A multisport epidemiologic comparison of anterior cruciate ligament injuries in high school athletics

The effects of heading motion and sex on lower extremity biomechanics in soccer players

BACKGROUND

Soccer is one of the most popular sports worldwide, which subsequently increases the number of injuries experienced by players. Furthermore, a large percentage of all anterior cruciate ligament injuries occur while playing soccer. In order to more clearly understand injury mechanisms, it is important to make the testing environment as real-life as possible. Inclusion of an external focus and secondary task, such as heading a soccer ball, may increase joint loading during landing. The purpose of this study was to investigate the effect of a forward heading motion on lower extremity kinetics and kinematics between sexes during a stop-jump task and a jump-heading task.

METHODS

Ten male and ten female soccer players performed stop-jumps with no soccer ball present and jump-headings with a soccer ball present. Three-dimensional kinematics and kinetics were collected and analyzed during the landing. 2 × 2 mixed design analysis of variances (ANOVA) were performed to examine sex × jump task interactions and determine the main effects of sex and jump task.

RESULTS

Results indicated jump-heading yields greater peak vertical ground reaction forces, an 8% increase in peak knee extension moments, a reduced initial knee flexion angle by approximately 5°, and an increased initial hip flexion angle by approximately 7°. Additionally, females exhibited 5.6° greater peak knee abduction angles compared to men, regardless of task.

CONCLUSIONS

Inclusion of an overhead target may have distracted the athletes from focusing on frontal plane knee control when landing, and could potentially lead to increased ACL stress.

Lower extremity return to sport testing: A systematic review

BACKGROUND

Lower extremity injuries account for an enormous portion of sports medicine cases in the United States each year. Unfortunately, there are no uniform criteria for athletes to complete prior to returning to sport (RTS) following a lower extremity injury. Therefore, the purpose of this systematic review is to review current literature for joint-specific and global lower extremity testing to determine the most valid functional test that can be utilized to reduce the risk of re-injury as athletes RTS.

METHODS

A systematic search of PubMed, PubMed Central, Cochrane Library, OVID, and Embase databases was conducted for studies prior to May 2024 following PRISMA guidelines. ROBINS-I Tool was utilized for the risk of bias assessment.

RESULTS

Of 19,189 studies, 114 (0.6%) studies published prior to May of 2024 met inclusion criteria and were analyzed. Eighty five percent of articles discussed RTS for individuals with knee pathology. Furthermore, 82% specifically analyzed RTS following ACL reconstruction. The most common RTS test was isokinetic dynamometry testing which is seen in 73% of studies. Only 6.2% of studies analyzed RTS for individuals with hip pathology and only two studies analyzed RTS for patients with ankle injuries.

CONCLUSION

Even with the enormous amount of literature that exists regarding ACL injuries and testing there is no standardized criterion for RTS clearance. The suggested test batteries from this review can serve as a framework for future research and validation for joint-specific RTS functional testing.

Clinical Utility of Qualitative Change of Direction Movement Assessment in ACL Injury Risk Evaluation

Anterior cruciate ligament (ACL) injuries are complex and influenced by numerous internal and external risk factors that should be considered to effectively mitigate injury and facilitate informed return to sport decision-making. Among these risk factors, movement quality exhibited during sport-specific tasks has been identified as a significant predictor of injury occurrence. Particularly, change of direction (COD) movements, when performed with sub-optimal movement quality, such as knee valgus and lateral trunk flexion, are prominent mechanisms of ACL injury in multidirectional sports. Unfortunately, the formal and objective assessment of COD movement quality is underutilized in clinical and sports practice, with existing methods often confined to expensive, sophisticated laboratory settings impractical for everyday clinicians. The purpose of this clinical commentary is to demonstrate the necessity of integrating COD movement assessments to screen for potential ACL injury risk, particularly among higher-risk populations. The authors will review cost-effective and clinic-friendly objective tests used to qualitatively screen COD movements, such as the Cutting Movement Assessment Score and The Expanded Cutting Alignment Tool. Additionally, this commentary will discuss key considerations when assessing COD movement.

Level of Evidence

5.

Association of the COVID-19 Pandemic With Outcomes After Anterior Cruciate Ligament Reconstruction: A Retrospective Comparative Study Examining Changes in Health Care Access, Delivery, and Functional Outcomes

Background

Structured rehabilitation optimizes outcomes and reduces reinjury risk after anterior cruciate ligament reconstruction (ACLR). The coronavirus 2019 (COVID-19) pandemic interrupted standard rehabilitation, possibly affecting ACLR outcomes.

Purpose

To characterize changes to ACLR functional outcomes related to the COVID-19 pandemic.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients who underwent ACLR between June 11, 2019, and March 11, 2020, (postpandemic group) were compared retrospectively with those who underwent ACLR the year before (June 11, 2018, to March 11, 2019). A mixed-effects linear regression model was used to estimate group differences in isokinetic quadriceps testing. A Kaplan-Meier analysis assessed the probability of achieving >90% limb symmetry index (LSI) for isokinetic quadriceps strength at 60 deg/s and passing all return-to-sport functional outcomes at 1 year postoperatively.

Results

A total of 176 patients (80 in the control group and 96 in the postpandemic group) were included. The rate of achieving >90% LSI in isokinetic strength at 60 deg/s at 1 year postoperatively was 39% (95% CI, 27%-49%) for the control group versus 22% (95% CI, 13%-30%) for the postpandemic group (P = .01). Similarly, the rate of achieving >90% LSI in all functional tests at 1 year postoperatively was 15% (95% CI, 7%-22%) for the control group versus 7% (95% CI, 2%-12%) for the postpandemic group (P = .04). The number of in-person physical therapy visits per patient was 25.8 ± 6.8 in the control group versus 24.4 ± 7.5 in the postpandemic group (P = .23). Only the postpandemic group accessed physical therapy using remote telemedicine. Each additional telehealth rehabilitation visit was associated with a 1-week delay in achieving >90% LSI in isokinetic quadriceps strength for the postpandemic group.

Conclusion

The COVID-19 pandemic was associated with a decrease in lower extremity strength and a lower probability of achieving limb symmetry and passing the criteria for return to sport at 1 year postoperatively. These results were not due to lack of access to physical therapy.

Perturbation Training in Anterior Cruciate Ligament Graft Tear and Posterolateral Corner Injury: A Case Report of a Combined Injury

This case study illustrates how rehabilitation for combination injuries necessitates a thorough, customized strategy that includes perturbation training to address complicated biomechanical impairments because of the complex relationship between the anterior cruciate ligament (ACL) and the posterolateral corner (PCL). An 18-year-old female basketball player visited the Sports Rehab Outpatient Department with a complaint of pain in the posterior aspect of her knee, difficulty fully flexing her right knee joint, and intermittent instability one month after an injury. Her grade 2 ACL tear was accompanied by thinning of the lateral collateral ligament and strain of the popliteofibular ligament as per the MRI findings before the ACL reconstruction surgery. She underwent a knee graft sprain and ACL re-injury. The decision was made to manage the injury conservatively by implementing a rehabilitation program focused on perturbations to improve neuromuscular control and functional stability of the knee. This case report highlights the significance of a multidisciplinary approach, evidence-based interventions (such as the Lysholm score, International Knee Documentation Committee-Subjective Knee Form, and Tempa Scale of Kinesiophobia as outcome measures), and patient-centered care. This study intends to make a significant contribution to sports medicine and orthopedic rehabilitation by clarifying the complexities of rehabilitation in such complicated circumstances.

A Severe Case of Arthrofibrosis After Anterior Cruciate Ligament (ACL) Reconstruction in a 25-Year-Old Female Hispanic Patient: A Case Report

Arthrofibrosis is the most common postoperative complication of anterior cruciate ligament (ACL) reconstruction. It is caused by an exaggerated immune reaction to a pro-inflammatory trigger that causes abnormal periarticular fibrosis and joint stiffness. The shoulder, elbow, and knee are especially prone to this condition, often following trauma, surgery, or adhesive capsulitis. We describe the case of a 25-year-old Hispanic female who presented to the clinic with knee instability after experiencing a twisting and popping sensation in her left knee while playing tennis. Physical examination revealed increased anterior tibial translation, and imaging confirmed a torn ACL. She subsequently underwent ACL reconstruction using the bone-patellar tendon-bone graft technique. However, during her follow-up appointments, she reported persistent difficulties with active and passive range of motion in both flexion and extension despite undergoing appropriate physical therapy. Now, three months post-operation, she continues to experience limited knee range of motion. To our knowledge, there are only a few reports of arthrofibrosis in this particular age group and demographic undergoing this procedure. Our objective is to contribute this case to the scientific community, aiming to encourage future studies and gather epidemiological data on this topic.

Differences in Overuse Injuries in Gender-Comparable Sports: A Nationally Representative Sample of High School Athletes

CONTEXT

Participation in high school sports has physical, physiological, and social development benefits, while also increasing the risk of acute and overuse injuries. Risk of sport-related overuse injury differs between boys and girls.

OBJECTIVE

To investigate differences in overuse injuries among US high school athletes participating in the gender-comparable sports of soccer, basketball, and baseball/softball.

DESIGN

Descriptive epidemiology study using a nationally representative sample from the High School Reporting Information Online (RIO) database.

SETTING

High schools.

PATIENTS OR OTHER PARTICIPANTS

Athletes with overuse injuries during the 2006-2007 through 2018-2019 academic years.

MAIN OUTCOME MEASURE(S)

National estimates and rates of overuse injuries were extrapolated from weighted observed numbers with the following independent variables: sport, gender, academic year, class year, event type, body site, diagnosis, recurrence, activity, and position.

RESULTS

Among an estimated 908 295 overuse injuries nationally, 43.9% (n = 398 419) occurred in boys' soccer, basketball, and baseball, whereas 56.1% (n = 509 876) occurred in girls' soccer, basketball, and softball. When comparing gender across sports, girls were more likely to sustain an overuse injury than boys (soccer, injury rate ratio [IRR]: 1.37, 95% CI = 1.20-1.57; basketball, IRR: 1.82, 95% CI = 1.56-2.14; baseball/softball, IRR: 1.21, 95% CI = 1.04-1.41). Most overuse injuries in soccer and basketball for both genders occurred to a lower extremity (soccer: 83.9% [175 369/209 071] for boys, 90.0% [243 879/271 092] for girls; basketball: 77.0% [59 239/76 884] for boys, 80.5% [81 826/101 709] for girls), whereas most overuse injuries in baseball and softball were to an upper extremity (72.5% [81 363/112 213] for boys, 53.7% [73 557/136 990] for girls). For boys' baseball, pitching (43.5% [47 007/107 984]) was the most common activity associated with an overuse injury, which differed from the most common activity of throwing (31.7% [39 921/126 104]) for girls' softball.

CONCLUSIONS

Gender differences observed in this study can help guide future strategies that are more specific to gender and sport to reduce overuse injuries among high school athletes.

Imaging and Surgical Procedures After Surface-Related Collegiate Football Injuries on Artificial Turf Versus Natural Grass: Prevalence and Trends Over 15 Seasons

Background

Few longitudinal studies exist comparing medical procedures after football injuries on artificial and natural grass surfaces.

Purpose/Hypothesis

The purpose of this study was to specifically compare imaging and surgical procedures after surface-related collegiate football injuries on artificial turf versus natural grass. It was hypothesized that there would be no difference in the incidence of imaging and surgical procedures, combined medical procedures, or combined substantial and severe injuries over time between these surfaces.

Study Design

Cohort study; Level of evidence, 2.

Methods

A total of 39 universities across all Football Bowl Subdivision conferences were evaluated over 15 seasons (2006-2020). Playing surfaces evaluated were either a heavyweight artificial turf infill system (≥9.0 lb infill/ft2) or natural grass. Outcomes of interest included medical procedures across injury category, primary injury type, injury location, and specific procedures. Data involved multivariate analyses of variance (MANOVA) and Wilks λ criteria using general linear model procedures and were expressed as medical procedure incidence rates (IRs) per 10-game season.

Results

Overall, 2224 games were documented: 1106 (49.7%) on artificial turf and 1118 (50.3%) on natural grass. Of the 9137 total injuries reported, 4010 (44%) were surface-related cases. MANOVA indicated significant main effects between surfaces according to imaging procedure (F 2,1738 = 4.718; P = .009), surgical procedure (F 1,539 = 5.974; P = .003), and medical diagnosis (F 2,456 = 2.643; P = .040). Post hoc analyses indicated significantly lower (P < .05) incidences on artificial turf versus natural grass, respectively, for the following outcomes: imaging procedures ordered after player-to-surface impact trauma (IR [95% CI], 1.5 [1.3-1.8] vs 2.1 [1.9-2.4]), shoe-to-surface trauma during physical contact (4.4 [4.1-4.7] vs 5.2 [4.9-5.5]), foot injuries (0.6 [0.5-0.7] vs 1.1 [0.9-1.2]), ligament sprains/tears (4.6 [4.3-4.9] vs 5.3 [5.0-5.6]), muscle strains/tears (0.2 [0.2-0.3] vs 0.7 [0.6-0.9]), surgeries performed after shoe-to-surface trauma during physical contact (1.1 [0.9-1.3] vs 1.6 [1.4-1.8]), lower body surgeries (1.8 [1.6-2.0] vs 2.3 [2.1-2.6]), and surgeries involving ligament tears (1.0 [0.9-1.2] vs 1.5 [1.3-1.7]), as well as fewer diagnoses of syndesmosis sprains/tears (0.7 [0.5-0.8] vs 1.0 [0.8-1.2]) and Lisfranc trauma (0.3 [0.2-0.4] vs 0.5 [0.4-0.7]). Trends over the 15 seasons indicated a significant rise in combined medical procedures (P = .005) and combined substantial and severe injuries (P = .0007) irrespective of surface.

Conclusion

Results indicated that collegiate football competition on heavyweight artificial turf resulted in lower incidences of imaging and surgical procedures and medical diagnoses compared with natural grass.

Anterior Cruciate Ligament Reconstruction in Young Athletes: A Comprehensive Review of Lateral Extra-Articular Tenodesis and Anterolateral Ligament Reconstruction Techniques

Anterior cruciate ligament (ACL) injuries are prevalent among young athletes and pose significant challenges due to their impact on immediate and long-term knee function. Traditional ACL reconstruction techniques, while effective, may not always meet the unique needs of this population, particularly given their high physical demands and the risk of future complications. This review evaluates two advanced surgical techniques - lateral extra-articular tenodesis (LEAT) and anterolateral ligament (ALL) reconstruction - as potential enhancements to conventional ACL reconstruction. LEAT involves augmenting knee stability by addressing lateral compartment issues, while ALL reconstruction focuses on reconstructing the ALL to improve overall knee function. The review compares these techniques regarding surgical procedures, clinical outcomes, biomechanical effectiveness, and complications. LEAT and ALL reconstruction are examined for their impact on recovery, return-to-sport rates, and long-term knee health, highlighting their advantages and limitations. Findings suggest that both techniques offer promising benefits, with the potential for improved outcomes compared to traditional methods. However, the effectiveness of each technique can vary based on individual factors and the specific demands of different sports. Further research is needed to fully understand the long-term implications and refine these approaches. This review aims to guide clinical decision-making and optimize treatment strategies for young athletes with ACL injuries, enhancing their prospects for a successful return to athletic activity.

Anterior Cruciate Ligament Tears in Soccer Players

Anterior cruciate ligament (ACL) injuries to soccer players present unique challenges in sports medicine, given the sport's global prevalence and intricate injury dynamics. These injuries, especially in the youth and female demographic, have become a substantial concern in sports medicine. This review explores the epidemiology, mechanism of injury, diagnostic procedures, treatment modalities, and rehabilitation strategies related to ACL tears within the soccer community. Progress in diagnostics, treatments, and rehabilitation underscores the importance of evidence-based approaches. As soccer continues its ascent in popularity, addressing the specific risks and nuances of ACL injuries in this context remains of paramount significance.

The 25 Most Cited Articles in Pediatric Orthopaedic Sports Medicine

Background

Citation analysis reflects the influence a work has on a field of research and can be used to identify "classic" works and their qualities in medical specialties. By analyzing the characteristics of these works, we intended to determine what qualities make for a highly cited work in pediatric orthopaedic sports medicine.

Purpose

To identify the top 25 most cited articles in the field of pediatric orthopaedic sports medicine.

Study Design

Cross-sectional study.

Methods

The Science Citation Index Expanded feature within the Web of Science database was searched using a Boolean string, generating 2008 pediatric orthopaedic sports medicine articles arranged by number of citations. The top 25 most cited articles were reviewed for authors, year of publication, source journal, country of origin, region of origin, diagnosis or condition of focus, and level of evidence (LOE).

Results

Most of the articles were published in the 2000s (range, 1992-2016). The mean number of citations was 166 (range, 119-329), and the mean citation density was 13.25 (range, 4.25-29.57). There were 18 of 25 studies performed in the United States. A plurality of the articles were published in the American Journal of Sports Medicine. The LOE ranged from 2 to 4, with the most common being level 2 (11/25). Anterior cruciate ligament (ACL) injury management (14/25) and epidemiological studies on the incidence of various sports injuries (6/25) were the most represented topics of study. Since the 1990s, the mean citation density for articles related to ACL injuries in young athletes and the epidemiology of sports injuries has been increasing.

Conclusion

This evaluation demonstrated that ACL injuries and the epidemiology of sports injuries had the highest citation density of the most influential studies in pediatric orthopaedic sports medicine. We identified attributes such as country of publication, journal of publication, and LOE that make for a highly cited pediatric orthopaedic sports medicine article. Overall, citation density in pediatric sports medicine is increasing. Nonetheless, the most represented LOE in the most cited works is level 2, with no level 1 studies being represented in the top 25. In terms of both topics and LOE, this study allows surgeons to identify deficiencies in the existing literature and meaningfully design future studies to improve on these.

Maturation and biomechanical risk factors associated with anterior cruciate ligament injury: Is there a link? A systematic review

OBJECTIVE

To establish the potential link between sex-specific maturation and biomechanical factors associated with ACL injury during dynamic tasks.

DESIGN

Systematic review.

LITERATURE SEARCH

Five databases (CINHAL®, Cochrane Library, PubMed®, Scopus®, and SPORTDiscus) were searched and monitored until 27 May 2024.

STUDY SELECTION CRITERIA

Cross-sectional, cohort, case-control, or interventional studies reporting one or more biomechanical variable linked with ACL injury and which assessed participants across two or more maturation phases were considered eligible.

DATA SYNTHESIS

Studies were assessed for risk of bias using a modified version of the Newcastle Ottawa Scale and overall quality of evidence was rated using GRADE. Metrics and effect sizes were presented where available.

RESULTS

Eighteen included studies examined 400 males, 1377 females, and 315 participants of undefined sex across various maturation phases. The methodological quality of most studies (n = 16) was considered good, and satisfactory for two. Knee abduction angle, knee abduction moment, knee flexion angle, and ground reaction forces were most commonly reported. Knee abduction angles and moments and knee flexion angles were greater in late and post-pubertal females than males and pre-pubertal females during both landing and cutting tasks. When normalised for body mass, ground reaction forces were generally greater in males compared to females overall and for less mature participants for both sexes. Overall quality of evidence was low or medium across the four biomechanical measures.

CONCLUSION

Sex-specific maturation considerations are important in the targeted development and implementation of ACL injury risk identification and prevention strategies.

Cross-cultural adaptation and measurement properties of the Persian version of the modified Cincinnati knee rating system

Purpose

To validate and assess the cross-sectional adaptation of the modified Cincinnati knee rating system (MCRKS) Persian translation.

Methods

To assess test-pretest reliability, 102 participants were asked to fill out the MCRKS (Per) scale after anterior cruciate ligament (ACL) reconstruction surgery. Internal consistency (Cronbach's α), reliability (intraclass correlation coefficients), construct validity (Pearson's r) and sensitivity (floor/ceiling effect) were determined. In addition, patients completed other relevant measures as the ACL return to sports after injury (ACL-RSI) survey, hospital for special surgery ACL satisfaction survey (HSS ACL-SS), visual analogue scale (VAS) of pain and patient's satisfaction, Tegner activity score (TAS), single assessment numeric evaluation, and Lysholm score.

Results

Using MCRKS (Per), the internal consistency (Cronbach's α) was 0.9 (if item deleted: 0.81-0.86); the construct validity (Pearson's r) varied between -0.50 (for VAS pain scale) and 0.79 (for Lysholm score); the reliability (ICC value) varied between 0.82 and 0.97; furthermore, no ceiling or floor effect was present.

Conclusion

The MCRKS (Per) has adequate measurement properties and is considered a valid, reliable and sensitive instrument which can identify clinical outcomes after ACLR surgery.

Level of Evidence

Level IV.

Test-retest reliability and concurrent validity of knee extensor strength measured by a novel device incorporated into a weight stack machine vs. handheld and isokinetic dynamometry

BACKGROUND

The current clinical gold standard for assessing isometric quadriceps muscle strength is an isokinetic dynamometer (IKD). However, in clinics without an IKD, clinicians default to using handheld dynamometers (HHD), which are less reliable and accurate than the IKD, particularly for large muscle groups. A novel device (ND) was developed that locks the weight stack of weight machines, and measures forces applied to the machine, turning this equipment into an isometric dynamometer. The objectives of this study were to characterize the test-retest reliability of the ND, determine the within-day and between-days inter-rater reliability and concurrent validity compared with that of the HHD, in healthy volunteers (HV) and individuals with knee osteoarthritis (OA) for measuring knee extensors isometric muscle force.

MATERIALS AND METHODS

29 healthy (age = 28.4 ± 7.4 years) and 15 knee OA (age = 37.6 ± 13.4 years) participants completed three maximum force isometric strength testing trials on dominant side knee extensor muscles on three devices (ND, HHD, and IKD) in two separate sessions by two raters. The maximum force (Fmax) produced, and the force-time series were recorded. Reliability and validity were assessed using Intraclass Correlation Coefficient (ICC), Bland-Altman Plots, Pearson's r, and cross-correlations.

RESULTS

The ND demonstrated excellent test-retest reliability (ICC2,3 = 0.97). The within-day (ICC2,3 = 0.88) and between-day inter-rater reliability (ICC2,3 = 0.87) was good for HHD. The ND showed excellent within-day (ICC2,3 = 0.93) and good between-day (ICC2,3 = 0.89) inter-rater reliability. The Bland-Altman analysis revealed HHD systematic bias and underestimation of force particularly with quadriceps force values exceeding 450 N. Mean differences were found in maximum force between HHD vs. IKD (MDabs = 58 N, p < .001) but not the HHD vs. ND (MDabs = 24 N, p = .267) or ND vs. IKD (MDabs = 34 N, p = .051). The concurrent validity of Fmax (r = 0.81) and force-time curve correlation (0.96 ± 0.05) were the highest between the ND and IKD.

CONCLUSIONS

The ND's test-retest reliability and concurrent validity make it a potential strength assessment tool with utility in physical therapy and fitness settings for large muscle groups such as the knee extensors.

Impact of Prolonged Sport Stoppage on Knee Injuries in High School Athletes: An Ecological Study

CONTEXT

In March 2020, public health concerns resulted in school closure throughout the United States. The prolonged sport cessation may affect knee injury risk in high school athletes. The purpose of this study was to describe and compare risk of knee injuries in high school athletes during 2019-2020 and 2020-2021 academic years, and stratify by gender, severity, mechanism of injury, injury type, and knee anatomic region.

DESIGN

Historical-prospective cohort study.

METHODS

This historical-prospective cohort study included 176 schools in 6 states matched by sport participation in control and COVID years from July 1, 2019 to June 30, 2021. Injury rates per 1000 athletes per year were calculated with 95% confidence intervals. A negative binomial regression was performed to assess potential differences in knee injuries between academic years.

RESULTS

94,847 and 72,521 high school athletes participated in the 2019-2020 (19-20) and 2020-2021 (20-21) seasons. Knee injury risk was higher in the 20-21 season (19-20: 28.89% [27.82-29.96]; 20-21: 33.82% [32.50-35.14]). Risk increased for male athletes from 2019-2020 to 2020-2021 (19-20: 29.42% [28.01-30.83]; 20-21: 40.32% [38.89-41.75]). Female knee injury risk was similar between years (19-20: 25.78% [24.29-27.27]; 20-21: 26.03% [24.31-27.75]). Knee injuries increased by a ratio of 1.2 ([95% CI, 1.1-1.3], P < .001) during 2020-2021.

CONCLUSIONS

Knee injury risk and relative risk increased among males in 2020-2021. Results indicate changes in knee injury risk following return from COVID shelter in place among high school athletes and implicate potential negative downstream effects of interrupted sports training and participation on high school injury risk.

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.

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).

Prevalence and Predictors of Concomitant Meniscal Surgery During Pediatric and Adolescent ACL Reconstruction: Analysis of 4729 Patients Over 20 Years at a Tertiary-Care Regional Children's Hospital

Background

The rate of concomitant meniscal procedures performed in conjunction with anterior cruciate ligament (ACL) reconstruction is increasing. Few studies have examined these procedures in high-risk pediatric cohorts.

Hypotheses

That (1) the rates of meniscal repair compared with meniscectomy would increase throughout the study period and (2) patient-related factors would be able to predict the type of meniscal operation, which would differ according to age.

Study Design

Cohort study (prevalence); Level of evidence, 2.

Methods

Natural language processing was used to extract clinical variables from notes of patients who underwent ACL reconstruction between 2000 and 2020 at a single institution. Patients were stratified to pediatric (5-13 years) and adolescent (14-19 years) cohorts. Linear regression was used to evaluate changes in the prevalence of concomitant meniscal surgery during the study period. Logistic regression was used to determine predictors of the need for and type of meniscal procedure.

Results

Of 4729 patients (mean age, 16 ± 2 years; 54.7% female) identified, 2458 patients (52%) underwent concomitant meniscal procedures (55% repair rate). The prevalence of lateral meniscal (LM) procedures increased in both pediatric and adolescent cohorts, whereas the prevalence of medial meniscal (MM) repair increased in the adolescent cohort (P = .02). In the adolescent cohort, older age was predictive of concomitant medial meniscectomy (P = .031). In the pediatric cohort, female sex was predictive of concomitant MM surgery and of undergoing lateral meniscectomy versus repair (P≤ .029). Female sex was associated with decreased odds of concomitant LM surgery in both cohorts (P≤ .018). Revision ACLR was predictive of concomitant MM surgery and of meniscectomy (medial and lateral) in the adolescent cohort (P < .001). Higher body mass index was associated with increased odds of undergoing medial meniscectomy versus repair in the pediatric cohort (P = .03).

Conclusion

More than half of the young patients who underwent ACLR had meniscal pathology warranting surgical intervention. The prevalence of MM repair compared with meniscectomy in adolescents increased throughout the study period. Patients who underwent revision ACLR were more likely to undergo concomitant meniscal surgeries, which were more often meniscectomy. Female sex had mixed effects in both the pediatric and adolescent cohorts.

Lower-extremity kinematics and kinetics differ based on drop vertical jump variation: An assessment of methodology for a return-to-play protocol using motion analysis

BACKGROUND

The drop vertical jump (DVJ) is commonly used in return-to-play evaluations to assess movement quality and risk during a dynamic task. However, across biomechanics literature, a multitude of DVJ variations have been used, influencing the generalizability and potential interpretation of the reported findings.

RESEARCH QUESTION

The purpose of this study was to identify differences in lower extremity kinematics and kinetics between DVJ variations that differ based on horizontal jump distance, verbal instructions, and the use of a jump target.

METHODS

A single-group repeated measures design was used in a laboratory setting. Twenty participants were tested, and three-dimensional angles and moments of the pelvis, hip, knee, and ankle were computed. Wilcoxon signed rank tests were performed to determine differences between DVJ variations.

RESULTS

Reduced knee flexion at initial contact and greater knee extensor moments across the descent phase were observed with increased horizontal jump distance. Additionally, both verbal instructions and a jump target influenced movement strategies at the pelvis, hip, and knee. Ground reaction forces were found to be similar across conditions and jump height following the first landing increased with a target.

SIGNIFICANCE

Although subtle, the biomechanical differences observed between task variations emphasize the importance of standardizing motion analysis protocols for research and clinical decision-making. Given the findings of the current study, the authors recommend using the Half Height variation in patients treated for a knee injury as it will likely be the most indicative of movement quality.

Alteration in ACL loading after total and partial medial meniscectomy

Anterior cruciate ligament (ACL) injuries are often caused by high impact loadings during competitive sports but may also happen during regular daily activities due to tissue degeneration or altered mechanics after a previous knee injury or surgery such as meniscectomy. Most existing research on ACL injury has focused on impact loading scenarios or the consequence of ACL injury on meniscus. The objective of the present study was to investigate the effects of varying degrees of medial meniscectomy on the mechanics of intact ACL by performing a poromechanical finite element analysis under moderate creep loadings. Four clinical scenarios with 25%, 50%, 75% and total medial meniscectomy were compared with the intact knee finite element model. Our results suggested that different medial meniscal resections may increase, at different extents, the knee laxity and peak tensile stress in the ACL, potentially leading to collagen fiber fatigue tearing and altered mechanobiology under normal joint loadings. Interestingly, the ACL stress actually increased during early knee creep (~ 3 min) before it reached an equilibrium. In addition, meniscectomy accelerated ACL stress reduction during knee creep, transferred more loading to tibial cartilage, increased contact pressure, and shifted the contact center posteriorly. This study may contribute to a better understanding of the interaction of meniscectomy and ACL integrity during daily loadings.

Neo-Natal Castration Leads to Subtle Differences in Porcine Anterior Cruciate Ligament Morphology and Function in Adolescence

Female adolescent athletes are at a higher risk of tearing their anterior cruciate ligament (ACL) than male counterparts. While most work related to hormones has focused on the effects of estrogen to understand the increased risk of ACL injury, there are other understudied factors, including testosterone. The purpose of this study was to determine how surgical castration in the male porcine model influences ACL size and function across skeletal growth. Thirty-six male Yorkshire crossbreed pigs were raised to 3 (juvenile), 4.5 (early adolescent), and 6 months (adolescent) of age. Animals were either castrated (barrows) within 2 weeks after birth or were left intact (boars). Posteuthanasia, joint and ACL size were assessed via MRI, and biomechanics were assessed via a robotic testing system. Joint size increased throughout age, yet barrows had smaller joints than boars. ACL cross-sectional area (CSA), length, volume, and in situ stiffness increased with age, as did the percent contribution of the ACL anteromedial (AM) bundle to resisting loads. Boar ACL, AM bundle, and PL bundle volumes were 19%, 25%, and 15% larger than barrows across ages. However, ACL CSA, in situ stiffness, and bundle contribution were similar between boars and barrows. The barrows had smaller temporal increases in AM bundle function than boars, but these data were highly variable. Early and sustained loss in testosterone leads to subtle differences in ACL morphology but may not influence measures associated with increased injury risk, such as CSA or bundle forces in response to applied loads.

Race and Gender Differences in Anterior Cruciate Ligament Femoral Footprint Location and Orientation: A 3D-MRI Study

OBJECTIVE

The femoral tunnel position is crucial to anatomic single-bundle anterior cruciate ligament (ACL) reconstruction, but the ideal femoral footprint position are mostly based on small-sized cadaveric studies and elderly patients with a single ethnic background. This study aimed to identify potential race- or gender-specific differences in the ACL femoral footprint location and ACL orientation, determine the correlation between the ACL orientation and the femoral footprint location.

METHODS

Magnetic resonance images (MRIs) of 90 Caucasian participants and 90 matched Chinese subjects were used for reconstruction of three-dimensional (3D) femur and tibial models. ACL footprints were sketched by several experienced orthopedic surgeons on the MRI photographs. The anatomical coordinate system was applied to reflect the ACL footprint location and orientation of scanned samples. The femoral ACL footprint locations were represented by their distance from the origin in the anteroposterior (A/P) and distal-proximal (D/P) directions. The orientation of the ACL was described with the sagittal, coronal and transverse deviation angles. The ACL orientation and femoral footprint position were compared by the two-sided t-test. Multiple regression analysis was used to study the correlation between the orientation and femoral footprint position.

RESULTS

The average femur footprint A/P position was -6.6 ± 1.6 mm in the Chinese group and -5.1 ± 2.3 mm in the Caucasian group, (p < 0.001). The average femur footprint D/P position was -2.8 ± 2.4 mm in Chinese and - 3.9 ± 2.0 mm in Caucasians, (p = 0.001). The Chinese group had a mean difference of a 1.5 mm (6.1%) more posterior and 1.1 mm (5.3%) more proximal in the position from the flexion-extension axis (FEA). And the males have a sagittal plane elevation about 4-5° higher than females in both racial groups. Furthermore, for every 1% (0.40 mm) increase in A/P and D/P values, the sagittal angle decreased by about 0.12° and 0.24°, respectively; the coronal angle decreased by about 0.10° and 0.30°, respectively. For every 1% (0.40 mm) increase in D/P value, the transverse angle increased by about 0.14°.

CONCLUSION

The significant race- and gender-specific differences in the femoral footprint and orientation of the ACL should be taken in consideration during anatomic single-bundle ACL reconstruction. Furthermore, the quantitative relationship between the ACL orientation and the footprint location might provide some reference for surgeons to develop a surgical strategy in ACL single-bundle reconstruction and revision.

Epidemiology of Anterior Cruciate Ligament Tears in National Collegiate Athletic Association Athletes: 2014/2015-2018/2019

PURPOSE

This study aimed to describe the epidemiology of ACL tears in NCAA men's and women's sports.

METHODS

Injury and exposure data collected within the NCAA Injury Surveillance Program from 2014/2015 to 2018/2019 were analyzed. ACL tear frequencies, injury rates (IR), and injury proportions were used to describe injury incidence by sport, event type, injury mechanism, and injury history. Injury rate ratios (IRR) were used to examine differential injury rates, and injury proportion ratios (IPR) were used to examine differential distributions.

RESULTS

A total of 729 ACL tears were reported from 8,474,401 recorded athlete exposures (AE) during the study period (IR = 0.86 per 10,000 AE), and the competition-related ACL tear rate was higher than the practice-related rate (IRR = 5.52, 95% confidence interval [CI] = 4.75-6.39). Among men's sports, the highest overall ACL tear rate was observed in men's football (IR = 1.44 per 10,000 AE), whereas among women's sports, the highest overall rate was observed in women's soccer (IR = 2.60 per 10,000 AE). Among sex-comparable sports, ACL tear rates were higher in women's basketball, softball, and soccer, as compared with their men's counterparts. ACL tears were more prevalently attributed to player contact mechanisms in men's sports than women's sports (IPR = 1.73, 95% CI = 1.37-2.19), but more prevalently attributed to noncontact mechanisms in women's sports than men's sports (IPR = 1.17, 95% CI = 1.01-1.35).

CONCLUSIONS

ACL tear risk in women's sports continues to warrant attention and prevention efforts. Given the differential rates by event type, future research efforts may also evaluate initiatives to reduce competition-related injury burden in NCAA sports.

Common Injuries in Female Competitive Softball Players

The popularity of softball is rising among female athletes with more than two million players between the ages of 12 and 18 competing per year. As participation rates increase, the frequency of injuries related to softball is on the rise. Softball injuries can differ from baseball injuries, and only a small amount of current literature focuses exclusively on softball injuries. Orthopaedic surgeons need to be prepared to evaluate, diagnose, and treat common injuries sustained while playing softball. The purpose of this study is to investigate the mechanisms of injury that are commonly encountered by female athletes in competitive fast-pitch softball and review current safety initiatives that have been implemented to aide in injury prevention.

Growth progression of anterior cruciate ligament bone grafts in a pediatric population: magnetic resonance imaging analysis

BACKGROUND

In children, the incidence of anterior cruciate ligament (ACL) ruptures and reconstructions has significantly risen. Unfortunately, re-rupture rates following surgery are substantially higher in children than adults. Previous research suggests that smaller graft diameters are predictive of re-rupture.

OBJECTIVE

This study aimed to investigate the growth progression of the ACL bone graft, specifically in terms of width and length, within the intra-articular portion and tunnels, using successive magnetic resonance imaging (MRI) scans. The hypothesis was that the ACL grafts would undergo thinning during growth.

MATERIALS AND METHODS

The cohort comprised 100 patients who underwent ACL reconstruction. Among them, 37 patients with significant residual growth were selected for analysis. Of these, 4 patients experienced graft rupture, 5 had "over-the-top" techniques, 12 had missing MRI scans and 5 were lost to follow-up. Each included patient underwent two MRI scans; the analyses of which were conducted in a double-masked manner.

RESULTS

A total of 13 knees (and patients) were analyzed, with a mean ± SD (range) delay of residual growth between the two MRI scans of 3.3 + / - 1.4 (1.2-5.2) years. The graft exhibited elongation, thinning and eventual integration with the surrounding bone in the tunnels. Within the intra-articular portion, the mean [95% CI] increase in graft size between the two MRI scans was 30.8% in length and 14.8% in width. The width/length ratio in the intra-articular part was 20.4% on the first MRI and 20.8% on the second MRI. Since this difference in the ratio (+ 0.4%) was not statistically significant (P=0.425), our results indicate that the grafts remained stable in terms of proportions without thinning or thickening. Therefore, the initial hypothesis was validated for the tunnel portion but not the intra-articular portion of the grafts.

CONCLUSION

In children with open physes, ACL grafts demonstrate smooth growth progression in all dimensions. However, this finding does not fully explain the high rate of re-rupture observed in children. Further research is needed to elucidate the underlying factors contributing to re-rupture in this population.

Anterior Cruciate Ligament Tears in the Adolescent Population: Injury Demographics and Risk of Reinjury Among High School Athletes

BACKGROUND

The incidence of anterior cruciate ligament (ACL) injuries is increasing among the adolescent population with a peak occurring in the high school age range.

PURPOSE

To characterize recent epidemiologic trends of ACL injuries, ACL reconstruction (ACLR), and retear rates in high school adolescents based on age, participating sport, and mechanism of injury.

STUDY DESIGN

Retrospective case series.

METHODS

A prospectively maintained institutional database was retrospectively reviewed for all patients 18 or younger who underwent primary ACLR between 2015 and 2020. Odds ratios were calculated for baseline patient characteristics and their association with risk of retear. Multivariate regression analysis was also performed to identify the relationship between retear and specific categorical variables.

RESULTS

A total of 482 patients were included, with a mean follow-up time of 13.0 ± 11.8 months. Patients were an average age of 16.1 ± 1.3 years old (range: 13 to 18 y). Initial presentation of ACL injuries in high school athletes often occurred at 16 years old regardless of the sport played. Based on age, high school freshmen and seniors are found to have an increased risk of ACL retear. One hundred three patients (21.6%) completed at least 2 or more years of follow-up after ACLR. Of these patients, 38.8% received a bone-tendon-bone (BTB) autograft, 36.9% hamstring autograft, 14.6% quadriceps tendon autograft, and 3.9% received hamstring allograft or other graft (eg, tibialis anterior and BTB allograft), respectively. There were 25 ipsilateral ACL retears that occurred in the patient cohort (5.2%). Thirteen (52%) of retears were females. Football and soccer were the most common sports played by patients with a retear of the ipsilateral knee (31.8% and 27.3%, respectively). Patients who were 13 to 14 or 18 years old ( P = 0.009 and 0.035, respectively) or who received a tibialis anterior/BTB allograft ( P = 0.002) were found to have increased risk of ACL retear compared with other age groups. When evaluating by sex, female soccer players had a greater risk of retear compared with male soccer players ( P = 0.007). When adjusting for multiple variables, (including age, sex, body mass index, primary reconstruction graft choice, sport, and length of follow-up), the odds of ipsilateral retear in patients who received hamstring autograft ( P = 0.02), sustained a contralateral ACL tear ( P = 0 .04), or a contact injury ( P = 0.01) were increased.

CONCLUSION

Initial presentation of ACL injuries in high school athletes often occurs at 16 years old regardless of the sport played. Based on age, high school freshmen and seniors are found to have an increased risk of ACL retear. However, the overall rate of ACL retear in high school athletes of all ages is low. Patients who underwent ACLR with hamstring tendon autograft had a greater risk of retear compared with other graft types. Female soccer players also had a greater risk of ACL retear. High school athletes must take caution when in the early high school years (underclassman) and more senior years (upperclassman), as susceptibility for ACL retears is elevated.

LEVEL OF EVIDENCE

Level IV.

Internal workload in elite female football players during the whole in-season: starters vs non-starters

The aim of this study was to quantify weekly internal workload across the in-season and compare the workload variables between starter and non-starter Spanish female first league (Liga Iberdrola) football players. Twenty-six participants belonging to the same team (age, height, and mass: 25.4 ± 6.1 years, 167.4 ± 4.8 cm and 57.96 ± 6.28 kg, respectively) participated in this study. Training loads (TL) and match loads (ML) were assessed through breath-cardiovascular (RPEbreath), leg-musculature (RPEleg) and cognitive (RPEcog) rating of perceived exertion (RPE0-10) for each training session and match during the in-season phase (35 weeks). Session-RPE (sRPE) was calculated by multiplying each RPE value by session duration (minutes). From these, total weekly TL (weekly TL+ML), weekly TL, weekly ML, chronic workload, acute:chronic workload ratio, training monotony, and training strain were calculated. Linear mixed models were used to assess differences for each dependent variable, with playing time (starter vs non-starter players) used as a fixed factor, and athlete, week, and team as random factors. The results showed that total weekly TL (d = 1.23-2.04), weekly ML (d = 4.65-5.31), training monotony (d = 0.48-1.66) and training strain (d = 0.24-1.82) for RPEbreath, RPEleg and RPEcog were higher for starters in comparison with non-starters (p = 0.01). Coaches involved in elite female football should consider implementing differential sRPE monitoring strategies to optimize the weekly load distribution for starters and non-starters and to introduce compensatory strategies to equalise players' total weekly load.

A multicomponent neuromuscular warm-up program reduces lower-extremity injuries in trained basketball players: a cluster randomized controlled trial

OBJECTIVE

To assess the effects of a novel multicomponent neuromuscular warm-up program on lower-extremity injury incidence in basketball players competing at the regional level.

METHODS

A cluster randomized controlled experimental design was adopted to compare injury incidence between players exposed to the injury prevention warm-up program and those exposed to a typical warm-up program across an entire basketball season. Four teams consisting of 57 players (male: n = 42; female: n = 15) were allocated to the intervention group (age: 21.6 ± 2.5 years; height: 186.2 ± 8.8 cm; body mass: 80.0 ± 10.4 kg) and four teams consisting of 55 players (male: n = 43; female: n = 12) were allocated to the control group (age: 21.6 ± 2.6 years; height: 186.9 ± 9.1 cm; body mass: 81.5 ± 10.9 kg). The novel warm-up combined running exercises with active stretching, plyometrics, balance, strength, and agility drills. Coaching and medical staff provided details on injury incidence each week. Data analyses included the use of poisson regression analyses and the incidence rate ratio (IRR) with 95% confidence intervals (CI).

RESULTS

The intervention group experienced a significantly lower ankle sprain incidence rate (IRR = 0.26, 95% CI = 0.05, 0.98, p = 0.02) and a tendency toward a lower knee injury incidence rate (IRR = 0.32, 95% CI = 0.03, 1.78, p = 0.07) compared to the control group. Considering only non-contact lower-extremity injuries of any type, the intervention group experienced a significantly lower incidence rate compared to the control group (IRR = 0.26, 95% CI = 0.05, 0.98, p < 0.001).

CONCLUSION

This multi-team study demonstrated a novel multicomponent warm-up program resulted in less lower-extremity injuries, particularly ankle sprains and knee injuries, compared to a typical warm-up program in regional-level male and female basketball players.

Effects of a proprioceptive focal stimulation (Equistasi®) on reducing the biomechanical risk factors associated with ACL injury in female footballers

Introduction

Football presents a high rate of lower limb injuries and high incidence of Anterior Cruciate Ligament (ACL) rupture, especially in women. Due to this there is the need to optimize current prevention programs. This study aims to verify the possibility to reduce the biomechanical risk factors associated with ACL injury, through the application of proprioceptive stimulation by means of the Equistasi® device.

Methods

Ten elite female footballers were enrolled and received the device for 4 weeks (5 days/week, 1h/day). Athletes were assessed directly on-field at four time points: T0 and T1 (evaluation without and with the device), T2 (after 2 weeks), T4 (after 4 weeks) while performing two different tasks: Romberg Test, and four sidestep cutting maneuvers bilaterally. Seven video cameras synchronized with a plantar pressure system were used, thirty double colored tapes were applied on anatomical landmarks, and three dimensional coordinates reconstructed. Vertical ground reaction forces and center of pressure data were extracted from the plantar pressure insoles. Hip, knee, and ankle flexion-extension angles and moments were computed as well as abd-adduction joint torques. From the Romberg Test both center of pressure descriptive variables and frequency analysis parameters were extracted. Each variable was compared among the different time frames, T1, T2 and T4, through Friedman Test for non-parametric repeated measures (p<0.05); Wilcoxon Signed Rank Test was used for comparing variables between T0 and T1 (p<0.05) and across the different time frames as follows: T1-T2, T2-T4 and T1-T4.

Results

Statistically significant differences in both posturographic and biomechanical variables between the assessment at T0 and T1 were detected. Reduced hip and knee abduction torques were revealed in association with reduced both ground reaction forces and ankle dorsiflexion torque from T1 up to T4.

Discussion

The proprioceptive stimuli showed to have the potential to improve cutting biomechanics mainly with respect to the ligament and quadriceps dominance theories. Results of the present study, even if preliminary and on a small sample size, could be considered promising towards the inclusion of proprioceptive training in injury prevention programs.

Collagen Gene Variants and Anterior Cruciate Ligament Rupture in Italian Athletes: A Preliminary Report

Several studies have investigated the role of genetics in anterior cruciate ligament (ACL) rupture, often returning conflicting results. The present pilot study aimed to analyze the association between six Single Nucleotide Polymorphisms (SNPs) (rs1800012; rs12722; rs13946; rs240736; rs970547; and rs4870723, located on the COL1A1, COL5A1, COL12A1, and COL14A1 genes), and ACL rupture, among Italian athletes. A hypothesis-driven association study was conducted. In total, 181 male and female athletes (n = 86 injured; n = 96 non-injured) were genotyped for the prioritized variants. All polymorphisms were genotyped using PCR RFLP, with the only exception being the rs1800012 on the COL1A1 gene, which was detected using MTPA PCR. The allele frequency distribution fell within the worldwide range. Despite the evident population variability, no selective pressure signals were recorded using PBS analysis. No significant difference was detected between the cases and controls for any of the SNPs (rs1800012; rs13946; rs240736; rs970547, and rs4870723) included in the analyses (p > 0.008, Bonferroni-adjusted for multiple comparisons). Moreover, no significant differences were found when males and females were assessed separately. Further investigations based on a larger sample size are needed, in order to draw solid conclusions for the influence between collagen genes and ACL rupture.

Anatomical factors associated with the development of anterior tibial spine fractures based on MRI measurements

BACKGROUND

Numerous studies have investigated anatomic factors for anterior cruciate ligament (ACL) injuries, such as posterior tibial slope (PTS) and notch width index (NWI). However, anterior tibial spine fracture (ATSF) as a specific pattern of ACL injury, a bony avulsion of the ACL from its insertion on the intercondylar spine of the tibia, has rarely been explored for its anatomical risk factors. Identifying anatomic parameters of the knee associated with ATSF is important for understanding injury mechanisms and prevention.

METHODS

Patients who underwent surgery for ATSF between January 2010 and December 2021 were retrospectively reviewed, and 38 patients were included in the study group. Thirty-eight patients who suffered from isolated meniscal tear without other pathologic findings were matched in a 1:1 fashion by age, sex and BMI to the study group. The lateral posterior tibial slope (LPTS), medial posterior tibial slope (MPTS), medial tibial depth, lateral tibial height, lateral femoral condyle ratio (LFCR) and NWI were measured and compared between the ATSF and control groups. Binary logistic regressions identified independent predictors of ATSF. Receiver operator characteristic (ROC) curves were performed to compare the diagnostic performance and determine the cutoff values of associated parameters.

RESULTS

The LPTS, LFCR and MPTS were significantly larger in the knees in the ATSF group than in the control group (P = 0.001, P = 0.012 and P = 0.005, respectively). The NWI was significantly smaller in the knees in the ATSF group than in the control group (P = 0.005). According to the results of logistic regression analysis, the LPTS, LFCR and NWI were independently associated with ATSF. The LPTS was the strongest predictor variable, and the ROC analysis revealed 63.2% sensitivity and 76.3% specificity (area under the curve, 0.731; 95% CI 0.619-0.844) for values above 6.9.

CONCLUSION

The LPTS, LFCR and NWI were found to be associated with the ATSF; in particular, LPTS could provide the most accurate predictive performance. The findings of this study may aid clinicians in identifying people at risk for ATSF and taking individualized preventive measures. However, further investigation regarding the pattern and biomechanical mechanisms of this injury is required.

YouTube Is a Poor-Quality Source for Patient Information Regarding Patellar Dislocations

Purpose

To evaluate the content and quality of YouTube videos concerning patellar dislocations.

Methods

"Patellar dislocation" and "kneecap dislocation" were searched on the YouTube library. The Uniform Resource Locator of the first 25 suggested videos was extracted, for a total of 50 videos. The following variables were collected for each video: number of views, duration in minutes, video source/uploader, content type, days since upload, view ratio (views/day), and number of likes. Video source/uploader was categorized as academic, physician, nonphysician, medical source, patient, commercial, and other. The Journal of the American Medical Association (JAMA), Global Quality Scale (GQS), Patellar Dislocation Specific Score (PDSS), and DISCERN scores were used to assess each video. A series of linear regression models were used to explore relationships between each of these scores and the aforementioned variables.

Results

The median video length was 4.11 minutes (interquartile range 2.07-6.03, range 0.31-53.56), and the total number of views for all 50 videos was 3,697,587 views. The mean overall JAMA benchmark score ± standard deviation was 2.56 ± 0.64, GQS: 3.54 ± 1.05, total PDSS: 5.76 ± 3.42. Physicians were the most common video source/uploader (42%). Academic sources had the greatest mean JAMA benchmark score (3.20), whereas nonphysician and physician sources had the greatest mean GQS scores (4.09 and 3.95, respectively). Videos uploaded by physicians had the greatest PDSS scores (7.5).

Conclusions

The overall transparency, reliability, and content quality of YouTube videos on patellar dislocation measured by the JAMA benchmark score and PDSS, respectively, are poor. Additionally, the overall educational and video quality, as assessed by the GQS, was intermediate.

Clinical Relevance

It is important to understand the quality of information patients receive on YouTube so providers can guide patients to greater-quality sources.

Functional Outcomes of Motor Learning Interventions in Anterior Cruciate Ligament Injuries

Anterior cruciate ligament injury is one of the pathologies that affect the daily and professional life of the majority of athletes. When the treatment options are examined, there are two options surgical treatment and conservative treatment. Rehabilitation is essential in both cases, with or without surgery. Especially for returning to sports, long-term rehabilitation after surgery has become essential. While many different exercise methods have been tried in the prevention of anterior cruciate ligament injury and rehabilitation after reconstructive surgery, many have focused on strength training. The abnormal movement pattern that occurs with the somatosensory loss seen after anterior cruciate ligament injury results in a functional loss in the injured extremity and the contralateral extremity in the long term. Considering the incidence of injury, studies to establish the normal movement pattern and restore motor control are very important. For this reason, motor learning-based interventions that support neuroplasticity are of great interest today. This review aims to examine the functional results of current motor learning-based interventions in anterior cruciate ligament rehabilitation in line with the literature.

Is muscular strength a predictor for primary or secondary ACL injury? A scoping review of prospective studies

OBJECTIVE

To identify strength-related risk factors of ACL injury by conducting a scoping review of the peer-reviewed literature.

METHODS

PubMed and EBSCO host (CINAHL Complete, MEDLINE Complete, SPORTDiscus) were searched from inception to August 2022. Prospective studies that examined strength strength-related risk factors for ACL injury (primary and secondary) were included. PRISMA Extension for Scoping Reviews guided data charting/extraction.

RESULTS

17 studies were included (eight primary ACL injury, nine secondary ACL injury). Knee flexor strength was the most studied predictor (10 studies), followed by hip abductor strength (9 studies). Across studies, measures of muscle performance were inconsistent. Significant strength-related risk factors were reported in seven of 17 studies. Potential strength-related risk factors of primary ACL injury included measures of hip strength (abductor or external rotator) and knee strength (knee flexor/extensor ratio and knee extensor strength symmetry) for secondary ACL injury. Limited/conflicting evidence was found for all strength-related risk factors.

CONCLUSION

Measures of muscle strength appear to be predictive of primary and secondary ACL injury in a subset of identified studies. The heterogeneity of study designs and lack of standardization related to strength testing make it difficult to determine the overall impact of strength in predicting ACL injury.

Age and Sex Comparisons in Pediatric Track and Field Hurdle Injuries Seen in Emergency Departments of the US

There is limited literature analyzing pediatric hurdle injuries based on sex and age. This study compares hurdle-related injury types, injured body parts, and injury mechanisms by age and sex in pediatrics. Hurdle-related injury data from the National Electronic Injury Surveillance System were used to retrospectively review the injuries of hurdlers 18 years and under. Differences in injured body parts, injury types, and mechanisms were analyzed by age (pre-high school vs. high school) and sex (male vs. female). A total of 749 cases were extracted. Fractures were more common in pre-high schoolers (34.1% vs. 21.5%, p = 0.001), while more sprains were identified in high schoolers (29.6%) than pre-high schoolers (22.8%, p = 0.036). Males suffered more fractures than females (35.1% vs. 24.3%, p = 0.001). Females sustained more joint sprains (29.1% vs. 21.0%, p = 0.012) and contusions/hematomas (12.7% vs. 7.5%, p = 0.020). Ankle injuries were more common in females (24.0%) than males (12.0%, p = 0.001), while wrist injuries were more prevalent in males (11.7% vs. 7.2%, p = 0.034). The most common injury mechanism was apparatus-related, with no differences based on age or sex. Injury types and injured body parts differed depending on age and sex in pediatric hurdle injuries seen in emergency departments. These findings may be helpful for injury prevention and medical care for pediatric hurdlers.

Preventing Osteoarthritis After an Anterior Cruciate Ligament Injury: An Osteoarthritis Action Alliance Consensus Statement

After an anterior cruciate ligament (ACL) injury, people need secondary prevention strategies to identify osteoarthritis at its earliest stages so that interventions can be implemented to halt or slow the progression toward its long-term burden. The Osteoarthritis Action Alliance formed an interdisciplinary Secondary Prevention Task Group to develop a consensus on recommendations to provide clinicians with secondary prevention strategies that are intended to reduce the risk of osteoarthritis after a person has an ACL injury. The group achieved consensus on 15 out of 16 recommendations that address patient education, exercise and rehabilitation, psychological skills training, graded-exposure therapy, cognitive-behavioral counseling (lacked consensus), outcomes to monitor, secondary injury prevention, system-level social support, leveraging technology, and coordinated care models. We hope this statement raises awareness among clinicians and researchers on the importance of taking steps to mitigate the risk of osteoarthritis after an ACL injury.

Evidence Review for Preventing Osteoarthritis After an Anterior Cruciate Ligament Injury: An Osteoarthritis Action Alliance Consensus Statement

CONTEXT

The Osteoarthritis Action Alliance formed a secondary prevention task group to develop a consensus on secondary prevention recommendations to reduce the risk of osteoarthritis after a knee injury.

OBJECTIVE

Our goal was to provide clinicians with secondary prevention recommendations that are intended to reduce the risk of osteoarthritis after a person has sustained an anterior cruciate ligament injury. Specifically, this manuscript describes our methods, literature reviews, and dissenting opinions to elaborate on the rationale for our recommendations and to identify critical gaps.

DESIGN

Consensus process.

SETTING

Virtual video conference calls and online voting.

PATIENTS OR OTHER PARTICIPANTS

The Secondary Prevention Task Group consisted of 29 members from various clinical backgrounds.

MAIN OUTCOME MEASURE(S)

The group initially convened online in August 2020 to discuss the target population, goals, and key topics. After a second call, the task group divided into 9 subgroups to draft the recommendations and supportive text for crucial content areas. Twenty-one members completed 2 rounds of voting and revising the recommendations and supportive text between February and April 2021. A virtual meeting was held to review the wording of the recommendations and obtain final votes. We defined consensus as >80% of voting members supporting a proposed recommendation.

RESULTS

The group achieved consensus on 15 of 16 recommendations. The recommendations address patient education, exercise and rehabilitation, psychological skills training, graded-exposure therapy, cognitive-behavioral counseling (lacked consensus), outcomes to monitor, secondary injury prevention, system-level social support, leveraging technology, and coordinated care models.

CONCLUSIONS

This consensus statement reflects information synthesized from an interdisciplinary group of experts based on the best available evidence from the literature or personal experience. We hope this document raises awareness among clinicians and researchers to take steps to mitigate the risk of osteoarthritis after an anterior cruciate ligament injury.

Neo-natal castration leads to subtle differences in porcine anterior cruciate ligament morphology and function in adolescence

Female adolescent athletes are at a higher risk of tearing their anterior cruciate ligament (ACL) than male counterparts. While most work related to hormones has focused on the effects of estrogen to understand the increased risk of ACL injury, there are other understudied factors, including testosterone. The purpose of this study was to determine how surgical castration in the male porcine model influences ACL size and function across skeletal growth. Thirty-six male Yorkshire crossbreed pigs were raised to 3 (juvenile), 4.5 (early adolescent), and 6 months (adolescent) of age. Animals were either castrated (barrows) within 1-2 weeks after birth or were left intact (boars). Post-euthanasia, joint and ACL size were assessed via MRI, and biomechanics were assessed via a robotic testing system. Joint size increased throughout age, yet barrows had smaller joints than boars (p<0.001 for all measures). ACL cross-sectional area (CSA), length, volume, and stiffness increased with age (p<0.0001), as did ACL anteromedial (AM) bundle percent contribution to resisting loads (p=0.012). Boar ACL, AM bundle, and PL bundle volumes were 19% (p=0.002), 25% (p=0.003), and 15% (p=0.04) larger than barrows across ages. However, CSA, stiffness, and bundle contribution were similar between boars and barrows (p>0.05). The barrows had smaller temporal increases in AM bundle percent function than boars, but these data were highly variable. Thus, early and sustained loss in testosterone leads to subtle differences in ACL morphology, but may not influence measures associated with increased injury risk, such as CSA or bundle forces in response to applied loads.

The incidence rate of ACL injuries and ankle sprains in basketball players: A systematic review and meta-analysis

OBJECTIVE

To quantify the incidence rate of anterior cruciate ligament (ACL) injuries and ankle sprains according to player sex, playing level, and exposure setting (training vs. games) in basketball players.

METHODS

PubMed, MEDLINE, Google Scholar, and ScienceDirect were searched. Only studies reporting the number of ACL injuries and/or ankle sprains alongside the number of athlete-exposures (training sessions and/or games) in basketball players were included.

RESULTS

Thirty studies (17 reporting ACL injuries and 16 reporting ankle sprains) were included in the meta-analysis. Higher (p < 0.05) ACL injury incidence rates per 1000 athlete-exposures were recorded in females (female: 0.20 95% confidence intervals [0.16-0.25]; male: 0.07 [0.05-0.08]; female-to-male ratio: 3.33 [3.10-3.57]), in players competing at higher playing levels (amateur: 0.06 [0.04-0.09]; intermediate: 0.16 [0.13-0.20]; elite: 0.25 [0.14-0.64]), and in games (games: female, 0.27 [0.21-0.32]; male, 0.06 [0.03-0.08]; training: female, 0.03 [0.02-0.05]; male: 0.01 [0.00-0.02]; game-to-training ratio: 7.90 [4.88-12.91]). Higher (p < 0.05) ankle sprain incidence rates per 1000 athlete-exposures were observed in males (female: 0.82 [0.61-1.03]; male: 0.90 [0.61-1.19]; female-to-male ratio: 0.91 [0.83-0.99]), in players competing at higher playing levels (amateur: 0.54 [0.51-0.57]; intermediate: 1.12 [1.00-1.24]; elite: 1.87 [1.29-2.46]), and in games (games: 2.51 [1.85-3.16]; training: 0.80 [0.52-0.80]; game-to-training ratio: 2.77 [2.35-3.26]).

CONCLUSION

According to player sex, ACL injury incidence rate is higher in females, while ankle sprain incidence rate is greater in males. ACL injury and ankle sprain incidence rates are greater in players competing at higher playing levels and during games compared to training.

High revision arthroscopy rate after ACL reconstruction in men's professional team sports

PURPOSE

The study analysed unique data on anterior cruciate ligament (ACL) injuries among German professional male team sports over five consecutive seasons with the aim of improving medical outcomes in the future. Sport-specific differences in injury occurrence, concomitant injuries, timing of ACL reconstruction, graft type selection and short-term complications were examined.

METHODS

This retrospective study analysed trauma insurance data on all complete ACL tears from players with at least one competitive match appearance in the two highest divisions of German male basketball, ice hockey, football and handball. Each complete ACL tear registered by clubs or physicians between the 2014/15 and 2018/19 seasons with the German statutory accidental insurance for professional athletes (VBG) as part of occupational accident reporting was included.

RESULTS

In total, 189 out of 7517 players (2.5%) sustained an ACL injury, mainly in handball (n = 82; 43.4%) and football (n = 72; 38.1%) followed by ice hockey (n = 20; 10.6%) and basketball (n = 15; 7.9%).Seventeen players (9.0%) also sustained a second ACL injury. Thus, 206 ACL injuries were included in the analysis. The overall match incidence of ACL injuries was 0.5 per 1000 h and was highest in handballs (1.1 injuries per 1000 h). A total of 70.4% of ACL injuries involved concomitant injury to other knee structures, and 29.6% were isolated ACL injuries. The highest rate of isolated ACL injuries was seen in ice hockey (42.9%). All ACL injuries, except for one career-ending injury, required surgery. In the four analysed team sports, hamstring tendons (71.4%) were the most commonly used grafts for ACL reconstruction; football had the highest percentage of alternative grafts (48.7%). During rehabilitation, 22.9% of all surgically treated ACL injuries (n = 205) required at least two surgical interventions, and 15.6% required revision arthroscopy. The main cause of revision arthroscopy (n = 32; 50.0%) was range-of-motion deficit due to arthrofibrosis or cyclops formation.

CONCLUSION

The present study shows an overall high rate of revision arthroscopy after ACLR (15.6%), which should encourage surgeons and therapists to evaluate their treatment and rehabilitation strategies in this specific subpopulation. Hamstring tendon grafts are most commonly used for ACL reconstruction but have the highest revision and infection rates. Handball shows the highest ACL injury risk of the four evaluated professional team sports. Concomitant injuries occur in the majority of cases, with the highest share of isolated ACL injuries occurring in ice hockey.

LEVEL OF EVIDENCE

Level III.

Physiotherapeutic approach to the preoperative period for the anterior cruciate ligament reconstruction: A systematic review

INTRODUCTION

The tearing of the anterior cruciate ligament (ACL) is one of the most common type of knee injury. Current evidence show that there are specific predictors for postoperative success in ACL injuries, but there is a limited number of studies on preoperative rehabilitation. Therefore, the goals of this review were to emphasize physiotherapy approaches to the preoperative period and to verify its effectiveness at the time the athlete returns to sport.

METHOD

We conducted a systematic search in these databases: Medline, Scielo, Lilacs, CINAHL, Web of Science, PeDro and Cochrane Library.

RESULTS

Our searches identified 553 occurences; of these, 511 titles and abstracts underwent triage after removal of duplicates. We identified 120 full texts for a stricter screening, amongst them, three studies included in the review for complying with the elegibility criteria.

CONCLUSION

Physiotherapic preoperative treatment exhibits weak evidence for strength gains and pain relief, as well as strong evidence of functional improvement compared to the control group. These results were reported 4 months after the ACLR, in average.

Biomechanical Effects of Prophylactic Knee Bracing on Anterior Cruciate Ligament Injury Risk: A Systematic Review

OBJECTIVE

Prophylactic knee braces (PKBs) are widely used by athletes in pivoting and landing sports and have the potential to influence knee movement and alignment, thus modulating anterior cruciate ligament (ACL) injury risk. This systematic review analyses current evidence on the biomechanical effects that PKBs have in the prevention of ACL injuries.

DATA SOURCES

The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Searches were conducted on PubMed, Web of Science, Scopus, Ovid MEDLINE, EMBASE, Cochrane, and CINAHL for studies published from inception until May 31, 2021. Included studies assessed the effects of PKBs on biomechanical variables associated with ACL injuries in landing or pivoting tasks, comparing between braced and unbraced conditions.

MAIN RESULTS

A total of 234 articles were identified; from which, 14 controlled, laboratory, biomechanical studies were included in this review. The effects of PKBs on knee biomechanics could be divided into kinematic variables in the coronal, sagittal, and transverse planes; and common kinetic variables, such as ground reaction force (GRF) and ACL load/strain. Also, PKBs were found to have protective effects in coronal and transverse plane kinematics, but results in the sagittal plane were inconclusive. Assessing knee kinetics, PKBs were advantageous in decreasing ACL load/strain but had no significant effect on GRF.

CONCLUSIONS

Prophylactic knee braces may serve to reduce ACL injury risk by modulating knee coronal and transverse plane movements and ACL load/strain during high-risk maneuvres. Precise recommendations are limited by study heterogeneity. More prospective studies are needed to assess ACL injury risk during high-risk sports using specific PKBs.

Sex Differences in the Association between Risk of Anterior Cruciate Ligament Rupture and COL5A1 Polymorphisms in Elite Footballers

BACKGROUND

Single-nucleotide polymorphisms (SNPs) in collagen genes are predisposing factors for anterior cruciate ligament (ACL) rupture. Although these events are more frequent in females, the sex-specific risk of reported SNPs has not been evaluated.

PURPOSE

We aimed to assess the sex-specific risk of historic non-contact ACL rupture considering candidate SNPs in genes previously associated with muscle, tendon, ligament and ACL injury in elite footballers.

STUDY DESIGN

This was a cohort genetic association study.

METHODS

Forty-six (twenty-four females) footballers playing for the first team of FC Barcelona (Spain) during the 2020-21 season were included in the study. We evaluated the association between a history of non-contact ACL rupture before July 2022 and 108 selected SNPs, stratified by sex. SNPs with nominally significant associations in one sex were then tested for their interactions with sex on ACL.

RESULTS

Seven female (29%) and one male (4%) participants had experienced non-contact ACL rupture during their professional football career before the last date of observation. We found a significant association between the rs13946 C/C genotype and ACL injury in women footballers (p = 0.017). No significant associations were found in male footballers. The interaction between rs13946 and sex was significant (p = 0.027). We found that the C-allele of rs13946 was exclusive to one haplotype of five SNPs spanning COL5A1.

CONCLUSIONS

The present study suggests the role of SNPs in genes encoding for collagens as female risk factors for ACL injury in football players.

CLINICAL RELEVANCE

The genetic profiling of athletes at high risk of ACL rupture can contribute to sex-specific strategies for injury prevention in footballers.

Indirect contact matters: Mid-flight external trunk perturbation increased unilateral anterior cruciate ligament loading variables during jump-landings

BACKGROUND

To determine the effect of unanticipated mid-flight medial-lateral external perturbation of the upper or lower trunk on anterior cruciate ligament (ACL) loading variables during jump-landings.

METHODS

Thirty-two participants performed double-leg vertical jump-landings while bilateral kinematics and kinetics were collected under 6 conditions (upper or lower trunk perturbation locations; no, left, or right perturbation directions). Two customized catapult apparatuses were created to apply pushing perturbation to participants near the maximal jump height.

RESULTS

The ball contacted participants near the center of mass for the lower-trunk conditions and approximately 23 cm above the center of mass for the upper-trunk conditions. Under upper-trunk perturbation, the contralateral leg demonstrated significantly smaller knee flexion angles at initial contact and greater peak knee abduction angles, peak vertical ground reaction forces, peak knee extension moments, and peak knee adduction moments compared to other legs among all conditions. Under lower-trunk perturbation, the contralateral leg showed significantly smaller knee flexion angles at initial contact and increased peak vertical ground reaction forces and peak knee extension moments compared to legs in the no-perturbation conditions.

CONCLUSION

Mid-flight external trunk pushing perturbation increased ACL loading variables for the leg contralateral to the perturbation. The upper-trunk perturbation resulted in greater changes in ACL loading variables compared to the lower-trunk perturbation, likely due to trunk and ipsilateral leg rotation and more laterally located center of mass relative to the contralateral leg. These findings may help us understand the mechanisms of indirect-contact ACL injuries and develop jump-landing training strategies under mid-flight trunk perturbation to better prevent ACL injury.

Tibial Spine Height Measured by Radiograph Is a Risk Factor for Non-Contact Anterior Cruciate Ligament Injury in Males: A Retrospective Case-Control Study

Various anatomic abnormalities are implicated in non-contact anterior cruciate ligament (ACL) injury, but researchers rarely deal with the relation between tibial spine height and ACL injury. We conducted a retrospective case-control study to include 96 patients with and without non-contact ACL injuries. Tibial plateau width (TPW), medial and lateral tibial spine height (MTSH and LTSH), and tibial spine width (TSW) were measured by radiographs. The parameters were compared among subgroups. Binary regression mode, receiver operating characteristic curves, and the area under the curve (AUC) were used to evaluate the specific correlation of the parameters with ACL injury. As a result, we found that the ratio of LTSH/TPW was larger in ACL-injured patients than in ACL-intact controls (p = 0.015). In the study group, LTSH/TPW (p = 0.007) and MTSH/TPW (p = 0.002) were larger in males than in females. The ratio of LTSH/TPW had an AUC of 0.60 and a significant OR of 1.3 for ACL injury in males, but not in females. In conclusion, LTSH was larger in patients with ACL injury and is a risk factor for ACL injury in males. The impact of increased LTSH on the impingement between the grafts and lateral tibial spine during ACL reconstruction warrants further investigation.

Strain-Dependent Diffusivity of Small and Large Molecules in Meniscus

Due to lack of full vascularization, the meniscus relies on diffusion through the extracellular matrix to deliver small (e.g., nutrients) and large (e.g., proteins) to resident cells. Under normal physiological conditions, the meniscus undergoes up to 20% compressive strains. While previous studies characterized solute diffusivity in the uncompressed meniscus, to date, little is known about the diffusive transport under physiological strain levels. This information is crucial to fully understand the pathophysiology of the meniscus. The objective of this study was to investigate strain-dependent diffusive properties of the meniscus fibrocartilage. Tissue samples were harvested from the central portion of porcine medial menisci and tested via fluorescence recovery after photobleaching to measure diffusivity of fluorescein (332 Da) and 40 K Da dextran (D40K) under 0%, 10%, and 20% compressive strain. Specifically, average diffusion coefficient and anisotropic ratio, defined as the ratio of the diffusion coefficient in the direction of the tissue collagen fibers to that orthogonal, were determined. For all the experimental conditions investigated, fluorescein diffusivity was statistically faster than that of D40K. Also, for both molecules, diffusion coefficients significantly decreased, up to ∼45%, as the strain increased. In contrast, the anisotropic ratios of both molecules were similar and not affected by the strain applied to the tissue. This suggests that compressive strains used in this study did not alter the diffusive pathways in the meniscus. Our findings provide new knowledge on the transport properties of the meniscus fibrocartilage that can be leveraged to further understand tissue pathophysiology and approaches to tissue restoration.

Single Bundle Versus Double Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

Background

Anterior cruciate ligament (ACL) tear is considered as one of the most common sport-related musculoskeletal injuries. Double bundle (DB) and single bundle (SB) surgical techniques has been widely adopted for ACL reconstruction. This systematic review aimed to provide updated evidence by comparing the short-term, mid-term, and long-term knee stability and functional outcomes of DB and SB reconstruction techniques.

Methods

We searched Medline, Web of Science, and CENTRAL. We have selected randomized controlled trials (RCTs) that compared DB and SB ACL reconstruction techniques for primary isolated ACL tear. We have assessed the following outcomes: pivot shift test, Lachman test, KT-1000/2000 knee ligament arthrometer, Lysholm knee function score, Tegner activity score, and graft failure. We have used the standardized mean difference (SMD) was to summarize the continuous outcomes while risk ratio (RR) was used to summarize the dichotomous outcomes.

Results

A total of 34 RCTs that enrolled 2,992 participants deemed eligible. Overall, DB showed significantly better outcomes in terms of pivot shift test (RR = 0.61, 95% confidence interval (CI) 0.49-0.75), Lachman test (RR = 0.77, 95% CI 0.62 to 0.95), and KT 1000/2000 arthrometer (SMD = - 0.21, 95% CI - 0.34 to - 0.08). No discernible difference was found between DB and SB techniques in the overall Lysholm score (SMD = 0.12, 95% CI - 0.03 to 0.27), Tegner score (SMD = 0.03, 95% CI - 0.17 to 0.24), or graft failure rate (RR = 0.78, 95% CI 0.33 to 1.85).

Conclusions

Our review suggests that DB ACL reconstruction technique shows significantly better knee stability and functional outcomes than SB at short-term follow-up. However, both techniques exhibit similar outcomes at mid-term and long-term follow-up.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-022-00718-0.

Non-contact Anterior Cruciate Ligament Injury Epidemiology in Team-Ball Sports: A Systematic Review with Meta-analysis by Sex, Age, Sport, Participation Level, and Exposure Type

BACKGROUND

Not all anterior cruciate ligament (ACL) injuries are preventable. While some ACL injuries are unavoidable such as those resulting from a tackle, others that occur in non-contact situations like twisting and turning in the absence of external contact might be more preventable. Because ACL injuries commonly occur in team ball-sports that involve jumping, landing and cutting manoeuvres, accurate information about the epidemiology of non-contact ACL injuries in these sports is needed to quantify their extent and burden to guide resource allocation for risk-reduction efforts.

OBJECTIVE

To synthesize the evidence on the incidence and proportion of non-contact to total ACL injuries by sex, age, sport, participation level and exposure type in team ball-sports.

METHODS

Six databases (MEDLINE, EMBASE, Web of Science, CINAHL, Scopus and SPORTDiscus) were searched from inception to July 2021. Cohort studies of team ball-sports reporting number of knee injuries as a function of exposure and injury mechanism were included.

RESULTS

Forty-five studies covering 13 team ball-sports were included. The overall proportion of non-contact to total ACL injuries was 55% (95% CI 48-62, I2 = 82%; females: 63%, 95% CI 53-71, I2 = 84%; males: 50%, 95% CI 42-58, I2 = 86%). The overall incidence of non-contact ACL injuries was 0.07 per 1000 player-hours (95% CI 0.05-0.10, I2 = 77%), and 0.05 per 1000 player-exposures (95% CI 0.03-0.07, I2 = 97%). Injury incidence was higher in female athletes (0.14 per 1000 player-hours, 95% CI 0.10-0.19, I2 = 40%) than male athletes (0.05 per 1000 player-hours, 95% CI 0.03-0.07, I2 = 48%), and this difference was significant. Injury incidence during competition was higher (0.48 per 1000 player-hours, 95% CI 0.32-0.72, I2 = 77%; 0.32 per 1000 player-exposures, 95% CI 0.15-0.70, I2 = 96%) than during training (0.04 per 1000 player-hours, 95% CI 0.02-0.07, I2 = 63%; 0.02 per 1000 player-exposures, 95% CI 0.01-0.05, I2 = 86%) and these differences were significant. Heterogeneity across studies was generally high.

CONCLUSION

This study quantifies several key epidemiological findings for ACL injuries in team ball-sports. Non-contact ACL injuries represented over half of all ACL injuries sustained. The proportion of non-contact to total ACL injuries and injury incidence were higher in female than in male athletes. Injuries mostly occurred in competition settings.

Effects of a soccer-specific vertical jump on lower extremity landing kinematics

Anterior cruciate ligament (ACL) injury frequently occurs in female soccer athletes during deceleration movements such as landings. In soccer, landings mostly occur following jumping headers. Little research has been done to determine the mechanics that follow and how they compare to standard drop vertical jumps (DVJ). The purpose of this study was to analyze differences in kinematics between the DVJ and the soccer-specific vertical jump (SSVJ) in female soccer athletes to better assess the sport-specific risk for ACL injury. A secondary aim was to compare second landings (L2) to first landings (L1). Eight female recreational soccer athletes performed DVJs and SSVJs initiated from a 31 ​cm height. Motion capture was performed during landings and data were analyzed using repeated-measures ANOVA. SSVJs produced less peak hip flexion (p ​= ​0.03) and less peak knee flexion (p ​= ​0.002) than DVJs. SSVJs also demonstrated increased ankle plantarflexion at initial contact (IC) than DVJs (p ​= ​0.005). L2s produced less peak hip (p ​= ​0.007) and knee flexion (p ​= ​0.002) than L1s. SSVJs and L2s displayed a more erect landing posture than the DVJs and L1s at the hip and knee, a known ACL risk factor. The significant results between jump styles show that the SSVJ displays mechanics that are different from the DVJ. The SSVJ may be a better sport-specific screening tool for ACL injury mechanisms than the DVJ in soccer athletes as it has a more direct translation to the sport.