reported a greater perception of the psychological readiness of the soccer players and a lower perception of pain than those who performed conventional therapy.

Consensus Delphi study on guidelines for the assessment of anterior cruciate ligament injuries in children

Background: Knee examination guidelines in minors are intended to aid decision-making in the management of knee instability. Clinical question: A Delphi study was conducted with a formal consensus process using a validated methodology with sufficient scientific evidence. A group consensus meeting was held to develop recommendations and practical guidelines for use in the assessment of instability injuries in children. Key findings: there is a lack of evidence to analyse anterior cruciate ligament injuries in children and their subsequent surgical management if necessary. Diagnostic guidelines and clinical assessment of the patient based on a thorough examination of the knee are performed and a guide to anterior cruciate ligament exploration in children is developed. Clinical application: In the absence of a strong evidence base, these established guidelines are intended to assist in that decision-making process to help the clinician decide on the most optimal treatment with the aim of benefiting the patient as much as possible. Following this expert consensus, surgical treatment is advised when the patient has a subjective sensation of instability accompanied by a pivot shift test ++, and may include an anterior drawer test + and a Lachman test +. If these conditions are not present, the conservative approach should be chosen, as the anatomical and functional development of children, together with a physiotherapy programme, may improve the evolution of the injury.

Impact of Anterior Cruciate Ligament Injury on European Professional Soccer Players

Background:

The impact of anterior cruciate ligament reconstruction (ACLR) on the performance and career of professional soccer players has not been extensively investigated.

Purpose:

To evaluate in professional European soccer players (1) the ACL injury incidence, (2) the return-to-play (RTP) rate and time after ACLR, (3) career survival and athlete performance in the first 3 postoperative seasons after RTP, (4) factors likely related to different outcomes after ACLR, and (5) any related differences between the top 8 European soccer leagues.

Study Design:

Descriptive epidemiology study.

Methods:

Included were professional soccer players in the top 8 European Soccer leagues (Serie A [Italy], Premier League [England], Ligue 1 [France], LaLiga [Spain], Bundesliga [Germany], Jupiler Pro League [Belgium], Liga NOS [Portugal], and Premier Liga [Russia]) who sustained an ACL injury during seasons 2014 to 2015, 2015 to 2016, and 2016 to 2017. Data were retrieved from publicly available online sources. Outcomes were evaluated based on player age (<25 years, 25-30 years, and >30 years), position (goalkeeper, defender, midfielder, and forward), affected side (dominant vs nondominant), and league.

Results:

Overall, 195 players sustained an ACL injury, for a mean annual ACL injury incidence of 1.42%. The RTP rate was 95%, with a mean RTP time of 248 ± 136 days. Within the third postoperative season, 66 players (36%) competed in a lower level national league, and 25 (13.6%) ended their careers; a significant reduction in the mean minutes played per season was found in all 3 postoperative seasons. Player age correlated significantly with reduction in performance or recovery from an ACL injury. No significant correlation was found between postoperative player performance and affected side, position, league, or time to RTP.

Conclusion:

A substantial ACL injury incidence was found in top European elite soccer players; however, a high RTP rate in a reasonable time was seen after ACLR. Nevertheless, professional soccer players experienced a short-term decline in their performance.

Isokinetic strength differences between elite senior and youth female soccer players identifies training requirements

OBJECTIVES

To compare traditional and angle-specific isokinetic strength of eccentric knee flexors and concentric knee extensors in female senior professional and youth soccer players.

DESIGN

Cross-sectional study design.

SETTING

University's Laboratory.

PARTICIPANTS

A total of 34 players (17 seniors [age 25.31 ± 4.51 years; height 167.89 ± 7.04 cm; mass 63.12 ± 7.79 kg] and 17 youths [16.91 ± 1.16 years; height 165.92 ± 4.42 cm; mass 60.07 ± 4.48 kg]) from the Women's Super League 1 completed strength assessments at 180, 270 and 60°∙s^-1.

MAIN OUTCOME MEASURES

Peak torque (PT), dynamic control ratio (DCR), angle of peak torque (APT), functional range (FR), angle-specific torque (AST) and angle-specific DCR (DCR_AST) were compared between age groups.

RESULTS

The PT (P = 0.016) AST (P = 0.041) were significantly higher in seniors compared to youths; however APT (P = 0.141), DCR (P = 0.524) FR (P = 0.821) and DCR_AST (P = 0.053) were not significant between playing age.

CONCLUSION

The use of absolute and angle-specific strength measures were able to distinguish between female playing ages, whereas DCR and DCR_AST was unable to identify differences. The PT and AST metrics may be the most useful metrics to help identify and inform training needs, particularly in youths.

Acute and overuse injuries among sports club members and non-members: the Finnish Health Promoting Sports Club (FHPSC) study

Background

Physical activity in adolescence is promoted for its multi-dimensional health benefits. However, too intensive sports participation is associated with an increased injury risk. Our aim was to compare the occurrence of acute and overuse injuries in Finnish sports club members and non-members and to report training and competing habits associated with a higher injury risk in sports club members.

Methods

In this cross-sectional survey targeted at 14–16-year-old adolescents, a structured questionnaire was completed by 1077 sports club members and 812 non-members. The main outcome measures were self-reported acute and overuse injuries, their location and type.

Results

At least one acute injury in the past year was reported by 44.0% of sports club members and 19.8% of non-members (P < 0.001). The sex-adjusted odds ratio (OR) for acute injury in sports club members compared to non-members was 3.13 (95% confidence interval (95% CI) 2.54–3.87). Thirty-five percent of sports club members and 17.4% of non-members (P < 0.001) reported at least one overuse injury during the past year. The overuse injury OR for sports club members was 2.61 (95% CI 2.09–3.26). Sports club members who trained 7–14 h per week during training (OR 1.61, 95% CI 1.21–2.12, P = 0.001) or competition season (OR 1.55, 95% CI 1.18–2.06, P = 0.002) were more likely to report an injury compared to members who trained 3–6 h per week. Those sports club members who participated in forty competitions or more compared to 7–19 competitions per year were more likely to report an acute injury (OR 1.55, 95% CI 1.05–2.08, P = 0.028) or for an overuse injury (OR 1.53, 95% CI 1.02–2.30, P = 0.038).

Conclusions

Both acute and overuse injuries are common among youth sports club members, and the number increases along with increasing amounts of training and competitions. More effective injury prevention is needed both for adolescents engaging in sports club activities and for other adolescents.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2417-3) contains supplementary material, which is available to authorized users.

The negative impact of anterior cruciate ligament reconstruction in professional male footballers

BACKGROUND

Soccer is one of the most common international sports in which ACL injuries occur, with previous studies reporting high return-to-play rates following ACL reconstruction (ACLR). Return-to-play analysis fails to take into consideration how effective a player remains once returning to competition. The aims of this study are to provide a large-scale international analysis of return-to-play and player performance statistics among professional soccer athletes following ACLR.

METHODS

Using publicly available sources, professional soccer athletes who have undergone ACLR between the 1996 and 2015 seasons were identified. Player metrics including statistical performance, recovery time, and return-to-play rates were analyzed both before and after reconstruction. Furthermore, player performance statistics during each of three consecutive seasons post-ACLR were compared.

RESULTS

A total of 176 athletes who underwent ACLR were included in this study. The return-to-play rate was 93.2% (164 athletes). Cumulative post-surgical statistical analysis of ACLR players demonstrated fewer games/season, minutes/season, minutes/game, goals/season, and more fouls/season following ACLR (p < 0.04). Analysis of player performance statistics suggests that athletes do not return to their baseline number of games/season and minutes/game until two and three seasons post-ACLR, respectively. At three seasons post-ACLR, athletes are still starting fewer games/season and scoring fewer goals/90 min (p < 0.04).

CONCLUSION

Return-to-play rate is high following ACLR; however, athletes exhibit poorer statistical performance, especially in the first few seasons upon return. Our data shows that athletes continue to start fewer games/season and score fewer goals/90 min at three seasons post-ACLR.

Anterior cruciate ligament ruptures in German elite soccer players: Epidemiology, mechanisms, and return to play

BACKGROUND

Anterior cruciate ligament ruptures (ACLRs) are severe sports-related injuries with significant consequences for affected players and teams. This study aims to identify the epidemiology and injury-related lay-off after ACLR in professional male soccer players from the first-division German Bundesliga.

METHODS

Exposure times and incidence of anterior cruciate ligament ruptures were collected during 7.5 consecutive seasons using two media-based registers.

RESULTS

A total of 72 total ACLRs were registered in 66 different players with an incidence of 0.040 per 1000h of exposure (95% CI 0.009-0.12). On average there were 9.6 ACLRs per season and 0.53 per team and season. The mean age of players affected was 24 (standard deviation±3.6) years. The number of ACLRs recorded per season fluctuated during the period observed. Goalkeepers are significantly (P<0.05) less prone to suffer an ACLR compared to outfield players.

CONCLUSIONS

Understanding ACLR loading mechanisms, knowing risk factors for the injury and mean off time after ACLR are essential information for the coach, the medical staff, the elite soccer players, the insurance and team managers. Our results are in accordance with reports based on information from medical team staff. Therefore, our analysis of ACLR based on media sources may serve as an alternative for injury reports in elite soccer. The information of this study may be helpful for the medical staff taking care of professional soccer players and for orthopedic surgeons performing ACL reconstructions in this patient population.

Update on Anterior Cruciate Ligament Rupture and Care in the Female Athlete

As female athlete sports participation has continued to increase, the rate of anterior cruciate ligament (ACL) rupture in female athletes has also increased. Individualized, patient-specific treatment is crucial to achieving optimal outcomes; ACL reconstruction must accurately restore native ACL anatomy and address any concomitant injury to secondary stabilizers. Rehabilitation programs should target hip, core, and trunk neuromuscular control; allow adequate time for graft ligamentization; and address the psychosocial needs of the athlete.

Weaker lower extremity muscle strength predicts traumatic knee injury in youth female but not male athletes

Background

The role of lower extremity (LE) muscle strength for predicting traumatic knee injury in youth athletes is largely unknown.

Aims

The aim was to investigate the influence of LE muscle strength on traumatic knee injury in youth female and male athletes.

Methods

225 athletes (40% females) from sport senior high schools in Sweden were included in this case-control study. The athletes recorded any traumatic knee injury that had occurred during their high-school period in a web-based injury form. A one repetition maximum (1RM) barbell squat test was used to measure LE muscle strength. The 1RM was dichotomised to analyse 'weak' versus 'strong' athletes according to the median (weak_median vs strong_median).

Results

63 traumatic knee injuries, including 18 ACL injuries, were registered. The majority of injured female athletes were in the weak group compared with the strong group (p=0.0001). The odds of sustaining a traumatic knee injury and an ACL injury was 9.5 times higher and 7 times higher, respectively, in the weak_median group compared with the strong_median group in females (p ≤0.011). A relative 1RM squat ≤1.05 kg (105% of bodyweight) was established as the best cut-off value to distinguish high versus low risk of injury in female athletes. No strength-injury relationships were observed for the male athletes (p ≥0.348).

Conclusions

Weaker LE muscle strength predicted traumatic knee injury in youth female athletes, but not in males. This suggests that LE muscle strength should be included in injury screening in youth female athletes.

Increase in ACL and PCL injuries after implementation of a new professional football league

PURPOSE

In the season 2008-2009, a third professional football league was established in Germany. This study analysed the influence of increased training and playing intensity on severe knee injuries in football players.

METHODS

In a prospective controlled one-season trial, injury incidence and injury patterns of players of the newly established professional football league were analysed, particularly with regard to ruptures of the anterior (ACL) and posterior (PCL) cruciate ligaments. Players of the highest amateur level served as a control group.

RESULTS

Four hundred and eight players of 24 teams were allocated to two groups. The overall training exposure was significantly (p < 0.001) higher in the new professional league (335.3 h per player) than at the amateur level (286.6 h per player). Players at both levels showed similar overall injury rates and injury patterns. However, players in the professional league had a significantly higher (p = 0.04) incidence of ACL and PCL injuries, than players at the amateur level. More than 90 % of all ACL and PCL ruptures in both groups were sustained by players, who had played at least one level lower in the previous season. In addition, injuries of players who had sustained repeat injuries over the season were more severe.

CONCLUSION

The introduction of a new professional football league increased the training and playing intensity of players as well as the number of ACL and PCL ruptures. A specific injury prevention concept, particularly for players facing rapidly increasing training and playing intensity, seems to be mandatory.

LEVEL OF EVIDENCE

Prospective controlled cohort study, Level II.

Risk factors for acute knee injury in female youth football

PURPOSE

To prospectively evaluate risk factors for acute time-loss knee injury, in particular ACL injury, in female youth football players.

METHODS

Risk factors were studied in 4556 players aged 12-17 years from a randomised controlled trial during the 2009 season. Covariates were both intrinsic (body mass index, age, relative age effect, onset of menarche, previous acute knee injury or ACL injury, current knee complaints, and familial disposition of ACL injury) and extrinsic (no. of training sessions/week, no. of matches/week, match exposure ratio, match play with other teams, and artificial turf exposure). Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated from individual variable and multiple Cox regression analyses.

RESULTS

Ninety-six acute knee injuries were recorded, 21 of them ACL injuries. Multiple Cox regression showed a fourfold higher ACL injury rate for players with familial disposition of ACL injury (HR 3.57; 95% CI 1.48-8.62). Significant predictor variables for acute knee injury were age >14 years (HR 1.97; 95% CI 1.30-2.97), knee complaints at the start of the season (HR 1.98; 95% CI 1.30-3.02), and familial disposition of ACL injury (HR 1.96; 95% CI 1.22-3.16). No differences in injury rates were seen when playing on artificial turf compared with natural grass.

CONCLUSION

Female youth football players with a familial disposition of ACL injury had an increased risk of ACL injury and acute knee injury. Older players and those with knee complaints at pre-season were more at risk of acute knee injury. Although the predictive values were low, these factors could be used in athlete screening to target preventive interventions.

LEVEL OF EVIDENCE

II.

Factors associated with returning to football after anterior cruciate ligament reconstruction

PURPOSE

The aim of the present investigation was to identify possible factors associated with returning to football on an average 3.2 ± 1.4 years after anterior cruciate ligament (ACL) reconstruction in both male and female football players.

METHODS

The players were recruited from a patient database of football players that have undergone an ACL reconstruction between 2004 and 2007 at the Capio Artro Clinic, Sophiahemmet in Stockholm, Sweden. Special attention was paid to gender, age, type of graft for ACL reconstruction, associated injuries, anterior knee laxity, thigh muscle torques and symptoms/problems during, and/or after physical activity. In the beginning of the summer of 2009, 205 players (37.9 %) out of 541 players filled out a questionnaire designed to evaluate physical activity and knee function in a sports-specific setting. A detailed dropout analysis showed that females responded to a higher degree than males. No other significant differences between responders and non-responders were found.

RESULTS

Fifty-four per cent (n = 111) had returned to football, and 46 % (n = 94) had not. Using logistic regression analyses, we found that the female gender (p = 0.036, OR 0.518), cartilage injury (p = 0.013, OR 0.368), and pain during physical activity (p = 0.002, OR 0.619) were significant negative predictors for returning to football after ACL reconstruction and rehabilitation. For players with all three significant factors, only 10 % returned to football compared to 76.5 % of those without any of these factors.

CONCLUSIONS

Female gender, cartilage injury, and knee pain during physical activity were independent negative predictors for returning to football after ACL reconstruction. At a mean follow-up of 3.2 ± 1.4 years after ACL reconstruction, pain during physical activity was reported to be the most common symptom/problem in football players. The clinical relevance of this study is to improve the treatment of ACL injured football players focusing on female gender and knee pain. Furthermore, ACL injury prevention should be highlighted in football players, especially female players.

Incidence and severity of reported acute sports injuries in 35 sports using insurance registry data

Acute injuries in sport are still a problem where limited knowledge of incidence and severity in different sports at national level exists. In Sweden, 80% of the sports federations have their mandatory injury insurance for all athletes in the same insurance company and injury data are systematically kept in a national database. The aim of the study was to identify high-risk sports with respect to incidence of acute and severe injuries in 35 sports reported to the database. The number and incidences of injuries as well as injuries leading to permanent medical impairment (PMI) were calculated during 2008-2011. Each year approximately 12,000 injuries and 1,162,660 licensed athletes were eligible for analysis. Eighty-five percent of the injuries were reported in football, ice hockey, floorball, and handball. The highest injury incidence as well as PMI was in motorcycle, handball, skating, and ice hockey. Females had higher risk of a PMI compared with males in automobile sport, handball, floorball, and football. High-risk sports with numerous injuries and high incidence of PMI injuries were motorcycle, handball, ice hockey, football, floorball, and automobile sports. Thus, these sports ought to be the target of preventive actions at national level.

Treatment of Anterior Cruciate Ligament Injuries by Major League Soccer Team Physicians

Background:

The treatment and rehabilitation procedures of anterior cruciate ligament (ACL) injuries in elite soccer players are controversial. Points of debate include surgical timing, technique, graft choice, rehabilitation, and return-to-sport criteria and timing.

Purpose:

To identify practice preferences among current Major League Soccer (MLS) team orthopaedic surgeons for ACL injuries.

Study Design:

Cross-sectional study; Level of evidence, 4.

Methods:

The survey was administered at the MLS team physician annual meeting in January 2013. At least 1 orthopaedic surgeon representative from each of the 19 clubs (16 from the United States, 3 from Canada) was in attendance. Teams with more than 1 affiliated orthopaedic surgeon were given an additional survey to be completed either at the meeting or returned via e-mail. Descriptive statistics, Wilcoxon Mann-Whitney (return-to-play parameters, running, and ball drills), and Fisher exact tests (graft selection, bracing, continuous passive motion) were applied to the various data sets from the survey responses.

Results:

A 100% survey participation rate was achieved (22 team orthopaedic surgeons representing 19 MLS teams). A single-incision, arthroscopically assisted, single-bundle reconstruction was the most common technique (91%). Surgeons were split regarding femoral tunnel drilling (50% transtibial, 46% accessory medial). Autograft bone–patellar tendon–bone (BPTB) was the most common preferred graft choice (68%). The biggest concerns about BPTB autograft and hamstring autograft were anterior knee pain (76%) and hamstring weakness (46%), respectively. Most surgeons did not recommend postoperative continuous passive motion (64%) or functional bracing (68%). Most surgeons permitted return to sport without restrictions at 6 to 8 months following surgery (82%). Surgeons who routinely used functional bracing after ACL surgery more frequently used hamstring autograft than those who used BPTB autograft (P = .04).

Conclusion:

This article successfully describes current management of ACL injuries among MLS team orthopaedic surgeons. The preference for single-bundle BPTB autograft is similar to published data in the National Football League and National Basketball Association.

Insurance claims data: a possible solution for a national sports injury surveillance system? An evaluation of data information against ASIDD and consensus statements on sports injury surveillance

BACKGROUND

Before preventive actions can be suggested for sports injuries at the national level, a solid surveillance system is required in order to study their epidemiology, risk factors and mechanisms. There are guidelines for sports injury data collection and classifications in the literature for that purpose. In Sweden, 90% of all athletes (57/70 sports federations) are insured with the same insurance company and data from their database could be a foundation for studies on acute sports injuries at the national level.

OBJECTIVE

To evaluate the usefulness of sports injury insurance claims data in sports injury surveillance at the national level.

METHOD

A database with 27 947 injuries was exported to an Excel file. Access to the corresponding text files was also obtained. Data were reviewed on available information, missing information and dropouts. Comparison with ASIDD (Australian Sports Injury Data Dictionary) and existing consensus statements in the literature (football (soccer), rugby union, tennis, cricket and thoroughbred horse racing) was performed in a structured manner.

RESULT

Comparison with ASIDD showed that 93% of the suggested data items were present in the database to at least some extent. Compliance with the consensus statements was generally high (13/18). Almost all claims (83%) contained text information concerning the injury.

CONCLUSIONS

Relatively high-quality sports injury data can be obtained from a specific insurance company at the national level in Sweden. The database has the potential to be a solid base for research on acute sports injuries in different sports at the national level.

Football injuries in children and adolescent players: are there clues for prevention?

Football (soccer) is the world's most popular sport with most players being younger than 18 years. Playing football can induce beneficial health effects, but there is also a high risk of injury. Therefore, it is necessary to implement measures for preventing injuries. The present review analyzes and summarizes published scientific information on the incidence and characteristics of football injuries in children and adolescent players to arrive at sound conclusions and valid considerations for the development of injury-prevention programs. A literature search was conducted up to November 2012. Fifty-three relevant scientific publications were detected. Thirty-two studies fulfilled the inclusion criteria for pooled analysis. Additional information from the remaining 21 studies was considered where appropriate to obtain a broader perspective on the injury problem in children and youth football. Training injury incidence was nearly constant for players aged 13-19 years, ranging from 1 to 5 injuries per 1,000 h training. Match injury incidence tended to increase with age through all age groups, with an average incidence of about 15 to 20 injuries per 1,000 match hours in players older than 15 years. Between 60 and 90 % of all football injuries were classified as traumatic and about 10-40 % were overuse injuries. Most injuries (60-90 %) were located at the lower extremities with the ankle, knee, and thigh being mostly affected. The frequency of upper-extremity and head/face injuries was higher in those studies that analyzed match injuries only. The most common injury types were strains, sprains, and contusions (10 up to 40 % each). There is some evidence that the risk of traumatic injuries and, in particular, of sustaining a fracture, contusion, or concussion was higher during match play than in practice sessions. Fractures were more frequent in children younger than 15 years than in older players. About half of all time-loss injuries led to an absence from sport of less than 1 week, one third resulted in an absence between 1 and 4 weeks, and 10 to 15 % of all injuries were severe. Separate data for players under the age of 11 years are almost absent. Maturation status seems to have an influence on injury characteristics, although evidence is not conclusive at this time. Three main areas seem to be of particular relevance for future prevention research in young football players: (1) the substantial number of severe contact injuries during matches, (2) the high number of fractures in younger players, and (3) the influence of maturation status and growth spurts.

Control of dynamic foot-ground interactions in male and female soccer athletes: females exhibit reduced dexterity and higher limb stiffness during landing

Controlling dynamic interactions between the lower limb and ground is important for skilled locomotion and may influence injury risk in athletes. It is well known that female athletes sustain anterior cruciate ligament (ACL) tears at higher rates than male athletes, and exhibit lower extremity biomechanics thought to increase injury risk during sport maneuvers. The purpose of this study was to examine whether lower extremity dexterity (LED)--the ability to dynamically control endpoint force magnitude and direction as quantified by compressing an unstable spring with the lower limb at submaximal forces--is a potential contributing factor to the "at-risk" movement behavior exhibited by female athletes. We tested this hypothesis by comparing LED-test performance and single-limb drop jump biomechanics between 14 female and 14 male high school soccer players. We found that female athletes exhibited reduced LED-test performance (p=0.001) and higher limb stiffness during landing (p=0.008) calculated on average within 51 ms of foot contact. Females also exhibited higher coactivation at the ankle (p=0.001) and knee (p=0.02) before landing. No sex differences in sagittal plane joint angles and center of mass velocity at foot contact were observed. Collectively, our results raise the possibility that the higher leg stiffness observed in females during landing is an anticipatory behavior due in part to reduced lower extremity dexterity. The reduced lower extremity dexterity and compensatory stiffening strategy may contribute to the heightened risk of ACL injury in this population.

Radioprotection provides functional mechanics but delays healing of irradiated tendon allografts after ACL reconstruction in sheep

Successful protection of tissue properties against ionizing radiation effects could allow its use for terminal sterilization of musculoskeletal allografts. In this study we functionally evaluate Achilles tendon allografts processed with a previously developed radioprotective treatment based on (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) crosslinking and free radical scavenging using ascorbate and riboflavin, for ovine anterior cruciate ligament reconstruction. Arthroscopic anterior cruciate ligament (ACL) reconstruction was performed using double looped allografts, while comparing radioprotected irradiated and fresh frozen allografts after 12 and 24 weeks post-implantation, and to control irradiated grafts after 12 weeks. Radioprotection was successful at preserving early subfailure mechanical properties comparable to fresh frozen allografts. Twelve week graft stiffness and anterior-tibial (A-T) translation for radioprotected and fresh frozen allografts were comparable at 30 % of native stiffness, and 4.6 and 5 times native A-T translation, respectively. Fresh frozen allograft possessed the greatest 24 week peak load at 840 N and stiffness at 177 N/mm. Histological evidence suggested a delay in tendon to bone healing for radioprotected allografts, which was reflected in mechanical properties. There was no evidence that radioprotective treatment inhibited intra-articular graft healing. This specific radioprotective method cannot be recommended for ACL reconstruction allografts, and data suggest that future efforts to improve allograft sterilization procedures should focus on modifying or eliminating the pre-crosslinking procedure.

Evaluation of functional limitations in female soccer players and their relationship with sports level--a cross sectional study

THE MAIN OBJECTIVES OF THE STUDY

the aim of this study was to analyze: a) abnormalities in the length of lower limb muscles, b) the correctness of movement patterns, and c) the impact of functional limitations of muscles on the correctness of fundamental movement patterns in a group of female soccer players, in relation to their skill level.

MATERIALS AND METHODS

21 female soccer players from Polish Ekstraklasa and 22 players from the 1(st) Division were tested for lower limb muscle length restrictions and level of fundamental movement skills (with the Fundamental Movement Screen™ test concept by Gray Cook). Chi-square test was used for categorical unrelated variables. Differences between groups in absolute point values were analyzed using the non-parametric Mann-Whitney U test. Statistical significance was set at p<0.05.

RESULTS

Statistically significant higher number of measurements indicating an abnormal length of rectus femoris was observed in the 1st Division group (p = 0.0433). In the group of Ekstraklasa the authors obtained a significantly higher number of abnormal hamstring test results (p = 0.0006). Ekstraklasa players scored higher in the rotational stability test of the trunk (p = 0.0008), whereas the 1st Division players scored higher in the following tests: deep squat (p = 0.0220), in-line lunge (p = 0.0042) and active straight leg raise (p = 0.0125). The results suggest that there are different functional reasons affecting point values obtained in the FMS™ tests in both analyzed groups.

CONCLUSIONS

The differences in the flexibility of rectus femoris and hamstring muscle observed between female soccer players with different levels of training, may result from a long-term impact of soccer training on the muscle-tendon system and articular structures. Different causes of abnormalities in fundamental movement patterns in both analyzed groups suggest the need for tailoring prevention programs to the level of sport skills represented by the players.

Return to play and future ACL injury risk after ACL reconstruction in soccer athletes from the Multicenter Orthopaedic Outcomes Network (MOON) group

BACKGROUND

There is limited information on outcomes and return to play (RTP) after anterior cruciate ligament reconstruction (ACLR) in soccer athletes.

PURPOSE

The purpose of this study was to (1) test the hypotheses that player sex, side of injury, and graft choice do not influence RTP and (2) define the risk for future ACL injury in soccer players after ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Soccer players in a prospective cohort were contacted to determine RTP after ACLR. Information regarding if and when they returned to play, their current playing status, the primary reason they stopped playing soccer (if relevant), and incidence of subsequent ACL surgery was recorded.

RESULTS

Initially, 72% of 100 soccer athletes (55 male, 45 female) with a mean age of 24.2 years at the time of ACLR returned to soccer. At average follow-up of 7.0 years, 36% were still playing, a significant decrease compared with initial RTP (P < .0001). Based on multivariate analysis, older athletes (P = .006) and females (P = .037) were less likely to return to play. Twelve soccer athletes had undergone further ACL surgery, including 9 on the contralateral knee and 3 on the ipsilateral knee. In a univariate analysis, females were more likely to have future ACL surgery (20% vs 5.5%, P = .03). Soccer athletes who underwent ACLR on their nondominant limb had a higher future rate of contralateral ACLR (16%) than soccer athletes who underwent ACLR on their dominant limb (3.5%) (P = .03).

CONCLUSION

Younger and male soccer players are more likely to return to play after ACL reconstruction. Return to soccer after ACLR declines over time. ACLR on the nondominant limb potentially places the dominant limb at risk for future ACL injury.

Sagittal Plane Knee Biomechanics and Vertical Ground Reaction Forces Are Modified Following ACL Injury Prevention Programs: A Systematic Review

Context:

Injuries to the anterior cruciate ligament (ACL) occur because of excessive loading on the knee. ACL injury prevention programs can influence sagittal plane ACL loading factors and vertical ground reaction force (VGRF).

Objective:

To determine the influence of ACL injury prevention programs on sagittal plane knee biomechanics (anterior tibial shear force, knee flexion angle/moments) and VGRF.

Data Sources:

The PubMed database was searched for studies published between January 1988 and June 2008. Reference lists of selected articles were also reviewed.

Study Selection:

Studies were included that evaluated healthy participants for knee flexion angle, sagittal plane knee kinetics, or VGRF after performing a multisession training program. Two individuals reviewed all articles and determined which articles met the selection criteria. Approximately 4% of the articles fulfilled the selection criteria.

Data Extraction:

Data were extracted regarding each program’s duration, frequency, exercise type, population, supervision, and testing procedures. Means and variability measures were recorded to calculate effect sizes. One reviewer extracted all data and assessed study quality using PEDro (Physiotherapy Evidence Database). A second reviewer (blinded) verified all information.

Results:

There is moderate evidence to indicate that knee flexion angle, external knee flexion moment, and VGRF can be successfully modified by an ACL injury prevention program. Programs utilizing multiple exercises (ie, integrated training) appear to produce the most improvement, in comparison to that of single-exercise programs. Knee flexion angle was improved following integrated training (combined balance and strength exercises or combined plyometric and strength exercises). Similarly, external knee flexion moment was improved following integrated training consisting of balance, plyometric, and strength exercises. VGRF was improved when incorporating supervision with instruction and feedback on proper technique.

Conclusion:

ACL injury prevention programs that are aimed at modifying sagittal plane knee biomechanics and VGRF should use an integrated training approach that incorporates instruction and feedback on proper movement technique.

Effects of dimethylolpropionic acid modification on the characteristics of polyethylene terephthalate fibers

Polyethylene terephthalate (PET) fibers are widely used in the preparation of artificial ligaments. However, due to their lack of hydrophilicity, PET fibers have low biocompatibility, which usually results in the poor biological activity of the products. In the present study, in order to improve the hydrophilicity and biocompatibility of PET fibers, we modified their surface using dimethylolpropionic acid (DMPA). Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), tensile testing and cell culture were employed to observe the effects of DMPA modification on the characteristics of the DMPA-PET fibers. In contrast to the original PET fibers, the surface of the DMPA-PET fibers became rough as demonstrated by SEM. The FTIR spectrum further confirmed that a number of hydrophilic groups were formed on the surface of DMPA-PET. However, there were no significant changes in crystallinity and tensile strength between the PET and the DMPA-PET fibers as revealed by DSC and XRD (P>0.05). Finally, the cell co-culture test revealed that the adhesion and proliferation of bone marrow‑derived stromal cells increased greatly on the DMPA-PET fibers compared to those on the original PET fibers (P<0.05). These results demonstrate that DMPA-PET fibers have significant potential as a material for the development of artificial ligaments.

Prevention of acute knee injuries in adolescent female football players: cluster randomised controlled trial

OBJECTIVE

To evaluate the effectiveness of neuromuscular training in reducing the rate of acute knee injury in adolescent female football players.

DESIGN

Stratified cluster randomised controlled trial with clubs as the unit of randomisation.

SETTING

230 Swedish football clubs (121 in the intervention group, 109 in the control group) were followed for one season (2009, seven months).

PARTICIPANTS

4564 players aged 12-17 years (2479 in the intervention group, 2085 in the control group) completed the study.

INTERVENTION

15 minute neuromuscular warm-up programme (targeting core stability, balance, and proper knee alignment) to be carried out twice a week throughout the season.

MAIN OUTCOME MEASURES

The primary outcome was rate of anterior cruciate ligament injury; secondary outcomes were rates of severe knee injury (>4 weeks' absence) and any acute knee injury.

RESULTS

Seven players (0.28%) in the intervention group, and 14 (0.67%) in the control group had an anterior cruciate ligament injury. By Cox regression analysis according to intention to treat, a 64% reduction in the rate of anterior cruciate ligament injury was seen in the intervention group (rate ratio 0.36, 95% confidence interval 0.15 to 0.85). The absolute rate difference was -0.07 (95% confidence interval -0.13 to 0.001) per 1000 playing hours in favour of the intervention group. No significant rate reductions were seen for secondary outcomes.

CONCLUSIONS

A neuromuscular warm-up programme significantly reduced the rate of anterior cruciate ligament injury in adolescent female football players. However, the absolute rate difference did not reach statistical significance, possibly owing to the small number of events.

TRIAL REGISTRATION

Clinical trials NCT00894595.

Anterior cruciate ligament injury in elite football: a prospective three-cohort study

Anterior cruciate ligament (ACL) injury causes long lay-off time and is often complicated with subsequent new knee injury and osteoarthritis. Female gender is associated with an increased ACL injury risk, but few studies have adjusted for gender-related differences in age although female players are often younger when sustaining their ACL injury. The objective of this three-cohort study was to describe ACL injury characteristics in teams from the Swedish men's and women's first leagues and from several European men's professional first leagues. Over a varying number of seasons from 2001 to 2009, 57 clubs (2,329 players) were followed prospectively and during this period 78 ACL injuries occurred (five partial). Mean age at ACL injury was lower in women compared to men (20.6 ± 2.2 vs. 25.2 ± 4.5 years, P = 0.0002). Using a Cox regression, the female-to-male hazard ratio (HR) was 2.6 (95% CI 1.4-4.6) in all three cohorts studied and 2.6 (95% CI 1.3-5.3) in the Swedish cohorts; adjusted for age, the HR was reduced to 2.4 (95% CI 1.3-4.2) and 2.1 (95% CI 1.0-4.2), respectively. Match play was associated with a higher ACL injury risk with a match-to-training ratio of 20.8 (95% CI 12.4-34.8) and 45 ACL injuries (58%) occurred due to non-contact mechanisms. Hamstrings grafts were used more often in Sweden than in Europe (67 vs. 34%, P = 0.028), and there were no differences in time to return to play after ACL reconstruction between the cohorts or different grafts. In conclusion, this study showed that the ACL injury incidence in female elite footballers was more than doubled compared to their male counterparts, but also that they were significantly younger at ACL injury than males. These findings suggest that future preventive research primarily should address the young female football player.

[Knee and ankle injuries from playing football]

Soccer is the most common sport activity worldwide. Over the last two decades the increase in soccer players has mainly been due to increased interest by females. In general, soccer is a relatively safe sport activity, especially if minor injuries resulting in short periods of absence from playing or training are neglected. However, due to the high number of soccer players severe injuries are also frequent. These are a problem not only for the injured player and the team but may also become problematic for the socio-economic system. In up to 80-90% structures of the lower extremities are injured. For sufficient radiological diagnosis knowledge of the biomechanics of the soccer game and some details about the history of the injury may be of help. To prevent soccer injuries or keep the degree of injury low, special programs had been developed.

Translational studies in anterior cruciate ligament repair

Translational research, which can be explained as the principle of combining advances in both basic research and clinical understanding in a bedside-to-bench-to-bedside approach, has become one of the central themes of present-day medical research. One orthopedic problem that has strongly benefited from such an approach is tissue-engineering-enhanced primary repair of the anterior cruciate ligament. Recent years have shown a clearer definition of the clinical problem and established an underlying mechanistic cause of the incapacity of the anterior cruciate ligament to heal-the premature loss of provisional scaffold in the wound site. These clinical findings were then translated into a research objective, namely, to replace the missing scaffold with a biomaterial with appropriate structural and bio-stimulatory characteristics. Subsequently, a tissue-engineering-based treatment using a collagen-platelet composite was developed and tested in vitro. After proofing the efficacy of this new treatment in the laboratory, it was translated into a potential clinical application, which showed highly successful results in structural integrity and biomechanical capacity in large animal testing. This approach of defining the scientific mechanism underlying a clinical observation and then using that information to design new therapies is but one example of how translational research in tissue engineering can help define and develop new treatments for challenging problems faced by patients.

Soccer injuries in children

Soccer is the most popular sport in the world, with FIFA recognising more than 265 million amateur players. Despite the fact that soccer is a contact sport, it is perceived to be relatively safe to play, a factor that has contributed to its status as the fastest growing team sport in the USA. Acute and minor injuries predominate in the statistics, with contusions and abrasions being the most commonly recorded. As would be expected, the majority of soccer injuries are to the lower limbs, with serious truncal and spinal trauma being rare. This article examines the type and anatomic location of injuries sustained by children and adolescents who play soccer, and the main mechanisms whereby such injuries occur. The risk factors underpinning injury occurrence are considered, along with injury avoidance tactics.

Injuries among male and female elite football players

All 12 female football clubs (228 players) and 11 of 14 male clubs (239 players) in the Swedish premier league were followed prospectively during the 2005 season. Individual exposure (playing time), injuries (time loss), and injury severity (days lost due to injury) were recorded by the team medical staffs. Injury incidence was higher for male players during both training (4.7 vs 3.8 injuries/1000 h, P=0.018) and match play (28.1 vs 16.1, P<0.001). However, no difference was found in the incidence of severe injury (absence >4 weeks) (0.7/1000 h in both groups). The thigh, especially the hamstrings, was the overall most commonly injured region in both sexes, while the hip/groin was more commonly injured in male players and the knee in female players. Knee ligament injuries accounted for 31% and 37% of the total time lost from football for male and female players, respectively. In conclusion, male elite players had a higher injury incidence than their female counterparts although no difference was observed in the incidence of moderate to severe injury. We recommend that preventive measures should be focused on hamstring and knee ligament injury in order to reduce the overall injury burden.

Preventing knee injuries in adolescent female football players - design of a cluster randomized controlled trial [NCT00894595]

Background

Knee injuries in football are common regardless of age, gender or playing level, but adolescent females seem to have the highest risk. The consequences after severe knee injury, for example anterior cruciate ligament (ACL) injury, are well-known, but less is known about knee injury prevention. We have designed a cluster randomized controlled trial (RCT) to evaluate the effect of a warm-up program aimed at preventing acute knee injury in adolescent female football.

Methods

In this cluster randomized trial 516 teams (309 clusters) in eight regional football districts in Sweden with female players aged 13–17 years were randomized into an intervention group (260 teams) or a control group (256 teams). The teams in the intervention group were instructed to do a structured warm-up program at two training sessions per week throughout the 2009 competitive season (April to October) and those in the control group were informed to train and play as usual. Sixty-eight sports physical therapists are assigned to the clubs to assist both groups in data collection and to examine the players' acute knee injuries during the study period. Three different forms are used in the trial: (1) baseline player data form collected at the start of the trial, (2) computer-based registration form collected every month, on which one of the coaches/team leaders documents individual player exposure, and (3) injury report form on which the study therapists report acute knee injuries resulting in time loss from training or match play. The primary outcome is the incidence of ACL injury and the secondary outcomes are the incidence of any acute knee injury (except contusion) and incidence of severe knee injury (defined as injury resulting in absence of more than 4 weeks). Outcome measures are assessed after the end of the 2009 season.

Discussion

Prevention of knee injury is beneficial for players, clubs, insurance companies, and society. If the warm-up program is proven to be effective in reducing the incidence of knee injury, it can have a major impact by reducing the future knee injury burden in female football as well as the negative long-term disabilities associated with knee injury.

Trial registration

NCT00894595

Landing mechanics between noninjured women and women with anterior cruciate ligament reconstruction during 2 jump tasks

BACKGROUND

Women with anterior cruciate ligament reconstruction have different neuromuscular strategies than noninjured women during functional tasks after ligament reconstruction and rehabilitation.

HYPOTHESIS

Landing from a jump creates high loads on the knee creating dynamic instability in women with anterior cruciate ligament reconstruction, whereas noninjured women have stable knee landing mechanics.

STUDY DESIGN

Controlled laboratory study.

METHODS

Fifteen noninjured women and 13 women with anterior cruciate ligament reconstruction performed 5 trials of a single-legged 40-cm drop jump and 2 trials of a 20-cm up-down hop task. Multivariate analyses of variance were used to compare hip and knee joint kinematics, knee joint moments, ground-reaction forces, and electromyographic findings between the dominant leg in noninjured women and reconstructed leg in women with anterior cruciate ligament reconstruction.

RESULTS

No statistically significant differences between groups were found for peak hip and knee joint angles for the drop jump task. Statistically significant differences in neuromuscular activity (P = .001) and anterior-posterior knee shear forces (P < .001) were seen in women with anterior cruciate ligament reconstruction compared with noninjured women in the drop jump task. However, no statistically significant differences (P > .05) between groups were found for either peak hip and knee joint angles, peak joint kinetics, or electromyographic findings during the up-down hop task.

CONCLUSION

Women with anterior cruciate ligament reconstruction have neuromuscular strategies that allow them to land from a jump similar to healthy women, but they exhibit joint moments that could predispose them to future injury if they participate in sports that require jumping and landing.

Tunnel positioning of anteromedial and posterolateral bundles in anatomic anterior cruciate ligament reconstruction: anatomic and radiographic findings

BACKGROUND

The interest in double-bundle anterior cruciate ligament (ACL) reconstructions has recently reawakened.

HYPOTHESIS

The center of the femoral posterolateral (PL) bundle and the center of the femoral anteromedial (AM) bundle are not within the same plane and change their orientation throughout passive knee flexion. Additionally, the tibial center of the AM bundle is aligned with the anterior horn of the lateral meniscus and the center of the PL bundle lies at the recommended tibial tunnel position for single-bundle ACL reconstruction reconstruction, 7 to 9 mm anterior to the posterior cruciate ligament.

STUDY DESIGN

Descriptive laboratory study.

MATERIALS

In 20 human cadaveric knees (age range, 45-87 years) the distances from the center of the AM and PL bundle to the articular cartilage were measured. Radiographic analyses were performed using the techniques of Bernard and Hertel at the femur as well as the method by Stäubli and Rauschning at the tibia.

RESULTS

The center of the AM bundle was at a point 5.3 mm ( +/- 0.7) from the roof of the notch and 5.7 mm ( +/- 0.5) from the intercondylar line. The center of the PL bundle is located at 6.5 mm from the shallow cartilage margin and 5.8 mm from the inferior cartilage margin. On the tibia, the center of the AM bundle is aligned with the anterior horn of the lateral meniscus, while the center of the PL bundle was located 11.2 mm ( +/- 1.2) posterior and 4.1 mm ( +/- 0.6) medial to the anterior insertion of the lateral meniscus. Radiographically, the center of the PL bundle is anterior along Blumensaat's line and lower in the femoral notch along the height of the condyles than the center of the AM bundle. At the tibia, the center of the AM bundle is at 30% and the PL bundle is located at 44% using the method of Stäubli and Rauschning.

CONCLUSION

The center of the femoral PL bundle is shallow and inferior to the AM bundle. On the tibia, the AM bundle lies anterior when compared with the typical single-bundle ACL tunnel that reflects the PL bundle.

CLINICAL RELEVANCE

To imitate the anatomy of the intact ACL, it is mandatory to place the tunnels exactly within the femoral origin and tibial insertion of the ACL.

Clinical outcomes of allograft versus autograft in anterior cruciate ligament reconstruction

Anterior cruciate ligament (ACL) injuries are the most common complete ligamentous injury to the knee. The optimal graft should be able to reproduce the anatomy and biomechanics of the ACL, be incorporated rapidly with strong initial fixation, and cause low graft-site morbidity. This article reviews the literature comparing the clinical outcomes following allograft and autograft ACL reconstruction and examines current issues regarding graft choice.

The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis

The objectives of this study are to review the long-term consequences of injuries to the anterior cruciate ligament and menisci, the pathogenic mechanisms, and the causes of the considerable variability in outcome. Injuries of the anterior cruciate ligament and menisci are common in both athletes and the general population. At 10 to 20 years after the diagnosis, on average, 50% of those with a diagnosed anterior cruciate ligament or meniscus tear have osteoarthritis with associated pain and functional impairment: the young patient with an old knee. These individuals make up a substantial proportion of the overall osteoarthritis population. There is a lack of evidence to support a protective role of repair or reconstructive surgery of the anterior cruciate ligament or meniscus against osteoarthritis development. A consistent finding in a review of the literature is the often poor reporting of critical study variables, precluding data pooling or a meta-analysis. Osteoarthritis development in the injured joints is caused by intra-articular pathogenic processes initiated at the time of injury, combined with long-term changes in dynamic joint loading. Variation in outcome is reinforced by additional variables associated with the individual such as age, sex, genetics, obesity, muscle strength, activity, and reinjury. A better understanding of these variables may improve future prevention and treatment strategies. In evaluating medical treatment, we now expect large randomized clinical trials complemented by postmarketing monitoring. We should strive toward a comparable level of quality of evidence in surgical treatment of knee injuries. In instances in which a randomized clinical trial is not feasible, natural history and other observational cohort studies need to be as carefully designed and reported as the classic randomized clinical trial, to yield useful information.

Injuries in female football players in top-level international tournaments

BACKGROUND

Despite the growing popularity of women's football and the increasing number of female players, there has been little research on injuries sustained by female football players.

PURPOSE

Analysis of the incidence, characteristics and circumstances of injury in elite female football players in top-level international tournaments.

STUDY DESIGN

Prospective survey.

METHODS

Injuries incurred in seven international football tournaments were analysed using an established injury report system. Doctors of all participating teams reported all injuries after each match on a standardised injury reporting form. The mean response rate was 95%.

RESULTS

387 injuries were reported from 174 matches, equivalent to an incidence of 67.4 injuries/1000 player hours (95% CI 60.7 to 74.1) or 2.2 injuries/match (95% CI 2.0 to 2.4). Most injuries (84%; 317/378) were caused by contact with another player. The injuries most commonly involved the lower extremity (n = 248; 65%), followed by injuries of the head and neck (n = 67, 18%), trunk (n = 33, 9%) and upper extremity (n = 32, 8%). Contusions (n = 166; 45%) were the most frequent type of injury, followed by sprains or ligament rupture (n = 96; 26%) and strains or muscle fibre ruptures (n = 31; 8%). The most common diagnosis was an ankle sprain. There were 7 ligament ruptures and 15 sprains of the knee. On average 1 injury/match (95% CI 0.8 to 1.2) was expected to result in absence from a match or training.

CONCLUSION

The injury rate in women's top-level tournaments was within the range reported previously for match injuries in elite male and female players. However, the diagnoses and mechanisms of injury among the female players differed substantially from those previously reported in male football players.

Intraarticular rupture pattern of the ACL

To date, the intraarticular rupture pattern of the anterior cruciate ligament (ACL) has not been reported. The ACL is a complex structure consisting of two functionally synergistic structures: the anteromedial (AM) and posterolateral (PL) bundle. The purpose of our study was to evaluate the intraarticular rupture pattern of the ACL with regard to its two functional bundles. We examined ACL rupture patterns with regard to the integrity of AM and PL bundle in 121 consecutive patients undergoing anterior cruciate ligament reconstruction surgery within 120 days after injury. The intraarticular pattern was observed by one experienced surgeon. In 25% of the patients a partial rupture of the ACL was found, whereas in the remaining 75% a complete rupture of AM and PL bundles was seen. A partial rupture could only be detected by careful dissection of the ligament. In 44% of all patients the AM and PL bundles did not rupture at the same location. In 12% of the patients the PL bundle showed no signs of rupture. When performing ACL reconstruction, care should be taken when dissecting down the ACL remnants to evaluate intact fiber bundles of the ACL.

A prospective comparison of bone-patellar tendon-bone and hamstring grafts for anterior cruciate ligament reconstruction in female patients

The aim of the study is to compare the results after arthroscopic anterior cruciate ligament (ACL) reconstruction using central-third, bone-patellar tendon-bone (BTB group) (n = 28) and four-strand semitendinosus/gracilis (ST/G group) (n = 31) autografts in female patients. The type of study was non-randomised prospective consecutive series. A consecutive series of 61 female patients, all with unilateral ACL ruptures, was included in the study. In both groups, interference screw fixation of the graft was used at both ends, and 59/61 (97%) of the patients returned for the follow-up examination after a period of 26 (23-31) months. The pre-operative assessments in both groups were similar in terms of the Lysholm score, KT-1000 measurements, one-leg-hop test, and knee-walking test. At the 2-year follow-up, the knee-walking test was significantly worse in the BTB group than in the ST/G group (P = 0.003). Furthermore, the knee-walking test was significantly worse at follow-up than pre-operatively in the BTB group (P < 0.005). The corresponding finding was not made in the ST/G group. A reduction in knee laxity compared with the pre-operative assessments was found in both groups. No significant difference in the post-operative knee laxity measurement was found between the groups. A significant increase in activity level and subjective scores was found in both groups compared with pre-operative values, without any significant differences between the groups. Two years after ACL reconstruction, the groups displayed no significant differences in terms of functional outcome and knee laxity. However, the use of ST/G autografts rendered significantly less discomfort during the knee-walking test than the use of BTB autografts.