Cruciate Ligament Injury Research Articles

Epidemiology and distribution of cruciate ligament injuries in children and adolescents, with an analysis of risk factors for concomitant meniscal tear.

To investigate the epidemiological features and prevalence of cruciate ligament injuries (CLI) in children and adolescents, and to examine the potential risk factors associated with concomitant meniscal tear (MT) among this population. The demographic data and injury details of children and adolescents with CLI from Southeast China were analyzed to describe their distribution characteristics, alongside an analysis of the prevalence of MTs, the most frequent complication. In addition, binary logistic analysis was employed to ascertain the risk factors linked to MT in individuals suffering from CLI. A total of 203 patients with CLI (n = 206) met the inclusion criteria, with a male-to-female ratio of 2.3:1. Notably, a higher proportion of females were aged ≤16 years old compared to males, who predominated in patients aged >16 years (P = 0.001). Among children and adolescents, anterior cruciate ligament (ACL) injuries were the primary type of CLI, accounting for 88.18% (179/203) of all cases. The majority of cases (132/203, 65.02%) were sustained during sports activities, and sprains were the predominant mechanism of injury (176/203, 86.7%). Additionally, the most common associated injury was an MT (157/203, 77.34%). The posterior horn is the most frequently affected site for both medial MT (62.93% out of 73 cases) and lateral MT (70.19% out of 73 cases). Moreover, vertical tears constituted the majority of medial MTs (59.48% out of 116 cases). Furthermore, patients with a higher BMI faced an increased risk of associated MT in comparison to non-overweight patients (88% vs. 73.86%; P = 0.038). Each increase in BMI unit was linked with a 14% higher probability of associated MT occurrence in children and adolescents with CLI (OR = 1.140; P = 0.036). ACL injuries are a common form of knee ligament injury among children and adolescents, especially those over the age of 16, and are often the result of a sprain. Meniscal posterior horn injury is the most commonly associated injury of youth with CLI. Additionally, overweight or obese people with CLI are at a greater risk of developing MT.

Development of radiographic knee osteoarthritis and the associations to radiographic changes and baseline variables in individuals with knee pain: a 2-year longitudinal study

ObjectivesThe aim was to study the development of radiographic knee osteoarthritis (RKOA) in individuals with knee pain over 2 years, and the associations between radiographic changes and baseline variables.DesignLongitudinal cohort...

Reconstruction of Superficial Medial Collateral Ligament: Modified Danish Technique with Dual Adjustable Loop Suspensory Fixation

Injury to the superficial medial collateral ligament (MCL) is treated conservatively for low-grade injury and with surgery for high-grade injury, especially in association with cruciate ligament injury. Acute injuries are treated with MCL repair, and chronic injury requires reconstruction. Anatomic MCL reconstruction can be done using free allograft or autograft and fixed using screws or suspensory fixation. We describe here an anatomic technique that is a modification of a Danish technique in which we reroute the semitendinosus, keeping its tibial attachment intact. The semitendinosus is rerouted anatomically in the tibial tunnel, and a graft is then passed anatomically in the femoral tunnel. The graft is fixed in both tunnels with adjustable loop suspensory fixation, which gives the unique advantage of controlled tensioning of the graft for MCL reconstruction. In this technique further re-tensioning is possible if the knee is unstable in valgus stress, even after final fixation.

Single Stage in Situ Suture Repair of a Multi-Ligament Knee Injury, an Observational Study

Objective: This study aims to observe the clinical outcomes associated with in situ single-stage suture repair for knee dislocation in patients suffering from multiple knee ligament injuries with the use of unabsorbable materials of the suture. Study design: A retrospective observational study Place and Duration this study was conducted in Gambat Medical College Pir Syed Abdul Qadir Shah Jellani Institute of Medical Science GIMS Gambat from May 2021 to May 2022. Methodology: In this study35 patients treated surgically with in situ suture repair were recruited. A retrospective analysis was done on 35 patients with a mean follow-up score of 3.8 ± 1.3 years. Patients were undergone in situ surgical procedures for all the ruptured ligaments followed by a proper rehabilitation protocol post-operatively. Outcome variables were assessed by Lysholm score, satisfactory score, Meyers functional rating score, VAS score, and Tegner score. Results: Results of the study states that the mean follow-up a score of VAS was recorded as 1.98 ± 0.4, Lysholm score was recorded as 82.5 ± 6.7, and the patient satisfaction score was recorded as 7.5 ± 0.9. Statistically, significant differences have been observed between the pre and post-scores of ranges of motion and Tegner activity scores with a p-value of < 0.001 for both activity and ROM scores. Final follow-up of these patients reported that patients were left with no ligament laxity except for two patients who were unable to restore back to work. Among 35 patients, 5 were unable to achieve full ROM and had stiffness whereas two had infections at the surgical site. Conclusion: In situ suture repair of multiple ligaments had shown significant improvement in terms of ligament repair and early rehabilitation and therefore can be considered an effective treatment approach for the management of multiple ligament injuries. Keywords: Multiple ligament injuries, in situ repair, knee dislocation, cruciate ligament injury, single-stage repair.

MRI findings of growth plate fractures of the knee: are there age- and fracture-dependent differences?

To investigate MRI findings in children with physeal fractures of the knee with respect to age, location, and articular involvement. Children with physeal fractures who underwent knee MRI between 2008 and 2021 were included. Two radiologists retrospectively reviewed all examinations to determine articular involvement, findings of physeal instability (perichondral disruption, periosteal entrapment), and internal derangement (cruciate ligament injury, meniscal tear, chondromalacia). Independent samples t, Mann-Whitney U, Pearson's chi-square, and Fisher's exact tests were used to compare findings. Fifty-six patients (37 boys, 19 girls; mean age: 12.2 ± 2.5years; 32 distal femur, 24 proximal tibial fractures) included 24(43%) intraarticular fractures. Fractures were more common in the tibia than the femur (67% versus 25%, p = 0.004) and intraarticular fractures were more common in older than younger children (13.1 ± 2.0 versus 11.5 ± 2.7years, p = 0.01), to associate with chondromalacia (46% versus 12%, p = 0.02) and undergo surgery (33% versus 10%, p = 0.04) when compared to extraarticular fractures. Perichondral disruption (n = 44, 79%) and periosteal entrapment (n = 13, 23%) did not significantly differ based on location or articular involvement (p > 0.05). At a median follow-up of 17.5months (interquartile range: 1.25-34), 3 patients (2 intraarticular, 1 extraarticular fractures) developed osteoarthritis, osteochondral lesion, and leg-length discrepancy from growth arrest, which required additional surgery. Intraarticular physeal fractures were more common with older children, associate with chondromalacia, and underdo surgical intervention when compared to extraarticular fractures of the knee. While MRI findings of physeal instability were common, no significant differences were found between fractures based on anatomic location or fracture pattern.

Outcomes of single-stage reconstruction with ipsilateral peroneus longus and hamstring graft in multiligament knee injuries: A case series

Abstract Background: The diagnosis and management of patients presenting with more than one ligament injury in the knee have been a controversial topic for several decades and it is difficult to draw any firm conclusions. No single approach has proven optimal for the treatment of multiligament knee injuries (MLKI) and there is no consensus between most specialists. This case series seeks to describe and clarify management's current state and future. Objective: The purpose of this study was to determine the outcome of single staged MLKI reconstruction. Materials and Methods: It is a hospital-based case series conducted on 10 patients. Patients who were surgically treated for MLKI between 2017 and 2020 were included in this study. In our study, we included patients with grade 3 or grade 4 cruciate ligament injury with grade 3 or 4 collaterals injury for arthroscopic reconstruction. Data were collected pre- and postoperatively and their Lysholm and International knee documentation committee (IKDC) scores were used to evaluate the outcomes. Results: A male predominance was noted in the present study. Road traffic accidents were the most common mode of injury (70%). Anterior cruciate ligament and medial collateral ligament combination constituted the most common injury pattern (70%). Overall, there was a statistically significant difference in outcomes postsurgery with regards to pre-operative and postoperative Lysholm and IKDC scores in our patients with a P-value of less than 0.0001, substantiating the need for surgical management of MLKI. With a mean postoperative Lysholm score of 89 and a mean postoperative IKDC score of 85, this study showed functionally good results in the patients treated in a single sitting. At the end of 1 year, none of the patients showed positive results for anterior drawer and valgus or varus stress tests. None of the patients showed extensor lag at the last follow-up. Conclusion: A wide variety of management approaches have been described for MLKI. Proper evaluation and full diagnosis are key in multiligament injury of the knee. Failure to treat all injured structures can lead to changes in knee kinematics, poorer outcomes, and increased risk for graft failure. Single-stage early surgical treatment with proper rehabilitation yields good functional and clinical outcomes with early return to work and sports activity.

Associations between metabolic factors and radiographic knee osteoarthritis in early disease - a cross-sectional study of individuals with knee pain

ObjectiveMetabolic factors have been shown to be associated to severe radiographic knee osteoarthritis (RKOA). However, more knowledge is needed in early clinical knee osteoarthritis (KOA). The aim was to study associations between metabolic factors and radiographic knee osteoarthritis (OA) in individuals with knee pain. A second aim was to study associations between metabolic factors and RKOA in those with normal BMI and in those overweight/obese, respectively.MethodThis cross-sectional study included 282 individuals with knee pain (without cruciate ligament injury) and aged 30–67 years, and 70% women. Waist circumference, body mass index (BMI), proportion of fat and visceral fat area (VFA) were assessed. RKOA was defined as Ahlbäck grade 1 in at least one knee. Fasting blood samples were taken and triglycerides, cholesterol (total, low density lipoprotein (LDL) and high density lipoprotein (HDL)), C-reactive protein (CRP), glucose, HbA1C were analysed. Metabolic syndrome was defined in accordance with the International Diabetes Federation (IDF). Associations were analysed by logistic regression.ResultsIndividuals with RKOA were older, had higher BMI, higher VFA, larger waist circumference and had increased total cholesterol, triglycerides and LDL-cholesterol, but not fasting glucose. There was no difference between the group with RKOA vs. non-radiographic group regarding the presence of metabolic syndrome. In a subgroup analysis of individuals with normal BMI (n = 126), those with RKOA had higher VFA, more central obesity, higher levels of CRP and total cholesterol, compared with individuals without RKOA. In individuals with obesity, age was the only outcome associated to RKOA.ConclusionThere were clear associations between metabolic factors and RKOA in individuals with knee pain, also in those with normal BMI. In individuals with obesity age was the only variable associated to RKOA.Trial registration:clinicalTrials.gov Identifier: NCT04928170.

Comparison between Clinical, Magnetic Resonance Imaging, and Arthroscopic Findings in Meniscal and Cruciate Ligament Injuries: A Cross-Sectional Study

Comparison between Clinical, Magnetic Resonance Imaging, and Arthroscopic Findings in Meniscal and Cruciate Ligament Injuries: A Cross-Sectional Study

The Investigation of the Application Value of Musculoskeletal Ultrasound in the Diagnosis and Conservative Treatment of Knee Osteoarthritis.

Objective To explore the application value of musculoskeletal ultrasound in the diagnosis and conservative treatment of knee osteoarthritis. Methods Patients with knee osteoarthritis who were treated in our hospital from January 1, 2020 to August 31, 2021 were selected as the research subjects. The subjects underwent musculoskeletal ultrasonography to record the thickness of the lateral femoral malleolus cartilage, the thickness of the medial femoral malleolus cartilage, the depth of the suprapatellar bursa effusion, and the thickness of the suprapatellar bursa synovium. All patients in the study group received acupuncture treatment after musculoskeletal ultrasonography, and musculoskeletal ultrasonography was performed again after 2 weeks of treatment. The differences in musculoskeletal ultrasound-related parameters were compared between the two groups. Results The thickness of the lateral femoral malleolus cartilage and medial femoral malleolus cartilage in the study group was significantly smaller than those in the control group. The depth of the effusion in the suprapatellar bursa and the thickness of the synovial membrane in the suprapatellar bursa were significantly greater than those in the control group. Ultrasonography showed no significant difference in abnormal status compared with arthroscopy, and musculoskeletal ultrasonography revealed knee osteoarthritis, such as cruciate ligament injury, joint effusion, synovial hyperplasia, meniscus injury, and patellar ligament injury. The cartilage thickness of the lateral femoral malleolus and medial malleolus of femur after treatment were significantly greater than those before treatment. The depth of the deep suprapatellar bursa effusion and the thickness of the suprapatellar bursa synovium were significantly smaller than those before treatment. Conclusion Musculoskeletal ultrasound has high diagnostic value in knee osteoarthritis. It can detect the lesion as soon as possible and can be used to evaluate the effect of conservative treatment, so as to provide reference basis for clinical formulation or adjustment of further intervention plan.

Smaller intercondylar notch size and smaller ACL volume increase posterior cruciate ligament rupture risk

PurposeLittle is known about risk factors for sustaining a posterior cruciate ligament (PCL) rupture. Identifying risk factors is the first step in preventing a PCL rupture from occurring. The morphology of the knee in patients who ruptured their PCL may differ from that of control patients. The hypothesis was that the intercondylar notch dimensions, 3-D volumes of the intercondylar notch and, the 3-D volumes of both the ACL and the PCL were correlated to the presence of a PCL rupture.MethodsThe magnetic resonance imaging (MRI) scans of 30 patients with a proven PCL rupture were compared to 30 matched control patients with proven intact ACL and PCL. Control patients were selected from patients with knee trauma during sports but without cruciate ligament injury. Patients have been matched for age, height, weight, BMI, and sex. The volumes of the intercondylar notch and both the ACL and PCL were measured on 3D reconstructions. Second, the bicondylar width, the notch width, and the notch width index were measured of all subjects. The relationship between our measurements and the presence of a PCL rupture was analysed.ResultsThe results show a significant difference in the volumes of the intercondylar notch and the ACL between patients with a ruptured PCL and control patients. Patients with a PCL rupture have smaller intercondylar notch volumes and smaller ACL volumes. There were no significant differences in the bicondylar width, notch width, and notch width index. In the control patients, a significant correlation between the volume of the PCL and the volume of the ACL was found (0.673, p < 0.001).ConclusionPatients with a PCL rupture have smaller intercondylar volumes and smaller ACL volumes when compared to control patients. Second, patients with smaller ACL volumes have smaller PCL volumes. This study shows, for the first time, that there are significant size and volume differences in the shape of the knee between patients with a PCL rupture and control patients.Level of evidenceIV.

Concurrent Validity of Movement Screening Criteria Designed to Identify Injury Risk Factors in Adolescent Female Volleyball Players.

Anterior cruciate ligament (ACL) injuries in female adolescent athletes occur at disproportionately high levels compared to their male counterparts. However, limited prospective data exist on the validity of low-cost screening tools that can proactively identify ACL injury risk, specifically for female athletes. The purpose of this study was to assess the concurrent validity of a three-task injury risk factor assessment by comparing visually derived outcome scores from two-dimensional (2D) video data with dichotomized three-dimensional (3D) biomechanical variables collected using motion capture technology. A total of 41 female club volleyball athletes (14.7 ± 1.4 years) were tested and asked to perform three tasks: double-leg vertical jump (DLVJ), single-leg squat (SLS), and single-leg drop landing (SLDL). One rater was trained on the scoring criteria for the 2D data and independently scored one forward-facing and one side-facing video for each task. Risk factors identified included poor knee position, lateral trunk lean, and excessive trunk flexion/extension. In addition, 3D joint angles were calculated for the trunk and knee in the sagittal and frontal planes and converted to dichotomous variables based on biomechanical thresholds of injury risk. For comparison of 2D and 3D outcomes, percent agreement and Cohen's kappa were calculated for each risk factor individually. Overall, 2D scores were found to exhibit moderate to excellent percent agreement with 3D outcomes for trunk position (69.1–97.1%). Specifically, ipsilateral trunk lean during single-leg tasks exhibited the highest agreement (85.3–88.2%) with moderate reliability (κ = 0.452–0.465). In addition, moderate to substantial reliability was found for trunk flexion during double-leg tasks (κ = 0.521–0.653); however, an evaluation of single-leg tasks resulted in only fair reliability (κ = 0.354). Furthermore, 2D scores were not successful in identifying poor knee position as percent agreement fell below 50% for both the single-leg tasks and averaged 60% agreement across both the phases of the DLVJ. Kappa coefficients further emphasized these trends indicating no to slight concurrent validity (κ = −0.047–0.167) across tasks. Overall, these findings emphasize the potential for valid, low-cost screening tools that can identify high-risk movement patterns. Further study is needed to develop improved assessment guidelines that may be employed through visual assessment in sports environments.

Automated detection of anterior cruciate ligament tears using a deep convolutional neural network

BackgroundThe development of computer-assisted technologies to diagnose anterior cruciate ligament (ACL) injury by analyzing knee magnetic resonance images (MRI) would be beneficial, and convolutional neural network (CNN)-based deep learning approaches may offer a solution. This study aimed to evaluate the accuracy of a CNN system in diagnosing ACL ruptures by a single slice from a knee MRI and to compare the results with that of experienced human readers.MethodsOne hundred sagittal MR images from patients with and without ACL injuries, confirmed by arthroscopy, were cropped and used for the CNN training. The final decision by the CNN for intact or torn ACL was based on the probability of ACL tear on a single MRI slice. Twelve board-certified physicians reviewed the same images used by CNN.ResultsThe sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the CNN classification was 91.0%, 86.0%, 88.5%, 87.0%, and 91.0%, respectively. The overall values of the physicians’ readings were similar, but the specificity was lower than the CNN classification for some of the physicians, thus resulting in lower accuracy for the human readers.ConclusionsThe trained CNN automatically detected the ACL tears with acceptable accuracy comparable to that of human readers.

Injury incidence, severity, and burden in elite youth soccer players – A 3-year prospective study

ObjectivesThis study aimed to investigate age-related injury incidence, severity, and burden over a 3-year period in U14 to U19 elite male soccer players in a German youth academy. DesignDescriptive epidemiology study. MethodsTime-loss injuries of 166 unique players were prospectively documented and injury incidence, severity, and burden were calculated for each age group, body part, and type of injuries. ResultsA total of 562 time-loss injuries were recorded. Across all age groups (U14 to U19), injury incidence was 42.2 per squad season (ranging from 30.5 in the U19 to 67.7 in the U15), severity was 11.0 days lost (ranging from 8.0 in the U15 to 17.0 in the U17), and burden was 464.1 days lost per squad season (ranging from 304.9 in the U19 to 756.7 in the U14). The thigh, knee and ankle were the body parts with the highest injury incidence (9.2; 5.9; 5.9), severity (11.0; 16.0; 13.0), and burden (101.6; 94.9; 76.1). Cruciate ligament injuries had both the highest burden (164.4) and severity (137.0), and muscle injuries the highest incidence (11.0) of all types of injuries. U15 had the highest injury incidence (67.7) of all age groups. U14 and U17 had both the highest injury severity (15.0; 17.0) and burden (756.7; 618.8) of all age groups. Age-related patterns were observed for selected types of injuries such as muscle injuries, tendinopathy, bone-stress injury, and fractures. ConclusionsInjury incidence, severity, and burden substantially differed descriptively between age groups and clear age-related patterns for selected types of injuries were evident.

Can MRI knee joint measurements predict the population at risk of ACL injury?

BackgroundAnterior cruciate ligament (ACL) injuries have been increasing significantly over time. The relationship between the ACL injury and the knee joint structures is poorly understood. The purpose of this study is to examine whether the measurements of different structures in the knee joint are linked with ACL injury in affected patients.MethodsThis retrospective case–control study included patients who suffered from ACL tears and underwent magnetic resonance imaging (MRI). A control group of patients with no knee pathologies on MRI was included. Fourteen knee variables, including lateral meniscus (LM) posterior horn height, length, depth, and volume; medial meniscus (MM) posterior horn height, length, depth, and volume; lateral and medial (MFC) femoral condyle sphere diameter; lateral and medial tibial plateau length; and patella tendon horizontal and vertical diameter, were collected. A multivariate logistic regression including LM posterior horn depth, MM posterior horn length, MM volume, MFC sphere diameter, and patella tendon horizontal diameter and receiver operating characteristic curve, was used to compare the two groups.ResultsA total of 85 patients were included in our study; 54 suffered from ACL injuries and 31 as a control group with normal knee MRI. Logistic regression revealed that increased LM posterior horn depth (OR = 1.27; 95% CI = 1.03–1.56; p = 0.028), decreased MM posterior horn length (OR = 0.71; 95% CI = 0.55–0.93; p = 0.013), and MFC sphere diameter (OR = 1.20; 95% CI = 1.01–1.43; p = 0.035) were independent risk factors for ACL rupture. The MFC sphere diameter yielded the highest area under the curve: 0.747 (95% CI, 0.632–0.862). No difference was found in the other measurements between the two groups.ConclusionsConcerning the difference in anatomical variations, the lateral meniscus posterior horn depth and medial femoral condyle sphere diameter were higher, while medial meniscus posterior horn length was lower in patients with an ACL injury. These structural knee measurements could have a possible increase in the likelihood of sustaining an ACL injury and can be used by clinicians to predict ACL injury.

Медицинская реабилитация в спорте высших достижений после реконструкции передней крестообразной связки коленного сустава

The professional activity of high performance, or elite sportsmen involves loads approaching extreme exertion, which often leads to injuries of the lower limbs. Anterior cruciate ligament (ACL) injury is one of the most common types of knee injuries. This study aimed to evaluate the effectiveness of a comprehensive rehabilitation program for athletes that underwent arthroscopic ACL reconstruction. The study involved 64 athletes aged from 17 to 31 years. Treatment group participants were offered a comprehensive medical rehabilitation program that included isokinetic training sessions on the TECNOBODY IsoMove biomechanical exercising machine; the sessions followed a purpose-designed method. The results of medical rehabilitation of the athletes were assessed through gait analysis done with a DIERS Motion 4D complex. The assessments took place 8 and 15 weeks after the reconstruction. At 8 weeks after the surgery, gait analysis parameters revealed no significant differences between the groups. Fifteen weeks after the reconstruction, when treatment group (TG) members were through all the isokinetic training sessions, the results were as follows: for the Stand Time parameter, the operated limb (OL) support deficit was 0.04% compared to the healthy limb (HL) support, and for the Single Limb Support parameter it was 3.71%, while in the control group (CG) that had no isokinetic training sessions the values were 12.44% and 18.55%, respectively. As for the Swing Time parameter, TG participants showed the deficit of HL transfer symmetry (relative to OL) of 3.99%, while the value of this parameter in the CG was 20.54%. The difference is significant, which proves the effectiveness of the developed isokinetic training method as part of the comprehensive medical rehabilitation program, the application of which resulted in faster recovery of muscle strength and compromised walking-associated support and locomotor functions in TG athletes.

Automatic segmentation model of intercondylar fossa based on deep learning: a novel and effective assessment method for the notch volume.

BackgroundNotch volume is associated with anterior cruciate ligament (ACL) injury. Manual tracking of intercondylar notch on MR images is time-consuming and laborious. Deep learning has become a powerful tool for processing medical images. This study aims to develop an MRI segmentation model of intercondylar fossa based on deep learning to automatically measure notch volume, and explore its correlation with ACL injury.MethodsThe MRI data of 363 subjects (311 males and 52 females) with ACL injuries incurred during non-contact sports and 232 subjects (147 males and 85 females) with intact ACL were retrospectively analyzed. Each layer of intercondylar fossa was manually traced by radiologists on axial MR images. Notch volume was then calculated. We constructed an automatic segmentation system based on the architecture of Res-UNet for intercondylar fossa and used dice similarity coefficient (DSC) to compare the performance of segmentation systems by different networks. Unpaired t-test was performed to determine differences in notch volume between ACL-injured and intact groups, and between males and females.ResultsThe DSCs of intercondylar fossa based on different networks were all more than 0.90, and Res-UNet showed the best performance. The notch volume was significantly lower in the ACL-injured group than in the control group (6.12 ± 1.34 cm3 vs. 6.95 ± 1.75 cm3, P < 0.001). Females had lower notch volume than males (5.41 ± 1.30 cm3 vs. 6.76 ± 1.51 cm3, P < 0.001). Males and females who had ACL injuries had smaller notch than those with intact ACL (p < 0.001 and p < 0.005). Men had larger notches than women, regardless of the ACL injuries (p < 0.001).ConclusionUsing a deep neural network to segment intercondylar fossa automatically provides a technical support for the clinical prediction and prevention of ACL injury and re-injury after surgery.

Plyometrics Did Not Improve Jump-Landing Biomechanics in Individuals With a History of Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

Second anterior cruciate ligament (ACL) injury has similar biomechanical risk factors as primary injury. Standard of care rehabilitation does not adequately mitigate these biomechanical risks. This study examined the effectiveness of a 4-week plyometric intervention on biomechanical risk factors of second ACL injury versus no intervention in patients with a history of ACL reconstruction. Thirty adults post-ACL reconstruction received 12 sessions of plyometric (age: 19.9 ± 1.62 years; body mass index: 23.9 ± 2.6 kg/m2; months postoperative: 35.7 ± 24.2) or no (age: 21.3 ± 3.5 years; body mass index: 27.7 ± 4.8 kg/m2; months postoperative: 45.3 ± 25.4) exercise intervention. Hip and knee biomechanics were quantified during a jump-landing task before and after the intervention. Individual response to the intervention was evaluated via minimal detectable change. Hip flexion angle had the greatest response to plyometric training. Overall, focused plyometric intervention did not adequately mitigate biomechanical risk factors of second ACL injury; thus, development of interventions capable of modifying biomechanics known to contribute to ACL injury risk remains necessary.

Knee Strength Outcomes in Adolescents by Age and Sex During Late-Stage Rehabilitation After Anterior Cruciate Ligament Reconstruction

Background:The incidence of anterior cruciate ligament (ACL) injuries have been consistently increasing in adolescents, with those who return to competitive sport having up to a 32% risk of a secondary ACL injury. There is limited evidence regarding knee strength outcomes in young adolescents following ACL reconstruction during late-stage rehabilitation when compared to older patient groups.Purpose:The purpose of this study was to 1) establish normative knee strength values according to age group in adolescent female and male patients during late-stage rehabilitation following ACLR and 2) determine whether strength differences exist between age groups.Methods:A retrospective review of adolescent patients who underwent primary ACL reconstruction was performed. Patients completed a standardized isokinetic (60°/sec) knee extension and flexion strength assessment during late-stage rehabilitation. Peak torque was normalized to the patient’s body mass (Nm/kg) and used to calculate Limb Symmetry Index (LSI). Analyses were conducted separately for female and male cohorts and grouped by early (11-14 years) and middle (15-17 years) adolescence. An independent samples t-test examined strength differences between age groups.Results:130 females (age=15.4 ± 1.4 years; days since surgery=239.0 ± 84.4) and 112 males (age=15.4 ± 1.5 years; days since surgery= 232.6 ± 91.2) were included. Normalized knee extension peak torque on the involved limb was reported for female (1.5 Nm/kg) and male (1.8 Nm/kg) cohorts. Differences between age groups in knee extension peak torque were found on the surgical and nonsurgical limbs in female (p = 0.02 – 0.05) and male (p<0.001 – 0.002) cohorts. No differences were found between age groups for either cohort when normalized to body mass (p = 0.30 – 0.89). Post hoc power analyses revealed 67% statistical power in the female cohort and 97% in the male cohort with an alpha level set to 0.05 based on the observed effect size for the differences in isokinetic knee extension/flexion peak torque between age groups.Conclusion:Early adolescents produced less knee extension and flexion peak torque compared to middle adolescents after ACLR, but no differences were found between age groups when normalized to body mass for female or male cohorts. Normalized knee extension strength in young adolescents may differ from older patients and should be considered in the rehabilitation process.TABLE 1:Patient Demographics - FemalesTABLE 2:Patient Demographics - MalesTABLE 3:Strength Outcomes by Age Group during Late-Stage Rehabilitation (Females)TABLE 4:Strength Outcomes by Age Group during Late-Stage Rehabilitation (Males)

Sex difference in frontal plane hip moment in response to lateral trunk obliquity during single-leg landing

BackgroundLateral trunk obliquity during landing is a characteristic of anterior cruciate ligament (ACL) injuries in female athletes and affects their knee and hip kinetics and kinematics. However, it is unclear whether these effects differ between females and males. The purpose of this study was to compare the effects of lateral trunk obliquity on knee and hip kinetics and kinematics in females and males during single-leg landing.MethodsEighteen female (aged 22.1 ± 1.5 years) and 18 male participants (aged 21.8 ± 1.1 years) performed single-leg landings under two conditions: (1) without any instructions about trunk position (natural) and (2) with leaning their trunks laterally 15° from the vertical line (trunk obliquity). The kinetics and kinematics of their hip and knee were analyzed using a three-dimensional motion analysis with a force plate. Two-way repeated-measures ANOVA (sex × trunk obliquity) and Bonferroni pairwise comparisons were conducted.ResultsThe trunk obliquity angle at initial contact was significantly greater in the trunk-obliquity landing condition than in the natural landing condition (natural 4.0 ± 2.2°, trunk-obliquity 15.1 ± 3.6°, P < 0.001) with no sex difference (95% CI − 1.2 to 2.2°, P = 0.555). The peak knee abduction moment was significantly larger in the trunk-obliquity landing condition than in the natural landing condition (trunk-obliquity, 0.09 ± 0.07 Nm/kg/m; natural, 0.04 ± 0.06 Nm/kg/m; P < 0.001), though there was no sex or interaction effect. A significant interaction between sex and landing condition was found for the peak hip abduction moment (P = 0.021). Males showed a significantly larger peak hip abduction moment in the trunk-obliquity landing condition than in the natural landing condition (95% CI 0.05 to 0.13 Nm/kg/m, P < 0.001), while females showed no difference in the peak hip abduction moment between the two landing conditions (95% CI − 0.02 to 0.06 Nm/kg/m, P = 0.355).ConclusionsThe knee abduction moment increased with a laterally inclined trunk for both female and male participants, while the hip abduction moment increased in males but not in females. It may be beneficial for females to focus on frontal plane hip joint control under lateral trunk-obliquity conditions during single-leg landing.

Biomechanical features of drop vertical jump are different among various sporting activities

BackgroundRisk for non-contact anterior cruciate ligament (ACL) injury can be assessed based on drop vertical jump (DVJ). However, biomechanics of DVJ may differ with various sporting activities. The purpose of the present study was to clarify whether biomechanical features of DVJ are different among various sporting activities in female athletes.MethodsA total of 42 female athletes, including 25 basketball, 8 soccer and 9 volleyball players, participated in the current investigation. DVJ was done for each female athlete using a three-dimensional motion analysis system which consisted of six cameras, two force plates and 46 retro-reflective markers. Kinematic and kinetic data were recorded for both limbs in each athlete. Simultaneously, frontal and sagittal plane views of the DVJ were recorded using two different high-resolution video cameras to evaluate Landing Error Scoring System (LESS) score. Three-dimensional biomechanical parameters at the knee joint and LESS were compared among three different sporting activities using ANOVA or Kruskal–Wallis test after confirming normality assumption. Thereafter post hoc Tukey or Steel–Dwass was utilized for multiple comparison.ResultsSoccer players had better LESS score, and peak knee flexion angle was significantly larger in soccer players compared to the other sports. In addition, knee abduction angle at initial contact (IC), peak knee abduction angle, knee internal rotation angle, and knee abduction moment within 40 ms from IC were significantly smaller in soccer players, compared to basketball players. In terms of volleyball players, knee abduction angle at IC and knee internal rotation angle at IC were significantly larger than soccer players, whereas no significant biomechanical differences were found between basketball and volleyball players.ConclusionsFrom the present study, female basketball and volleyball players have worse LESS score, smaller peak knee flexion angle, greater knee abduction angle at IC and greater knee internal rotation angle at IC, compared to female soccer players. Thus, female basketball and volleyball players may have an increased risk of non-contact ACL injury during the jump-landing task, compared to soccer players. Biomechanics of DVJ depends on characteristics of the athlete's primary sport.