Incidence Of Anterior Cruciate Ligament Injuries Research Articles

Biophysics of ACL injuries

Anterior Cruciate Ligament (ACL) injuries rank among the most prevalent and severe types of injuries, significantly impacting both athletes and non-athletes alike. These injuries not only result in immediate physical impairment, such as intense pain, substantial swelling, and a marked loss of mobility, but also carry long-term health consequences that can alter a person’s quality of life. Chronic pain, persistent instability, and an increased risk of developing osteoarthritis are among the lasting effects that can follow an ACL injury. An in-depth understanding of the biophysics behind ACL injuries is paramount for devising effective prevention and treatment protocols. Biophysics, which combines principles from physics with biological systems, provides crucial insights into the mechanical and structural integrity of the ACL and its susceptibility to injury under various conditions. This systematic review aims to collate and synthesize the current knowledge surrounding the biophysical mechanisms that underlie ACL injuries. The review encompasses a range of factors, including the biomechanical forces that place stress on the ligament, anatomical structures that may predispose individuals to injury, and physiological conditions that affect ligament health and resilience. Each of these factors plays a crucial role in the incidence and severity of ACL injuries. Biomechanical forces, for example, can involve sudden changes in direction or impact during physical activity, leading to excessive stress on the ACL. Anatomical factors might include variations in bone structure or ligament alignment that inherently increase the risk of injury. Additionally, physiological conditions such as muscle strength, flexibility, and overall ligament health can influence the likelihood and extent of an ACL injury. The findings of this review underscore the necessity of adopting integrated approaches in both injury prevention and rehabilitation. Such approaches must consider the multifaceted nature of ACL injuries, involving not only mechanical and anatomical aspects but also physiological and possibly even genetic factors. By emphasizing a multi-faceted understanding, interventions can be more effectively tailored to address the complex interplay of elements that contribute to ACL injuries. This holistic approach can lead to better outcomes for those at risk of or recovering from ACL injuries, enhancing the efficacy of prevention strategies and rehabilitation protocols.

Prescription Testosterone is Associated with an Increased Risk of Anterior Cruciate Ligament Injury

To characterize the relationship between testosterone replacement therapy (TRT) and anterior cruciate ligament (ACL) injuries. A retrospective cohort study using a large insurance database was conducted. Patients who were prescribed TRT for at least 3 months were matched with controls who were not prescribed TRT. Rates of ACL tears were compared between the cohorts. Multiple subgroups were created based on age (<25 years, 25-35, 36-45, 46-55, 56-65, and 65+). Multivariable logistic regressions were performed to determine the association of TRT with ACL tears while accounting for demographic variables and comorbidities. After matching, there were 160,839 patients in both the TRT cohort and control cohort. The incidence of ACL injuries was 17.8 per 10,000 person-years (95% CI: 16.4-19.2) for patients who were prescribed TRT and 4.9 per 10,000 person-years (95% CI: 4.1-5.7) for controls (p<0.001). Within 2 years of filling a testosterone prescription for at least 3 months, 572 (0.35%) patients experienced an ACL injury compared to only 157 (0.10%) controls during the same follow-up period (OR: 2.77; 95% CI: 2.26-3.42, p<0.001). When stratified by age, all groups except the <25 years of age group demonstrated significantly higher rate of ACL tears (OR 3.91-12.3, p<0.001-0.009). When separated by sex, males on TRT were 3.13 (95% CI: 2.50-3.93, p<0.001) times more likely while females on TRT were 1.94 (95% CI: 1.13-3.41, p=0.018) times more likely to experience an ACL injury compared to controls. This study found that patients prescribed at least three months of TRT had a significantly higher incidence of ACL injuries compared to controls within a two-year follow-up period. Level III, retrospective comparative study.

The gender and sex data gap in anterior cruciate ligament injuries in paediatric patients.

Anterior cruciate ligament (ACL) injury is a concerning problem in the paediatric population, impacting joint health and longevity. Moreover, ACL injury hampers physical activity, which is important for children's social network and general well-being. Recent data demonstrates a rise in paediatric ACL reconstructions, affecting both girls and boys. However, it is unclear whether this rise reflects a higher injury rate or a more proactive approach towards surgery, as information on nonoperated patients is lacking. Regarding gender differences, increasing evidence implies that girls engaged in pivoting sports experience a higher incidence of ACL injuries and reinjuries compared to boys. Furthermore, data suggestthat girls have inferior outcomes and lower return-to-sport rates than boys. The social context in which girls compete in sports is likely a significant contributing factor to the risk of serious knee injuries. Lack of attention and insufficient data on gender-based differences in ACL injuries, outcomesand evidence-based treatment guidelines highlight the need for further research on this topic. LEVEL OF EVIDENCE: Level IV.

Mechanisms and Prevention Strategies of Anterior Cruciate Ligament Injuries in Alpine Skiers

Alpine skiing is a sport enjoyed by more than 50 million people across the world every year. However, despite advancements in safety practices and technology, anterior cruciate ligament (ACL) injuries remain a significant concern. This narrative review investigates the prevalence and mechanisms of ACL injuries in alpine skiing and differentiates between intrinsic (e.g., age, sex, and skill level) and extrinsic factors (e.g., equipment design and environmental conditions) that contribute to the risk of ACL injuries. This article outlines 4 primary mechanisms through which ACL injuries occur, highlighting the complex physical demands of skiing and the role of skier behavior and environmental interactions in injury occurrence. Based on these findings, this article advocates for neuromuscular training (NMT) as a possible effective prevention strategy. NMT enhances muscular coordination and strength, balance, and agility through exercises that mimic skiing movements, potentially lowering the risk of ACL injuries. By providing a detailed analysis of ACL injury risk factors and prevention strategies in the sport, this review offers valuable insights for reducing injury rates and underscores the importance of NMT to mitigate the high incidence of ACL injuries in alpine skiing.

Biomechanical Demand during 90° and 135° Cutting Manoeuvres: Implications for Anterior Cruciate Ligament Injury

Background: Anterior cruciate ligament (ACL) injuries in athletes have financial and health consequences and are considered career-threatening. The current study aimed to shed light on biomechanical differences between various change of direction (COD) manoeuvres. Understanding such differences is important, given their association with the incidence of non-contact ACL injuries. Methods: Thirty-six male recreational soccer players participated and performed 90° and 135° COD manoeuvres. For gait analysis, the Vicon system was used. The speed and shoe-surface interface were standardized in the COD manoeuvres. Paired sample t-tests were used to compare conditions. Results: A Greater peak external knee abduction moment (PEKAM) (p&lt;0.001) and knee abduction angle at initial contact (IC) (p&lt;0.001) in the 135° COD manoeuvre compared to the 90° COD manoeuvre were observed, highlighting the increased injury risk potential at greater COD angles. In addition, the hip sagittal plane range of motion (RoM) from IC to peak knee valgus angle was higher in the 135° COD manoeuvre than 90° COD manoeuvre (p&lt;0.001). Conclusion: The results of the current study support the idea that ACL biomechanical risk factors are angle-dependent. A sharper cutting angle showed a higher risk of ACL injury due to the increase in the PEKAM and the knee abduction angle at initial contact. Therefore, players should be trained to reduce high PEKAM and the knee abduction angle by using different strategies.

Effect of Preoperative Anterolateral Ligament Injury on Outcomes After Isolated Acute ACL Reconstruction With Hamstring Graft: A Prospective Study With Minimum 5-Year Follow-up

Background: The potential influence of a preoperative anterolateral ligament (ALL) lesion seen on magnetic resonance imaging (MRI) on the mid- and long-term surgical outcomes of anterior cruciate ligament (ACL) reconstruction is still controversial. Purpose: To evaluate the clinical outcomes and failure rate of isolated ACL reconstruction at a minimum 5-year follow-up in patients with and without ALL injury diagnosed preoperatively using MRI. Study Design: Cohort study; Level of evidence, 2. Methods: A prospective cohort of patients with acute ACL injury was divided into 2 groups based on the presence (ALL injury group) or absence (control group) of ALL injury on preoperative MRI. This is a longer-term follow-up study of a previously published study that had a minimum 2-year follow-up. Both groups underwent anatomic isolated reconstruction of the ACL. The Lysholm and subjective International Knee Documentation Committee scores, KT-1000 arthrometer and pivot-shift tests, reconstruction failure rate, incidence of contralateral ACL injury, presence of associated meniscal injury, and presence of knee hyperextension were evaluated. The evaluation at the 5-year follow-up was also compared with the same patient’s evaluation at 2 years of follow-up. Results: A total of 156 patients were evaluated. No significant differences were found between the groups in the preoperative evaluation. In the postoperative evaluation, patients in the ALL injury group had a higher reconstruction failure rate (14.3% vs 4.6% for the control group; P = .049) and worse clinical outcomes according to the Lysholm scores (85.0 ± 10.3 vs 92.3 ± 6.6; P < .00001). Although the pivot-shift test results were similar, anteroposterior translation using the KT-1000 arthrometer revealed worse results for the ALL injury group (2.8 ± 1.4 mm vs 1.9 ± 1.3 mm; P = .00018). Patients in the ALL injury group also had an increase in KT-1000 arthrometer values from 2 to 5 years (2.4 ± 1.6 vs 2.8 ± 1.4; P = .038). Patients in the control group had no differences in outcomes from 2 to 5 years of follow-up. Conclusion: Combined ACL and ALL injuries were associated with significantly less favorable outcomes than were isolated ACL injuries at a minimum follow-up of 5 years after isolated ACL reconstruction with hamstring autograft. Patients with concomitant ALL injury showed a higher failure rate and worse functional scores. Also, knee stability tended to slightly worsen from 2 to 5 years in cases of associated ALL injury.

Lower-Extremity Visuomotor Reaction Time Is Not Different Between Males and Females Following Anterior Cruciate Ligament Reconstruction

Visuomotor reaction time (VMRT) is predictive of lower-extremity musculoskeletal injury and may be a modifiable anterior cruciate ligament (ACL) injury risk factor that affects the incidence of primary and secondary ACL injuries in females. However, it is unknown if females with ACL reconstruction (ACLR) experience diminished VMRT compared with their male counterparts. The purpose of this study was to compare lower-extremity VMRT (LEVMRT) between males and females with ACLR. Female (n = 40) and male (n = 20) participants who were between 4 and 12 months after primary, unilateral ACLR completed a LEVMRT task with each limb using a series of wireless light discs. Mann–Whitney U tests were used to compare between-group differences for LEVMRT (in milliseconds). No statistically significant sex differences were observed for LEVMRT when the ACLR limb deactivated the light discs (females = 509.5 [132.5], males = 507.0 [79.8]; p = .77) or when the ACLR limb was stabilizing while the nonsurgical limb deactivated the light discs (females = 528.5 [105.3], males = 546.0 [92.5]; p = .77). Both males and females may benefit from visual motor training to improve VMRT after ACLR.

Total knee arthroplasty after anterior cruciate ligament reconstruction: a narrative review.

Knee replacement following anterior cruciate ligament (ACL) reconstruction can be demanding due to altered anatomy, soft tissue scars, bone loss, extensor mechanism complications, and knee instability. This narrative review summarizes the strategies and approaches to managing operative challenges in total knee arthroplasty (TKA) following ACL reconstruction. Studies reporting outcomes of patients who underwent TKA after ACL reconstruction were retrieved and assessed to be included in this review that synthesizes the available evidence highlighting the pitfalls encountered during surgery, the intraoperative challenges posed by ligament balancing and exposure, and the leading role of modular and retained implants. TKA following ACL reconstruction has a high rate of intra-operative complications such as instability, bone loss, difficult exposure and demanding soft tissue balancing, representing a revision surgery rather than routine primary knee arthroplasty and a revision-oriented skill set and modular components are recommended to significantly optimize both surgical strategy and patient outcomes. With a rising incidence of ACL injuries and growing reconstructions, anticipating an increase in TKA procedures, this review aims to provide a call for rethinking clinical approaches to ensure effective and patient-centric care. This narrative review seems to indicate that TKA after ACL reconstruction should be considered as revision surgery and modular components should be used. However, future prospective and high-quality studies are required to better clarify risk factors and give strong recommendations for this complex surgery.

Evaluating the Efficacy of Reconstruction: Systematic Review of Six-Strand Hamstring Autografts for Anterior Cruciate Ligament Reconstruction: Biomechanical and Clinical Outcomes

Introduction: Anterior Cruciate Ligament (ACL) injuries are a major concern in orthopedics, particularly affecting active individuals and often necessitating surgery. The incidence of ACL injuries is rising, especially in women, comprising half of knee joint injuries. These injuries, common in sports with pivoting actions, can lead to long-term joint issues like osteoarthritis. Advances in surgical methods and understanding of postoperative recovery are crucial for improving patient outcomes, with considerations for graft size, material, and reconstruction technique critical in the rehabilitation process. Material and Methods: A systematic review was conducted by searching PubMed, MEDLINE, and SCOPUS for studies from 2009 to 10 February 2024, focusing on “six-strand hamstring graft” outcomes in ACL reconstruction. Inclusion criteria were English publications on 6HS autografts’ biomechanical and clinical outcomes. Excluded were non-specific, BTB, or hybrid studies, and non-research articles. Out of 347 records, 9 were analyzed after rigorous screening and quality assessment. This review, emphasizing six-strand hamstring autografts, enriches orthopedic knowledge, particularly for ACL surgery. Results: This review evaluated studies on six-strand hamstring (6HS) autografts for ACL reconstruction, encompassing prospective, retrospective, and cadaveric studies with subjects ranging from 12 to 413. Findings indicate that 6HS autografts enhance knee stability and increase graft diameter, correlating with reduced graft failure rates and improved clinical outcomes, including high patient satisfaction and low re-injury rates. Rehabilitation varied, with recovery times quicker due to larger graft sizes, and most studies reported low complication rates, underscoring 6HS autografts’ efficacy in ACL surgery. Conclusions: Performing 6HS autografts in ACL reconstruction reveals that they offer improved knee stability and graft diameter, leading to better clinical outcomes. These autografts are associated with high patient satisfaction and low re-injury rates, suggesting their effectiveness in mimicking native ACL function and enhancing rehabilitation. However, research limitations highlight the need for further long-term, comprehensive studies.

Influence of the Menstrual Cycle and Training on the Performance of a Perturbed Single-Leg Squatting Task in Female Collegiate Athletes.

Anterior cruciate ligament (ACL) injuries often occur when an athlete experiences an unexpected disruption, or perturbation, during sports. ACL injury rates may also be influenced by the menstrual cycle. To determine whether training adaptations to knee control and muscle activity during a perturbed single-leg squatting (SLS) task depend on menstrual cycle phase in female athletes. Controlled laboratory study. A total of 21 healthy female collegiate athletes (current or former [<3 years]) who competed in 9 different sports performed an SLS task in which they attempted to match their knee position (user signal) to a target signal. The protocol consisted of a 9-condition pretest, 5 sets of 3 training trials, and a 9-condition posttest. One perturbation was delivered in each condition by altering the resistance of the device. Sagittal knee control (absolute error between the target signal and user signal) was assessed using a potentiometer. Muscle activity during perturbed squat cycles was normalized to maximal activation and to corresponding muscle activity during unperturbed squat cycles (%unperturbed) within the same test condition. Athletes performed the protocol during a distinct menstrual cycle phase (early follicular [EF], late follicular [LF], midluteal [ML]). Two-way mixed analysis of variance was used to determine the effects of the menstrual cycle and training on knee control and muscle activity during task performance. Venous blood was collected for hormonal analysis, and a series of health questionnaires and anthropometric measures were also assessed to determine differences among the menstrual cycle groups. After training, athletes demonstrated better knee control during the perturbed squat cycles (lower absolute error, P < .001) and greater soleus feedback responses to the perturbation (%unperturbed, P = .035). Better knee control was demonstrated in the ML phase versus the EF phase during unperturbed and perturbed squat cycles (P < .039 for both). Quadriceps activation was greater in the ML phase compared with the EF and LF phases, both immediately before and after the perturbation (P < .001 for all). Athletes learned to improve knee control during the perturbed performance regardless of menstrual cycle phase. The best knee control and greatest quadriceps activation during the perturbed squatting task was found in the ML phase. These findings may correspond to a lower incidence of ACL injury in the luteal phase and alterations in exercise performance across the menstrual cycle.

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

To identify the risk of anterior cruciate ligament (ACL) injury in adolescent athletes based on sex, sport, and sport affiliation. A literature search was performed using 3 online databases (PubMed, Cochrane Library, andEMBASE) 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 andCross-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). 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. 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 II; meta-analysis of Level I and II studies.

The Relationship Between Isometric Hip Strength and Incidence of Noncontact Anterior Cruciate Ligament Injuries in Female Athletes: A Critically Appraised Topic

Clinical Scenario: Noncontact anterior cruciate ligament (ACL) injuries are prevalent among athletes in multiplanar sports, especially females. Hip strength may contribute to the incidence of these injuries due to dynamic movement patterns at the knee. Clinical Question: Does hip strength impact the incidence of noncontact ACL injuries in female athletes? Summary of Key Findings: A literature search was conducted on the relationship between hip strength and noncontact ACLs. Three prospective studies measuring isometric hip strength and recording the number of noncontact ACL injuries that occurred within a time period were included. One study demonstrated lower isometric hip adductor-to-abductor ratio was associated with noncontact ACL injuries. Two studies demonstrated those with noncontact ACL injuries had greater isometric hip abduction strength. Clinical Bottom Line: Evidence suggests that greater isometric hip strength and low hip adductor-to-abductor strength ratio may be a risk factor that is associated with noncontact ACL injuries in females. Future research should investigate the impact of hip strength on the incidence of noncontact ACL injuries, across all genders. Strength of Recommendation: Based on the Center of Evidence-Based Medicine, these studies provide Level 3 evidence that hip strength is associated with the risk of noncontact ACL injuries in females.

A Critical Analysis of the Factors Contributing to Anterior Cruciate Ligament Injuries in Female Athletes.

Anterior Cruciate Ligament (ACL) injuries are a prevalent concern in athletic population, particularly among female athletes who are disproportionately affected. The increased incidence of ACL injuries in females is attributed to a combination of anatomical, physiological, and biomechanical factors that influence knee stability. This review comprehensively explores these contributing factors, highlighting gender-specific anatomical differences such as wider pelvis, increased quadriceps (Q) angle, and steeper tibial slopes, all of which predispose females to greater knee valgus during dynamic activities. Furthermore, hormonal influences and greater ligament laxity are discussed as physiological contributors to increased ACL injury risk. Biomechanical factors such as reduced knee flexion, increased knee valgus, and altered muscle activation patterns further amplify the risk of ACL tears in female athletes. Despite extensive research, gaps remain in the understanding of how these factors interact and influence injury susceptibility. This article is focussed on the critical points in the current literature, analyzing key risk factors, and identifying future research directions that can inform more effective prevention strategies. A better understanding of these factors will ultimately contribute to reducing the incidence of ACL injuries among female athletes and improving long-term strength and stability of knee joint.

Physeal-Sparing, All-Inside Anterior Cruciate Ligament Reconstruction Using Quadrupled Semitendinosus Autograft and Suture Tape Augmentation for Skeletally Immature Patients

The anterior cruciate ligament (ACL) is the primary soft-tissue structure for anterior stabilization of the knee and is one of the most frequently injured structures. The incidence of ACL injuries in children and adolescents ranges from 92 to 151 per 100,000 person-years. The choice of surgical treatment for this population group is controversial, with a widespread concern that adult reconstruction techniques may damage the epiphyseal plate, compromise growth, or cause deformity. In this article, we describe a physeal-sparing, all-inside ACL reconstruction technique for skeletally immature patients. This technique is supported by retrograde drilling of the femoral tunnel and retrograde drilling of the tibial tunnel, both of which are able to avoid the epiphyseal growth line. Fixation of the quadrupled semitendinosus autograft and suture tape augmentation are achieved by soft-tissue buttons on the femur and tibia. The surgical details of this reproducible reconstruction technique are elaborated.

Prevalence and mechanisms of anterior cruciate ligament tears in military personnel: A cross-sectional study in Iran.

Anterior cruciate ligament (ACL) tear is common in military setting; such an injury increase institutional costs and workforce strain, however, few studies have investigated the mechanism and associated factors of ACL tear specifically in a military setting. The aim of this study was to investigate the prevalence and mechanisms of ACL tears in military personnel at a military referral hospital in Iran. This cross-sectional study examined 402 military personnel who presented with knee complaints at a single referral Iranian military hospital. The ACL injury prevalence and mechanisms were assessed by physical examination, medical records, and magnetic resonance imaging (MRI) of the knee. Data were collected by an orthopedic resident. Of the total 402 patients, 285 were diagnosed with ACL tears; the prevalence was 70.9%. The most common mechanism leading to ACL tear was noncontact events. The knee changing direction-knee pivoting (54%) was the most frequent lower limb status, followed by a fall with the knee in valgus position (20.7%). The most commonly associated activity was military training (63.9%) and sports activities (32.6%). The incidence of ACL injuries was higher in soldiers compared with officers during military training, but higher in officers during sports exercises (P = 0.002). Common associated injuries involved the knee meniscus and cartilage. The findings support those of previous studies, that in military personnel, the most common knee injury is damage to the ACL, most frequently through noncontact events, specifically knee pivoting, during military activities rather than sports and among soldiers. These findings help develop ACL injury prevention programs.

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

The effect of trunk stability and dynamic balance warm-up exercises on physical functional improvement remains unelucidated. This study examined whether exercises could prevent anterior cruciate ligament (ACL) injury and improve trunk muscle activation and dynamic balance in gymnasts. This comparison study, involving gymnastics practice sessions, included 31 university gymnasts and was conducted in two periods: 1 year of observation followed by 2 years of intervention. Participants performed a trunk and dynamic balance warm-up exercise program during the intervention. The effect of exercise on the incidence of ACL injury was evaluated. In addition, the paired t-test was used to compare the Y-balance distance and the changes in muscle thickness associated with trunk muscle activation at rest and during plank. ACL injury risk during the intervention was significantly lower, with a relative risk of 0.23 (P=0.02, 95% CI: 0.06-0.88). Changes in muscle thickness with activation of the transversus abdominis (P<0.01, mean difference 4.1, 95% CI: 9.97-28.07, Cohen's d=0.52), internal oblique (P<0.01, mean difference 5.2, 95% CI: 9.72-21.55, Cohen's d=0.65), and external oblique (P<0.01, mean difference 5.5, 95% CI: 20.44-39.09, Cohen's d=0.71) muscles were significantly higher during the intervention. The Y-balance distance was also significantly greater in the posterior medial reach (P<0.01, mean difference 3.3, 95% CI: 1.56-6.26, Cohen's d=0.46) during the intervention. Exercise-based warm-up programs may decrease ACL injuries. It can improve physical functions, such as the rate of change in trunk muscle thickness and the posterior medial distance during Y balance.

Better Safe Than Sorry? A Systematic Review with Meta-analysis on Time to Return to Sport After ACL Reconstruction as a Risk Factor for Second ACL Injury.

OBJECTIVE: To compare the time to return to sport (RTS) between patients who did and did not suffer a second anterior cruciate ligament (ACL) injury after ACL reconstruction. DESIGN: Etiology systematic review with meta-analysis. LITERATURE SEARCH: Cochrane Library, Embase, Medline, AMED, and PEDro databases were searched in August 2021 and again in November 2022. STUDY SELECTION CRITERIA: Clinical studies reporting time to RTS after ACL reconstruction and second ACL injury were eligible. DATA SYNTHESIS: We pooled continuous data (time [months] and proportions [%]), with random-effects meta-analyses. Pooled estimates were summarized in forest plots. A qualitative data synthesis was also performed. RESULTS: Twenty-one studies were included in the meta-analysis and 33 in the qualitative synthesis. Pooled incidence of second ACL injury was 16.9% (95% confidence interval [CI]: 12.8, 21.6). Patients who suffered a second ACL injury returned to sport significantly earlier (25 days; 95% CI: 9.5, 40.4) than those who did not suffer another injury. There was no difference in time to RTS for professional athletes who suffered a second ACL injury and those who did not. The certainty of evidence was very low. CONCLUSION: There was very low-certainty evidence that patients who suffered a second ACL injury had returned to sport 25 days earlier than patients who did not have another injury. For professional athletes, there was no difference in time to RTS between athletes who suffered a second ACL injury and athletes who did not. J Orthop Sports Phys Ther 2024;54(3):1-15. Epub 30 November 2023. doi:10.2519/jospt.2023.11977.

Anterior cruciate ligament (ACL) injury: correlation with MRI morphometry

BackgroundThis study aims to investigate the association between bony morphological features and ACL injury and to identify potential risk factors for the identification and prevention of ACL injuries. The study used knee MRIs to examine the distal femoral and proximal tibia morphology of 500 patients aged 19–50, including 250 cases with an injured ACL and 250 controls with a non-injured ACL. Previous literature has shown that ACL injuries are a common occurrence in sports and can have serious long-term consequences. Several risk factors have been identified, including anatomical variations in the bony structures of the knee. However, the relationship between bony morphology and ACL injury is not well understood, and there is a need to investigate the potential role of these factors in the identification and prevention of ACL injuries. This study was necessary because of the high incidence of ACL injuries and the potential long-term consequences, such as osteoarthritis, associated with this injury. By identifying potential risk factors, such as bony morphological features, it may be possible to develop targeted prevention strategies to reduce the incidence of ACL injuries. The study also adds to the existing literature by providing new insights into the relationship between bony morphology and ACL injury, and by identifying specific parameters that can be used to predict ACL injury. ResultsThere was a significant difference in bony morphology between ACL-injured and non-injured patients. The most convincing parameters of femur and tibia were notch width index (NWI), medial tibial plateau depth (MTPD), and lateral tibial plateau slope (LTPS). A significantly smaller intercondylar notch was seen in the injured patients (mean 17.25 mm) than in controls (mean 18.41 mm) (p < 0.001, unpaired t test). The findings indicate that among all the features assessed, the medial tibial plateau depth (MTPD) stands out as the most statistically significant with an odds ratio of 2.4, and it demonstrates a substantial association.ConclusionsACL-injured patients have a narrower NWI, shallower MTPD, and steeper LTPS, which appear to be associated with ACL injury. Identifying the cut-off values for these parameters can help predict ACL injury.

Poster 323: Factors Impacting Return to Sport Timing Following ACL Reconstruction

Objectives: Forty-one percent of sports injuries are knee injuries. One-fifth of knee injuries involve the anterior cruciate ligament (ACL). The high incidence of ACL injuries results in approximately 129,000 ACL reconstructions in the United States each year. Timing of return to sport (RTS) after ACL reconstruction (ACLR) depends on clearance by the medical team, patients meeting objective RTS criteria, and patient selected timing. A criterion-based approach to RTS commonly includes measurements of quadriceps strength, hop performance, and subjective knee function to guide the decision-making of orthopedic surgeons and physical therapists regarding patient readiness and safety to RTS. Therefore, the purpose of this study was to assess patient-related predictors (age, sex, graft type, psychological readiness, and the duration of physical therapy) of time to pass RTS criteria. We hypothesized that patients with more positive psychological readiness, those who were still completing physical therapy, and male patients would pass RTS testing at earlier time points, while graft type and age would have no effect. Methods: Fifty-four participants between the ages of 10 and 25 years and within 5 to 15 months of ACL reconstruction who were planning to return to at least 50 hours per year of cutting and pivoting activities were included. Patients with a previous history of surgery to either knee or concomitant posterior cruciate ligament reconstruction were excluded from the study. Participants completed clinic testing when RTS was being planned. Testing included unilateral quadriceps strength in each limb (isometric at 90° knee flexion using a crane scale and 1-repetition maximum using a knee extension machine), 4 single-legged hop tests (single, crossover and triple hop for distance; 6-meter timed hop), and self-reported knee function (International Knee Documentation Committee Subjective Knee Form 2000 [IKDC], Global Rating Scale). In order to pass, participants needed scores of at least 90% symmetry for both quadriceps strength measures and all 4 single-legged hop tests as well as 90% on the IKDC and Global Rating Scale. Participants repeated clinic testing until they passed the entire testing battery in a single session. On the day of passing all RTS criteria, psychological readiness was assessed using the ACL Return to Sport after Injury (ACL-RSI) survey. The ACL-RSI is a valid and reliable outcome tool that assesses the participant’s emotional wellbeing, confidence in performance, and risk appraisal. An additional survey question was used to identify if participants were still participating in physical therapy (PT) at the time of passing RTS testing or when they had finished working with a physical therapist. PT was categorized as either a) &lt;6 months of PT, b) 6-8 months of PT, or c) &gt;8 months of PT or still currently in PT. Multivariate linear regression was used to assess the association between age, sex, graft type, ACL-RSI score, and duration of PT on the time to passing RTS testing after ACL reconstruction. An alpha level of p&lt;0.05 was set a priori. Results: The mean age of the participants in this study was 17.3±2.7 years and 50% were female. Graft type and duration of physical therapy data are presented in Table 1. The mean time for passing all components of the RTS test battery was 10.3 ±2.6 months. At the time of passing RTS testing, the mean ACL-RSI score was 86.1±14.2%. Age, sex, graft type, ACL-RSI scores and duration of PT accounted for 44.5% of the variation in the time to pass RTS testing (p&lt;0.001). Sex (β=-0.426; p&lt;0.001), graft type (β=0.340; p=0.008), and age (β=0.194; p=0.111) were the strongest predictors of time to pass RTS testing with younger age correlating with shorter RTS times. Sex (Male: 8.6±3.1 months; Female: 11.1±3.5 months) and graft type (Hamstring: 7.7± 3.9 months; Quadriceps Tendon: 10.8±2.7 months; Patellar Tendon: 11.5±2.6 months; Allografts and IT band: 7.2±1.4 months), were significant predictors of time to pass RTS criteria while PT duration and ACL-RSI were not significant predictors. Conclusions: Female patients and patients with a patellar tendon or quadriceps graft took longer to meet objective RTS criteria after ACL reconstruction. Education with female patients and those with quadriceps and patellar tendon autografts may be required to establish realistic expectations for RTS readiness. While many factors impact graft choice, time to pass RTS criteria is an additional consideration for surgeons and patients. Additionally, previous studies have shown that male patients are more likely to experience graft retear following ACLR than females. This finding could be the result of male patients returning to sport earlier than females, giving the graft less time to heal. [Table: see text]

Generalised joint hypermobility leads to increased odds of sustaining a second ACL injury within 12 months of return to sport after ACL reconstruction

ObjectivesTo determine the 12-month risk of a second anterior cruciate ligament (ACL) injury in a population of patients with and without generalised joint hypermobility (GJH) who return to sports (RTS)...