A Comparative Analysis of Quadriceps Tendon, Patellar Tendon Bone Allograft, and Cadaver Graft in Anterior Cruciate Ligament (ACL) Repair and Reconstructive Surgery.

Anterior cruciate ligament (ACL) injuries are a common occurrence among athletes and active individuals, often necessitating surgical intervention for optimal recovery. The choice of graft material for ACL reconstruction remains a topic of debate, with various options available, including quadriceps tendon (QT), patellar tendon bone allograft (PTBA), and cadaver graft (CG). This paper aims to provide an extensive review and comparison of the efficacy, outcomes, and complications associated with these graft types based on recent research. A systematic literature search following PRISMA guidelines was conducted to identify relevant studies published in the past six years. The findings suggest that while each graft type has its advantages and limitations, there is no definitive superior choice. Factors such as patient age, activity level, comorbidities, and surgeon preference should be considered when selecting the most appropriate graft for ACL repair surgery. QT grafts are associated with lower donor-site morbidity compared to patellar tendon grafts. However, QT grafts may have a higher risk of graft rupture and decreased knee flexion strength. PTBA grafts, compared to QT grafts, have a higher risk of donor-site morbidity but a lower risk of graft rupture and improved knee stability. CG grafts have lower donor-site morbidity compared to PTBA grafts but may have a higher risk of graft rupture and decreased knee flexion strength compared to PTBA grafts. In conclusion, the choice of graft material for ACL reconstruction is a complex decision that requires careful consideration of various factors, including patient age, activity level, comorbidities, and surgeon preference. While each graft type has its advantages and limitations, there is no definitive superior choice. Therefore, it is essential to carefully weigh the risks and benefits of each graft type to ensure optimal outcomes for patients undergoing ACL repair surgery.

Unanticipated mid-flight external trunk perturbation increased frontal plane ACL loading variables during sidestep cuttings.

Unanticipated trunk perturbation is commonly observed when anterior cruciate ligament (ACL) injuries occur during direction-changing manoeuvres. This study aimed to quantify the effect of mid-flight medial-lateral external trunk perturbation directions/locations on ACL loading variables during sidestep cuttings. Thirty-two recreational athletes performed sidestep cuttings under combinations of three perturbation directions (no-perturbation, ipsilateral-perturbation, and contralateral-perturbation relative to the cutting leg) and two perturbation locations (upper-trunk versus lower-trunk). The pushing perturbation was created by customised devices releasing a slam ball to contact participants near maximum jump height prior to cutting. Perturbation generally resulted in greater peak vertical ground reaction force and slower cutting velocity. Upper-trunk contralateral perturbation showed the greatest lateral trunk bending away from the travel direction, greatest peak knee flexion and abduction angles, and greatest peak internal knee adduction moments compared to other conditions. Such increased ACL loading variables were likely due to the increased lateral trunk bending and whole-body horizontal velocity away from the cutting direction caused by the contralateral perturbation act at the upper trunk. The findings may help understand the mechanisms of indirect contact ACL injuries and develop effective cutting techniques for ACL injury prevention.

Hereditary Anatomical Risk Factors for Anterior Cruciate Ligament Injuries.

INTRODUCTION:  Genetic and anatomical factors have been reported as risk factors for anterior cruciate ligament (ACL) injuries. This study aimed to investigate anatomical characteristics in family members sustaining ACL injuries, compared with age- and sex-matched patients with simple meniscus injuries. MATERIALS AND METHODS:  Medical records of 1548 patients who underwent ACL reconstruction were reviewed. Cases of ACL injury occurring in first-degree relatives were selected. Forty-one patients from 20 families were included in the study (F-ACL group). Fifty patients with meniscus injuries were included as controls. Anatomical factors comprising posterior-inferior tibial slope (PITS), notch width index (NWI), notch angle (NA), and intercondylar notch roof inclination angle (RA) were compared between groups. The correlation of these anatomical factors between parent and child or siblings was also investigated. RESULTS:  The 41 patients (20 families) consisted of 12 parent-child pairs and 29 siblings (13 pairs and one trio). Injuries occurred during playing the same sport in 11 families (55%). PITS was significantly steeper in the F-ACL group (9.9 vs. 7.8 degrees). NWI and NA were significantly smaller in the F-ACL group (0.262 vs. 0.278 and 50.5 vs. 58.8 degrees). RA was significantly greater in the F-ACL group (130 vs. 126.9 degrees). A positive correlation in NA (r = 0.677) and a weak correlation in NWI and RA were observed between family members. CONCLUSIONS:  Common anatomical risk factors of ACL injury exist within families, including intercondylar notch stenosis and steep posterior tibial slope. The findings suggest the potential for developing effective ACL injury prevention programs targeting these risk factors.

Psychosocial experiences of competitive rugby players on the "long, long journey" to recovery following ACL ruptures and reconstruction.

Anterior Cruciate Ligament (ACL) injuries are serious and potentially career-ending. Reconstruction surgery and extended rehabilitation typically follow, but some athletes never attain the same level of sport performance. The psychosocial experiences of athletes who sustain ACL injuries and their cognitive appraisal, emotional and behavioral responses to the injury, and reconstruction require further attention during the different recovery phases. The aim is to explore these psychosocial experiences, social support needs and sources thereof of competitive athletes who sustained unilateral ACL ruptures and underwent reconstruction surgery. Semi-structured interviews with six competitive rugby players (M age: 22.3 ± 2.92 years), elicited information at seven time-points. We analyzed the qualitative information through thematic analysis. Five common themes emerged: (1) cognitive appraisal, (2) emotional responses (negative and positive affective responses), (3) behavioral responses, (4) social support needs and sources thereof, and (5) adversity-induced identity expansion (athletic and person-centered identities). In-vivo quotes gave a rich description of the athletes' experiences throughout the "long, long journey" to return-to-sport. These findings may sensitize and assist sports healthcare professionals, coaches, teammates, family, and friends to explore various psychosocial experiences throughout the injury and recovery period. Phase-appropriate psychosocial support or referral to sport psychology services is recommended to enhance the recovery process, improve long-term physical and mental health, and subsequent performance.

Imaging of soccer injuries in adolescent female athletes.

Soccer participation is increasing among female adolescents with a concomitant rise of injuries in this group. Age- and sex-related factors, such as the transition from skeletal immaturity to skeletal maturity as well as anatomic, physiologic, neuromuscular, and behavioral differences between females and males, all play a role in injury patterns for these athletes. Anterior cruciate ligament (ACL) tears in this group have received a great deal of attention in the medical literature and the media in recent years with increasing knowledge about causative factors, surgical management, and injury prevention. There have been fewer studies specifically focused on female adolescent soccer players in relation to other types of injuries, such as patellar dislocation/instability; other knee and ankle ligament tears; hip labral tears; muscle strains and tears; and overuse injuries such as apophysitis, patellofemoral pain syndrome, and bone stress injuries. Because imaging plays a critical role in diagnosis of soccer-related injuries in female adolescents, knowledge of the mechanisms of injury, imaging findings, and clinical considerations are essential for radiologists involved in the care of these patients.

Restoring Knee Flexor Strength Symmetry Requires 2 Years After ACL Reconstruction, But Does It Matter for Second ACL Injuries? A Systematic Review and Meta-analysis.

BACKGROUND: It is unknown whether knee flexor strength recovers after anterior cruciate ligament (ACL) reconstruction with a hamstring tendon (HT) autograft and whether persistent knee flexor strength asymmetry is associated to a second ACL injury. OBJECTIVE: We aimed to systematically review (1) whether knee flexor strength recovers after ACL reconstruction with HT autografts, and (2) whether it influences the association with a second ACL injury. A third aim was to summarize the methodology used to assess knee flexor strength. DESIGN: Systematic review and meta-analysis reported according to PRISMA. METHODS: A systematic search was performed using the Cochrane Library, Embase, Medline, PEDRo, and AMED databases from inception to December 2021 and until completion in January 2023. Human clinical trials written in English and conducted as randomized controlled trials, longitudinal cohort, cross-sectional, and case-control studies on patients with index ACL reconstructions with HT autografts harvested from the ipsilateral side were considered. Knee flexor strength was measured isokinetically in both the reconstructed and uninjured limb to enable the calculation of the limb symmetry index (LSI). The Risk of Bias Assessment Tool for Non-Randomized Studies was used to assess risk of bias for non-randomized studies and the revised Cochrane Risk of Bias tool was used for randomized controlled trials. For the meta-analysis, the LSI (mean ± standard error) for concentric knee flexor strength at angular velocities of 60°/second (s) and 180°/s preoperatively and at 3 months, 6 months, 12 months, and 24 months were pooled as weighted means with standard errors. RESULTS: The search yielded 64 studies with a total of 8378 patients, which were included for the assessment of recovery of knee flexor strength LSI, and a total of 610 patients from four studies that investigated the association between knee flexor strength and second ACL injuries. At 1 year after ACL reconstruction, the knee flexor strength LSI had recovered to 89.0% (95% CI 87.3; 90.7%) and 88.3% (95% CI 85.5; 91.1%) for the velocities of 60°/s and 180°/s, respectively. At 2 years, the LSI was 91.7% (95% CI 90.8; 92.6%) and 91.2% (95% CI 88.1; 94.2%), for velocities of 60°/s and 180°/s, respectively. For the association between knee flexor strength and second ACL injuries, there was insufficient and contradictory data. CONCLUSIONS: There was low to very low certainty of evidence indicating that the recovery of knee flexor strength LSI, defined as ≥ 90% of the uninjured side, takes up to 2 years after ACL reconstruction with HT autografts. Whether knee flexor strength deficits influence the association of second ACL injuries is still uncertain. There was considerable heterogeneity in the methodology used for knee flexor strength assessment, which together with the low to very low certainty of evidence, warrants further caution in the interpretation of our results. REGISTRATION NUMBER: CRD42022286773.

Bilateral Deficits in Dynamic Postural Stability in Females Persist Years after Unilateral ACL Injury and Are Modulated by the Match between Injury Side and Leg Dominance.

Previous research has documented brain plasticity after an anterior cruciate ligament (ACL) tear and suggests that these neural adaptations contribute to poorer motor control. Since both brain hemispheres show adaptations, we hypothesized that reduced dynamic stability occurs not only in the injured, but also the contralateral, uninjured leg. Further, given brain hemispheric specialization's impact on motor coordination, we hypothesized the need to consider the injury side. A total of 41 female athletes and 18 controls performed single-leg jump-landings. Dynamic postural stability was measured as time-to-stabilization (TTS). We found reduced medio-lateral dynamic stability for the ACL injured leg (p = 0.006) with a similar trend for the contralateral leg (p = 0.050) compared to the control group. However, when distinguishing between injuries to the dominant and non-dominant legs, we found increased medio-lateral TTS only if the injury had occurred on the dominant side where landings on injured (p = 0.006) and contralateral (p = 0.036) legs required increased TTS. Assessments of dynamic stability, e.g., in the context of return-to-sport, should consider the injury side and compare results not only between the injured and the contralateral leg, but also to uninjured controls. Future research should not pool data from the dominant-leg ACL with non-dominant-leg ACL injuries when assessing post-injury motor performance.

[New treatment methods in competitive sports : What can we learn from the medical care of top athletes?] / Neue Therapieverfahren im Wettkampfsport : Was können wir aus der Betreuung von Spitzensportlern lernen?

BACKGROUND: As elite sport becomes more professional, the medical-psychological care of athletes is an important factor in providing them with the best possible support and thus optimising their performance. Our experience in the fields of prevention, conservative and surgical treatment, and rehabilitation also provides valuable insights for the treatment of our patients in daily practice. PREVENTION: Designed to improve static and dynamic muscle strength, kinaesthetic sensitivity, and neuromuscular control, the FIFA 11+ injury prevention programme is a three-part warm-up programme that is widely used in coaching and recreational sports. CONSERVATIVE TREATMENT: Platelet-rich plasma (PRP) is probably the most widely used orthobiologic treatment modality for the conservative management of tendon, muscle and cartilage injuries. Its effectiveness depends on the underlying pathology and the affected body region. The best evidence exists for the treatment of patellar tendinitis ("jumper's knee") and epicondylitis humeri radialis ("tennis elbow"). SURGICAL TREATMENT: The treatment of ACL injuries in competitive athletes is challenging due to the high physical demands. Prompt surgical intervention, anatomical reconstruction and additional extra-articular stabilisation are associated with improved surgical outcomes. Graft selection must be individualised, adapted to the needs of the athletes and our patients. REHABILITATION: Electromyography (EMG) is a diagnostic tool to identify muscular imbalances in rehabilitation and, at the same time, to help reduce them through biofeedback training. COGNITIVE TRAINING: Training for the development of basic cognitive skills helps to optimise performance through its potentially positive influence on the executive functions of athletes.

Insurance cost and injury characteristics of anterior cruciate ligament injuries in sub-elite football: A population analysis involving 3 years of Australian insurance data.

OBJECTIVES: To investigate the injury characteristics and insurance cost of anterior cruciate ligament injuries in sub-elite football players in New South Wales, Australia. DESIGN: Descriptive epidemiological study. METHODS: Three years of insurance records (2018-2020) was used to describe anterior cruciate ligament injury costs and characteristics. Concomitant injuries and the mechanism of injury were determined by analysing the injury descriptions. Claim characteristics and costs are presented by age group (junior = 7-17 years, senior = 18-34 years, and veteran = 35 + years) and sex. Categorical data (including age-groups and sex) are presented as counts and percentages and analysed using a Chi squared or Fisher's exact test. Cost data are reported as means ±â€¯standard deviation with 95 % confidence intervals. RESULTS: Over the course of three football seasons (2018-2020), 786 anterior cruciate ligament injuries were reported to the injury insurance company. The total insurance cost was AU$3,614,742 with direct injury insurance costs accounting for 36.3 % of the total costs. The mean indirect insurance costs were six-fold higher than direct insurance costs (AU$11,458 vs AU$1914). Isolated injuries had an average cost of $4466 whilst concomitant injuries had an average cost of $4951. Surgical costs are excluded from direct cost calculations. The peak injury count occurred in the first month of all three football seasons, immediately after the pre-season. CONCLUSIONS: Anterior cruciate ligament injuries represent a substantial economic burden to the insurer and individual. The cost data provided can be used for future economic and modelling studies.

Return to Sport After Anterior Cruciate Ligament Reconstruction Among Physically Active Adults.

An anterior cruciate ligament (ACL) is one of athletes' most severe and frequent knee ligament injuries. The primary function of the ACL is preventing excessive anterior tibial translation, and it limits varus/valgus stress when the knee is in full extension and rotatory movements. Returning to sport after an ACL injury is a crucial aim of ACL reconstruction (ACLR). Multiple factors, modifiable and nonmodifiable, can influence the time to return to sport. This study aimed to discuss factors that affect optimal return-to-play (RTP) timing, symptom recurrence, and long-term consequences of an ACL injury. This is a cross-sectional study involving patients who are following in orthopedic surgery outpatient clinics with a history of ACLR at least six months before surgery and not beyond six years after surgery. Participants received a survey about their sociodemographic data, details of the type and site of injury, and ACL return to sport before and after reconstruction scale. Full data description and testing of dependent variables against participant variables using two-sided tests were performed with a significance level of P ≤ 0.05. The study involved 129 participants, of which the majority were male Bisha residents aged 20 to 29 years. The study found that the right leg was the most commonly injured, with the dominant leg being the most frequently reconstructed due to problems with knee function. Before the injury, most participants ran, cut (quick changes of direction during running), decelerated, and pivoted activities four or more times per month. However, physical activities notably reduced after ACLR. Age and body mass index (BMI) showed statistical significance related to the likelihood of returning to physical activities.  The study found a significant reduction in the frequency of activities such as cutting, deceleration, and running after ACLR. Age was identified as a predictor affecting the likelihood of returning to the sport, with older patients being less likely to return than younger ones.

Translation, Validity, and Reliability of the Indonesian Version of the Anterior Cruciate Ligament-Return to Sport After Injury Scale.

Background: The Anterior Cruciate Ligament-Return to Sport After Injury (ACL-RSI) scale measures athletes' emotion, confidence, and risk appraisal when returning to sports after an anterior cruciate ligament (ACL) injury and/or ACL reconstruction (ACLR). Purpose: To translate the ACL-RSI into the Indonesian language and to assess its validity and reliability in Indonesian-speaking patients after ACLR. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: After a forward-and-backward translation procedure, the validity and reliability of the Indonesian version of the ACL-RSI (I-ACL-RSI) were investigated. Patients who had undergone ACLR at a single hospital were asked to complete 4 questionnaires: I-ACL-RSI, Injury-Psychological Readiness to Return to Sport, Tampa Scale of Kinesiophobia, and International Knee Documentation Committee. After a 2-week interval, patients were asked to complete the I-ACL-RSI a second time. Following the COSMIN reporting guidelines (Consensus-Based Standards for the Selection of Health Measurement Instruments), we determined construct validity using hypothesis testing, as well as test-retest reliability, internal consistency, floor and ceiling effects, and measurement error. Results: Of 200 eligible patients, 102 (51%) were included in the analysis. All predefined hypotheses on correlations between the I-ACL-RSI and the other questionnaires were confirmed, indicating good construct validity. An intraclass correlation coefficient of 0.90 (2-way random, type agreement) was found for the first and second I-ACL-RSI scores, indicating good test-retest reliability. A Cronbach α of 0.95 indicated good internal consistency, and no floor or ceiling effects were found. The standard error of measurement was 3.9, with the minimal detectable change calculated as 10.9 points at the individual level and 1.1 points at the group level. Conclusion: Based on the study findings, the I-ACL-RSI can be considered a valid and reliable questionnaire for Indonesian-speaking patients after ACL injury and/or ACLR.

The Effect of a Knee Brace on Muscle Forces during Single-Leg Landings at Two Heights.

Single-leg landing is one of the maneuvers that has been linked to non-contact anterior cruciate ligament (ACL) injuries, and wearing knee braces has been shown to reduce ACL injury incidence. The purpose of this study was to determine whether wearing a knee brace has an effect on muscle force during single-leg landings at two heights through musculoskeletal simulation. Eleven healthy male participants, some braced and some non-braced were recruited to perform single-leg landings at 30 cm and 45 cm. We recorded the trajectories and ground reaction forces (GRF) using an eight-camera motion capture system and a force platform. The captured data were imported into the generic musculoskeletal model (Gait2392) in OpenSim. Static optimization was used to calculate the muscle forces. The gluteus minimus, rectus femoris, vastus medialis, vastus lateralis, vastus medialis medial gastrocnemius, lateral gartrocnemius, and soleus muscle forces were all statistically significant different between the braced and non-braced participants. Simultaneously, increasing the landing height significantly affected the gluteus maximums, vastus medialis, and vastus intermedia muscle forces. Our findings imply that wearing a knee brace may alter muscle forces during single-leg landings, preventing ACL injuries. Additionally, research demonstrates that people should avoid landing from heights due to the increased risk of knee injuries.

Beyond peak torque: Longitudinal analysis of angle-specific isokinetic knee torques in collegiate athletes post-ACLR.

OBJECTIVES: To investigate changes in angle-specific knee extensor torque between limbs from 4 to 12 months post-anterior cruciate ligament reconstruction(ACLR) in Division I collegiate athletes at two different isokinetic velocities. DESIGN: Case-series study. SETTING: Laboratory-based. PARTICIPANTS: Isokinetic knee flexion and extension assessments of 17 athletes (11 female) at 4, 8, and 12 months after ACLR with bone-patellar tendon-bone autograft were evaluated. MAIN OUTCOME MEASURES: Angle-specific curve analyses were performed using statistical parametric mapping for torque data obtained between 14 and 101° at 60°/s and 240°/s velocities. RESULTS: At 60°/s, knee extensor torque of the operated limb increased between 4 and 8 months (18-101°,p < 0.001), 4 and 12 months (28-101°,p < 0.001), and 8 and 12 months post-surgery (62-70°,p = 0.002, and 79-90°,p < 0.001). Knee extensor torque was lower in the operated limb compared to the non-operated limb at 4 (47-97°,p < 0.001) and 8 months (65-90°,p < 0.001) for 60°/s, at 4 (21-89°,p < 0.001) and 8 months (50-77°,p < 0.001) for 240°/s, with no between-limb differences at 12 months post-ACLR for both velocities. CONCLUSIONS: Operated limb knee extensor torque increased throughout the majority of knee range of motion from 4 to 12 months post-ACLR at both isokinetic velocities, while non-operated limb torque only improved through a reduced arc of motion in greater knee flexion angles.

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

PURPOSE: 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.

Utility of axial magnetic resonance images for detecting meniscal ramp lesions associated with anterior cruciate ligament injuries.

Background: Ramp lesions (RLs), associated with anterior cruciate ligament (ACL) injuries, should be repaired to ensure postoperative knee stability. However, it is difficult to identify all RLs before surgery using conventional sagittal magnetic resonance (MR) images and arthroscopy from the anterior, medial, and lateral portals that are usually used during ACL reconstruction. We report the effectiveness of axial images for detecting RL. Methods: From January 2018, a total of 316 knees underwent primary ACL reconstruction with preoperative magnetic resonance imaging (MRI) examination at our hospital. Among these, 149 knees, which required meniscal suturing at the same time, were retrospectively investigated. This study evaluated 22 knees with confirmed RLs around the posterior horn of the medial meniscus. The effectiveness of the preoperative sagittal and axial MR images for detecting RL was assessed. With the MR image, a three-dimensional double-echo steady-state image with a flip angle of 25° was reconstructed into the sagittal and axial planes, respectively. Reconstructed images with 3-mm slices for sagittal slices and 1-mm slices for axial sections were used. The diagnosis was made based on the presence of RL (RL was present, RL may be present, and RL was not present) by four knee surgeons with more than 10 years of experience. Results: Approximately 53% of knee cases were diagnosed with RLs using sagittal images. Meanwhile, a diagnosis was achieved using axial images in 89% of cases. Conclusion: Axial MRI may be superior in detecting RLs.

Anterior cruciate ligament microfatigue damage detected by collagen autofluorescence in situ.

PURPOSE: Certain types of repetitive sub-maximal knee loading cause microfatigue damage in the human anterior cruciate ligament (ACL) that can accumulate to produce macroscopic tissue failure. However, monitoring the progression of that ACL microfatigue damage as a function of loading cycles has not been reported. To explore the fatigue process, a confocal laser endomicroscope (CLEM) was employed to capture sub-micron resolution fluorescence images of the tissue in situ. The goal of this study was to quantify the in situ changes in ACL autofluorescence (AF) signal intensity and collagen microstructure as a function of the number of loading cycles. METHODS: Three paired and four single cadaveric knees were subjected to a repeated 4 times bodyweight landing maneuver known to strain the ACL. The paired knees were used to compare the development of ACL microfatigue damage on the loaded knee after 100 consecutive loading cycles, relative to the contralateral unloaded control knee, through second harmonic generation (SHG) and AF imaging using confocal microscopy (CM). The four single knees were used for monitoring progressive ACL microfatigue damage development by AF imaging using CLEM. RESULTS: The loaded knees from each pair exhibited a statistically significant increase in AF signal intensity and decrease in SHG signal intensity as compared to the contralateral control knees. Additionally, the anisotropy of the collagen fibers in the loaded knees increased as indicated by the reduced coherency coefficient. Two out of the four single knee ACLs failed during fatigue loading, and they exhibited an order of magnitude higher increase in autofluorescence intensity per loading cycle as compared to the intact knees. Of the three regions of the ACL - proximal, midsubstance and distal - the proximal region of ACL fibers exhibited the highest AF intensity change and anisotropy of fibers. CONCLUSIONS: CLEM can capture changes in ACL AF and collagen microstructures in situ during and after microfatigue damage development. Results suggest a large increase in AF may occur in the final few cycles immediately prior to or at failure, representing a greater plastic deformation of the tissue. This reinforces the argument that existing microfatigue damage can accumulate to induce bulk mechanical failure in ACL injuries. The variation in fiber organization changes in the ACL regions with application of load is consistent with the known differences in loading distribution at the ACL femoral enthesis.

Reliability and Differences Between Sexes in Landing Mechanics when Performing the Lateral Bound Test.

Background and Purpose: Anterior cruciate ligament injuries are prevalent among the athletic population, imposing a heavy economic burden, and the risk of re-injury. Most current biomechanical screening tasks are performed in the sagittal plane, and there is a need for more screening tools that assess sports specific movements in the frontal plane. The purpose of this study was to determine the reliability of and examine differences between sexes in the performance of the Lateral Bound Test (LBT). Materials/Methods: Each subject performed three trials of a LBT which included jumping laterally from one leg over a hurdle and landing on the opposite leg. Two cameras were placed six feet from the landing marker. Maximum dynamic knee valgus using the frontal plane projection angle and knee flexion angle at initial contact and maximal knee flexion were measured upon landing leg using 2D video analysis software. Additionally, video of 10 individuals' trials were analyzed twice with one week between the analyses to obtain intra-rater reliability while 12 participants were retested one week later to determine test-retest reliability. Results: Thirty healthy subjects, 16 males, 14 females participated. Intra-rater reliability was determined to be excellent for all variables (ICC>0.96). In contrast, the test-retest reliability had greater disparity. Test-retest reliability ranged from poor (ICC = 0.47) to excellent (ICC > 0.90). Significant differences existed between the sexes, including males being significantly taller, weighing more, and demonstrating greater bilateral dynamic knee valgus (p < 0.05). No significant differences existed between sexes for knee flexion angles. Conclusion: The new LBT had excellent intra-rater reliability for assessing dynamic knee valgus and initial and maximum knee flexion angle when performing a functional movement in the frontal plane. Furthermore, males landed with more dynamic knee valgus than females which is contradictory to what has been observed with functional screening tools performed in the sagittal plane. Level of Evidence: 3b (reliability study).

Meniscal Tear and ACL Injury Detection Model Based on AlexNet and Iterative ReliefF.

Magnetic resonance (MR) is one of the special imaging techniques used to diagnose orthopedics and traumatology. In this study, a new method has been proposed to detect highly accurate automatic meniscal tear and anterior cruciate ligament (ACL) injuries. In this study, images in three different slices were collected. These are the sagittal, coronal, and axial slices, respectively. Images taken from each slice were categorized in 3 different ways: sagittal database (sDB), coronal database (cDB), and axial database (aDB). The proposed model in the study uses deep feature extraction. In this context, deep features have been obtained by using fully-connected layers of AlexNet architecture. In the second stage of the study, the most significant features were selected using the iterative RelifF (IRF) algorithm. In the last step of the application, the features are classified by using the k-nearest neighbor (kNN) method. Three datasets were used in the study. These datasets, sDB, and cDB, have four classes and consist of 442 and 457 images, respectively. The aDB used in the study has two class labels and consists of 190 images. The model proposed within the scope of the study was applied in 3 datasets. In this context, 98.42%, 100%, and 100% accuracy values were obtained for sDB, cDB, and aDB datasets, respectively. The study results showed that the proposed method detected meniscal tear and anterior cruciate ligament (ACL) injuries with high accuracy.

Proprioceptive postural control strategies differ among non-injured athletes.

Postural control during complex tasks requires adequate sensory integration and somaesthetic reweighting: suboptimal postural strategies can lead to injury. We assessed the ability of healthy athletes to reweight somaesthetic signals during postural perturbations on different surfaces. Thirty-five young (16 ± 1 years), healthy, elite handball players participated in this cross-sectional study. Proprioceptive reweighting was evaluated via vibration of the triceps surae and lumbar muscles on firm and foam surfaces. Postural variables and the electromyographic activity of the gluteus medius (GM), semitendinosus (ST) and fibularis longus (FL) were recorded during the PRE (10 s), VIBRATION (20 s) and POST (20 s) periods. Ankle proprioception was predominantly used on the firm compared to foam support. However, two opposing behaviours were observed: a "rigid" strategy in which reliance on ankle proprioception increased on the foam, and a "plastic" strategy that involved a proximal shift of proprioceptive reliance (p < 0.001). The plastic strategy was associated with a more effective recovery of balance after vibration cessation (p < 0.05). ST activation was higher during POST in the rigid strategy and did not return to the PRE level (p < 0.05) whereas it did in the plastic strategy. Proprioceptive strategies for postural control are highly variable and future studies should evaluate their contribution to injury.

Quadriceps muscle strength recovery with the use of high tone power therapy after anterior cruciate ligament reconstruction: a randomized controlled trial.

BACKGROUND: There are no scientific reports clearly describing the effectiveness of the High Tone Power Therapy in patients after ACL reconstruction. This caused that in own research an attempt was made to present the possibilities of using the selected method of electrical stimulation in the treatment of an orthopaedic patient. The aim was to assess the effectiveness of electro stimulation of the quadriceps muscle in patients after ACL reconstruction, with the use of High Tone Power Therapy. METHODS: In randomized controlled trial took part thirty-five men, aged 21-50, after ACL reconstruction. The tests were carried prior to and 6 months following the ACL reconstruction. After the surgery, the patients were randomly divided into experimental group (17 patients) with the High Tone Power Therapy in rehabilitation and control group (18 patients) without the High Tone Power Therapy. Patients were subjected to 6-month rehabilitation. Research tools included the measurement of muscle strength torque, ROM, knee and thigh circumference measurements, the Lysholm and the VAS scale. RESULTS: After applying HiToP, the analysis showed a statistically significant improvement of muscle torque (p = 0.041, Es = 3.71), knee circumference (p = 0.039, Es = 1.65), thigh circumference (p = 0.049, Es = 1.26), knee extension (p < 0.001, Es = 2.20) in Experimental group compared to the control group. Only the results of the VAS scale did not differ statistically significantly both within a given group and between groups. CONCLUSIONS: The results confirm the hypothesis that the use of HiToP in patients after ACLr have a beneficial effect on muscle strength, reduction of joint effusion, muscle mass gain and joint function. The assumption that HiToP significantly reduces pain levels is not supported - the results in both groups are statistically insignificant. TRIAL REGISTRATION: The research project was retrospectively registered in the Australian New Zealand Clinical Trials Registry (ANZCTR). Date of first registration 11.10.2016. Registration number: ACTRN12616001416482 .