The medial ligaments and the ACL restrain anteromedial laxity of the knee

Abstract Purpose The purpose of this study was to determine the contribution of each of the ACL and medial ligament structures in resisting anteromedial rotatory instability (AMRI) loads applied in vitro. Methods Twelve knees were tested using a robotic system. It imposed loads simulating clinical laxity tests at 0° to 90° flexion: ±90 N anterior–posterior force, ±8 Nm varus–valgus moment, and ±5 Nm internal–external rotation, and the tibial displacements were measured in the intact knee. The ACL and individual medial structures—retinaculum, superficial and deep medial collateral ligament (sMCL and dMCL), and posteromedial capsule with oblique ligament (POL + PMC)—were sectioned sequentially. The tibial displacements were reapplied after each cut and the reduced loads required allowed the contribution of each structure to be calculated. Results For anterior translation, the ACL was the primary restraint, resisting 63–77% of the drawer force across 0° to 90°, the sMCL contributing 4–7%. For posterior translation, the POL + PMC contributed 10% of the restraint in extension; other structures were not significant. For valgus load, the sMCL was the primary restraint (40–54%) across 0° to 90°, the dMCL 12%, and POL + PMC 16% in extension. For external rotation, the dMCL resisted 23–13% across 0° to 90°, the sMCL 13–22%, and the ACL 6–9%. Conclusion The dMCL is the largest medial restraint to tibial external rotation in extension. Therefore, following a combined ACL + MCL injury, AMRI may persist if there is inadequate healing of both the sMCL and dMCL, and MCL deficiency increases the risk of ACL graft failure.

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The Joint Biomechanics Change by Different Anterior Cruciate Ligament Constitutive Models Under Axial Torque Load

Volume 2: Biomedical and Biotechnology ◽

10.1115/imece2012-85758 ◽

2012 ◽

Cited By ~ 1

Author(s):

Chao Wan ◽

Zhixiu Hao ◽

Shizhu Wen

Keyword(s):

Knee Joint ◽

External Rotation ◽

Cruciate Ligament ◽

Constitutive Models ◽

Collateral Ligament ◽

Torque Load ◽

Joint Biomechanics ◽

Hyperelastic Model ◽

Anterior Cruciate ◽

Anterior Posterior

According to the previous papers, it was demonstrated that anterior cruciate ligament (ACL) played an important role in resisting the coupled anterior-posterior laxity rather than the rotation laxity under axial torque load of knee joint. In the biomechanics simulation research of knee joint, some different ligament constitutive models were presented to describe the ACL material behavior. However, there is few published paper to study the effect of variable ligament constitutive model on the joint biomechanics under axial torque load. In this paper, a 3-dimension finite element model of an intact tibiofemoral joint including all the main anatomical structures was reconstructed and two ACL constitutive models were compared under 10 Nm femur external torque load. The two ACL constitutive models corresponded to an isotropic hyperelastic model and a transversely isotropic hyperelastic model considering fiber effect, respectively. All the ACL material properties of the two constitutive models were defined by fitting the same stress-strain data. Another model with ACL resected was also analyzed under the same load to estimate the function ACL played under joint axial torque load. It was found that the resection of ACL changed the knee joint deformations significantly in all directions except the distal-proximal translation. In the ACL resected joint model, the internal-external rotation, anterior-posterior and medial-lateral translations increased by about 20%, 500% and 600%, respectively. Comparing to the ACL intact joint model, the Mises stress values of medial collateral ligament decreased while that on lateral collateral ligament increased greatly (from 35 MPa to 61 MPa). In the comparison of the two different ACL constitutive models, the internal-external rotation, as the highest deformation of the knee joint, changed by about 11% and the maximal deformation alteration was obtained in the anterior-posterior translation (about 80%). Both the highest stress value and distribution on ACL have altered mostly while the Mises stress distributions of other ligaments and menisci have changed slightly. The alteration of joint kinematics and ligament biomechanics by different ACL constitutive models would be due to the different descriptions of the material transverse behavior and the real complex ACL stress distribution under an axial torque load, although the longitudinal material behaviors described by different ACL constitutive models were almost the same based on the same experiment data.

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Medial Collateral Ligament Reconstruction With Anteromedial Reinforcement for Medial and Anteromedial Rotatory Instability of the Knee

Arthroscopy Techniques ◽

10.1016/j.eats.2019.03.019 ◽

2019 ◽

Vol 8 (8) ◽

pp. e807-e814

Author(s):

Konrad Malinowski ◽

Krzysztof Hermanowicz ◽

Adrian Góralczyk ◽

Robert F. LaPrade

Keyword(s):

Medial Collateral Ligament ◽

Ligament Reconstruction ◽

Collateral Ligament ◽

Rotatory Instability ◽

Medial Collateral Ligament Reconstruction ◽

Anteromedial Rotatory Instability

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Anterior-Posterior Translation and Axial Rotation of the Fibula are Significantly Increased with Sequential Disruption of the Syndesmosis

Foot & Ankle Orthopaedics ◽

10.1177/2473011417s000303 ◽

2017 ◽

Vol 2 (3) ◽

pp. 2473011417S0003

Author(s):

Conor Murphy ◽

Thomas Pfeiffer ◽

Jason Zlotnicki ◽

Volker Musahl ◽

Richard Debski ◽

...

Keyword(s):

External Rotation ◽

Optical Tracking ◽

Flexion Angle ◽

Rotational Instability ◽

Syndesmotic Injury ◽

Combined Injury ◽

Tibiofibular Ligament ◽

Significant Difference ◽

Posterior Translation ◽

Anterior Posterior

Category: Ankle, Sports, Trauma Introduction/Purpose: Injury to the Anterior inferior tibiofibular ligament (AITFL), Posterior inferior tibiofibular ligament (PITFL) and Interosseus membrane (IOM) predicts residual symptoms in ankle sprains. Limited kinematic knowledge of the tibiofibular joint results in missed diagnosis and poor clinical outcomes. Lateral fibular displacement on radiologic assessment signifies syndesmotic disruption which dictates operative management. Previous studies demonstrated that fibular motion is multiplanar after injury. The objective of this study is to determine increases in fibular motion with sequential syndesmotic injury and the contribution of the AITFL. Methods: Five fresh-frozen human cadaveric tibial plateau-to-toe specimens with a mean age of 58 years (range 38-73 years) were tested using a 6-degree-of-freedom robotic testing system. The tibia and calcaneus were rigidly fixed. The subtalar joint was fused. The full fibular length was maintained and fibular motion was unconstrained. A 5 Nm external rotation and 5 Nm inversion moment were applied to the ankle at 0°, 15°, and 30° plantarflexion and 10° dorsiflexion. The motion of the fibula was tracked by a 3D optical tracking system. Outcome variables included fibular medial-lateral (ML) translation, anterior-posterior (AP) translation, and external rotation (ER) during each applied moment and flexion angle in the following conditions: 1) intact ankle, 2) AITFL transected, 3) PITFL and IOM transected. Statistical analysis included an ANOVA with a post-hoc Tukey analysis to compare the changes in fibular motion between the intact and injury models at each applied moment and flexion angle (*p<0.05). Results: The only significant differences in fibular motion were during the 5 Nm inversion moment. The posterior translation of the fibula was significantly greater with AITFL injury compared to the intact ankle at 15° and 30° plantarflexion. Significant increases in posterior translation between the intact ankle and AITFL, PITFL, and IOM injury existed at 0°, 15°, and 30° plantarflexion. No significant motion differences were observed between the AITFL injury and combined injury at any condition. When comparing the intact ankle and combined injury, significant increases in ER existed at 0° and 30° plantarflexion and 10° dorsiflexion. The only significant difference in ER between the intact ankle and AITFL injury existed at 0° plantarflexion. Conclusion: This study showed that transecting the AITFL resulted in the largest increases in fibular motion with only minimal further increases after complete syndesmotic injury. Fibular displacement was primarily in the sagittal plane. This study utilized a novel setup with unconstrained motion in a full length, intact fibula. Measuring ML translation alone could underestimate sagittal and rotational instability of the syndesmosis in AITFL injuries. Evaluating fibular AP translation and ER are not part of current standard diagnostic protocols. Physicians may consider more aggressive treatment of isolated AITFL injuries.

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Kinematics of the posterolateral corner of the knee: A human cadaveric cutting study.

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967117s00136 ◽

2017 ◽

Vol 5 (4_suppl4) ◽

pp. 2325967117S0013

Author(s):

Tobias Drenck ◽

Christoph Domnick ◽

Mirco Herbort ◽

Michael Raschke ◽

Karl-Heinz Frosch

Keyword(s):

Knee Flexion ◽

External Rotation ◽

Lateral Collateral Ligament ◽

Posterolateral Corner ◽

Clinical Diagnostics ◽

Popliteus Tendon ◽

Collateral Ligament ◽

Intact State ◽

Posterior Tibial ◽

Intact Knee

Aims and Objectives: The posterolateral corner of the knee consists of different structures, which contribute to instability when damaged after injury or within surgery. Knowing the kinematic influences may help to improve clinical diagnostics and surgical techniques. The purpose was to determine static stabilizing effects of the posterolateral corner by dissecting stepwise all fibers and ligaments (the arcuat complex, AC) connected with the popliteus tendon (PLT) and the influence on lateral stability in the lateral collateral ligament (LCL) intact-state. Materials ans Methods: Kinematics were examined in 13 fresh-frozen human cadaveric knees using a robotic/UFS testing system with an optical tracking system. The knee kinematics were determined for 134 N anterior/posterior loads, 10 Nm valgus/varus loads and 5 Nm internal/external rotational loads in 0°, 20°, 30°, 60° and 90° of knee flexion. The posterolateral corner structures were consecutively dissected: The I.) intact knee joint, II.) with dissected posterior cruciate ligament, III.) meniscofibular/-tibial fibers, IV.) popliteofibular ligament, V.) popliteotibial fascicle (last structure of static AC), VI.) PLT and VII.) LCL. Results: The external rotation angle increased significantly by 2.6° to 7.9° (P<.05) in 0° to 90° of knee flexion and posterior tibial translation increased by 2.9 mm to 5.9 mm in 20° to 90° of knee flexion (P<.05) after cutting the AC/PLT structures (with intact LCL) in contrast to the PCL deficient knee. Differences between dissected static AC and dissected PLT were only found in 60° and 90° external rotation tests (by 2.1° and 3.1°; P<.05). In the other 28 kinematic tests, no significant differences between PLT and AC were found. Cutting the AC/PLT complex did not further decrease varus, valgus or anterior tibial stability in any flexion angle in comparison to the PCL dissected state. Conclusion: The arcuat complex is an important static stabilizer for external rotatory and posterior tibial loads of the knee, even in the lateral collateral ligament intact-state. After dissecting the major parts of the arcuat complex, the static stabilizing function of the popliteus tendon is lost. The arcuat complex has no varus-stabilizing function in the LCL-intact knee. The anatomy and function of these structures for external-rotational and posterior-translational stabilization should be considered for clinical diagnostics and when performing surgery in the posterolateral corner.

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In Vitro Kinematic Analysis of Single Axis Radius Posterior-Substituting Total Knee Arthroplasty

The Journal of Knee Surgery ◽

10.1055/s-0040-1708039 ◽

2020 ◽

Cited By ~ 1

Author(s):

Paul Arauz ◽

Yun Peng ◽

Tiffany Castillo ◽

Christian Klemt ◽

Young-Min Kwon

Keyword(s):

Knee Flexion ◽

Knee Kinematics ◽

Lateral Collateral Ligament ◽

Collateral Ligament ◽

Flexion Extension ◽

Healthy Knee ◽

Joint Biomechanics ◽

Total Knee ◽

Intact Knee

AbstractThis is an experimental study. As current posterior-substituting (PS) total knee arthroplasties have been reported to incompletely restore intrinsic joint biomechanics of the healthy knee, the recently designed single axis radius PS knee system was introduced to increase posterior femoral translation and promote ligament isometry. As there is a paucity of data available regarding its ability to replicate healthy knee biomechanics, this study aimed to assess joint and articular contact kinematics as well as ligament isometry of the contemporary single axis radius PS knee system. Implant kinematics were measured from 11 cadaveric knees using an in vitro robotic testing system. In addition, medial collateral ligament (MCL) and lateral collateral ligament (LCL) forces were quantified under simulated functional loads during knee flexion for the contemporary PS knee system. Posterior femoral translation between the intact knee and the single axis radius PS knee system differed significantly (p < 0.05) at 60, 90, and 120 degrees of flexion. The LCL force at 60 degrees (9.06 ± 2.81 N) was significantly lower (p < 0.05) than those at 30, 90, and 120 degrees of flexion, while MCL forces did not differ significantly throughout the range of tested flexion angles. The results from this study suggest that although the contemporary single axis radius PS knee system has the potential to mimic the intact knee kinematics under muscle loading during flexion extension due to its design features, single axis radius PS knee system did not fully replicate posterior femoral translation and ligament isometry of the healthy knee during knee flexion.

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Establishing the Role of Elbow Muscles by Evaluating Muscle Activation and Co-contraction Levels at Maximal External Rotation in Fastball Pitching

Frontiers in Sports and Active Living ◽

10.3389/fspor.2021.698592 ◽

2021 ◽

Vol 3 ◽

Author(s):

Bart van Trigt ◽

Eva Galjee ◽

Marco J. M. Hoozemans ◽

Frans C. T. van der Helm ◽

DirkJan H. E. J. Veeger

Keyword(s):

Injury Risk ◽

Muscle Activation ◽

Biceps Brachii ◽

External Rotation ◽

Ulnar Collateral Ligament ◽

Moderate Activity ◽

Triceps Brachii ◽

Collateral Ligament ◽

Medial Side

Background: Baseball pitching is associated with a high prevalence of ulnar collateral ligament injuries, potentially due to the high external valgus load on the medial side of the elbow at the instant of maximal shoulder external rotation (MER). In-vitro studies show that external valgus torque is resisted by the ulnar collateral ligament but could also be compensated by elbow muscles. As the potential active contribution of these muscles in counteracting external valgus load during baseball pitching is unknown, the aim of this study is to determine whether and to what extent the elbow muscles are active at and around MER during a fastball pitch in baseball.Methods: Eleven uninjured pitchers threw 15 fastball pitches. Surface electromyography of six muscles crossing the elbow were measured at 2000 Hz. Electromyography signals were normalized to maximal activity values. Co-contraction index (CCI) was calculated between two pairs of the flexor and extensor elbow muscles. Confidence intervals were calculated at the instant of MER. Four ranges of muscle activity were considered; 0–20% was considered low; 21–40% moderate; 41–60% high and over 60% as very high. To determine MER, the pitching motion was captured with a highspeed camera at 240 Hz.Results: The flexor pronator mass, pronator teres, triceps brachii, biceps brachii, extensor supinator mass and anconeus show moderate activity at MER. Considerable variation between participants was found in all muscles. The CCI revealed co-contraction of the two flexor-extensor muscle pairs at MER.Interpretation: The muscle activation of the flexor and pronator muscles at MER indicates a direct contribution of forearm muscles crossing the medial side of the elbow in counteracting the external valgus load during fastball pitching. The activation of both flexor and extensor muscles indicates an in-direct contributory effect as the combined activity of these muscles counteract opening of the humeroulnar joint space. We believe that active muscular contributions counteracting the elbow valgus torque can be presumed to relieve the ulnar collateral ligament from maximal stress and are thus of importance in injury risk assessment in fastball pitching in baseball.

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ANTEROMEDIAL ROTATORY INSTABILITY: A BIOMECHANICAL STUDY OF MEDIAL SOFT-TISSUE RESTRAINTS IN-VITRO

The Knee ◽

10.1016/j.knee.2020.07.019 ◽

2020 ◽

Vol 27 ◽

pp. S6

Author(s):

S. Ball ◽

J. Stephen ◽

H. El-Daou ◽

A. Williams ◽

A. Amis

Keyword(s):

Soft Tissue ◽

Biomechanical Study ◽

Rotatory Instability ◽

Anteromedial Rotatory Instability

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Long-term results for Kinemax and Kinematic knee bearings on a six-station knee wear simulator

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1243/0954411001535462 ◽

2000 ◽

Vol 214 (5) ◽

pp. 437-447 ◽

Cited By ~ 12

Author(s):

H E Ash ◽

I C Burgess ◽

A Unsworth

Keyword(s):

External Rotation ◽

Wear Test ◽

Long Term Results ◽

Wear Rates ◽

Flexion Extension ◽

Average Wear ◽

Posterior Translation ◽

Wear Simulator

A long-term wear test was performed on Kinemax and Kinematic (Howmedica Inc.) knee bearings on the Durham six-station knee wear simulator. The bearings were subjected to flexion/extension of 65–0°, anterior-posterior translation of between 4.5 and 8.5 mm and a maximum axial load of 3 kN. Passive abduction/adduction and internal/external rotation were also permitted, however, two of the stations had a linkage system which produced ± 5° active internal/external rotation. The bearings were tested at 37 °C in a 30 per cent bovine serum solution and the test was run to 5.6 × 106 cycles. The bearings from stations 2 and 3, and stations 4 and 5 were swapped during the test to investigate the effects of interstation variability. The average wear rate and standard error was 3.00 ± 0.98 mg/106 cycles (range 1.33-4.72 mg/106 cycles) for the Kinemax bearings and 3.78 ± 1.04 mg/106 cycles (range 1.87-4.89 mg/106 cycles) for the Kinematic bearings. There were no significant differences in wear rates between the different bearing designs, the addition of active internal/external rotation or a change of stations. However, the wear tracks were different for the two types of bearings and with active internal/external rotation. The wear rates and factors were generally lower than previously published in vitro wear results; however, this may have been due to a difference in the axial loads and lubricants used. The appearance of the wear tracks with active internal/external rotation was comparable with those seen on explanted knee bearings.

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Computational Wear Prediction for Impact of Kinematics Boundary Conditions on Wear of Total Knee Replacement Using Two Cross-Shear Models

Journal of Tribology ◽

10.1115/1.4044377 ◽

2019 ◽

Vol 141 (11) ◽

Author(s):

Jing Zhang ◽

Zhenxian Chen ◽

Yongchang Gao ◽

Xuan Zhang ◽

Lei Guo ◽

...

Keyword(s):

Total Knee Replacement ◽

Contact Pressure ◽

Knee Replacement ◽

External Rotation ◽

Posterior Translation ◽

Total Knee ◽

Dependent Model ◽

Pressure Independent ◽

Anterior Posterior ◽

Independent Model

Abstract Wear particle-induced osteolysis is the main reason for the long-term failure of total knee replacement. Simulator testing is the standard procedure for validating wear performance pre-clinically. The load and kinematics specified in the International Organization for Standardization (ISO) are standard input profiles for wear testing of implants. Directions of internal–external (IE) rotation and anterior–posterior (AP) translation have been modified in the new version of ISO 14243-3 2014. This study focused on investigating the effects of internal–external rotation and anterior–posterior translation on the wear of knee implants. Numerical wear prediction was performed using the finite element model along with two wear models, namely the contact pressure independent model and contact pressure dependent model. Addition of internal–external rotation significantly increased the wear, and the two wear models obtained similar results. The effect of internal–external rotation direction on wear was slight. Forward movement of the tibial insert during flexion decreased the wear under the contact pressure independent model and increased the wear under the contact pressure dependent model. When the AP direction switched, the two models obtained opposite wear tendencies. The results predicted by the contact pressure dependent model were consistent with those of wear tendency experiments reported in the literature. Further investigation of wear physical principles was necessary to gain a more reliable model. This study demonstrated that both internal–external rotation and anterior–posterior translation were pivotal factors influencing the contact mechanism and wear of total knee implants. More realistic kinematics are necessary for accurate wear assessment.

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