Anterior Cruciate Ligament Injury Risk in Sport: A Systematic Review and Meta-Analysis of Injury Incidence by Sex and Sport Classification

Asymmetry in kinematics of dominant/nondominant lower limbs in central and lateral positioned college and sub-elite soccer players

Change of direction, stops, and pivots are among the most common non-contact movements associated with anterior cruciate ligament (ACL) injuries in soccer. By observing these dynamic movements, clinicians recognize abnormal kinematic patterns that contribute to ACL tears such as increased knee valgus or reduced knee flexion. Different motions and physical demands are observed across playing positions, which may result in varied lower limb kinematic patterns. In the present study, 28 college and sub-elite soccer players performed four dynamic motions (change of direction with and without ball, header, and instep kick) with the goal of examining the effect of on-field positioning, leg dominance, and gender in lower body kinematics. Motion capture software monitored joint angles in the knee, hip, and ankle. A three-way ANOVA showed significant differences in each category. Remarkably, centrally positioned players displayed significantly greater knee adduction (5° difference, p = 0.013), hip flexion (9° difference, p = 0.034), hip adduction (7° difference, p = 0.016), and dorsiflexion (12° difference, p = 0.022) when performing the instep kick in comparison to their laterally positioned counterparts. These findings suggest that central players tend to exhibit a greater range of motion when performing an instep kicking task compared to laterally positioned players. At a competitive level, this discrepancy could potentially lead to differences in lower limb muscle development among on-field positions. Accordingly, it is suggested to implement position-specific prevention programs to address these asymmetries in lower limb kinematics, which can help mitigate dangerous kinematic patterns and consequently reduce the risk of ACL injury in soccer players.

Effect of open vs. closed kinetic chain exercises in ACL rehabilitation on knee joint pain, laxity, extensor muscles strength, and function: a systematic review with meta-analysis

Anterior cruciate ligament (ACL) injuries are common among physically active individuals, often requiring ACL reconstruction (ACLR) for recovery. Rehabilitating these injuries involves determining the appropriate timing for initiating open kinetic chain (OKC) exercises. Although OKC exercises are effective post-ACLR, their use in rehabilitation remains a subject of debate. Therefore, this study aims to conduct a systematic review to determine whether OKC or closed kinetic chain (CKC) exercises result in differences in laxity, strength of the knee extensor muscle group, function, and functional performance in ACL rehabilitation. Five electronic databases were searched for randomized controlled between-group trials (RCTs). Two reviewers independently evaluated the risk of bias using the PEDro scale. We performed a meta-analysis using a random-effects model or calculated mean differences (fixed-effect) where appropriate. Certainty of evidence was judged using the GRADE approach. The systematic literature search yielded 480 articles, of which 9 met the inclusion criteria. The evidence for all outcomes ranged from very low to low certainty. Across all comparisons, inconsistent results were found in outcome measures related to knee function between OKC and CKC exercises post-ACLR. A significant increase in quadriceps isokinetic strength was found in post-ACLR and ACL-deficient knees in favor of OKC exercises at 3 (p = 0.03) and 4 (p = 0.008) months, respectively. A significant decrease in knee laxity was observed in ACL-deficient knees in favor of OKC at 10 weeks (p = 0.01), although inconsistency was noted at 4 months. Finally, a significant decrease in pain was found in favor of early OKC compared to late OKC (p < 0.003). Additionally, in ACL-deficient knees, low load resistance training (LLRT) OKC showed no significant laxity difference compared to controls (p > 0.05). In contrast, high load resistance training (HLRT) OKC had less laxity than controls at 6 weeks (p = 0.02) but not at 12 weeks (p > 0.05). OKC exercises appear to be superior to CKC for improving quadriceps strength 3-4 months post-injury, whether as a part of conservative or post-surgery rehabilitation. On the other hand, OKC exercises seem to be either superior or equally effective to CKC for improving knee laxity, thus presenting their importance in being included in a rehabilitation protocol from the initial phase.

Systematic Review Registration

PROSPERO [CRD42023475230].

Acute anterior cruciate ligament rupture: can repair become an alternative to reconstruction: a meta-analysis of randomized controlled trials and cohort studies

PURPOSE

To perform a meta-analysis to compare clinical outcomes of anterior cruciate ligament (ACL) repair and ACL reconstruction for acute ACL rupture.

METHOD

We searched Pubmed, Embase, the Cochrane Library, and Web of Science databases to seek relevant studies. Clinical outcomes included failure rate, hardware removal rate, anteroposterior (AP) knee laxity, and patient-reported outcomes. In addition, subgroup analysis was carried out according to repair techniques, rupture locations, and study designs. Funnel plots were used to detect publication bias. All statistical analysis was performed using STATA (version 14.2, StataCorp).

RESULTS

A total of 10 articles were included in this study, comprising 5 randomized controlled trials (RCTs) and 5 cohort studies, involving a total of 549 patients. We found no statistical differences between the ACL repair and ACL reconstruction in the following outcomes: failure rate, AP knee laxity, International Knee Documentation Committee (IKDC) score, Lysholm score, Knee Injury and Osteoarthritis Outcome (KOOS) Score, and Tegner score. However, the ACL repair group had a higher hardware removal rate. Except for AP knee laxity results on different repair techniques, there was no statistical difference in other subgroup analyses.

CONCLUSION

Compared with ACL reconstruction, ACL repair shows similar results in clinical outcomes, and it is promising to be an effective alternative treatment for acute ACL rupture. Larger samples and higher-quality studies are needed to support our results and further explore the advantages of ACL repair in other aspects.

LEVEL OF EVIDENCE

Level III.

Rehabilitation Following ACL Repair with Internal Brace Ligament Augmentation in Female Gymnast: A Resident's Case Report

Introduction

Anterior Cruciate Ligament (ACL) injuries continue to be a major source of morbidity in gymnastics. The gold standard is to perform an ACL Reconstruction (ACLR). However, injuries to the proximal femoral attachment of the ACL have demonstrated an ability to regenerate. An alternative surgical intervention to the ACLR in this ACL tear subgroup is an ACL repair. The purpose of this case report is to provide a rehabilitation progression for a female gymnast after an ACL repair with Internal Brace Ligament Augmentation (IBLA).

Case Description

The subject was a 16-year-old female who presented with a Sherman Type 1 proximal avulsion of her ACL. She underwent an ACL repair with IBLA. Physical therapy interventions followed a sequential and multi-phased approach based on time for tissue physiologic healing and individual progression. Patient reported outcomes including the International Knee Documentation Committee (IKDC), the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) and the Optimal Screening for Prediction of Referral and Outcome Yellow Flag (OSPRO-YF) were assessed in conjunction with isokinetic strength and hop performance testing to determine return to sport readiness.

Outcomes

The subject completed 42 sessions over the course of 26 weeks in addition to a home exercise program. At return to sport, clinically meaningful improvement was observed in patient reported outcomes including the IKDC, ACL-RSI, and OSPRO-YF. Additionally, strength and hop performance surpassed established thresholds of clinical significance. The subject returned to sport at six months post-operatively.

Conclusion

The subject in this case report returned to full participation in gymnastics six months after an ACL repair with internal bracing following a sequential and multi-phased rehabilitation. The primary ACL repair with IBLA appeared beneficial to this patient and could benefit from additional study in other athletes and athletic populations.

Level of Evidence

Level 5.

Relationship between Kinesiophobia and Dynamic Postural Stability after Anterior Cruciate Ligament Reconstruction: A Prospective Cohort Study

INTRODUCTION

 Anterior cruciate ligament (ACL) injuries in young, active patients generally require ACL reconstruction (ACLR) to restore mechanical and postural stability. The fear of movement or reinjury (kinesiophobia) has become increasingly recognized in the post-ACLR population; however, the association between restoration of postural stability and kinesiophobia remains largely unknown. The purpose of this study was to investigate changes in mean Tampa Scale of Kinesiophobia-11 (TSK-11), dynamic motion analysis (DMA) scores, and time on the testing platform, as well as any correlation between TSK-11 and mean overall and individual translational and rotational DMA scores during the first 12 months following ACLR.

DESIGN

 Cohort study.

METHODS

 Patients undergoing ACLR were prospectively enrolled and dynamic postural stability and kinesiophobia based on the TSK-11 were collected within 2 days prior to surgery and at 6 and 12 months following ACLR. Dynamic postural stability was quantified by calculating a DMA score, with score calculated in three translational (anterior/posterior [AP], up/down [UD], medial/lateral [ML]) and three rotational (left/right [LR], flexion/extension, and internal/external rotation) independent planes of motions. Correlations between DMA and TSK-11 scores at each time point were analyzed.

RESULTS

 A total of 25 patients meeting inclusion criteria were analyzed. Mean overall DMA and TSK-11 scores increased with each successive testing interval. At 6-month follow-up, a weakly positive association between TSK-11 and DMA scores was appreciated based on overall DMA, AP, UD, ML, and LR. At 12 months, a moderately positive correlation was appreciated between TSK-11 and the translational, but not rotational, planes of motion.

CONCLUSIONS

 Following ACLR, lower level of kinesiophobia were found to be moderately associated with improved dynamic stability, especially in the translation planes of motion.

Effects of various load magnitudes on ACL: an in vitro study using adolescent porcine stifle joints

INTRODUCTION

The escalating incidence of anterior cruciate ligament (ACL) injuries, particularly among adolescents, is a pressing concern. The study of ACL biomechanics in this demographic presents challenges due to the scarcity of cadaveric specimens. This research endeavors to validate the adolescent porcine stifle joint as a fitting model for ACL studies.

METHODS

We conducted experiments on 30 fresh porcine stifle knee joints. (Breed: Yorkshire, Weight: avg 90 lbs, Age Range: 2-4 months). They were stored at - 22 °C and a subsequent 24-h thaw at room temperature before being prepared for the experiment. These joints were randomly assigned to three groups. The first group served as a control and underwent only the load-to-failure test. The remaining two groups were subjected to 100 cycles, with forces of 300N and 520N, respectively. The load values of 300N and 520N correspond to three and five times the body weight (BW) of our juvenile porcine, respectively.

RESULT

The 520N force demonstrated a higher strain than the 300N, indicating a direct correlation between ACL strain and augmented loads. A significant difference in load-to-failure (p = 0.014) was observed between non-cyclically loaded ACLs and those subjected to 100 cycles at 520N. Three of the ten samples in the 520N group failed before completing 100 cycles. The ruptured ACLs from these tests closely resembled adolescent ACL injuries in detachment patterns. ACL stiffness was also measured post-cyclical loading by applying force and pulling the ACL at a rate of 1 mm per sec. Moreover, ACL stiffness measurements decreased from 152.46 N/mm in the control group to 129.42 N/mm after 100 cycles at 300N and a more significant drop to 86.90 N/mm after 100 cycles at 520N. A one-way analysis of variance (ANOVA) and t-test were chosen for statistical analysis.

CONCLUSIONS

The porcine stifle joint is an appropriate model for understanding ACL biomechanics in the skeletally immature demographic. The results emphasize the ligament's susceptibility to injury under high-impact loads pertinent to sports activities. The study advocates for further research into different loading scenarios and the protective role of muscle co-activation in ACL injury prevention.

Unraveling sex-specific risks of knee osteoarthritis before menopause: Do sex differences start early in life?

OBJECTIVE

Sufficient evidence within the past two decades have shown that osteoarthritis (OA) has a sex-specific component. However, efforts to reveal the biological causes of this disparity have emerged more gradually. In this narrative review, we discuss anatomical differences within the knee, incidence of injuries in youth sports, and metabolic factors that present early in life (childhood and early adulthood) that can contribute to a higher risk of OA in females.

DESIGN

We compiled clinical data from multiple tissues within the knee joint-since OA is a whole joint disorder-aiming to reveal relevant factors behind the sex differences from different perspectives.

RESULTS

The data gathered in this review indicate that sex differences in articular cartilage, meniscus, and anterior cruciate ligament are detected as early as childhood and are not only explained by sex hormones. Aiming to unveil the biological causes of the uneven sex-specific risks for knee OA, we review the current knowledge of sex differences mostly in young, but also including old populations, from the perspective of (i) human anatomy in both healthy and pathological conditions, (ii) physical activity and response to injury, and (iii) metabolic signatures.

CONCLUSIONS

We propose that to close the gap in health disparities, and specifically regarding OA, we should address sex-specific anatomic, biologic, and metabolic factors at early stages in life, as a way to prevent the higher severity and incidence of OA in women later in life.

The incidence of floorball injuries-A systematic review and meta-analysis

OBJECTIVE

Floorball is a swift sport; players perform multiple quick turns during practices and games. The aim of this study was to examine the incidence of floorball injuries. In addition, we aimed to examine the differences in the incidences between sexes and anatomical locations.

METHODS

The PubMed (National Library of Medicine), Web of Science (Clarivate), Scopus (Elsevier), and SPORTDiscus (EBSCO) databases were searched from inception to January 6th, 2023. A study was eligible for analysis if the number of injuries per exposure time was reported. The study protocol was prospectively registered in the PROSPERO database (CRD42023390659).

RESULTS

The total pooled incidence of floorball injuries was 2.28 (confidence interval [CI] 1.27 to 4.10) injuries per 1000 h for all included studies. For females, the pooled incidence was 2.33 (CI 1.22 to 4.46) injuries per 1000 h, and for males, the incidence was 1.98 (CI 1.83 to 2.14) injuries per 1000-h. For adults, the pooled incidence was 3.11 (CI 1.58 to 6.12) injuries per 1000 h and for youths, the incidence was 1.40 (CI 0.50 to 3.94) injuries per 1000 h.

CONCLUSIONS

The incidence of floorball injuries is high, especially among women. When considering the growing popularity of floorball, these pooled incidences serve as reference values for future injury prevention programs.

Anterior Cruciate Ligament Return to Sport after Injury Scale (ACL-RSI) Scores over Time After Anterior Cruciate Ligament Reconstruction: A Systematic Review with Meta-analysis

BACKGROUND

Psychological readiness is an important consideration for athletes and clinicians when making return to sport decisions following anterior cruciate ligament reconstruction (ACLR). To improve our understanding of the extent of deficits in psychological readiness, a systematic review is necessary.

OBJECTIVE

To investigate psychological readiness (measured via the Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI)) over time after ACL tear and understand if time between injury and surgery, age, and sex are associated with ACL-RSI scores.

METHODS

Seven databases were searched from the earliest date available to March 22, 2022. Articles reporting ACL-RSI scores after ACL tear were included. Risk of bias was assessed using the ROBINS-I, RoB-2, and RoBANS tools based on the study design. Evidence certainty was assessed for each analysis. Random-effects meta-analyses pooled ACL-RSI scores, stratified by time post-injury and based on treatment approach (i.e., early ACLR, delayed ACLR, and unclear approach).

RESULTS

A total of 83 studies were included in this review (78% high risk of bias). Evidence certainty was 'weak' or 'limited' for all analyses. Overall, ACL-RSI scores were higher at 3 to 6 months post-ACLR (mean = 61.5 [95% confidence interval (CI) 58.6, 64.4], I2 = 94%) compared to pre-ACLR (mean = 44.4 [95% CI 38.2, 50.7], I2 = 98%), remained relatively stable, until they reached the highest point 2 to 5 years after ACLR (mean = 70.7 [95% CI 63.0, 78.5], I2 = 98%). Meta-regression suggests shorter time from injury to surgery, male sex, and older age were associated with higher ACL-RSI scores only 3 to 6 months post-ACLR (heterogeneity explained R2 = 47.6%), and this reduced 1-2 years after ACLR (heterogeneity explained R2 = 27.0%).

CONCLUSION

Psychological readiness to return to sport appears to improve early after ACL injury, with little subsequent improvement until ≥ 2-years after ACLR. Longer time from injury to surgery, female sex and older age might be negatively related to ACL-RSI scores 12-24 months after ACLR. Due to the weak evidence quality rating and the considerable importance of psychological readiness for long-term outcomes after ACL injury, there is an urgent need for well-designed studies that maximize internal validity and identify additional prognostic factors for psychological readiness at times critical for return to sport decisions.

REGISTRATION

Open Science Framework (OSF), https://osf.io/2tezs/ .

Reported Anterior Cruciate Ligament Injury Incidence in Adolescent Athletes Is Greatest in Female Soccer Players and Athletes Participating in Club Sports: A Systematic Review and Meta-analysis

PURPOSE

To identify the risk of anterior cruciate ligament (ACL) injury in adolescent athletes based on sex, sport, and sport affiliation.

METHODS

A literature search was performed using 3 online databases (PubMed, Cochrane Library, and EMBASE) from database inception to November 2023 per the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included studies consisted of Level I or II studies reporting on ACL injury exposures in time (hours) or injuries per 1,000 athlete-exposures (AEs) (1 game or practice) in adolescent athletes. Exclusion criteria consisted of non-English studies, case reports, animal/cadaveric studies, and review articles. Methodological quality and bias assessment of the included studies was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. ACL injuries were analyzed and pooled to calculate incidence rates (IRs), per-season risk, and relative risk (RR) based on sex, sport, and sport affiliation (club sport participation vs school sport participation).

RESULTS

A total of 1,389 ACL injuries over 19,134,167 AEs were identified (IR, 0.075; 95% confidence interval [CI], 0.071-0.079). Of these, 670 ACL injuries were reported in female athletes over 7,549,892 AEs (IR, 0.089; 95% CI, 0.087-0.091) with 719 in males over 11,584,275 AEs (IR, 0.062; 95% CI, 0.058-0.067). The greatest RR for ACL injury in females was in soccer (RR, 3.12; 95% CI, 2.58-3.77) for AEs. The greatest per-season risk of ACL injuries reported in female athletes occurred in soccer (1.08%), basketball (1.03%), and gymnastics (1.01%). The greatest per-season risk of ACL injuries reported in male athletes occurred in football (0.82%), lacrosse (0.64%), and soccer (0.35%). Club sport participation, in both AEs (RR, 3.94; 95% CI, 3.19-4.87) and hours of exposure (RR, 1.57; 95% CI, 1.07-2.28), demonstrated an increased risk of ACL injury.

CONCLUSIONS

The risk of ACL injuries was 1.56-fold greater in adolescent female athletes compared with male athletes. The highest-risk sport for females was soccer. Participation in club sports possessed higher rates of injury compared with school sports.

LEVEL OF EVIDENCE

Level II; meta-analysis of Level I and II studies.

Most Anterior Cruciate Ligament Injuries in Professional Athletes Occur Without Contact to the Injured Knee: A Systematic Review of Video Analysis Studies

PURPOSE

To systematically review studies using video analyses to evaluate anterior cruciate ligament (ACL) injury mechanisms in athletes during sport to better understand risk factors and the potential for injury prevention.

METHODS

A literature search was conducted in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines statement using SCOPUS, PubMed, Medline, and the Cochrane Central Register for Controlled Trials from database inception through June 2023. Inclusion criteria included studies reporting on ACL injury mechanisms occurring in athletes based on video analysis. Athlete demographics, injury mechanisms, position of the lower extremity, and activity at the time of injury were recorded.

RESULTS

A total of 13 studies, consisting of 542 athletes, met inclusion criteria. Most athletes competed at the professional level (91%, n = 495/542), with 79% (n = 422/536) of athletes being male. The most common sports were soccer (33%, n = 178/542) and American football (26%, n = 140/542). The most common injury mechanism was noncontact in 42.9% (n = 230/536) of athletes, followed by indirect contact (32.6%, n = 175/536) and direct contact (22.4%, n = 120/536). The most common position of injury was with a planted foot (91.7%, n = 110/120), full or near-full knee extension (84.4%, n = 49/58), and axial loading (81.3%, n = 87/107). Injuries commonly involved a deceleration/shift in momentum (50.4%, n = 123/244) or pivoting maneuver (36.1%, n = 77/213). At the time of injury, the knee commonly fell into valgus (76.8%, n = 225/293) with associated internal (53.5%, n = 46/86) or external tibiofemoral rotation (57.7%, n = 101/175).

CONCLUSIONS

Most ACL injuries, when evaluated by video analysis, involve professional athletes participating in soccer and American football. The most common injury mechanism occurred without contact with the knee in extension during a deceleration or momentum shift, with resultant valgus and rotational force across the knee.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Current views on preoperative rehabilitation practice after anterior cruciate ligament injury among licensed physical therapists in Saudi Arabia: An online-based cross-sectional survey

Preoperative rehabilitation is an important stage to both physically and mentally prepare patients for anterior cruciate ligament reconstruction (ACLR) and postoperative rehabilitation. This study aimed to investigate the current preoperative rehabilitation practice after anterior cruciate ligament injury among licensed physical therapists in Saudi Arabia. This was an online-based cross-sectional survey. A total of 114 physical therapists completed the survey. The survey consisted of 16 mandatory questions about management strategies, prescribed exercises, patients' physical and psychological concerns, and discussions about nonoperative management. The majority of the respondents used the following preoperative interventions: education (89.5%), closed kinetic chain exercises (66.7%), stretches (63.2%), open kinetic chain exercises (61.4%), proprioceptive exercises (59.6%), cold (56.1%), and activity modification advice (52.6%). More than half of the respondents would recommend patients awaiting ACLR to complete the exercises 2 to 4 times weekly (56.1%) for up to 8 weeks (80.7%) before ACLR. The respondents (73.7%) reported that patients awaiting ACLR did not receive preoperative rehabilitation due to 2 primary factors: the orthopedic team did not refer patients to rehabilitation specialists, and there was a lack of awareness about preoperative rehabilitation. Most therapists (86%) would discuss conservative management if a patient returned to their preinjury level of function before surgery. The surveyed physical therapists reported using various interventions and preoperative rehabilitation lengths with patients awaiting ACLR. The majority of the therapists indicated that patients awaiting ACLR did not receive preoperative rehabilitation. Future studies are needed to establish a consensus on the optimal preoperative rehabilitation program.

Extrinsic Risk Factors for Primary Noncontact Anterior Cruciate Ligament Injury in Adolescents Aged between 14 and 18 years: A Systematic Review

BACKGROUND

Adolescents present a high incidence of ACL injury compared with other age groups. Examining the risk factors that predispose adolescents to primary noncontact ACL injury is a key strategy to decrease the number of injuries in this population.

OBJECTIVE

The aim of this systematic review was to summarise the existing literature investigating extrinsic risk factors that have been linked with primary noncontact ACL injury risk (identified either using ACL injury occurrence or using screening tests measuring biomechanical mechanisms for noncontact ACL injury) in adolescents including research investigating: (1) the association between extrinsic risk factors and primary noncontact ACL injury risk; and (2) whether primary noncontact ACL injury risk was different in populations or groups exposed to different extrinsic risk factors in adolescents.

METHODS

The same search strategy was used in MEDLINE, SPORTDiscus, CINAHL, PubMed and Embase. Articles were included if: written in English; published in peer-reviewed journals; investigating and discussing primary noncontact ACL injury risk associated with extrinsic risk factors; they were original research articles with an observational design; and participants presented a mean age ranging between 14 and 18 years. The Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies (QATOCCS) was used to assess the quality and risk of bias of the articles included in this systematic review.

RESULTS

The systematic review included 16 eligible articles published up to August 2022 about extrinsic risk factors for primary noncontact ACL injury including: sport (8 studies); sport exposure amount (5); sport level (3); sport season (1); environment (2); equipment (1). Differences in biomechanical risk factors predisposing to ACL injury were reported by sport in female adolescents playing basketball and soccer; however, no good evidence of differences in primary noncontact ACL injury rate by sport was reported in both male and female adolescents. There was contrasting evidence about associations between sport exposure and biomechanical and neuromuscular risk factors predisposing to ACL injury or primary noncontact ACL injury rate in both male and female adolescent players from different sports. There was weak evidence of differences in biomechanical risk factors predisposing to ACL injury by environmental condition in both male and female adolescents playing soccer and season phase in male adolescents playing basketball. Lastly, few good-quality articles suggested that higher sport level might be associated with increased primary noncontact ACL injury rate in female adolescents playing basketball and floorball and that bracing might not prevent primary noncontact ACL injuries in both male and female adolescent players from different sports.

DISCUSSION

The findings emphasise the need for further research to clarify the evidence about extrinsic risk factors and primary noncontact ACL injury in adolescents to develop ACL injury prevention guidelines that would help practitioners and researchers identify adolescents at risk and design future interventions. Future epidemiological studies should collect data about extrinsic factors as well as data about primary noncontact injury separately from secondary injuries or contact injuries to better inform primary noncontact ACL injury prevention in adolescents.

REGISTRATION

https://doi.org/10.17605/OSF.IO/VM82F (11/08/2021).

Injury Prevention Programmes Fail to Change Most Lower Limb Kinematics and Kinetics in Female Team Field and Court Sports: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

BACKGROUND

One mechanism by which exercise interventions may be effective in reducing anterior cruciate ligament (ACL) injury risk is through changes in lower limb biomechanics. Understanding how training programmes affect lower-limb kinematics and kinetics may help refine injury prevention programmes.

OBJECTIVE

The aim of this systematic review and meta-analysis was to assess the effect of injury prevention programmes on kinematics and kinetics during tasks related to ACL injury in female team field and court sports.

DATA SOURCES

Five databases were searched in October 2022.

ELIGIBILITY CRITERIA

Randomised controlled trials assessing the effect of injury prevention programmes compared with usual training/no training on lower limb kinematics and kinetics in female team field and court sports were eligible for review.

RESULTS

Sixteen studies were included. A total of 976 female athletes were included. Most of the studies included interventions with multiple components (12/16). Commonly used components were plyometrics (12/16), strength (8/16), and balance/stability (7/16). Thirteen studies had routine training or sham interventions as the control group and three studies had no training. Very low certainty evidence suggests that injury prevention programmes increase knee flexion angles (mean difference = 3.1° [95% confidence interval 0.8-5.5]); however, very low to low certainty evidence suggests no effect on hip flexion angles/moments, knee flexion moments, hip adduction angles/moments, knee adduction angles/moments, hip internal rotation angles/moments, ankle dorsiflexion angles, and ground reaction forces, compared with usual training/no training.

CONCLUSION

Injury prevention programmes may be effective in increasing knee flexion angles during dynamic landing and cutting tasks but may have no effect on other lower limb biomechanical variables. As such, the benefits of injury prevention programmes may be mediated by factors other than altered biomechanics and/or may happen through other biomechanical measures not included in this review.

Comparison of Graft Type and Fixation Method in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis Based on Randomized Control Studies

BACKGROUND

The anterior cruciate ligament (ACL) is the most commonly injured ligament in the knee. ACL reconstruction (ACLR) proves the standard for treating this injury. However, graft choice and method of fixation remain a heavily debated topic. This study investigates the following: bone-patellar tendon-bone (BPTB) vs. hamstring tendon (HT) autograft, single-bundle vs. double-bundle hamstring graft, and metal vs. bioabsorbable screws in ACLR.

METHODS

A systematic review was performed on PubMed and Google Scholar according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data were collected on patient demographics, complications, and functionality scores including International Knee Documentation Committee (IKDC) and Lysholm scores. A systematic review and meta-analysis were conducted with Review Manager. Outcome measurements were determined using forest plots with significant differences considered p < 0.05.

RESULTS

Twenty-five studies were included, accounting for 2,170 patients. No statistically significant difference was appreciated when comparing BPTB to hamstring autografts. Patients who received a double bundle HT autograft exhibited significantly superior outcomes in terms of revision (p = 0.05), failure (p = 0.002), normal pivot shift tests (p = 0.04), and normal IKDC (p = 0.008). When comparing screw types, bioabsorbable screws had a greater Lysholm score (p = 0.01) and lower failure rates for copolymer screws (p = 0.03).

CONCLUSION

Overall, the data collected suggested that BPTB and HT autografts display similar postoperative results. However, if an HT autograft is used, the data suggest a double-bundle graft improves both functionality and decreases the possible complications. Finally, bioabsorbable screws prove superior to metal screws when looking at both functionality and failure rates. Further research into the superior graft type is still needed.

LEVEL OF EVIDENCE

Level II. See Instructions for Authors for a complete description of levels of evidence.

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.

The relationship between lateral femoral condyle ratio measured by MRI and anterior cruciate ligament injury

Background

Previous studies have shown that the lateral femoral condyle ratio (LFCR) measured by X-ray has a significant relationship with the anterior cruciate ligament (ACL) injury. However, few relevant studies have been performed on LFCR measured by magnetic resonance imaging (MRI).

Purpose

(1) To evaluate the relationship between LFCR measured by MRI and ACL injury or rerupture. (2) To compare the LFCR measured by MRI with existing bony morphological risk factors and screen out the most predictive risk factors for primary ACL injury or rerupture.

Study Design

Cohort study; Level of evidence, 3.

Methods

Totally 147 patients who underwent knee arthroscopic surgery from 2015 to 2019 with minimum follow-up of 48 months were retrospectively evaluated. Patients were placed into three groups: 1) the control group of patients with simple meniscus tears without ligament injury; 2) the primary noncontact ACL injury group; 3) ACL rerupture group (ACL reconstruction failure). The LFCR measured by MRI and other previous known risk factors associated with MRI (notch width index, medial tibial slope, lateral tibial slope, medial tibial depth, lateral tibial height) were performed to evaluate their predictive value for ACL injury and rerupture. All the risk factors with p < 0.01 according to univariate analysis were included in the logistic regression models. Receiver operating characteristic (ROC) curves were analyzed for sensitivity, specificity, cut-off, and area under the curve (AUC). Z tests were used to compare the AUC values.

Results

The LFCR measured by MRI was obviously higher in primary ACL injury group (0.628 ± 0.020) and in ACL rerupture group (0.625 ± 0.021) than that in the control group (0.593 ± 0.030). The best risk factor was the LFCR with a cut-off of 0.602 (AUC, 0.818; 95% CI, 0.748-0.878; sensitivity, 90%; specificity, 66%). When combined with lateral tibial slope (cutoff, 7°) and lateral tibial height (cutoff, 3.6 mm), the diagnostic performance was improved significantly (AUC, 0.896; 95% CI, 0.890-0.950; sensitivity, 87%; specificity, 80%).

Conclusion

The increased LFCR measured by MRI was associated with a significantly higher risk for ACL injury or rerupture. The combination of LFCR, lateral tibial slope and lateral tibial height were the most predictive risk factors. This may help clinicians identify susceptible individuals and allow precision approaches for better prevention, treatment and management of this disease.

Injury prevention for women and girls playing Australian Football: programme cocreation, dissemination and early adopter coach feedback

Background

Adherence to injury prevention programmes may improve with greater end-user involvement and application of implementation frameworks during development. We describe the cocreation, initial dissemination and feedback from programme early adopters (coaches), to develop the first evidence-informed injury prevention programme for women playing community Australian Football (Prep-to-Play).

Methods

We used a pragmatic seven-step process for developing sports injury prevention programmes to (1) gain organisational support, (2) compile research evidence, (3) consult experts, (4) engage end-users, (5) test programme acceptability, (6) evaluate against theory and (7) gain early adopter feedback. All Australian Football-registered coaches of women's/girls' teams were sent a postseason survey to determine initial awareness, adoption and implementation (steps 5 and 6). Purposively selected coaches were invited to interviews/focus groups (step 7) to identify competency, organisational and leadership implementation drivers with a deductive thematic analysis applied.

Results

Prep-to-Play was cocreated using previous efficacious programmes and expert input (steps 1-4), and disseminated via the national sporting organisation in preseason 2019 to all registered coaches (step 5). 343 coaches (90 women) completed the postseason survey and 22 coaches (5 women) participated in an interview (n=9) or focus group (n=13) (steps 6 and 7). 268 coaches (78%) were aware of Prep-to-Play. Of those aware, 218 (81%) had used (at least one element) Prep-to-Play, and 143 (53%) used it at least twice per week. Competency drivers included local expert-delivered face-to-face workshops complimented by online content and ongoing support. Organisational drivers included coach education integrated into existing league/club. Leadership drivers included compulsory injury prevention education integrated into coach reaccreditation processes or incentivisation via recognition (eg, professional development points).

Conclusions

Cocreation and organisational support resulted in high programme awareness and adoption. However, high fidelity implementation and maintenance may need to be facilitated by competency, organisational and leadership drivers. Responsibility should be shared among all stakeholders.

Influence of hamstring stiffness on anterior tibial translation after anterior cruciate ligament rupture

BACKGROUND

There is a correlation between the hamstring stiffness and the decrease of anterior tibial translation in athletic patients with healthy knees. This observation could question the clinical reliability of the Lachman-Trillat test to detect complete ACL ruptures in patients with an important hamstring stiffness. This study aims to determine if anterior tibial translation is correlated with hamstring stiffness in patients with complete ACL rupture.

METHODS

This is a prospective study including patients with unilateral complete ACL rupture confirmed by MRI. The arthrometer GNRB® was used to measure anterior tibial translation on both knees at 134 N and compute the side-to-side difference. The hamstring stiffness was assessed with the eccentric peak torque using the isokinetic dynamometer CON-TREX. Linear regressions were done between these two parameters on two study groups: one included all patients (GR1), and the other included only isolated ACL injuries without associated lesions (GR2).

RESULTS

Fifty-two patients were included (29 men, 23 women) with an average of 34.9 years old. The mean eccentric peak torque of the hamstrings for pathological knees was 94.9Nm for GR1 and 91.7Nm for GR2. The mean side-to-side difference was 2.42 mm for GR1 and 1.99 mm for GR2. No significant correlations were identified for GR1 (p = 0.66) and GR2 (p = 0.105).

CONCLUSION

No significant linear correlation was found between side-to-side difference measured by GNRB® and hamstring stiffness for pathological knees with complete ACL rupture. These results lead to believe that the Lachman-Trillat clinical test is not influenced by hamstring stiffness.

LEVEL OF EVIDENCE

Prospective study, level of evidence IV.

Higher Eccentric Hamstring Muscle Fatigue After Participation in a Soccer Match in Young Female Athletes

BACKGROUND

Hamstring (HS) strength deficits and imbalances have been identified as risk factors for sustaining anterior cruciate ligament (ACL) injuries and muscular strains, with HS injuries being the most prevalent muscle injuries in soccer athletes. The aim of this study was to investigate HS eccentric strength before and after a soccer match in both male and female soccer athletes.

HYPOTHESIS

Soccer athletes have changes in eccentric HS strength after a soccer game.

STUDY DESIGN

Cohort observational study.

LEVEL OF EVIDENCE

Level 3.

METHODS

HS eccentric strength (mean and absolute peak torque and total work) was measured in 64 healthy male and female competitive football athletes (14-25 years) with an automatic device during the execution of the Nordic hamstring exercise (NHE) test before and after a 90-minute soccer match. The anterior-knee laxity (AKL) was quantified with an arthrometer.

RESULTS

Mean and absolute eccentric HS peak torque decreased by 24.5 N.m (-12.34%; P < 0.01) and 21.9 N.m (-10.08%; P < 0.01) in female athletes, whereas their male peers improved by 19.9 N.m (+9.01%; P = 0.01) and by 20.9 N.m (+8.51%; P = 0.02), respectively. HS total work in female athletes decreased by 831.1 J (P < 0.01) compared with the male athlete reduction of 235.3 J. Both the pre- versus postmatch intersex mean and absolute eccentric HS peak torque changes were significant (P < 0.01), as were the changes in HS total work (P < 0.01). The pre- versus postmatch AKL difference and the dominant versus nondominant limb comparison of the strength parameters were not significantly different. Younger female athletes (14-19 years old) presented a greater decrease in mean and absolute peak HS eccentric strength compared with those in older female athletes and men.

CONCLUSION

HS eccentric strength and work differ based on athlete sex, as measured by the NHE test. Mean peak, absolute peak, and total work showed greater reductions in female athletes than those in their male peers. The subgroup of 14- to 19-year-old female athletes experienced the highest reduction in strength parameters.

Independent data collectors decrease bias in the measurement of adherence to anterior cruciate ligament injury prevention programs

OBJECTIVES

Studies on adherence to neuromuscular training (NMT) for anterior cruciate ligament (ACL) injury prevention are frequently biased due to the use of self-reporting by coaches or the athletes themselves. Few NMT studies use data collectors (aside from the athletes or the individuals administering the NMT program) to decrease bias when assessing the adherence of coaches and sports teams. We hypothesized that the use of a data collector who is independent of the team to evaluate adherence to NMT programs would be reliable.

METHODS

In a prior a cluster-randomized controlled trial evaluating adherence to NMT training trial, twelve boys' and nine girls' high school athletic teams in a variety of sports were enrolled. Eight data collectors (unaffiliated with the NMT program) were hired specifically to record adherence of the athletes to the NMT exercises at each team's warm-ups 2-3 times a week, prior to practices and games. In addition to the data collectors, a control group of independent observers made visits throughout the season to also record adherence (solely for the purpose of this study, alongside the data collectors and in the same fashion) in order to evaluate the data collectors' performance and determine inter-observer reliability. The inter-observer reliability between data collectors and independent observers was measured using the Kappa statistic.

RESULTS

A total of 399 warm-ups for practices or games were observed by data collectors to obtain adherence data. Independent observers also measured adherence at 58 practices or games for inter-observer reliability. Exercise instruction and alignment cues for 29 different exercises were analysed. The Kappa values ranged from 0.63 to 1.0, indicating substantial to perfect agreement. The overall Kappa values of 0.89 and 0.90 for exercise instruction and alignment cues, respectively, indicated almost perfect agreement.

CONCLUSION

The use of a data collector who is independent of the team to evaluate adherence to NMT programs (rather than athlete or coach self-reporting), was shown to be a reliable method for measurement of adherence in studies of NMT for injury prevention. Avoiding self-reporting in adherence research to NMT training may decrease bias.

LEVEL OF EVIDENCE

I.

Falling decreased anterior cruciate ligament loading variables during single-leg landings after mid-flight external trunk perturbation

Mid-flight external upper-trunk perturbation is associated with increased anterior cruciate ligament (ACL) injury risk during landing. This study aimed to assess the effect of natural, soft, and falling landing techniques on knee mechanics and vertical ground reaction forces (VGRF) during single-leg landings with/without mid-flight medial-lateral external upper-trunk pushing perturbation. Twenty-eight participants performed single-leg landings using the three landing techniques with/without mid-flight pushing perturbation. The perturbation was created by a customized apparatus releasing a slam ball and pushing the participants near the peak jump height at the upper trunk. Perturbation resulted in significantly greater lateral trunk bending angles, knee flexion angles at initial contact, peak knee abduction angles, and peak knee adduction moments compared to no perturbation. The falling condition significantly demonstrated the greatest lateral trunk bending angles, knee flexion angles, and peak knee external rotation moments and the smallest peak knee abduction angles, peak VGRF, and peak knee extension moments compared to natural/soft landings regardless of perturbation conditions. Mid-flight external perturbation resulted in variables associated with greater ACL loading during single-leg landings. Falling demonstrated variables associated with smaller ACL loading, particularly for perturbation conditions. Incorporating falling techniques into jump-landing training programs may guide players to safely fall on the ground when perturbation occurs. Falling provides an alternative strategy to potentially decrease indirect contact ACL injury risk when the sports environment allows.

Effectiveness of warm-up and dynamic balance training in preventing anterior cruciate ligament injuries in college gymnasts: a 3-year prospective study for one team

BACKGROUND

The effect of trunk stability and dynamic balance warm-up exercises on physical functional improvement remains unelucidated. This study examined whether exercises could prevent anterior cruciate ligament (ACL) injury and improve trunk muscle activation and dynamic balance in gymnasts.

METHODS

This comparison study, involving gymnastics practice sessions, included 31 university gymnasts and was conducted in two periods: 1 year of observation followed by 2 years of intervention. Participants performed a trunk and dynamic balance warm-up exercise program during the intervention. The effect of exercise on the incidence of ACL injury was evaluated. In addition, the paired t-test was used to compare the Y-balance distance and the changes in muscle thickness associated with trunk muscle activation at rest and during plank.

RESULTS

ACL injury risk during the intervention was significantly lower, with a relative risk of 0.23 (P=0.02, 95% CI: 0.06-0.88). Changes in muscle thickness with activation of the transversus abdominis (P<0.01, mean difference 4.1, 95% CI: 9.97-28.07, Cohen's d=0.52), internal oblique (P<0.01, mean difference 5.2, 95% CI: 9.72-21.55, Cohen's d=0.65), and external oblique (P<0.01, mean difference 5.5, 95% CI: 20.44-39.09, Cohen's d=0.71) muscles were significantly higher during the intervention. The Y-balance distance was also significantly greater in the posterior medial reach (P<0.01, mean difference 3.3, 95% CI: 1.56-6.26, Cohen's d=0.46) during the intervention.

CONCLUSIONS

Exercise-based warm-up programs may decrease ACL injuries. It can improve physical functions, such as the rate of change in trunk muscle thickness and the posterior medial distance during Y balance.

Suture Augmentation of a Four-Strand Semitendinosus Graft Improves Time-Zero Biomechanical Properties

PURPOSE

To compare the time-zero biomechanical properties of hamstring graft preparations with or without suture augmentation for anterior cruciate ligament reconstruction (ACLR) in a full-construct cadaveric model.

METHODS

Hamstring grafts were harvested from 24 fresh frozen human cadavers and prepared in 1 of 3 ways: quadrupled SemiTendinosus (SemiT), and quadrupled SemiT with suture augmentation (SemiT+2.0-mm tape or SemiT+1.3-mm tape; n = 8 per group). Adjustable loop suspensory implants and cortical buttons were used for fixation on a porcine tibia and acrylic block. Testing included force-controlled cyclic loading at 250 N and 400 N followed by load to failure.

RESULTS

The 2 suture augmentation groups had less total elongation and increased stiffness compared to the nonsuture-augmented group (P = .025). The SemiT+2.0-mm tape group had 36% less total elongation and 34% increased stiffness compared to SemiT+1.3mm tape (P < .001).

CONCLUSIONS

Suture augmentation improves construct biomechanics at time zero following hamstring tendon ACLR. Augmentation with 2.0-mm tape suture improves construct biomechanics compared to 1.3-mm tape suture.

CLINICAL RELEVANCE

Independent suture augmentation of a quadrupled SemiT graft improves ACLR construct biomechanics. Outcomes were improved with augmentation using 2.0-mm tape suture compared to 1.3-mm tape suture.

Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) subcategories are affected by subjective running ability and medial single-leg hop distance in postreconstruction patients at 6 months

Purpose

This study aimed to investigate the intricate relationship between physical function factors and each subcategory score of the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale among patients following ACL reconstruction.

Methods

Participants comprised 59 patients who had undergone primary ACL reconstruction using hamstring tendon. The ACL-RSI was completed 6 months after reconstruction and five physical functions were measured in patients on the same day. Simple linear regression was performed multiple times to investigate the relationship between ACL-RSI subcategory scores as a dependent variable and each independent variable (knee strength, leg anterior reach distance, single-leg hop [SLH] distances, side bridge endurance, and subjective running ability). Multiple regression analysis was performed using a stepwise method, with factors showing a risk rate <0.05 in simple linear regression analyses as independent variables and the ACL-RSI in each subcategory score as the dependent variable.

Results

Multiple regression analysis showed that subjective running ability affected all subcategories (p ≤ 0.001), and that the limb symmetry index of medial SLH distance affected both the Emotions (p = 0.047) and Confidence (p = 0.009) subcategories. Higher subjective running ability and greater limb symmetry in the medial SLH were thus positively associated with each dimension of psychological readiness.

Conclusions

This study highlights the differential impact of physical function factors on specific subcategories of the ACL-RSI scale, providing clinicians with insights for designing targeted rehabilitation strategies. This original paper suggests the importance of analysing factors related to subcategory scores in addition to total ACL-RSI score, and could contribute to the understanding of determinants for a successful return to sport following ACL reconstruction.

Level of Evidence

Level IV.

[Treatment of acute injury of the anterior cruciate ligament : Always only reconstruction?]

The aim of treatment of a ruptured anterior cruciate ligament (ACL) is the return of the patient to an acceptable level of activity without giving way phenomena as well as adequate treatment of prognostically relevant concomitant lesions. The treatment of acute ACL ruptures can be either early reconstruction or a primary physiotherapy with optional later reconstruction. Which path is taken depends on possible concomitant injuries that require early surgical intervention (e.g., repairable meniscal injury or distal rupture of the medial collateral ligament) and on patient-specific factors (age, level of activity). Isolated ruptures of the ACL can also be primarily treated without surgery. Then the injured knee joint should first be so far conditioned by rehabilitative measures that pain, swelling and posttraumatic restriction of movement are improved and neuromuscular training can be started. A screening test consisting of jumping tests, patient-reported outcome measures and the testing for giving way phenomena can be suitable to differentiate compensators (copers) from noncompensators (non-copers). Surgical reconstruction of the ACL should be recommended to non-compensators in the sense of participatory decision-making. Activity modification (adapter) can also be considered as a treatment strategy. If instability events (giving way) or secondary meniscal lesions occur during nonsurgical therapy, cruciate ligament reconstruction should be considered.

Incidence of injury and illness among paediatric Team USA athletes competing in the 2020 Tokyo and 2022 Beijing Olympic and Paralympic Games

Objective

To describe the incidence of injuries and illnesses among paediatric Team USA athletes competing in the Tokyo 2020 Olympic and Paralympic Games, and the 2022 Beijing Olympic and Paralympic Games.

Methods

An electronic medical record system documented all injuries and illnesses that occurred while competing in the four Games periods. Incidence (IR) with 95% CI per 1000 athlete days were calculated for both injuries and illnesses. Incidence rate ratios (IRR) were calculated to compare injury and illness rates based on age (paediatric vs non-paediatric) sex, Games period and sport type.

Results

Two hundred paediatric athletes (age range, 15-21 years) competed across the four Games periods, representing 16.1% of all Team USA athletes. The overall injury IR (95% CI) was 13.4 (9.8 to 18.1), and the overall illness IR was 5.5 (3.3 to 8.7). There were no differences in incidence between paediatric and non-paediatric athletes for either injury (IRR (95% CI): 0.9 (0.6 to 1.2)) or illness (IRR (95% CI): 0.9 (0.5 to 1.5)). Female paediatric athletes were more likely to sustain an injury compared with male paediatric athletes (IRR (95% CI): 2.4 (1.1 to 5.3)). The most common mechanism of injury was gradual onset (IR, 4.3 (2.3 to 7.2)), and injuries most commonly occurred during practices (IR, 7.0 (4.5 to 10.5)).

Conclusion

Paediatric athletes account for a substantial proportion of Team USA athletes. It is essential that paediatric sports medicine experts are included in the medical team given that paediatric Team USA athletes are just as likely as their adult teammates to sustain an injury or illness.

Isometric and isokinetic strength of lower-limb muscles in female athletes during different phases of menstrual cycle: a causal-comparative study

BACKGROUND

Muscle strength is affected by different stages of the menstrual cycle in women. Since the strength of the lower limb muscles plays a significant role in the occurrence of anterior cruciate ligament injury, it seems necessary to study the strength of the lower limb muscles at different stages of this cycle to take preventive measures. Therefore, this study aimed to compare the isometric and isokinetic strength of lower limb muscles in female athletes at different menstrual cycle stages.

METHODS

The present study is of a causal-comparative type. Thirty-seven female athletes in anterior cruciate ligament injury high-risk disciplines participated in this study. Isometric and isokinetic knee extensors and flexors muscle strength status, including the traditional hamstrings/quadriceps (H/Q) ratios, were recorded at different stages of the menstrual cycle (follicular, ovulatory, luteal) by Biodex isokinetic dynamometry system 4. Then, the obtained results were analyzed by repeated measure analysis of variance.

RESULTS

Analysis of variance with repeated measures showed isokinetic and isometric strength in the knee flexor and extensor muscles at an angular velocity of 60˚/s in the ovulatory phase are higher than the follicular and luteal ones. The strength of the muscles declined during the follicular and luteal phases (p ≤ 0.05).

CONCLUSIONS

Due to the negative effect of the follicular and luteal stages of the menstrual cycle on the strength of the flexor and extensor muscles of the knee, the risk of anterior cruciate ligament injury may increase during this period. Therefore, it is recommended that all female coaches and athletes take preventive measures during this period.

Age and Gender-Dependence of Single-and Bi-Exponential T1ρ MR Parameters in Knee Ligaments

BACKGROUND

There is limited understanding of differences in the composition and structure of ligaments between healthy males and females, and individuals of different ages. Females present higher risk for ligament injuries than males and there are conflicting reports on its cause. This study looks into T1ρ parameters for an explanation as it relates to proteoglycan, collagen, and water content in these tissues.

PURPOSE

To investigate gender-related and age-related differences in T1ρ parameters in knee joint ligaments in healthy volunteers using a T1ρ -prepared zero echo-time (ZTE)-based pointwise-encoding time-reduction with radial acquisition (T1ρ -PETRA) sequence.

STUDY TYPE

Prospective.

POPULATION

The study group consisted of 22 healthy subjects (11 females, ages: 41 ± 18 years, and 11 males, ages: 41 ± 14 years) with no known inflammation, trauma, or pain in the knee joint.

FIELD STRENGTH/SEQUENCE

A T1ρ -prepared 3D-PETRA sequence was used to acquire fat-suppressed images with varying spin-lock lengths (TSLs) of the knee joint at 3T.

ASSESSMENT

Monoexponential, biexponential, and stretched-exponential 3D-PETRA-T1ρ parameters were measured in the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and patellar tendon (PT) by manually drawing ROIs over the entirety of the tissues.

STATISTICAL TESTS

Mann-Whitney U-tests were used to compare 3D-PETRA-T1ρ parameters in the ACL, PCL, and PT between males and females. Spearman correlation coefficients were used to determine the association between age and T1ρ parameters. Statistical significance was defined as P < 0.05.

RESULTS

Significant correlations with age were found the three ligaments with most of the measured T1ρ parameters (rs  = 0.28-0.74) with the exception of the short fraction in the PCL (P = 0.18), and the short relaxation time in the ACL (P = 0.58) and in the PCL (P = 0.14).

DATA CONCLUSION

3D-PETRA-T1ρ can detect age-related differences in monoexponential, biexponential, and stretched-exponential T1ρ parameters in three ligaments of healthy volunteers, which are thought to be related to changes in tissue composition and structure during the aging process.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 1.

The Role of Strength-Related Factors on Psychological Readiness for Return to Sport Following Anterior Cruciate Ligament (ACL) Reconstruction

Psychological readiness following anterior cruciate ligament reconstruction (ACLR) correlates with different return to sport outcomes. However, the relationship between strength and power and psychological readiness remains unexplored. The aim of this study was to investigate the relationship between anterior cruciate ligament return to sport after injury (ACL-RSI) scores and various hamstrings and quadriceps strength and power variables. Twelve participants (20.7 ± 2.5 years old; 174.2 ± 7.5 cm; 70.2 ± 8.5 kg; 18.2 ± 8.3% of body fat) who had an ACLR nine months or more before the study completed the ACL-RSI questionnaire and isokinetic strength testing of the hamstrings and quadriceps (60°·s-1 and 180°·s-1). Based on ACL-RSI scores, they were divided into "cases" and "controls", deemed not psychologically ready and psychologically ready to return to previous sport performance (PILOS), respectively. The main findings are that quadriceps' and hamstrings' rate of torque development (RTD) and time since surgery were determinants of psychological readiness following ACLR. Furthermore, compared to controls, cases showed significantly lower quadriceps torque at angles close to full knee extension (40 deg and 30 deg from extension). They also showed lower RTD than controls, but no difference in peak torque. These results suggest that physiotherapists should facilitate athletes' return to sport (RTS) by focusing on the restoration of RTD and strength at angles close to full knee extension.

Automated diagnosis of anterior cruciate ligament via a weighted multi-view network

Objective: To build a three-dimensional (3D) deep learning-based computer-aided diagnosis (CAD) system and investigate its applicability for automatic detection of anterior cruciate ligament (ACL) of the knee joint in magnetic resonance imaging (MRI). Methods: In this study, we develop a 3D weighted multi-view convolutional neural network by fusing different views of MRI to detect ACL. The network is evaluated on two MRI datasets, the in-house MRI-ACL dataset and the publicly available MRNet-v1.0 dataset. In the MRI-ACL dataset, the retrospective study collects 100 cases, and four views per patient are included. There are 50 ACL patients and 50 normal patients, respectively. The MRNet-v1.0 dataset contains 1,250 cases with three views, of which 208 are ACL patients, and the rest are normal or other abnormal patients. Results: The area under the receiver operating characteristic curve (AUC) of the ACL diagnosis system is 97.00% and 92.86% at the optimal threshold for the MRI-ACL dataset and the MRNet-v1.0 dataset, respectively, indicating a high overall diagnostic accuracy. In comparison, the best AUC of the single-view diagnosis methods are 96.00% (MRI-ACL dataset) and 91.78% (MRNet-v1.0 dataset), and our method improves by about 1.00% and 1.08%. Furthermore, our method also improves by about 1.00% (MRI-ACL dataset) and 0.28% (MRNet-v1.0 dataset) compared with the multi-view network (i.e., MRNet). Conclusion: The presented 3D weighted multi-view network achieves superior AUC in diagnosing ACL, not only in the in-house MRI-ACL dataset but also in the publicly available MRNet-v1.0 dataset, which demonstrates its clinical applicability for the automatic detection of ACL.

High prevalence of associated intra-articular injuries with increasing time period from anterior cruciate ligament injury to reconstruction, even in apparent copers

BACKGROUND

It still unclear whether copers may bear the same time-sensitive risk of intra-articular injury as non-copers. The objectives were to investigate the clinical characteristics of copers and non-copers that have sustained an anterior cruciate ligament (ACL) injury, and to examine and compare the intra-articular pathologies in delayed ACL reconstruction (ACLR) in copers and noncopers.

METHODS

Patients who sustained ACL injury while participating in high-performance sports and opted for non-operative treatment were enrolled in this study. Depending on the occurrence of the knee giving way, patients were classified into copers and noncopers. Clinical characteristics were compared between the two groups. Additionally, intra-articular injuries were evaluated for those who eventually underwent delayed ACLR.

RESULTS

11 of the 75 patients (14.7%) were classified as copers. No major differences were found in the clinical characteristics between groups. Following the initial non-operative treatment, 67 patients underwent delayed ACLR. When examining intra-articular abrasions at the time of surgery, non-copers who continued sports activities for 3 to 12 months exhibited a significantly higher rate of injury as opposed to their coper counterparts. However, the difference in the prevalence of intra-articular lesions between the two groups in patients who continued to play sports for at least 12 months before surgery was nominal.

CONCLUSION

The rate of copers was relatively low in patients who resumed playing high-level sports after ACL injury. Additionally, even in copers, those who continued sports activities for more than 12 months had comparably high prevalence of intra-articular injuries with noncopers.

STUDY DESIGN

Retrospective case-control study; Level of evidence, 3.

Favorable Patient-Reported, Clinical, and Functional Outcomes 2 Years After ACL Repair and InternalBrace Augmentation Compared With ACL Reconstruction and Healthy Controls

BACKGROUND

Recently, interest in anterior cruciate ligament (ACL) preservation and repair after proximal ACL tears has been resurrected. Although good clinical outcomes have been reported in the literature with adequate patient selection, to date detailed scientific evidence for the functional benefit of primary ACL repair with ligament augmentation is scarce.

PURPOSE

To compare patient-reported, clinical, and functional outcomes in patients 2 years after ACL repair and InternalBrace augmentation (ACL-IB) with age- and sex-matched patients 2 years after ACL reconstruction (ACL-R) and with matched healthy controls.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

In total, 29 patients 2 years after ACL-IB, 27 sex- and age- matched patients 2 years after ACL-R (hamstring autografts), and 29 matched healthy controls were included. Patient-reported outcomes were assessed using the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, EQ-5D-5L, Tegner Activity Scale, and Anterior Cruciate Ligament Return to Sports after Injury scale. Surgery time was recorded. For clinical outcomes, range of motion and thigh and shank circumference were measured, and passive anterior translation was determined using the Rolimeter. Isokinetic muscle strength was measured using a Biodex dynamometer. The limb symmetry index (operated/contralateral or nondominant/dominant × 100), side-to-side differences (operated - contralateral, nondominant - dominant), and hamstring-quadriceps ratios were calculated for functional parameters. Failure and reoperation rates were not compared.

RESULTS

Two years after surgery, patients treated with ACL-IB showed good to excellent patient-reported outcomes comparable with those of patients after ACL-R. Surgery time, including concomitant surgeries, was significantly shorter in the ACL-IB group (mean, 81 minutes) compared with the ACL-R group (mean, 97 minutes) (P = .024). Isokinetic muscle strength was comparable between patient groups without significant differences in extensor and flexor strength or in hamstring-quadriceps ratios.

CONCLUSION

These results suggest that ACL-IB achieves comparable patient-reported, clinical, and functional outcomes with ACL-R at 2 years postoperatively and, after careful patient selection, should be considered as a valuable early treatment alternative for proximal ACL tears.

REGISTRATION

NCT04429165 (ClinicalTrials.gov identifier).

A Novel Sensor-Based Application for Home-Based Rehabilitation Can Objectively Measure Postoperative Outcomes following Anterior Cruciate Ligament Reconstruction

In order to successfully implement individualized patient rehabilitation and home-based rehabilitation programs, the rehabilitation process should be objectifiable, monitorable and comprehensible. For this purpose, objective measurements are required in addition to subjective measurement tools. Thus, the aim of this prospective, single-center clinical trial is the clinical validation of an objective, digital medical device (DMD) during the rehabilitation after anterior cruciate ligament reconstruction (ACLR) with regards to an internationally accepted measurement tool. Sixty-seven patients planned for primary ACLR (70:30% male-female, aged 25 years [21-32], IKDC-SKF 47 [31-60], Tegner Activity Scale 6 [4-7], Lysholm Score 57 [42-72]) were included and received physical therapy and the DMD after surgery. For clinical validation, combined measures of range of motion (ROM), coordination, strength and agility were assessed using the DMD in addition to patient-reported outcome measures (PROMs) at three and six months after ACLR. Significant correlations were detected for ROM (rs = 0.36-0.46, p < 0.025) and strength/agility via the single-leg vertical jump (rs = 0.43, p = 0.011) and side hop test (rs = 0.37, p = 0.042), as well as for coordination via the Y-Balance test (rs = 0.58, p ≤ 0.0001) regarding the IKDC-SKF at three months. Additionally, DMD test results for coordination, strength and agility (Y-Balance test (rs = 0.50, p = 0.008), side hop test (rs = 0.54, p = 0.004) and single-leg vertical jump (rs = 0.44, p = 0.018)) correlate significantly with the IKDC-SKF at six months. No adverse events related to the use of the sensor-based application were reported. These findings confirm the clinical validity of a DMD to objectively quantify knee joint function for the first time. This will have further implications for clinical and therapeutic decision making, quality control and monitoring of rehabilitation measures as well as scientific research.

The effects of sex hormones during the menstrual cycle on knee kinematics

The effects of the menstrual cycle and sex hormones on knee kinematics remain unclear. The purpose of the study was to investigate the effects of the menstrual cycle and serum sex hormone concentrations on knee kinematic parameters of the 90°cutting in female college soccer athletes. Three female college soccer teams (53 subjects) participated in the study. During the first menstrual cycle, a three-step method was used to exclude subjects with anovulatory and luteal phase-deficient (LPD) (12 subjects). The subjects' menstrual cycle was divided into the menstrual phase, late-follicular phase, ovulatory phase, and mid-luteal phase (group 1, 2, 3, 4). In each phase of the second menstrual cycle, we used a portable motion analysis system to enter the teams and tested the sex hormones concentrations and knee kinematics parameters in three universities in turn. We found that subjects had a lower maximum knee valgus in group 4 compared with other groups. This meant that subjects had a lower biomechanical risk of non-contact anterior cruciate ligament (ACL) injury in the mid-luteal phase. There was no significant correlation between serum estrogen, progesterone concentration, and knee kinematic parameters. This meant that sex hormones did not have a protective effect. Future studies need to incorporate more factors (such as neuromuscular control, etc.) to investigate.

Knee lesions with anterior cruciate ligament (ACL) tear in Iraqi adult males: arthroscopic findings

This cross-sectional study aimed at exploring the frequency and extent of knee joint lesions associated with delayed treatment of anterior cruciate ligament (ACL) injury. It enrolled 300 patients from 2020 to 2022 who were subjected to arthroscopy for anterior cruciate ligament reconstruction. The sample was comprised of Iraqi adult male patients from different regions of Iraq, and the surgical procedure was carried out in Al-Diwaniyah Teaching Hospital. The findings were recorded by Karl Storz's camera system. Dissection and arthroscopy were done under general anesthesia using an anterolateral portal technique. The study employed a visualization of the anterior cruciate ligament probing the meniscus and reaching the posteromedial space for the ramp lesion. The mean age of patients was 28.05±6.92 years, ranging from 19 to 35 years and the mean duration from onset of injury to the time of operation was 3.69±1.07 years, ranging from 6 months to 10 years. The arthroscopic examination revealed medial meniscus tear in 80% of the cases, lateral meniscus tear in 40% of the cases, cartilage lesion in 40% of the cases, and meniscus ramp lesions in 10% of the cases. Most cases of ACL tear are associated with a meniscus injury, cartilage defect, and collateral ligament tear. These serious lesions, such as complex meniscus tears or full articular cartilage defects, are a direct consequence of delayed treatment. Consequently, it is crucial to inform the patients about the significant issues that can arise due to treatment delays.

Kinesiophobia Is Negatively Associated With Psychological Readiness to Return to Sport in Patients Awaiting Anterior Cruciate Ligament Reconstruction

PURPOSE

To identify the factors associated with anterior cruciate ligament return to sport after injury (ACL-RSI) scores in patients awaiting ACL reconstruction (ACLR).

METHODS

This was a retrospective cross-sectional observational study conducted at a single clinical center. We recruited patients scheduled for primary ACLR, aged 16-45 years, and with modified Tegner activity scale scores ≥5 before ACL injury. The main outcome was psychological readiness to return to sport (RTS), as measured using the ACL-RSI scale. Participants' personal and injury-related information were obtained, and their psychological status (Tampa Scale for Kinesiophobia [TSK] and athletic identity measurement scale) and knee functions (effusion, range of motion, joint stability, and knee flexion angle during a single-leg squat) were examined. All variables were assessed the day before the surgery.

RESULTS

A total of 105 patients (median [interquartile range]: age, 20.0 [9.0] years; body mass index, 22.8 [4.3] kg/m2; days from injury to surgery, 63.0 [65.0] days; 44% female) were enrolled. Univariate analysis indicated that only the TSK score was associated with the ACL-RSI scores (r = -0.305; P = .02). Multiple regression analysis of factors, including sex, preinjury Tegner activity scale score, and days from injury to surgery, further showed that only the TSK score was associated with the ACL-RSI scores (P = .002; 95% confidence interval -1.738 to -0.394).

CONCLUSIONS

In patients awaiting ACLR, kinesiophobia was moderately negatively associated with psychological readiness to RTS, while other factors were not.

LEVEL OF EVIDENCE

Level III, retrospective cross-sectional observational study.

Combined hormonal contraceptive use is not protective against musculoskeletal conditions or injuries: a systematic review with data from 5 million females

OBJECTIVE

Assess the association between combined hormonal contraceptives (CHC) use and musculoskeletal tissue pathophysiology, injuries or conditions.

DESIGN

Systematic review with semiquantitative analyses and certainty of evidence assessment, guided by the Grading of Recommendations Assessment, Development and Evaluation approach.

DATA SOURCES

MEDLINE, EMBASE, CENTRAL, SPORTDiscus, CINAHL searched from inception to April 2022.

ELIGIBILITY

Intervention and cohort studies that assessed the association between new or ongoing use of CHC and an outcome of musculoskeletal tissue pathophysiology, injury or condition in postpubertal premenopausal females.

RESULTS

Across 50 included studies, we assessed the effect of CHC use on 30 unique musculoskeletal outcomes (75% bone related). Serious risk of bias was judged present in 82% of studies, with 52% adequately adjusting for confounding. Meta-analyses were not possible due to poor outcome reporting, and heterogeneity in estimate statistics and comparison conditions. Based on semiquantitative synthesis, there is low certainty evidence that CHC use was associated with elevated future fracture risk (risk ratio 1.02-1.20) and total knee arthroplasty (risk ratio 1.00-1.36). There is very low certainty evidence of unclear relationships between CHC use and a wide range of bone turnover and bone health outcomes. Evidence about the effect of CHC use on musculoskeletal tissues beyond bone, and the influence of CHC use in adolescence versus adulthood, is limited.

CONCLUSION

Given a paucity of high certainty evidence that CHC use is protective against musculoskeletal pathophysiology, injury or conditions, it is premature and inappropriate to advocate, or prescribe CHC for these purposes.

PROSPERO REGISTRATION NUMBER

This review was registered on PROSPERO CRD42021224582 on 8 January 2021.

Knowledge and awareness of anterior cruciate ligament injury among Turkish professional athletes: an online survey

The purpose of this study was to assess the awareness and knowledge of professional team sport athletes about ACL injuries, injury prevention programs, and the return to sports after ACL injuries. A total of 419 athletes representing soccer, basketball, volleyball and handball sports were included in the study. We utilized a 15-item self-report survey to assess the awareness of athletes about ACL injury, ACL injury prevention program, and return to sport after ACL injuries. Male and soccer players participated in prevention programs more than female athletes (p = 0.001). Participation in prevention programs was significantly higher in the ≥ 18 years old group than in the < 18 years old group (p = 0.040). Participants who were informed about ACL injuries were 8.4 times more likely to participate in the ACL injuries prevention program than others (OR: 8.38, 95% CI: 3.823-18.376, p < 0.001). The majority of participants believed that return to sport after ACL injury takes 6 months and 81.4% of them thought that it is not possible to do sport without an ACL. This study revealed that the awareness and performance of ACL prevention training programs among professional team sport athletes were insufficient. The athletes' knowledge regarding return to sports after ACL injuries was also inadequate. Improving athletes' knowledge of ACL injuries may lead to increased participation in ACL injury prevention programs. Thus, the provision of tailored educational interventions to athletes could potentially enhance their awareness and understanding of ACL injuries, consequently contributing towards the prevention of such injuries.

Intra-Tester and Inter-Tester Reliability of the Lachmeter When Measuring Knee Joint Laxity

Knee injuries are common among all age groups, and clinical knee examination is essential for the prognosis, follow-up, and rehabilitation process. The Lachmeter is a newly developed digitized modification of the Rolimeter, making it easier and faster for the test personnel to read the test result. In the present study, we aimed to evaluate the intra-tester and inter-tester reliability of the Lachmeter when testing healthy and traumatic knees. 24 healthy participants and a smaller sample of six ACL patients were examined with the Lachmeter by two intermediate testers and re-examined on a second visit within 21 days. All measurements were performed using two different grip techniques: a Lachman grip and an anterior drawer grip. Intra- and inter-tester reliability was evaluated using intra-class correlation coefficient (ICC), standard error of measurement (SEM), smallest detectable change (SDC), Student's paired t-test, and Bland-Altman plots. The results showed in healthy subjects poor to good intra-tester reliability (ICC range: -0.28-0.87, SEM range: 0.33-1.14 mm, and SDC range: 0.91-3.17 mm) and inter-tester reliability (ICC range: 0.41-0.87, SEM range: 0.27-0.67 mm, and SDC range: 0.75-1.87 mm). In ACL patients, intra-tester reliability was moderate to excellent (ICC range: 0.53-0.94, SEM range: 0.14-0.88 mm, and SDC range: 0.38-2.44 mm), with the exception of one measurement (ICC: 0.26 95% CI [-3.43; 0.89]), whereas inter-tester reliability was overall good (ICC range: 0.61-0.89, SEM range: 0.29-0.71 mm, and SDC range: 0.79-1.97 mm). Reliability measures between grip techniques indicated that the Lachman grip was more reliable than the anterior drawer grip. In conclusion, the Lachmeter showed variation between reliability measures, ranging from poor to good in healthy subjects and moderate to excellent in ACL patients. Future studies are needed to validate the Lachmeter against a gold-standard knee laxity assessment.

Double-Versus Single-Bundle Anterior Cruciate Ligament Reconstructive Surgery: A Prospective Study With >1 Year Follow-Up

Background The increased prevalence of knee trauma predominantly adds to the anterior cruciate ligament (ACL) tear frequencies that require single- or double-bundle reconstructive surgeries. Few studies have demonstrated the superior results of double-bundle reconstruction compared to single-bundle approaches. This study investigated the knee function improvement capacity of both reconstruction techniques in patients with ACL tears. Methods Thirty cases with ACL tears have been enrolled and segregated equally in distinct (single-bundle versus double-bundle) batches. The diagnostic assessments were undertaken through comprehensive clinical history, knee radiographs, Lysholm scoring, the International Knee Documentation Committee (IKDC) scale, the Lachman analysis, the International Knee Documentation Committee (IKDC) scale, and the pivot shift method. Results After one year, there was a significant enhancement in the postoperative versus preoperative Lysholm scores in the single-bundle (58.5 ± 21.2 vs. 82.4 ± 26.2, p<0.001) and double-bundle (86.4 ± 22.8 vs 60.3 ± 19.2, p<0.001) groups. There was a significant improvement in the IKDC scores after a follow-up period of one year (p-value: 0.012 and p-value: 0.002, respectively) in both of the study batches. After a year of follow-up, Lysholm scores (p=0.352) and IKDC scores (p=0.574) between the study groups (82.4 ± 26.2 vs. 86.4 ± 22.8) were comparable. Conclusion The clinical outcomes remained comparable between subjects with single-bundle reconstruction versus double-bundle reconstruction subjects with ACL injuries. Findings were similar between the groups after one year and two years of surgical interventions.

Comparison of Hip and Knee Biomechanics during Sidestep Cutting in Male Basketball Athletes with and without Anterior Cruciate Ligament Reconstruction

This study aimed to compare hip and knee biomechanics during sidestep cutting on the operated and non-operated sides in individuals with anterior cruciate ligament reconstruction (ACLR), and in an uninjured control group. Twenty male basketball athletes, 10 individuals with ACLR and 10 controls, were recruited. Hip and knee joint angles and angular velocities were investigated with a three-dimensional motion analysis system, and ground reaction forces (GRF) along with moments were collected during the deceleration phase of the stance limb during sidestep cutting maneuvers. We found significantly higher peak hip flexion, hip internal rotation angular velocities, and peak thigh angular velocity in the sagittal plane in the ACLR group. In addition, the peak vertical GRF and peak posterior GRF of the ACLR group were significantly higher than those of the control group. Univariate analyses indicated that the posterior GRF of the non-operated side was significantly higher than in the matched operated side in the control group. The operated and non-operated sides in male basketball athletes with ACLR showed alterations in hip and knee biomechanics compared with a control group, especially in the sagittal plane. Therefore, the emphasis of neuromuscular control training for the hip and the knee in basketball players with ACLR is required.

Genetic Determinants of the Anterior Cruciate Ligament Rupture in Sport: An Up-to-Date Systematic Review

Anterior cruciate ligament injuries (ACLIs) are one of the most common knee injuries in sports. Although numerous factors have been related to the risk of ACLIs, it is still unclear why some individuals are more susceptible than others due to the intricate etiology of ACLIs. Several genetic factors have been identified as contributing to ACLIs. This systematic review summarizes the current evidence regarding the genetic causes of ACLIs based on the available literature. Five electronic databases were searched from 2017 to 2022. All titles, abstracts, and full texts were reviewed in detail to determine the inclusions and exclusions. The Newcastle-Ottawa Scale was used to evaluate the risk of bias. The studies' characteristics and results are presented in both narrative and tabular formats. A total of 24 studies examined 31 genes and 62 variants associated with ACLIs in the global population. Ten studies investigated seven collagens and ten SNPs for the ACL injury. The majority of studies found no significant difference in the association of the COL1A1 rs1800012, COL5A1 rs12722, VEGFA rs1570360, IL6R rs2228145, IL6 rs1800795, IL1B rs16944 and rs1143627, however, contrary results were found when nationality and gender were considered together. Conflicting evidence was found for polymorphisms rs2010963, rs699947 of the VEGFA gene in different studies. Due to a lack of data, it was impossible to determine the relationship between the anterior cruciate ligament rupture (ACLR) and the other polymorphisms. More research is required to establish a clear relationship between the ACLR and genetic variants, particularly when gender and nationality are taken into account separately.

Early Complication Analysis of Dynamic Intraligamentary Stabilization versus Anterior Cruciate Ligament Reconstruction

PURPOSE

Both dynamic intraligamentary stabilization (DIS) and reconstruction (RECO) are common treatment methods for anterior cruciate ligament (ACL) rupture. We report short term outcomes after DIS (Ligamys, Mathys, Bettlach, Switzerland) and RECO using semitendinosus tendon. We compared postoperative complications, deficits of range-of-motion (ROM), and revision rates between the two treatment options.

METHODS

A total of 690 patients (437 male, 253 female), after either DIS or RECO, were included. Of these, 147 patients (21%) received DIS and 543 (79%) underwent RECO. Follow-up examination focused on clinical examination, complications and revision rates. Anteroposterior instability and ROM deficits were analyzed in order to evaluate our policy of early intervention for all cases of ROM restrictions.

RESULTS

Relevant ROM restrictions occurred at a significantly higher rate after DIS than after RECO (4.8% vs. 1.3%; p = 0.008). Flexion was more restricted after DIS than RECO (110° vs. 124°, p < 0.001). Extension deficits also occurred more frequently after DIS compared to RECO (49.7% vs. 24.5%; p < 0.001). Total revision surgery rate was 9.1%, with patients after DIS being significantly more frequently affected (20.4% vs. 6.1%; p < 0.001).

CONCLUSIONS

Our findings indicate a significantly higher risk for ROM restriction after DIS compared to RECO, resulting in a significantly higher revision rate.

Preoperative predictors for return to physical activity following anterior cruciate ligament reconstruction (ACLR): a systematic review

BACKGROUND

Rates of return to physical activity after anterior cruciate ligament reconstruction surgery are sub-optimal. Optimising presurgical treatment may improve return rates. The purpose of this systematic review was to identify modifiable preoperative predictors for return to physical activity after anterior cruciate ligament reconstruction.

METHODS

Seven electronic databases (CINAHL, MEDLINE and SPORTDiscus via EBSCOhost, AMED, PsycINFO and EMBASE via OVID and Web of Science) were searched from inception to 31 March 2023. The population of focus was adults aged 18-65 who had undergone primary anterior cruciate ligament reconstruction. Studies needed to identify at least one potential modifiable preoperative predictor variable and the relationship between the predictor(s) and return to physical activity. All time-points of assessment and study designs were included. Data extraction was completed by one reviewer and verified by a second reviewer. Two reviewers completed the risk of bias assessment using the Quality in Prognostic Studies tool and Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

The search identified 2281 studies, eight met the inclusion criteria. Five studies scored 'high', and three studies scored 'moderate' risk-of-bias. All preoperative predictors were of very low-quality evidence. Five different outcome measures were used to assess return to physical activity including Tegner, Marx, Physical Activity Scale, return to play at the elite level and return to preinjury level (undefined). This was measured between 1- and 10-years post-surgery. Nine preoperative physical, six psychosocial and five demographic/clinical factors were assessed and four were found to be predictive. These included quadriceps strength, psychological profile, patient estimated ability to return and graft type (patella tendon, BPTB).

CONCLUSION

Very-low level evidence suggests that increasing quadriceps strength, managing patient expectations of their treatment outcomes, improving motivation to resume preinjury activity levels and considering the use of a BPTB graft will support return to physical activity after ACLR.

TRIAL REGISTRATION

This study was prospectively registered in PROSPERO: CRD 42020222567.

Demographic characteristics of patients who underwent anterior cruciate ligament reconstruction at a tertiary care hospital in India

BACKGROUND

Anterior cruciate ligament (ACL) tears are common sports-related injuries. Their incidence is not the same either for all the sports or for the same sport across various nations. This information is maintained by many sports leagues in their registries. However, very few nationwide registries exist for such injuries. This study is carried out to know the demographic characteristics of patients who underwent ACL reconstruction at our hospital in India.

AIM

To know the demographic characteristics of patients who underwent ACL reconstruction at a tertiary care hospital in India.

METHODS

All the patients who underwent ACL reconstruction from January 2020 to December 2021 were retrospectively studied. Patients with multi-ligament injuries or a history of previous knee surgery were excluded. The patients’ history was obtained from the hospital records, they were interviewed telephonically, and online questionnaires were given. Their demographic data was analyzed and compared to the existing literature.

RESULTS

A total of 124 patients were operated on for ACL reconstruction during this period. The mean age of the patients was 27.97 years. One hundred and thirteen patients (91.1%) were male and 11 (8.9%) were female. The majority of the patients (47.6%) sustained this injury by road traffic accidents (RTA) followed by sports-related injuries (39.5%). The commonest presenting complaint was giving way of the knee in 118 patients (95.2%). The mean duration from the injury to the first hospital visit among the patients was 290.1 d. The mean duration from the injury to surgery was 421.8 d.

CONCLUSION

ACL patients’ demography is different in developing nations as compared to the developed world. RTA are the leading cause of ACL injuries and are followed by recreational sports as a cause. There is delayed access to healthcare leading to delayed diagnosis as well as even greater time to surgery. This, in turn, leads to poorer prognosis and longer rehabilitation. National registries for developing nations are the need of the hour due to the different demographics of ACL injuries in developing countries.

Demographic Factors and Instantaneous Lower Extremity Injury Occurrence in a National Collegiate Athletic Association Division I Population

CONTEXT

Temporal prediction of the lower extremity (LE) injury risk will benefit clinicians by allowing them to better leverage limited resources and target those athletes most at risk.

OBJECTIVE

To characterize the instantaneous risk of LE injury by demographic factors of sex, sport, body mass index (BMI), and injury history.

DESIGN

Descriptive epidemiologic study.

SETTING

National Collegiate Athletic Association Division I athletic program.

PATIENTS OR OTHER PARTICIPANTS

A total of 278 National Collegiate Athletic Association Division I varsity student-athletes (119 males, 159 females; age = 19.07 ± 1.21 years, height = 175.48 ± 11.06 cm, mass = 72.24 ± 12.87 kg).

MAIN OUTCOME MEASURE(S)

Injuries to the LE were tracked for 237 ± 235 consecutive days. Sex-stratified univariate Cox regression models were used to investigate the association between time to first LE injury and sport, BMI, and LE injury history. The instantaneous LE injury risk was defined as the injury risk at any given point in time after the baseline measurement. Relative risk ratios and Kaplan-Meier curves were generated. Variables identified in the univariate analysis were included in a multivariate Cox regression model.

RESULTS

Female athletes displayed similar instantaneous LE injury risk to male athletes (hazard ratio [HR] = 1.29; 95% CI= 0.91, 1.83; P = .16). Overweight athletes (BMI >25 kg/m2) had similar instantaneous LE injury risk compared with athletes with a BMI of <25 kg/m2 (HR = 1.23; 95% CI = 0.84, 1.82; P = .29). Athletes with previous LE injuries were not more likely to sustain subsequent LE injury than athletes with no previous injury (HR = 1.09; 95% CI = 0.76, 1.54; P = .64). Basketball (HR = 3.12; 95% CI = 1.51, 6.44; P = .002) and soccer (HR = 2.78; 95% CI = 1.46, 5.31; P = .002) athletes had a higher risk of LE injury than cross-country athletes. In the multivariate model, instantaneous LE injury risk was greater in female than in male athletes (HR = 1.55; 95% CI = 1.00, 2.39; P = .05), and it was greater in male athletes with a BMI of >25 kg/m2 than that in all other athletes (HR = 0.44; 95% CI = 0.19, 1.00; P = .05), but these findings were not significantly different.

CONCLUSIONS

In a collegiate athlete population, previous LE injury was not a contributor to the risk of future LE injury, whereas being female or being male with a BMI of >25 kg/m2 resulted in an increased risk of LE injury. Clinicians can use these data to extrapolate the LE injury risk occurrence to specific populations.

Neuromuscular activity of the lower-extremities during running, landing and changing-of-direction movements in individuals with anterior cruciate ligament reconstruction: a review of electromyographic studies

PURPOSE

Running, jumping/landing and cutting/change of direction (CoD) are critical components of return to sport (RTS) following anterior cruciate ligament reconstruction (ACLR), however the electromyographic (EMG) activity patterns of the operated leg during the execution of these tasks are not clear.

METHODS

A systematic review was conducted to retrieve EMG studies during running, jumping/landing and cutting/(CoD) in ACLR patients. MEDLINE, PubMed, SPORTDiscus and Web of Science databases were searched from 2000 to May, 2022 using a combination of keywords and their variations: "anterior cruciate ligament reconstruction" OR "ACLR", "electromyography" OR "EMG", "running", "jumping" OR "landing", "cutting" OR "change-of-direction" OR "CoD". The search identified studies comparing EMG data during running, landing and cutting/(CoD) between the involved limb and contralateral or control limbs. Risk of bias was assessed and quantitative analyses using effect sizes were performed.

RESULTS

Thirty two studies met the inclusion criteria. Seventy five percent (24/32) of the studies reported altered EMG activity pattern of the ACLR leg during running, jumping/landing and cutting/(CoD) when compared with either the healthy control leg or the contra-lateral leg. Twelve studies showed decreased, delayed or earlier onset and delayed peak in quadriceps EMG activity with small to large effect sizes and 9 studies showed increased, delayed or earlier onset and delayed peak in hamstrings EMG activity with small to large effect sizes. Four studies showed a "hamstrings-dominant" strategy i.e. decreased quadriceps coupled with increased hamstrings EMG activity in both running and jumping/landing irrespective of graft type. One study reported that on the grounds of decreased quadriceps activity, lower hamstrings EMG activity was predictive of ipsilateral re-injury in ACLR patients.

CONCLUSION

This systematic review of Level III evidence showed that the ACLR leg displays decreased quadriceps or increased hamstrings EMG activity or both despite RTS. Simultaneous decreased quadriceps and increased hamstrings EMG activity was shown for both running and jumping/landing. From a clinical perspective this "hamstrings dominant" strategy can serve as a protective mechanism against graft re-injury.

LEVEL OF EVIDENCE

III.

Intersession Reliability of Quadriceps Corticospinal Excitability: A Functional Transcranial Magnetic Stimulation Study

Recording transcranial magnetic stimulation-derived measures during a closed kinetic chain task can serve as a functional technique to assess corticomotor function, which may have implications for activities of daily living or lower extremity injury in physically active individuals. Given the novelty of TMS use in this way, our purpose was to first determine the intersession reliability of quadriceps corticospinal excitability during a single-leg squat. We used a descriptive laboratory study to assess 20 physically active females (22.1 ± 2.5 years, 1.7 ± 0.7 m, 66.3 ± 13.6 kg, Tegner Activity Scale: 5.90 ± 1.12) over a 14-day period. Two-way mixed effects Intraclass Correlation Coefficients (3,1) (ICC) for absolute agreement were used to assess intersession reliability. The active motor threshold (AMT) and normalized motor evoked potential (MEP) amplitudes were assessed in the vastus medialis of each limb. The dominant limb AMTs demonstrated moderate-to-good reliability (ICC = 0.771, 95% CI = 0.51-0.90; p < 0.001). The non-dominant limb AMTs (ICC = 0.364, 95% CI = 0.00-0.68, p = 0.047), dominant limb MEPs (ICC = 0.192, 95% CI = 0.00-0.71; p = 0.340), and non-dominant limb MEPs (ICC = 0.272, 95% CI = 0.00-0.71; p = 0.235) demonstrated poor-to-moderate reliability. These findings may provide insight into corticomotor function during activities requiring weight-bearing, single-leg movement. However, variability in agreement suggests further work is warranted to improve the standardization of this technique prior to incorporating in clinical outcomes research.

single-leg medial drop landing with trunk lean includes improper body mechanics related to anterior cruciate ligament injury risk: A comparison of body mechanics between successful trials and failed trials in the drop landing test among female basketball athletes

BACKGROUND

Improper body mechanics during landing is a typical risk factor of anterior cruciate ligament injury. Drop landing test is used to evaluate landing mechanics by observing not only successful trials but also failed trials. Leaning of the trunk, which is frequently observed during failed trials, may lead to improper body mechanics related to anterior cruciate ligament injury. This study aimed to elucidate the mechanisms of landing with trunk lean that may underlie the risks of anterior cruciate ligament injury by comparing body mechanics between failed and successful trials.

METHODS

Participants were 72 female basketball athletes. The athletic task was single-leg medial drop landing, and the body mechanics was recorded by a motion capture system and force plate. Participants fixed the landing pose for ≥3 s in successful trials but failed to do so in failed trials.

FINDINGS

Failed trials included the large lean of trunk. There were significant changes in thoracic and pelvic leans at initial contact in failed trials with medial trunk lean (p < 0.05). Kinematics and kinetics during the landing phase in failed trials were associated with the risks of anterior cruciate ligament injury.

INTERPRETATION

These findings suggest that landing mechanics with trunk lean involves many biomechanical factors related to anterior cruciate ligament injury and demonstrates the inappropriate pose of trunk from the dropping phase. Exercise programs aimed at the landing manoeuver without trunk lean may contribute to reduce the risks of anterior cruciate ligament injury in female basketball athletes.