Anterior Cruciate Ligament Injured Subjects Research Articles

Tibiofemoral bony morphology features associated with ACL injury and sex utilizing three-dimensional statistical shape modeling.

Statistical shape modeling was employed to assess three-dimensional (3D) bony morphology between distal femurs and proximal tibiae of anterior cruciate ligament (ACL) injured knees, the contralateral uninjured knees of ACL injured subjects, and knees with no history of injury. Surface models were created by segmenting bone from bilateral computed-tomography scans of 20 subjects of their ACL injured knees and non-injured contralateral knees, and 20 knees of control subjects with no history of a knee injury. Correspondence particles were placed on each surface, and a principal component analysis determined modes of variation in the positions of the correspondence particles describing anatomical variation. ANOVAs assessed the statistical differences of 3D bony morphological features with main effects of injury state and sex. ACL injured knees were determined to have a more lateral femoral mechanical axis and a greater angle between the long axis and condylar axis of the femur. A smaller anterior-posterior dimension of the lateral tibial plateau was also associated with ACL injured knees. Results of this study demonstrate that there are more bony morphological features predisposing individuals for ACL injury than previously established. These bony morphological parameters may cause greater internal and valgus torques increasing stresses in the ACL. No differences were determined between the ACL injured knees and their uninjured contralateral knees demonstrating that knees of ACL injured individuals are at similar risk for injury. Further understanding of the effect of bony morphology on the risk for ACL injury could improve individualized ACL injury treatment and prevention.

Relationship between synovial fluid biomarkers of articular cartilage metabolism and the patient's perspective of outcome depends on the severity of articular cartilage damage following ACL trauma.

Anterior cruciate ligament (ACL) trauma often occurs in combination with injury to the articular cartilage of the knee, this can result in earlier radiographic evidence of post traumatic osteoarthritis (OA) of the knee compared to the contralateral, ACL intact knee; however, the biomechanical and biological mechanisms associated with the onset and progression of this disease are not understood. We sought to gain insight into the mechanisms by determining the relationship between articular cartilage injury associated with ACL trauma and the expression of synovial fluid biomarkers of articular cartilage metabolism, and to evaluate the relationship between these biomarkers and the patient's perspective of the outcomes. Synovial fluid samples were acquired from 39 ACL injured subjects at an average of 10 weeks after injury, and 32 control subjects with normal knees (documented with clinical exam and MRI assessment). Subjects in the ACL-injured group were classified as low-risk for future OA if they displayed an International Cartilage Repair Society (ICRS) Grade 2 articular cartilage lesion or less and high-risk for future OA if they had an ICRS Grade 3A articular cartilage lesion. The patient's perspective of the injury was evaluated with the Knee Injury and Osteoarthritis Outcomes Score (KOOS). There were no significant differences in mean concentrations of the markers of type II collagen metabolism (CPII, C2C, and C1,2C) or the aggrecan breakdown Alanine-Arginine-Glycine-Serine (ARGS) -fragment between control subjects and the subjects in the low- and high-risk groups (p-value range: 0.80-0.43). Associations between ARGS-aggrecan concentration and KOOS subscales of symptoms and pain were significantly different between the low- and high-risk groups (p = 0.03 and p = 0.01, respectively). Likewise, there was strong evidence in support of an association between the markers of type II collagen metabolism (C1,2C and CPII concentrations) and the KOOS subscale of pain between the low- and high-risk groups (p = 0.051 and 0.077, correspondingly). In ACL injured subjects with concomitant Grade 3A articular cartilage injuries, concentrations of synovial fluid ARGS-aggrecan were directly associated with improvements in KOOS symptoms and pain. These findings suggest the possible involvement of ARGS-aggrecan in a localized tissue repair response involving an increase in aggrecan turnover following severe knee trauma. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:820-827, 2016.

Lower extremity muscle activation onset times during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects

The goal of this study was to evaluate muscle activation onset times (MAOT) of both legs during a transition task from double-leg stance (DLS) to single-leg stance (SLS) in anterior cruciate ligament injured (ACLI) (n=15) and non-injured control subjects (n=15) with eyes open and eyes closed. Significantly delayed MAOT were found in the ACLI group compared to the control group for vastus lateralis, vastus medialis obliquus, hamstrings medial, hamstrings lateral, tibialis anterior, peroneus longus and gastrocnemius in both vision conditions, for gluteus maximus and gluteus medius with eyes open and for tensor fascia latae with eyes closed. Within the ACLI group, delayed MAOT of tibialis anterior with eyes open and gastrocnemius with eyes closed were found in the injured leg compared to the non-injured leg. All other muscles were not significantly different between legs. In conclusion, the ACLI group showed delayed MAOT not only around the knee, but also at the hip and ankle muscles compared to the non-injured control group. No differences between both legs of the ACLI group were found, except for tibialis anterior and gastrocnemius. These findings indirectly support including central nervous system re-education training to target the underlying mechanisms of these altered MAOT after ACL injury.

Postural stability during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects

BackgroundAn anterior cruciate ligament injury may lead to deteriorations in postural stability. The goal of this study was to evaluate postural stability during the transition from double-leg stance to single-leg stance of both legs in anterior cruciate ligament injured subjects and non-injured control subjects with a standardized methodology. MethodsFifteen control subjects and 15 anterior cruciate ligament injured subjects (time after injury: mean (SD)=1.4 (0.7) months) participated in the study. Both groups were similar for age, gender, height, weight and body mass index. Spatiotemporal center of pressure outcomes of both legs of each subject were measured during the transition from double-leg stance to single-leg stance in eyes open and eyes closed conditions. Movement speed was standardized. FindingsThe center of pressure displacement after a new stability point was reached during the single-leg stance phase was significantly increased in the anterior cruciate ligament injured group compared to the control group in the eyes closed condition (P<.001). No significant different postural stability outcomes were found between both legs within both groups (P>.05). No significant differences were found during the transition itself (P>.05). InterpretationThe anterior cruciate ligament injured group showed postural stability deficits during the single-leg stance phase compared to the non-injured control group in the eyes closed condition. Using the non-injured leg as a normal reference when evaluating postural stability of the injured leg may lead to misinterpretations, as no significant differences were found between the injured and non-injured leg of the anterior cruciate ligament injured group.

Contributing factors in children who present with calcaneal apophysitis

Background: Rupture of the Anterior Cruciate Ligament (ACL) results in increased tibiofemoral laxity and usually disturbs neuromuscular function, thereby ultimately resulting in knee instability and dysfunction. However, ACL rupture does not automatically result in functional impairment and instability, as confirmed by the ACL deficient (ACLD) coper, who can resume pre-morbid activity levels. Few studies have shown that ACL reconstruction (ACLR) actually restores dynamic knee stability or enables full return to pre-injury activity level in most individuals. The purpose of this meta-analysis was to review the dilemma regarding which ACL injured individuals need to undergo ACLR. Methods: Electronic searches of Medline, EMBase, CINAHL and the Musculoskeletal Injuries Group’s specialized register were performed up to June 2009 using medical subject headings and free-text words. Subject-specific search was based on the terms “ACL rehabilitation”, “copers” “noncopers”. Results: Three prospective, longitudinal trials have been undertaken following an ACL screening examination. Copers (nonoperated) and noncopers (operated) have been followed over a few years post-injury. The results show that a similar percentage of subjects in both groups return to sporting activity. Regarding the differences between copers and noncopers, there exists investigative evidence that noncopers have deficits in quadriceps strength, vastus lateralis atrophy, quadriceps activation deficits, altered knee movement patterns, reduced knee flexion moment, higher quadriceps/hamstring co-contraction and a tendency to hold the tibia in a more posterior position. Conclusion: No single measurement tool is sufficient in determining the functional status of the ACLD individual. Passive instability tests are a poor predictor of future rehabilitation outcome. A collaboration of tests to determine the functional status of the ACL deficient individual is recommended, specifically incorporating the KOS-Sport, Global Knee Function Rating, hop tests and Quadriceps Index. The ACL screening examination shows preliminary evidence for detecting potential copers, however a gold-standard method of detecting who will be successful is still lacking. ACL injured subjects should be informed of the possibility of good knee function following a non-operative rehabilitation program.

Contributing factors in children who present with calcaneal apophysitis

Background: Rupture of the Anterior Cruciate Ligament (ACL) results in increased tibiofemoral laxity and usually disturbs neuromuscular function, thereby ultimately resulting in knee instability and dysfunction. However, ACL rupture does not automatically result in functional impairment and instability, as confirmed by the ACL deficient (ACLD) coper, who can resume pre-morbid activity levels. Few studies have shown that ACL reconstruction (ACLR) actually restores dynamic knee stability or enables full return to pre-injury activity level in most individuals. The purpose of this meta-analysis was to review the dilemma regarding which ACL injured individuals need to undergo ACLR. Methods: Electronic searches of Medline, EMBase, CINAHL and the Musculoskeletal Injuries Group’s specialized register were performed up to June 2009 using medical subject headings and free-text words. Subject-specific search was based on the terms “ACL rehabilitation”, “copers” “noncopers”. Results: Three prospective, longitudinal trials have been undertaken following an ACL screening examination. Copers (nonoperated) and noncopers (operated) have been followed over a few years post-injury. The results show that a similar percentage of subjects in both groups return to sporting activity. Regarding the differences between copers and noncopers, there exists investigative evidence that noncopers have deficits in quadriceps strength, vastus lateralis atrophy, quadriceps activation deficits, altered knee movement patterns, reduced knee flexion moment, higher quadriceps/hamstring co-contraction and a tendency to hold the tibia in a more posterior position. Conclusion: No single measurement tool is sufficient in determining the functional status of the ACLD individual. Passive instability tests are a poor predictor of future rehabilitation outcome. A collaboration of tests to determine the functional status of the ACL deficient individual is recommended, specifically incorporating the KOS-Sport, Global Knee Function Rating, hop tests and Quadriceps Index. The ACL screening examination shows preliminary evidence for detecting potential copers, however a gold-standard method of detecting who will be successful is still lacking. ACL injured subjects should be informed of the possibility of good knee function following a non-operative rehabilitation program.

Correlation of Notch Configuration between Subjects with and Subjects without Anterior Cruciate Ligament Injury

Purpose: The aim of this study was to evaluate the correlation between the 3-dimensional (D) notch volume and the 2D notch width and notch shape as measured on magnetic resonance imaging (MRI), between subjects with anterior cruciate ligament (ACL) injury and those without ACL injury. Materials and Methods: Knee MRI images were taken from 72 subjects with ACL injury and 80 subjects without ACL injury (January 2007 to January 2012; Gyeongsang National University Hospital, Jinju, Korea). We measured 3D notch volume and 2D notch width and notch shape. The measured values from MRI figures between ACL-injured subjects and non-ACL-injured subjects were compared and analyzed. These measurements (notch width, notch ratio) were correlated to notch volume. Both intra-observer reliability and inter-observer reliability were calculated. Results: Notch width differed significantly between ACL injured subjects and non-injured subjects (p<0.001), while no significant differences in notch volume and notch shape were observed between the groups (male: p=0.43, female: p=0.22). Conclusion: The results of this study might suggest that certain 2D measurements (notch width) of the notch could be better than notch volume for prediction of ACL rupture risk.

Assessing activity participation in the ACL injured population: a systematic review of activity rating scale measurement properties

Background: Participation is an important factor in assessing both the requirement for and outcome from anterior cruciate ligament reconstruction. Many patient-reported rating scales exist; however, measurement properties have not been well established.Objective: To provide a systematic review to identify currently available activity rating scales for anterior cruciate ligament injured subjects and to evaluate current knowledge of their measurement properties.Methods: Systematic searches of four databases (Medline, AMED, EMBASE, and CINAHL) without date or language restriction, using terms structured around the PICOS system were completed on 1st March 2011. Citation tracking, reference screening and contact with lead authors of key papers completed the search strategy. Studies using participation rating scales were identified to assess frequency of reporting and cited validation. Studies assessing one or more psychometric properties of the identified rating scales were subject to independent data extraction and critical appraisal by two independent authors using published tools.Results: Thirty-one rating scales were identified from 241 outcome studies. Most scales were inadequately developed or validated prior to use. Only three scales (Tegner, CSAS, and Marx) had psychometric analysis in eight studies of mixed quality. Only the Tegner scale has adequate assessment of reliability, validity, and responsiveness. The use of type, intensity, and frequency variables in the identified scales is discussed.Conclusions: The Tegner scale has been adequately validated; however, other rating scales require further validation. A comprehensive comparative analysis of clinical applicability and psychometric testing of existing scales, including clinically useful statistics, is required.

Effect of Strength Training with Enhanced Sensory Input on Quadriceps Voluntary Activation and Landing Performance in Subjects with Anterior Cruciate Ligament Injury

Anterior cruciate ligament (ACL) ruptures often accompanied by severe quadriceps muscle atrophy and voluntary activation (VA) failure. It has been shown that additional enhanced sensory input (SI) with electrical stimulation (ES) could efficiently enhance the VA of the quadriceps muscle. The present study was aimed to investigate the effect of strength training with additional enhanced sensory input induced by ES on the voluntary activation, as well as the functional outcome in subjects with chronic ACL injury. Nineteen ACL injured subjects with VA below 90% were randomly divided into two groups: the strength training with additional SI group, and only the strength training (control) group. Isokinetic strength training program was conducted for three days per week, over a four weeks period. For the SI group, low intensity electrical stimulations were applied in the 30-minute strength training period. Maximum quadriceps isometric strength, voluntary activation, and single leg landings were performed before and after training. In the results, it was found that the maximum quadriceps strength, the VA and the maximal vertical ground reaction force were significantly (p＜.05) increased after training in both groups. The maximum knee flexion angle after landing remains unchanged in both groups. The strength training program has been shown to efficiently improve the quadriceps muscle strength, the central drive and the ability to support the body weight. The effect of strength training with additional enhanced sensory input by ES was similar to that of strength training alone.

Kinetic alterations of the lower limb during stair locomotion in anterior cruciate ligament injured subjects

Kinetic alterations of the lower limb during stair locomotion in anterior cruciate ligament injured subjects

Rotary instability of the knee joint during walking in anterior cruciate ligament injured subjects

Posterolateral instability is defined as the instability that results from injuries to the posterolateral stabilising structures of the knee. This instability is posterior, varus and external rotation. Isolated posterolateral ligamentous instability of the knee is however uncommon. Instability usually occurs in association with other ligamentous injuries, in particular, injuries to either the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), or both.The recognition and adequate management of this injury pattern is crucial, particularly as any cruciate ligament reconstruction will be compromised if there is a combined injury and repair of the posterolateral corner is omitted. There should always therefore be a high degree of suspicion when examining the knee, particularly in those patients where the mechanism of injury and symptoms are suggestive of a complex knee injury.

Biomechanical And Clinical Changes In ACL Injured Subjects Following A Neuromuscular Training Program

Neuromuscular exercises to induce changes in lower extremity neuromuscular responses are being implemented for subjects with anterior cruciate ligament (ACL) injury during the rehabilitation programs. While effectiveness has been demonstrated in a few studies, the mechanism responsible is for these changes are unknown. PURPOSE The purpose of this study was to determine changes in biomechanical-, electromyographic (EMG)-, and clinical outcome following a rehabilitation program including neuromuscular exercises in ACL injured subjects. SUBJECTS Thirty ACL injured subjects with a mean age of 26 years, participated in a 20 session rehabilitation program consisting of balance-, jumping-, perturbation exercises and lower extremity strengthening exercises. METHODS Prior to training, and after completing training, subjects were examined using knee arthrometer (KT-1000), Knee Outcome Survey (KOS-ADL), VAS for satisfaction, the new version of the IKDC form, quadriceps and hamstring muscles strength (Cybex 6000), 4 functional knee tests, and motion analysis testing (Qualysis); first, ten trials of free-speed walking were collected, followed by three trails of one-leg jumping on each leg. An 8-camera motion analysis system was used to collect lower extremity kinetic and kinematic data at a frequency of 240 Hz. Rigid body analysis was used to calculate the hip, knee, and ankle angles and moments at initial contact, peak knee flexion, and peak knee extension. EMG data were collected at a frequency of 960 Hz with active surface electrodes over the vastus lateralis and medialis, medial and lateral hamstrings, medial gastrocnemius, soleus, and tibialis anterior muscles. RESULTS Significant improvement in knee function was found for the KOS-ADL (p<0.05), VAS (p<0.01), IKDC (p<0.001), one leg hop test (p<0.01) and thigh muscle strength (p<0.05). There was a significant reduced knee excursion and knee moments between involved and uninvolved leg during gait and hop. There were three different movement patterns in the sagittal plane; 67% walk with a biphasic pattern (normal), 11% with an extension moment, and 22% with a flexion moment. After rehabilitation these movement patterns were normalized. CONCLUSIONS This rehabilitation program significantly improved clinical outcome, induced changes in the lower extremity kinematics, kinetics, and muscle activity patterns. This study provides insight into the possible mechanisms underlying the effect of neuromuscular training program.

Biomechanical And Clinical Changes In ACL Injured Subjects Following A Neuromuscular Training Program

Neuromuscular exercises to induce changes in lower extremity neuromuscular responses are being implemented for subjects with anterior cruciate ligament (ACL) injury during the rehabilitation programs. While effectiveness has been demonstrated in a few studies, the mechanism responsible is for these changes are unknown. PURPOSE The purpose of this study was to determine changes in biomechanical-, electromyographic (EMG)-, and clinical outcome following a rehabilitation program including neuromuscular exercises in ACL injured subjects. SUBJECTS Thirty ACL injured subjects with a mean age of 26 years, participated in a 20 session rehabilitation program consisting of balance-, jumping-, perturbation exercises and lower extremity strengthening exercises. METHODS Prior to training, and after completing training, subjects were examined using knee arthrometer (KT-1000), Knee Outcome Survey (KOS-ADL), VAS for satisfaction, the new version of the IKDC form, quadriceps and hamstring muscles strength (Cybex 6000), 4 functional knee tests, and motion analysis testing (Qualysis); first, ten trials of free-speed walking were collected, followed by three trails of one-leg jumping on each leg. An 8-camera motion analysis system was used to collect lower extremity kinetic and kinematic data at a frequency of 240 Hz. Rigid body analysis was used to calculate the hip, knee, and ankle angles and moments at initial contact, peak knee flexion, and peak knee extension. EMG data were collected at a frequency of 960 Hz with active surface electrodes over the vastus lateralis and medialis, medial and lateral hamstrings, medial gastrocnemius, soleus, and tibialis anterior muscles. RESULTS Significant improvement in knee function was found for the KOS-ADL (p<0.05), VAS (p<0.01), IKDC (p<0.001), one leg hop test (p<0.01) and thigh muscle strength (p<0.05). There was a significant reduced knee excursion and knee moments between involved and uninvolved leg during gait and hop. There were three different movement patterns in the sagittal plane; 67% walk with a biphasic pattern (normal), 11% with an extension moment, and 22% with a flexion moment. After rehabilitation these movement patterns were normalized. CONCLUSIONS This rehabilitation program significantly improved clinical outcome, induced changes in the lower extremity kinematics, kinetics, and muscle activity patterns. This study provides insight into the possible mechanisms underlying the effect of neuromuscular training program.

Gait perturbation response in chronic anterior cruciate ligament deficiency and repair

Objective. To determine how chronic anterior cruciate ligament deficient and surgically repaired subjects react to unexpected forward perturbations during gait as compared to healthy controls. Design. Gait testing of 10 chronic anterior cruciate ligament deficient subjects prior to and three months following reconstructive surgery, and 10 uninjured controls. Background. The ability of an anterior cruciate ligament injured individual to react and maintain equilibrium during gait perturbations is critical for the prevention of reinjury. No studies have investigated how these individuals respond to unexpected perturbations during normal gait. Methods. An unexpected forward perturbation was induced upon heel strike using a force plate capable of translational movement. Results. Prior to surgery, the anterior cruciate ligament subjects exhibited a greater knee extensor moment in response to the perturbation compared to healthy controls. Following surgery, the anterior cruciate ligament injured subjects exhibited a static knee position and a sustained knee extensor moment throughout stance in response to the perturbation as compared to controls. Conclusions. These data suggest that chronic anterior cruciate ligament deficient subjects rely heavily on knee extensor musculature to prevent collapse in response to an unexpected perturbation. This same reactive response was more pronounced 3 months following surgery. Relevance The results suggest that, prior to and following surgery, chronic anterior cruciate ligament injured subjects respond differently than healthy controls to an unexpected perturbation during gait. Anterior cruciate ligament injured or repaired subjects do not reduce or avoid vigorous contraction of the quadriceps muscles when responding to gait perturbations.