Anterior Cruciate Ligament Deficient Patients Research Articles

Dependence on visual information in patients with ACL injury for multi-joint coordination during single-leg squats: a case control study.

The influence of vision on multi-joint control during dynamic tasks in anterior cruciate ligament (ACL) deficient patients is unknown. Thus, the purpose of this study was to establish a new method for quantifying neuromuscular control by focusing on the variability of multi-joint movement under conditions with different visual information and to determine the cutoff for potential biomarkers of injury risk in ACL deficient individuals. Twenty-three ACL deficient patients and 23 healthy subjects participated in this study. They performed single-leg squats under two different conditions: open eyes (OE) and closed eyes (CE). Multi-joint coordination was calculated with the coupling angle of hip flexion, hip abduction and knee flexion. Non-linear analyses were performed on the coupling angle. Dependence on vision was compared between groups by calculating the CE/OE index for each variable. Cutoff values were calculated using ROC curves with ACL injury as the dependent variable and significant variables as independent variables. The sample entropy of the coupling angle was increased in all groups under the CE condition (P < 0.001). The CE/OE index of coupling angle variability during the descending phase was higher in ACL deficient limbs than in the limbs of healthy participants (P = 0.036). The CE/OE index of sample entropy was higher in the uninjured limbs of ACL deficient patients than in the limbs of healthy participants (P = 0.027). The cutoff value of the CE/OE index of sample entropy was calculated to be 1.477 (Sensitivity 0.957, specificity 0.478). ACL deficient patients depended on vision to control multiple joint movements not only on the ACL deficient side but also on the uninjured side during single leg squat task. These findings underscore the importance of considering visual dependence in the assessment and rehabilitation of neuromuscular control in ACL deficient individuals.

Static Foot Pressure and Percentage Contact Area of the Foot as an Assessment Tool for the Success of Anterior Cruciate Ligament Reconstruction: A Cross-sectional Study

Introduction: Anterior Cruciate Ligament (ACL) plays a vital role in gait balancing and lower limb kinematics. Any injury to the ACL leads to gait imbalance and alterations in foot pressure distribution. The stability and biomechanics of the lower limb after ACL Reconstruction (ACLR) can be measured through foot pressure analysis, gait analysis, and percentage contact area of the foot, among others. Aim: To evaluate the static foot pressure and percentage contact area of the foot in ACL deficient group, comparing it with the ACLR group and the normal healthy individual group. Materials and Methods: An analytical cross-sectional study was conducted at the Department of Sports Medicine, King George Medical University, Lucknow, Uttar Pradesh, India from March 10, 2021 to March 15, 2023. A total of 15 patients in each group (ACL injury, ACLR patients, and normal healthy individuals) were included in this study. Foot pressures (static) were recorded in all three groups using the BTS P-WALK system with BTS Biomedical software, which included high- density sensors and a plate size of 700 × 500 × 5 mm. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) software version 26.0. Chi-square and linear regression tests were used to analyse the differences between the groups. Results: In the intragroup analysis, ACL deficient patients’ ipsilateral limbs showed lower foot pressure in the mid-foot (7±3.4), hind-foot (40.33±10.08), and whole foot pressure (110.19±34.7 Pascal (N/M2)) (p-value&gt;0.05) compared to normal healthy individuals (126.06±19.4 Pascal (N/M2) (p&gt;0.05) and ACLR (125.06±14.3 Pascal (N/M2)) (p-value&gt;0.05) groups, which suggested insignificant differences. The percentage contact area of the foot was significantly lower (43.15±3.4) (p-value&lt;0.001) compared to normal healthy individuals (49.82±0.84) and ACLR (49.02±0.91) groups. However, in intergroup comparisons, the differences in mid-foot, whole foot pressure, and percentage contact area of the foot were significant (p-value &lt;0.001) within the groups. Conclusion: Although there is a wide range of variation in the values of static foot pressure and percentage contact area of the foot in ACL deficient patients, after ACLR, these values become nearly similar to those of normal healthy individuals at around one year after ACLR.

Outcome Analysis of Arthroscopic Single Bundle Anterior Cruciate Ligament Reconstruction Using Semitendinosus and Gracilis as Quadrupled Graft in Adults – A Case Series Study

Anterior cruciate ligament (ACL) injury is the common knee injury consequent to contact sports. There are different techniques recommended for the ACL reconstruction, with different graft materials. The aim of this study is to evaluate the functional outcome of arthroscopic single bundle ACL reconstruction using hamstring tendon graft in ACL deficient knees in adults. Between 2014 and 2017, a prospective study was conducted in Thanjavur Medical College on 10 ACL deficient patients. All patients were evaluated preoperatively using the Lysholm and Gillquist score and IKDC - 2000 score. All patients underwent arthroscopic single bundle ACL reconstruction with hamstring tendon graft, which was fixed with an endo-button CL fixation system on the femoral side and an interference screw on tibial side. They were advised a regular rehabilitation protocol. All patients were evaluated post-operatively at 6 weeks, 3 months, 6 months, and a year by same assessment scores. Ten patients were available for follow up for a period of 6 months to 2 years. The mean follow-up period was 10.5 months. When compared with their respective pre-operative knee assessment scores, it was found that a definite improvement was there in their knee function. The results were good to excellent in 80% patients, fair in 10%, and poor in 10% cases. For young active adults, single bundle reconstruction by arthroscopic methods gives acceptable results. The problems which are faced post-operatively can be again settled arthroscopically. A long-term follow-up of these cases is a must to analyze if there is degeneration that happened in the time between injury and ligament reconstruction.

How Does Anterior Cruciate Ligament Incompetence Influence the Varus Osteoarthritic Knee?

Introduction: The aims of our study were: (i) to assess the correlation of anterior cruciate ligament (ACL) deficiency with severity of preoperative varus deformity in osteoarthritic knees, (ii) to compare posterior medial femoral condyle (MFC) changes in ACL deficient vs ACL competent knees, and (iii) to compare the mean femoral external rotation of ACL deficient vs ACL competent knees. Methods: 250 consecutive ACL deficient and ACL competent patients each, undergoing total knee arthroplasty (TKA) for osteoarthritis with a varus deformity were reviewed retrospectively. Data from a prospectively collected computer navigation assisted TKA database was analyzed for an association between ACL insufficiency and: severity of the varus deformity, incidence of posterior MFC compensatory changes, and the magnitude of femoral component external rotation. Results: A statistically significant positive correlation was found between ACL incompetence and- (1) Severity of the knee varus deformity (p < 0.001), (2) Incidence of compensatory posterior MFC hypertrophy (p < 0.001) and (3) Femoral component external rotation required to balance the knee in flexion during TKA (p < 0.001). Conclusion: ACL deficiency is associated with an increase in the severity of the varus deformity. A significantly higher incidence of posterior MFC hypertrophy and increased values of the combined Whiteside-PCA angle are noted in ACL deficient knees compared with knees with an intact ACL. Multiple intraoperative landmarks must be assessed for setting femoral component rotation while performing TKA in the ACL deficient knee.

Effect of Fatigue on Hip and Knee Joint Biomechanics in Anterior Cruciate Ligament Deficient Patients

The influence of fatigue on landing biomechanics in anterior cruciate ligament deficient (ACLD) patients is poorly understood. The purpose of this study was to examine the effect of fatigue on hip and knee joint biomechanics in deficient patients. Twelve ACLD males and 12 healthy control subjects participated in the study. The ACLD patients landed with increased peak knee flexion angle (F = 15.71, p &lt; .01) and decreased peak knee flexion moment (F = 9.13, p &lt; .01) after fatigue. Furthermore, ACLD patients experienced lower vertical ground reaction forces compared with controls regardless of fatigue state (F = 9.75, p &lt; .01). It seems that ACLD patients use protective strategy in response to fatigue in order to prevent further injury in knee point.

Correlation among Knee Muscle Strength and Self-Reported Outcomes Score, Anterior Tibial Displacement, and Time Post-Injury in Non-Coper Anterior Cruciate Ligament Deficient Patients: A Cross-Sectional Study.

Little attention has been paid to knee muscle strength after ACL rupture and its effect on prognostic outcomes and treatment decisions. We studied hamstrings (H) and quadriceps (Q) strength correlation with a patient-reported outcome measures score (International Knee Documentation Committee, IKDC), anterior tibial translation (ATT), and time post-injury in 194 anterior cruciate ligament deficient patients (ACLD) who required surgery after a failed rehabilitation program (non-copers). The correlation between knee muscle strength and ATT was also studied in 53 non-injured controls. ACLD patients showed decreased knee muscle strength of both the injured and non-injured limbs. The median (interquartile range) values of the H/Q ratio were 0.61 (0.52–0.81) for patients’ injured side and 0.65 (0.57–0.8) for the non-injured side (p = 0.010). The median H/Q ratio for the controls was 0.52 (0.45–0.66) on both knees (p < 0.001, compared with the non-injured side of patients). The H/Q, ATT, and time post-injury were not significantly correlated with the IKDC score. ATT was significantly correlated with the H/Q of the injured and non-injured knees of patients, but not in the knees of the controls. Quadriceps strength and H/Q ratio were significantly correlated with ATT for both limbs of the patients. IKDC score correlated significantly with the quadriceps and hamstrings strengths of the injured limb but not with the H/Q ratio, ATT or time passed after injury.

Study of relationship of posterior tibial slope in anterior cruciate ligament injury

ObjectiveTo determine the relationship between Posterior Tibial slope in terms of medial and lateral in Anterior cruciate ligament deficient patients. MethodsMagnetic resonance images (MRI) of the knee of 100 ACL injured patients and 100 ACL intact patients were studied. Their medial and lateral posterior tibial slopes were measured using MRI. Of 200 subjects, 100 (Male- 63, Female- 37) were controls, other 100 (Male – 68, Female-32) were ACL injured cases. Using DIACOM viewer software,the slopes of both medial and lateral slopes were measured. Range of Variation, mean value and standard deviation of medial tibial plateau slope (MTS), lateral tibia plateau slope (LTS) of controls and ACL injured patients were measured. The data collected were entered into Microsoft excel worksheet and analysed using statistical package for social sciences, Version 15.0 (SPSS Inc. Chicago, IL, USA). Distribution of data was confirmed using Shapiro's Wilk Test and appropriate parametric statistics were applied. For all analysis p value < 0.05 was set to be significant. ResultsIn control (ACL uninjured) population mean MTS was 5.95° with SD 3.09°, mean LTS was 6.08° with SD 3.48°. In ACL injured population mean MTS 6.41° with SD 2.66°, mean LTS was 8.12° with SD 3.65°. So ACL injured population had MTS steeper than control population with no statistical significance (p value < 0.27) and LTS was steeper than control population with statistical significance (p value < 0.001),where as there were comparable results between male and females. ConclusionOur current results indicate that lateral PTS is a risk factor for patients with primary ACL tears as compared with ligament-intact controls. Therefore,PTS should be considered as independent modifiable risk factors in ACL injury.

Sex Differences In The Morphology Of The Vastus Lateralis After An Anterior Cruciate Ligament Tear

Females are three times more susceptible to tear their anterior cruciate ligament (ACL) and have significantly weaker quadriceps after injury. Despite the high frequency of injury, little is known about whether the morphology of the quadriceps alters in a sex specific manner. Muscle imaging of volume, fibrosis, pennation angle, and fiber tract length could provide valuable insights into these differences. PURPOSE: To investigate sex differences in morphology of the vastus lateralis (VL) after ACL injury. METHODS: 24 ACL deficient patients (11M, 13F, 21.8 ± 5.0 y, 25.0 ± 3.7 kg/m2, days since injury 24.6 ± 16.2) underwent magnetic resonance imaging including multi echo T1ρ, DTI, and 2D turbo spin echo. Data was post-processed in MATLAB, where a mono exponential decay curve was fitted to analyze the T1ρ signal. Muscle fiber bundles were tracked by taking the first eigenvector of diffusion tensor starting at the aponeurosis until the fiber exited the side or top of the selected slices. From these tracks pennation angle and fiber length were calculated. Muscle volume was calculated by manually outlining the border of the VL. Independent t-tests compared differences between males and females. RESULTS: T1ρ times (M: 0.031 ± 0.003 s; F: 0.028 ± 0.002 s; p = 0.06) and pennation angle (M: 16.6 ± 2.6°; F: 14.9 ± 1.8°) of the involved limb was not significantly different between sexes; however, fiber length was significantly longer in females compared to males (F: 55.1 ± 6.2 mm; M: 48.3 ± 7.0 mm; p = 0.04). Volume of the vastus lateralis was not significantly different between sexes (M: 355.1 ± 117.5 cm3; F: 335.9 ± 97.1 cm3; p = 0.6). CONCLUSIONS: We show that ACL injury results in a sex specific difference in muscle fiber length. Fiber length is an important determinant in physiological cross-sectional area (PCSA). The longer fiber lengths seen in the females may lead to decreased PCSA which could have a negative influence on quadriceps muscle strength. Potentially, this longer fiber length prior to surgery may be one factor that drives differences in recovery of muscle strength after surgery. Future work is needed to examine how these morphological aspects change over time following ACL reconstruction.

Dynamic Between-Leg Differences While Walking in Anterior Cruciate Ligament-Deficient Patients With and Without Medial Meniscal Posterior Horn Tears.

Background:Patients with anterior cruciate ligament–deficient (ACLD) knees with medial meniscal posterior horn tears (MMPHTs) have been reported to demonstrate a combined stiffening and pivot-shift gait pattern compared with healthy controls. Movement asymmetries are implicated in the development and progression of osteoarthritis.Purpose:To investigate the knee kinematics and kinetic asymmetries in ACLD patients with (ACLD + MMPHT group) and without (ACLD group) MMPHTs while walking on level ground.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A total of 15 patients with isolated unilateral ACL ruptures, 10 with unilateral ACL ruptures and MMPHTs, and 22 healthy controls underwent gait testing between January 2014 and December 2016. Between-leg differences (BLDs) in knee kinematics and kinetics were compared among participants in all groups.Results:The ACLD + MMPHT group demonstrated significantly greater BLDs in knee moments in the sagittal plane during the loading response phase than the ACLD and control groups. Compared with the control group, the ACLD and ACLD + MMPHT groups demonstrated significantly greater BLDs in knee angles in the sagittal plane during the midstance and terminal stance phases. Compared with the control group, significantly greater BLDs in knee rotation moments were found throughout the stance phase in both the ACLD and the ACLD + MMPHT groups. BLDs in lateral ground-reaction forces (GRFs) in the ACLD + MMPHT and ACLD groups were both significantly greater than the control group during the loading response phase. BLDs in anterior GRFs in the ACLD + MMPHT and ACLD groups were both significantly greater than the control group during the loading response phase. Only the ACLD + MMPHT group demonstrated greater BLDs in vertical GRFs than the control group during the loading response phase, while no significant differences were observed between the ACLD and control groups.Conclusion:The ACLD + MMPHT group demonstrated significantly more knee flexion moment asymmetries than the ACLD and control groups during the loading response phase. Both the ACLD + MMPHT and the ACLD groups demonstrated significant knee angle and moment asymmetries in the sagittal plane during the terminal stance phase than the control group. Both the ACLD + MMPHT and the ACLD groups demonstrated knee rotation moment asymmetries during the midstance and terminal stance phases compared with the control group. A rehabilitation program for ACLD patients both with and without MMPHTs should take into consideration these asymmetric gait patterns.

Evaluation of a Functional Brace in ACL-Deficient Subjects Measuring Ground Reaction Forces and Contact Pressure: A Pilot Study

ABSTRACT Introduction An ideal functional brace for anterior cruciate ligament-deficient (ACLD) patients should control anterior movement of the tibia and simultaneously decrease the effects of ground reaction shearing force. The current study was aimed to compare the interface pressure between the anterior shell of a functional brace and proximal of tibia in both sound and ACLD limbs, and to assess the effect of using functional brace on the symmetry of vertical and anteroposterior components of ground reaction force and impulse of ground reaction force during level walking. Methods Seven unilateral ACLD men participated in this study. The interface pressure between the anterior shell and proximal of the tibia and ground reaction force was recorded by means of Novel Pliance X and Kistler force platform, respectively. Wilcoxon ranked-sign test and factor analysis repeated measure analysis of variance were used to analyze data. Results The use of functional brace had no significant effect on interface pressure and peak points of the ground reaction force. By use of a functional brace, the valley and the impulse of the vertical component of ground reaction force on ACLD limb increased significantly (P &lt; 0.05) and also improved limb symmetry of all parameters. The interface pressure was greater at distal contact points of the shell, which are at the middle level of the tibia crest. Conclusions The results suggest that functional brace could not apply force on proximal tibia especially at ACLD limb and therefore could not normalize vertical component of ground reaction force during level walking.

Static patellofemoral alignment in anterior cruciate ligament deficient knees; a retrospective analysis with magnetic resonance imaging

Static patellofemoral alignment in anterior cruciate ligament deficient knees; a retrospective analysis with magnetic resonance imaging

Anterior cruciate ligament reconstruction improves subjective ability but not neuromuscular biomechanics during dynamic tasks.

The purpose of this study was to identify high-functioning anterior cruciate ligament-deficient patients and assess the effects of reconstruction on their self-reported functionality, muscle activations and biomechanical properties. Twenty young and active patients participated pre- (11.5 ± 14.3 months post-injury) and again 10.5 ± 1.7 months post-reconstruction and were individually matched to 20 healthy controls. Participants completed hop and sidecut movements while patient-related outcome measures, lower limb electromyography, kinetic, and whole body kinematic data were collected. One-dimensional statistical parametric mapping was used to test for group differences (healthy vs deficient; deficient vs reconstructed; reconstructed vs healthy). When comparing healthy to anterior cruciate ligament-deficient participants, all questionnaires indicated significant lower subjective function while the only substantial biomechanical difference between these participants was a decreased knee extensor moment in both the hop (peak difference: 0.63Nm/kg, p < 0.001) and side cut (peak difference: 0.76Nm/kg, p < 0.001). When comparing patients' pre- and post-reconstruction, no biomechanical differences were observed whereas only half of the questionnaires (Tegner, Lysholm, KNEES-ADL, KNEES-Slackness, KNEES-Looseness, KNEES-Sport Behaviour, IKDC, and KOOS-QoL) indicated higher function in the reconstructed state. When comparing the reconstructed patients to the healthy participants, all questionnaires were still significantly higher in the healthy controls. The reconstructed group also had a smaller flexion angle (peak difference: 14.5°, p = 0.007) and knee extensor moment (peak difference: 0.62Nm/kg, p < 0.001) during the hop and a smaller knee extensor moment (peak difference: 0.90Nm/kg, p < 0.001) during the side-cut task. At 10-months post-reconstruction, the current results indicate that in high-functioning anterior cruciate ligament-deficient patients, reconstruction had little impact on objective measures of functional ability during dynamic tasks although self-reported function was improved. Therapeutic prospective cohort study, Level II.

A comparison of patellofemoral cartilage morphology and deformation in anterior cruciate ligament deficient versus uninjured knees

Anterior cruciate ligament (ACL) deficient patients have an increased rate of patellofemoral joint (PFJ) osteoarthritis (OA) as compared to the general population. Although the cause of post-injury OA is multi-factorial, alterations in joint biomechanics may predispose patients to cartilage degeneration. This study aimed to compare in vivo PFJ morphology and mechanics between ACL deficient and intact knees in subjects with unilateral ACL ruptures. Eight male subjects underwent baseline MRI scans of both knees. They then performed a series of 60 single-legged hops, followed by a post-exercise MRI scan. This process was repeated for the contralateral knee. The MR images were converted into three-dimensional surface models of cartilage and bone in order to assess cartilage thickness distributions and strain following exercise. Prior to exercise, patellar cartilage was significantly thicker in intact knees as compared to ACL deficient knees by 1.8%. In response to exercise, we observed average patellar cartilage strains of 5.4 ± 1.1% and 2.5 ± 1.4% in the ACL deficient and intact knees, respectively. Importantly, the magnitude of patellar cartilage strain in the ACL deficient knees was significantly higher than in the intact knees. However, while trochlear cartilage experienced a mean strain of 2.4 ± 1.6%, there was no difference in trochlear cartilage strain between the ACL deficient and uninjured knees. In summary, we found that ACL deficiency was associated with decreased patellar cartilage thickness and increased exercise-induced patellar cartilage strain when compared to the uninjured contralateral knees.

The role of anterior cruciate ligament in the control of posture; possible neural contribution.

The anterior cruciate ligament (ACL) is not only a mechanical structure for knee joint stability but is also a source of sensory information which could be used in the control of standing posture. It has been shown that the center of pressure (COP) time series during normal standing may be decomposed into two components which are hypothetically governed by different neural mechanisms, namely rambling and trembling. The aim of the present study was to investigate to what extent an injury to the ACL structure would affect these two control mechanisms. In this study the balance of a group of ACL deficient (ACLD) patients during double and single leg standing was examined and compared with that of a group of healthy individuals. We not only calculated the traditional measures of COP, but also decomposed this complex signal to investigate if ACL deficiency would affect the rambling and trembling components differently. The results showed that rambling was not significantly different between the two groups; however the trembling component was significantly greater for the ACLD group in both the single leg and the double leg condition. Further, there was also a component (rambling/trembling) by direction (anterior-posterior/mediolateral) interaction for both groups, indicating that the rambling component exhibited differences between directions of sway whereas the trembling component did not. This study provided evidence that the two components of postural control are differently affected by ACL deficiency, and that the rambling component is influenced by direction of sway.

Short-term Impact of Anterior Cruciate Ligament Reconstruction in an Adolescent Population on 3D Knee Kinematics

Objectives:Gait analysis is a proven method for assessing knee biomechanical adaptations in anterior cruciate ligament deficient (ACLD) patients and to quantify the impact of the reconstructive surgery (ACLR). In an adult population, ACLR has shown partial kinematic correction, as they remain in internal tibial rotation, putting them at risk of rotational instability and develop osteoartitis. ACLD adolescents likely adopt similar gait changes to reduce knee instability, but may show quicker or more return to the normal compared to adults. The purpose of this study is to compare the tridimensional (3D) knee kinematics before and after ACLR in adolescents.Methods:25 ACLD patients aged between 13 and 19 years old on a waiting list for ACLR were recruited. Bilateral knee 3D kinematic data was gathered during treadmill walking at comfortable self-selected speed using the KneeKGTM System before and 6-9 months after ACLR. Each participant underwent the same surgical protocol (2-strand hamstring tendon graft, hamstring harvest proximally and kept distally, transphyseal tibial tunnel and transepiphyseal femoral tunnel) by the same experienced surgeon. Three analyses were done: ACLD knee pre vs. post-surgery, contralateral healthy knee pre vs. post-surgery, and ACLR knee vs. healthy contralateral knee.Results:In the sagittal and transverse planes, kinematic patterns remained similar to the pre-op; maintaining the characteristic knee flexion gait pattern during single support phase which is well documented in adult ACLD (hamstring facilitation strategy). The ACLR knee exhibited a more valgus dynamic alignment compared to pre-surgery throughout the gait cycle. The healthy contralateral knee kinematics displayed no significant changes in the frontal and sagittal planes after surgery compared to the pre-op pattern. In the transverse plane, post-op gait analysis showed significantly more external rotation at heel-strike and through weight acceptance. While looking at the gait symmetry post-surgery, ACLR knee revealed significantly more valgus while remaining in greater flexion during single limb support. In the transverse plane, an external rotation tendency is observed in the ACLR knee throughout the gait cycle, except during weight acceptance.Conclusion:This study shows that kinematic adaptations found in ACLD adolescents are likely to endure short term after surgery. For example, the greater knee flexion gait pattern used before surgery is still used after ACLR. Interestingly, adolescents used an external tibial rotation adaptation to limit internal tibial instability before the surgery and this pattern was still present post-surgery. Even if theses protection strategies are efficient, the increased dynamical valgus movement seen could place the graft under pressure while increasing patellofemoral stresses, a common complaint after ACLR. Lastly, post-surgery, the contralateral knee seems to mimic the external tibial rotation gait pattern strategy seen in ACL-knee. This study demonstrates that gait protective strategies are still present short term after the surgery. Biomechanical assessment helps ID these adaptations to optimize post-op rehabilitation and prevent secondary injuries.

Similarity of Center of Pressure Progression during Walking and Jogging of Anterior Cruciate Ligament Deficient Patients.

ObjectiveTo evaluate the center of pressure (COP) progression similarity and its change during walking and jogging in Anterior Cruciate Ligament deficient (ACLD) patients.MethodsA study was performed in 64 unilateral ACLD subjects and 32 healthy volunteers who walked and jogged on footscan® system at a self-selected speed. COP trajectory during walking and jogging was calculated. The robustness and similarity scores of COP (SSCOP, similarity scores with respect to corresponding COP trajectories) were computed, and then the Analysis of Variance test was employed to compare among different conditions (left or right side, within a subject or between subjects, walking or jogging).Results(1) During the same motion status (walking or jogging), SSCOP were higher than 0.885. However, SSCOP between walking and jogging were lower than 0.25 in both the healthy and ACLD group. SSCOP between the intrasubjects were statistically higher than those between the intersubjects (p<0.01). (2) SSCOP in the ACLD group were statistically significantly reduced to 0.885±0.074 compared to 0.912±0.057 in healthy volunteers during walking, and 0.903±0.066 in the ACLD group compared to 0.919±0.050 in the healthy group during jogging (p<0.01).ConclusionsSSCOP can distinguish walking from jogging, and SSCOP of ACLD patients would be different from that of healthy controls.The study protocol was approved by the Institutional Research Board of Peking University Third Hospital (IRB00006761-2012010).

Three-dimensional kinematic and kinetic analysis of knee rotational stability in ACL-deficient patients during walking, running and pivoting

BackgroundAnterior cruciate ligament (ACL) deficiency leads to altered stability of the knee. The purpose of this study was to compare the dynamic, rotational stability of the knee, expressed as rotational stiffness, between anterior cruciate ligament-deficient (ACLD) knees, their contralateral intact knees (ACLI) and a knee healthy control group during walking, running and 90° pivoting. We hypothesized a larger tibial internal rotation, a smaller knee joint external moment and a lower rotational stiffness in the ACLD group compared to the ACLI and the control group.MethodsKinematic and kinetic data were collected from both legs of 44 ACLD patients and 16 healthy controls during walking, running and a pivoting maneuver (descending a staircase and immediately pivoting 90° on the landing leg). Motion data were captured using 8 high-speed cameras and a force-plate. Reflective markers were attached to bony landmarks of the lower limb and rigid clusters on the shank and thigh (CASH model). Maximum internal tibial rotation and the corresponding rotational moment were identified for all tasks and groups and used to calculate rotational stiffness (= Δmoment /Δrotation) of the knee.ResultsThe tibial internal rotation of the ACLD knee was not significantly different from the ACLI knee during all three tasks. During walking and running, the tibial rotation of the control group was significantly different from both legs of the ACL-injured patient. For pivoting, no difference in tibial rotation between knees of the ACLD, ACLI and the control group was found. Knee joint external moments were not significantly different between the three groups during walking and pivoting. During running, the moments of the ACLI group were significantly higher than both the knees of the ACLD and the control group. Rotational stiffness did not differ significantly between groups in any of the three tasks.ConclusionA high-intensity activity combining stair descent and pivoting produces similar angular rotations, knee joint external moments and rotational stiffness in ACLD knees compared to ACLI knees and the control group. During running, the ACLI knee displayed a higher external moment than the ACLD and the healthy control group. This could indicate some type of protective strategy or muscular adaptation in the ACL-injured patients.

Measurement properties of the Star Excursion Balance Test in the anterior crucial ligament-deficient subjects – preliminary analysis

The Star Excursion Balance Test (SEBT) has been lately used in the anterior cruciate ligament (ACL) deficient patients but its measurement properties are still unknown in this population. The purpose of this study was to estimate: the intrarater reliability, agreement, the construct validity of the SEBT, versus the one leg hop test (OLHT) and the self-reported function. The ACL-deficient patients (n = 18) performed three trials of the SEBT in the anterior (A), posteromedial (PM) and posterolateral (PL) direction and three trials of the OLHT bilaterally. The self-reported function was evaluated with the Lysholm score and the International Knee Documentation Form (IKDC 2000). The intrarater reliability was excellent for the SEBT (ICC: 0.94–0.99) with acceptable agreement (MDC: 1.39–6.00). Significant correlations (P < 0.05) were found for the injured limb: SEBT-PM vs. Lysholm score (r = 0.56), SEBT composite score vs. Lysholm score (r = 0.50), SEBT-A vs. OLHT (r = −0.56) and for the non-injured limb: SEBT-PM and OLHT (r = 0.64), SEBT-PM vs. Lysholm score (r = 0.54), SEBT-PL vs. Lysholm score (r = 0.53), SEBT composite score vs. Lysholm score (r = 0.57). The excellent reliability and agreement of the SEBT are in concordance with the results obtained in healthy subjects, indicating that the SEBT can be reliably employed in ACL-deficient patients. Moderate positives correlations found between the SEBT parameters and the Lysholm score reveal good construct validity of the SEBT. However, moderate negative correlation found between SEBT-A and OLHT suggest that these two parameters seem evaluate different construct.

Anterolateral Ligament Reconstruction Technique: An Anatomic-Based Approach

Restoration of anteroposterior laxity after an anterior cruciate ligament reconstruction has been predictable with traditional open and endoscopic techniques. However, anterolateral rotational stability has been difficult to achieve in a subset of patients, even with appropriate anatomic techniques. Therefore, differing techniques have attempted to address this rotational laxity by augmenting or reconstructing lateral-sided structures about the knee. In recent years, there has been a renewed interest in the anterolateral ligament as a potential contributor to residual anterolateral rotatory instability in anterior cruciate ligament–deficient patients. Numerous anatomic and biomechanical studies have been performed to further define the functional importance of the anterolateral ligament, highlighting the need for surgical techniques to address these injuries in the unstable knee. This article details our technique for an anatomic anterolateral ligament reconstruction using a semitendinosus tendon allograft.

Sagittal kinematics of mobile unicompartmental knee replacement in anterior cruciate ligament deficient knees

BackgroundThere is a greater risk of tibial component loosening when mobile unicompartmental knee replacement is performed in anterior cruciate ligament deficient knees. We previously reported on a cohort of anterior cruciate ligament deficient patients (n=46) who had undergone surgery, but no difference was found in implant survivorship at a mean 5-year follow-up. The purpose of this study was to examine the kinematic behaviour of a subcohort of these patients. MethodsThe kinematic behaviour of anterior cruciate deficient knees (n=16) after mobile unicompartmental knee replacement was compared to matched intact knees (n=16). Sagittal plane knee fluoroscopy was taken while patients performed step-up and forward lunge exercises. The patellar tendon angle, knee flexion angle and implant position was calculated for each video frame. FindingsThe patellar tendon angle was 5° lower in the deficient group, indicating greater anterior tibial translation compared to the intact group between 30 and 40° of flexion. Large variability, particularly from 40–60° of flexion, was observed in the bearing position of the deficient group, which may represent different coping mechanisms. The deficient group took 38% longer to perform the exercises. InterpretationKinematic differences were found between the deficient and intact knees after mobile unicompartmental knee replacement; but these kinematic changes do not seem to affect the medium-term clinical outcome. Whether these altered knee kinematics will have a clinical impact is as yet undetermined, but more long-term outcome data is required before mobile unicompartmental knee replacement can be recommended for an anterior cruciate ligament deficient patient.