Higher Anterior Cruciate Ligament Injury Research Articles

Soccer and volleyball players do not land differently: implications for anterior cruciate ligament injury risk.

Non-contact anterior cruciate ligament injuries are common in soccer and volleyball, occurring during changes of direction and landings. This study aimed to investigate kinematic differences between soccer and volleyball players in single-planar and multiplanar landing tasks, simulating sport-specific injury mechanisms. Since the anterior cruciate ligament injury rate in soccer is higher than in volleyball, we hypothesized that volleyball players would adopt safer landing strategies, especially in single-planar landing tasks. Twenty-two soccer and 19 volleyball players performed single-leg drop landing, drop jump in vertical, 45°-medial and 45°-lateral directions. Box height and jump length were adapted to the subject's height and performance level, respectively. A 9-camera motion capture system provided lower limb kinematics. Two mixed multivariate analyses of covariance (sport, task, sex as covariate) were used to compare soccer and volleyball players' initial contact and peak kinematics (α=0.05). Task had significant effects on lower limb initial contact and peak angles, as expected. Sport and task × sport interaction had no significant effects on kinematics. Soccer and volleyball players' landing strategies were thus similar in each task, in opposition to initial hypotheses. We might speculate that the higher anterior cruciate ligament injury rate in soccer may be more related to non-predictable factors than the isolated landing kinematics.

Clinical Outcomes After ACL Reconstruction in Soccer (Football, Futbol) Players: A Systematic Review and Meta-Analysis.

The risk factors for anterior cruciate ligament (ACL) tear for athletes participating in pivoting sports includes young age and female sex. A previous meta-analysis has reported a reinjury rate of 15% after ACL reconstruction (ACLR) for athletes across all sports. To the best of the authors' knowledge, this is the first systematic review and meta-analysis of available literature reporting outcomes after ACLR in soccer players. To review and aggregate soccer-specific outcomes data after ACLR found in current literature to help guide a more tailored discussion regarding expectations and prognosis for soccer players seeking operative management of ACL injuries. A comprehensive search of publications was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SPORTDiscus databases. Inclusion criteria consisted of original studies, level of evidence 1 to 4, studies reporting clinical and patient-reported outcomes (PROs) after primary ACLR in soccer players at all follow-up length. The primary outcomes of interest were graft failure/reoperation rates, ACL injury in contralateral knee, return to soccer time, and PROs. Level 4. Search of literature yielded 32 studies for inclusion that involved 3112 soccer players after ACLR. The overall graft failure/reoperation rate ranged between 3.0% and 24.8% (mean follow-up range, 2.3-10 years) and the combined ACL graft failure and contralateral ACL injury rate after initial ACLR was 1.0% to 16.7% (mean follow-up range, 3-10 years); a subgroup analysis for female and male players revealed a secondary ACL injury incidence rate of 27%, 95% CI (22%, 32%) and 10%, 95% CI (6%, 15%), respectively. Soccer players were able to return to play between 6.1 and 11.1 months and the majority of PROs showed favorable scores at medium-term follow-up. Soccer players experience high ACL injury rates after primary ACLR and demonstrated similar reinjury rates as found in previous literature of athletes who participate in high-demand pivoting sports.

Preliminary brain-behavioral neural correlates of anterior cruciate ligament injury risk landing biomechanicsusing a novelbilateral leg press neuroimaging paradigm.

Anterior cruciate ligament (ACL) injury risk reduction strategies primarily focus on biomechanical factors related to frontal plane knee motion and loading. Although central nervous system processing has emerged as a contributor to injury risk, brain activity associated with the resultant ACL injury-risk biomechanics is limited. Thus, the purposes of this preliminary study were to determine the relationship between bilateral motor control brain activity and injury risk biomechanics and isolate differences in brain activity for those who demonstrate high versus low ACL injury risk. Thirty-one high school female athletes completed a novel, multi-joint leg press during brain functional magnetic resonance imaging (fMRI) to characterize bilateral motor control brain activity. Athletes also completed an established biomechanical assessment of ACL injury risk biomechanics within a 3D motion analysis laboratory. Knee abduction moments during landing were modelled as a covariate of interest within the fMRI analyses to identify directional relationships with brain activity and an injury-risk group classification analysis, based on established knee abduction moment cut-points. Greater landing knee abduction moments were associated with greater lingual gyrus, intracalcarine cortex, posterior cingulate cortex and precuneus activity when performing the bilateral leg press (all z > 3.1, p < .05; multiple comparison corrected). In the follow-up injury-risk classification analysis, those classified as high ACL injury-risk had greater activity in the lingual gyrus, parietal cortex and bilateral primary and secondary motor cortices relative to those classified as low ACL injury-risk (all z > 3.1, p < .05; multiple comparison corrected). In young female athletes, elevated brain activity for bilateral leg motor control in regions that integrate sensory, spatial, and attentional information were related to ACL injury-risk landing biomechanics. These data implicate crossmodal visual and proprioceptive integration brain activity and knee spatial awareness as potential neurotherapeutic targets to optimize ACL injury-risk reduction strategies.

Revision Anterior Cruciate Ligament Reconstruction Outcomes in Younger Patients: Medial Meniscal Pathology and High Rates of Return to Sport Are Associated With Third ACL Injuries

Background: There are limited data evaluating the outcomes of revision anterior cruciate ligament (ACL) reconstruction surgery in younger patients despite recent reports that the rates of graft rupture are higher in young cohorts. Purpose: To explore the outcomes of revision ACL reconstruction surgery in younger patients with the specific aims of determining the rates of third ACL injury and whether knee pathology at the time of revision surgery and return to sport were associated with further injury. Study Design: Case-control study; Level of evidence, 3. Methods: The study cohort consisted of 151 consecutive patients who were aged 25 years or younger at the time of their first revision ACL reconstruction. The number of subsequent ACL injuries (graft rerupture or contralateral injury to the native ACL) was determined at a mean follow-up time of 4.5 years (range, 2-9 years). Surgical details were recorded, along with a range of sport participation outcomes. Contingency tables were used to assess the associations between subsequent ACL injury and return to sport, knee pathology, and the drilling of new femoral or tibial tunnels at revision surgery. Results: The follow-up rate was 85% (128/151). Graft reruptures occurred in 20 patients (16%) at a mean time of 2 years after revision surgery. Contralateral ACL injuries occurred in 15 patients (12%) at a mean time of 3.9 years. The total number of patients who had a third ACL injury was 35 (27%). There was a significant association between having medial meniscal pathology and sustaining a graft rerupture (P = .03), but there was no association between graft rerupture and using the same tunnels from the primary procedure at revision surgery. After revision reconstruction, 68% of patients (95% CI, 55%-71%) returned to their preinjury level of sport, compared with 83% (95% CI, 69%-84%) after primary reconstruction in the same patients. Those who had a third ACL injury had a significantly higher rate of return to preinjury sport (83%) after the revision procedure than did the group that did not have further ACL injuries (62%, P = .02). Conclusion: Younger patients are at significant risk of having multiple ACL injuries. The high rate of third ACL injuries presents a significant issue for future knee health in these young athletes. Medial meniscal pathology and returning to high-risk sport are factors that are significantly associated with the high multiple ACL injury rate in the young.

The use of rapid prototyping in the design of a customised ankle brace structure for ACL injury risk reduction

Rapid prototyping, or additive manufacturing, is becoming more useful in creating functional prototypes, especially when customisation is required. This paper explores the use of three-dimensional (3D) printing in designing a customised ankle brace structure for anterior cruciate ligament (ACL) injury risk reduction. A new process is proposed to obtain ankle flexion angles and the corresponding foot surface strain associated with high ACL injury risks through motion analysis. This data is used in the design of the customised ankle brace structure and printed using rapid prototyping. One customised ankle brace structure was printed and tested to demonstrate this proposed framework. The ankle flexion range of motion (ROM) was significantly reduced in the high-risk ankle positions with the ankle brace structure. Rapid prototyping could thus be used to design customised ankle brace structures and this is useful in reducing fabrication time and complexity of customisation.

Preferential Loading of the ACL Compared to the MCL during Landing: A Novel In Sim Approach Yields the Multi-Planar Mechanism of Dynamic Valgus during ACL Injury

Objectives:Strong biomechanical and epidemiologic evidence associates knee valgus collapse with isolated non-contact ACL injury. However, the predominance of isolated non-contact anterior cruciate ligament (ACL) injuries is challenging for clinicians and researchers to explain, as the medial collateral ligament (MCL) has been reported to be the primary restraint against knee valgus. The purpose of this study was to investigate the relative ACL to MCL strain patterns during physiologic simulations of a wide range of high-risk dynamic landing scenarios. We hypothesized that both knee abduction and internal tibial rotation moments would generate a disproportionate increase in ACL strain relative to MCL strain. However, the physiologic range of knee abduction and internal tibial rotation moments that produce ACL injuries would not be of sufficient magnitude to consistently compromise MCL integrity.Methods:A novel in sim approach was used to test our hypotheses. 17 cadaveric lower extremities (45 ± 7 years, 9 female & 8 male) were tested to simulate a broad range of landing conditions following a jump under anterior tibial shear, knee abduction and internal tibial rotation. Specimens were oriented to simulate lower extremity posture during ground strike while landing from a jump. Landing was simulated by applying an impulsive axial impact load (simulating ground reaction forces) under simulated muscle forces. ACL and MCL strains were quantified using DVRT displacement transducers arthroscopically placed across the ACL AM-bundle and sutured to the anterior/middle/posterior aspects of superficial MCL across the joint line. Specimens were tested until failure. Multiple paired and independent t-tests along with general linear models were used to investigate the changes in strain levels under each modes of loading. An extensively validated, detailed finite element model of the lower extremity was used to better interpret experimental findings.Results:ACL failure was generated in 15 of 17 specimens (88%). Increased anterior tibial shear force, and knee abduction and internal tibial rotation moments resulted in significantly higher ACL: MCL strain ratios (p<0.05) compared to landing under no applied external loads. Under all modes of single- and multi-planar loading, ACL: MCL strain ratio remained greater than 1.7, and relative ACL strain was significantly higher than relative MCL strain (p<0.003, Figure 1). Relative change in ACL strain was significantly greater under combined multi-planar loading compared to ACL strain under anterior tibial shear force (p=0.016), knee abduction (p=0.018) and internal tibial rotation (p<0.0005) moments alone.Conclusion:The tibiofemoral frontal plane loading mechanism has become a recent topic of debate as a contributing factor to non-contact ACL injuries. Both in vivo and video analyses studies indicate that increased knee abduction is associated with increased risk for ACL injury. The current findings demonstrates that while both the ACL and MCL resist knee valgus during landing, physiological magnitudes of the applied loads that lead to high ACL strain levels and injury were not sufficient to compromise MCL integrity. Further, these findings support multi-planar knee valgus collapse as a primary mechanism of non-contact ACL injury. This enhances our understanding of the non-contact ACL injury mechanism, and provides insight that can improve current risk screening and injury prevention strategies.

An Integrated Approach to Change the Outcome Part I

An important step for treatment of a particular injury etiology is the appropriate application of a treatment targeted to the population at risk. An anterior cruciate ligament (ACL) injury risk algorithm has been defined that employs field-based techniques in lieu of laboratory-based motion analysis systems to identify athletes with high ACL injury risk landing strategies. The resultant field-based assessment techniques, in combination with the developed prediction algorithm, allow for low-cost identification of athletes who may be at increased risk of sustaining ACL injury. The combined simplicity and accuracy of the field-based tool facilitate its use to identify specific factors that may increase risk of injury in female athletes. The purpose of this report is to demonstrate novel algorithmic techniques to accurately capture and analyze measures of knee valgus motion, knee flexion range of motion, body mass, tibia length and quadriceps to hamstrings ratio with video analysis software typically used by coaches, strength and conditioning specialists, and athletic trainers. The field-based measurements and software analyses were used in a prediction algorithm to identify those at potential risk of noncontact ACL injury that may directly benefit from neuromuscular training.

Three-Dimensional Motion Analysis Validation of a Clinic-Based Nomogram Designed to Identify High ACL Injury Risk in Female Athletes

Aims: Prospective measures of high knee abduction moment (KAM) during landing identify female athletes at increased risk for anterior cruciate ligament (ACL) injury. Laboratory-driven measurements predict high KAM with 90% accuracy. This study aimed to validate the clinic-based variables against 3-dimensional motion analysis measurements. Methods: Twenty female basketball, soccer, and volleyball players (age, 15.9 ± 1.3 years; height, 163.6 ± 9.9 cm; body mass, 57.0 ± 12.1 kg) were tested using 3-dimensional motion analysis and clinic-based techniques simultaneously. Multiple logistic regression models have been developed to predict high KAM (a surrogate for ACL injury risk) using both measurement techniques. Clinic-based measurements were validated against 3-dimensional motion analysis measures, which were recorded simultaneously, using within- and between-method reliability as well as sensitivity and specificity comparisons. Results: The within-variable analysis showed excellent inter-rater reliability for all variables using both 3-dimensional motion analysis and clinic-based methods, with intraclass correlation coefficients (ICCs) that ranged from moderate to high (0.60-0.97). In addition, moderate-to-high agreement was observed between 3-dimensional motion analysis and clinic-based measures, with ICCs ranging from 0.66 to 0.99. Bland-Altman plots confirmed that each variable provided no systematic shift between 3-dimensional motion analysis and clinic-based methods, and there was no association between difference and average. A developed regression equation also supported model validity with > 75% prediction accuracy of high KAM using both the 3-dimensional motion analysis and clinic-based techniques. Conclusion: The current validation provides the critical next step to merge the gap between laboratory identification of injury risk factors and clinical practice. Implementation of the developed prediction tool to identify female athletes with high KAM may facilitate the entry of female athletes with high ACL injury risk into appropriate injury-prevention programs.

Three-Dimensional Motion Analysis Validation of a Clinic-Based Nomogram Designed to Identify High ACL Injury Risk in Female Athletes

Aims: Prospective measures of high knee abduction moment (KAM) during landing identify female athletes at increased risk for anterior cruciate ligament (ACL) injury. Laboratory-driven measurements predict high KAM with 90% accuracy. This study aimed to validate the clinic-based variables against 3-dimensional motion analysis measurements. Methods: Twenty female basketball, soccer, and volleyball players (age, 15.9 ± 1.3 years; height, 163.6 ± 9.9 cm; body mass, 57.0 ± 12.1 kg) were tested using 3-dimensional motion analysis and clinic-based techniques simultaneously. Multiple logistic regression models have been developed to predict high KAM (a surrogate for ACL injury risk) using both measurement techniques. Clinic-based measurements were validated against 3-dimensional motion analysis measures, which were recorded simultaneously, using within- and between-method reliability as well as sensitivity and specificity comparisons. Results: The within-variable analysis showed excellent inter-rater reliability for all variables using both 3-dimensional motion analysis and clinic-based methods, with intraclass correlation coefficients (ICCs) that ranged from moderate to high (0.60-0.97). In addition, moderate-to-high agreement was observed between 3-dimensional motion analysis and clinic-based measures, with ICCs ranging from 0.66 to 0.99. Bland-Altman plots confirmed that each variable provided no systematic shift between 3-dimensional motion analysis and clinic-based methods, and there was no association between difference and average. A developed regression equation also supported model validity with > 75% prediction accuracy of high KAM using both the 3-dimensional motion analysis and clinic-based techniques. Conclusion: The current validation provides the critical next step to merge the gap between laboratory identification of injury risk factors and clinical practice. Implementation of the developed prediction tool to identify female athletes with high KAM may facilitate the entry of female athletes with high ACL injury risk into appropriate injury-prevention programs.

Fatigue after eccentric quadriceps femoris work produces earlier gastrocnemius and delayed quadriceps femoris activation during crossover cutting among normal athletic women.

Athletic women are at greater risk of anterior cruciate ligament (ACL) injury than men. Twenty, healthy, athletic women were evaluated for the effect of preferred stance limb isokinetic quadriceps femoris and hamstring fatigue from eccentric work compared with controls on the activation onset of vastus medialis, rectus femoris, vastus lateralis, the medial hamstrings, biceps femoris, and gastrocnemius muscles. Following 3 weeks of crossover cut training, subjects were tested for fatigue effects (5 subjects/week, 3 conditions, 1 condition/day, order effect controlled) on muscle activation onsets prior to crossover cut landing heelstrike (mixed model, ANOVA, P < 0.05). Fatigue from eccentric quadriceps femoris work produced delayed vastus medialis (P = 0.03), rectus femoris (P = 0.007), and vastus lateralis (P = 0.03) activation onsets compared with control, but did not differ compared to hamstring fatigue. Neither hamstring nor quadriceps femoris fatigue produced differences (P > 0.05) in medial hamstring or biceps femoris activation onsets compared to control. Quadriceps femoris fatigue from eccentric work produced earlier gastrocnemius activation onsets (P = 0.048) than control, but did not differ for hamstring fatigue. The gastrocnemius appears to provide synergistic and compensatory dynamic knee stabilization in closed kinetic chain function during quadriceps femoris fatigue. This finding in a normal group at high risk of ACL injury while performing a maneuver with a high ACL injury risk supports gastrocnemius inclusion in knee rehabilitation and conditioning programs and suggests the need for comparative evaluations of knee injured/reconstructed subjects.

Football cleat design and its effect on anterior cruciate ligament injuries. A three-year prospective study.

A 3-year prospective study was initiated to evaluate torsional resistance of modern football cleat designs and the incidence of surgically documented anterior cruciate ligament tears in high school football players wearing different cleat types. We compared four styles of football shoes and evaluated the incidence of anterior cruciate ligament tears among 3119 high school football players during the 1989 to 1991 competitive seasons. The four cleat designs were 1) Edge, longer irregular cleats placed at the peripheral margin of the sole with a number of smaller pointed cleats positioned interiorly (number of players wearing this shoe, 2231); 2) Flat, cleats on the forefoot are the same height, shape, and diameter, such as found on the soccer-style shoe (N = 832); 3) Screw-in, seven screw-in cleats of 0.5 inch height and 0.5 inch diameter (N = 46); and 4) Pivot disk, a 10-cm circular edge is on the sole of the forefoot, with one 0.5-inch cleat in the center (N = 10). The results showed that the Edge design produced significantly higher torsional resistance than the other designs (P < 0.05) and was associated with a significantly higher anterior cruciate ligament injury rate (0.017%) than the other three designs combined (0.005%).