Effect of Meniscal Ramp Lesion Repair on Knee Kinematics, ACL In-Situ Forces and Bony Contact Forces – A Biomechanical Study

Aims and Objectives: While recent studies showed that all inside meniscal ramp repair is able to restore knee kinematics, the effects of ramp repairs on ACL in-situ forces and bony contact forces is still unclear. Therefore, the purpose of this study is to determine the effect of ramp lesion repair on knee kinematics, the ACL-ISF and bony contact forces using a 6-degree-of-freedom (DOF) robotic testing system. It was hypothesized that ramp repair will restore kinematics, ACL-ISF and bony contact forces comparably to the forces of the intact knee. Materials and Methods: Nine fresh-frozen human cadaveric knee specimens were tested using a 6-degree-of-freedom robotic testing system (FRS2010) to continuously flex the knee from full extension to 90° and apply continuous loading conditions: 1) 90 N of anterior force, 2) 5 Nm of external rotation torque, 3) 134 N anterior force + 200 N compression force, 4) 4 Nm external rotation torque + 200 N compression force, 5) 4 Nm internal rotation torque + 200 N compression force. Loading conditions were applied to the intact knee, a knee with an arthroscopically induced 25 mm ramp lesion, and a knee with an all-inside repaired ramp lesion. ACL in-situ forces, medial compartment bony contact forces and lateral compartment bony contact forces were quantified. Repeated measure ANOVAs were performed to compare knee states at each flexion angle (p<0.05). Results: In response to all loading conditions, no differences with respect to kinematics, ACL in-situ forces, and bony contact forces between the intact state and the ramp lesion state were detected. However, compared to the intact state, ramp lesion repair significantly reduced anterior translation in flexion angles from full extension to 40° in response to 5 N anterior force (p < 0.05). In addition, a significant decrease in the ACL in-situ forces after ramp repair was detected only for higher flexion angles when 4 Nm external rotation torque combined with 200 N compression force (p < 0.05) and when 4 Nm internal rotation torque combined with 200 N compression force were applied (p < 0.05). Conclusion: In this biomechanical study, ramp lesions did not significantly affect knee biomechanics. Care must be taken to avoid potential overconstraint when performing all-inside ramp lesion repairs. From biomechanical time-zero perspective, it is debatable if stable ramp lesions need to be addressed surgically. As stable ramp lesions do not significantly change knee biomechanics, the indications for ramp lesion repair may be limited.

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Effect of Meniscal Ramp Repair on Knee Kinematics, ACL In Situ Force and Bony Contact Forces - A Biomechanical Study

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967118s00157 ◽

2018 ◽

Vol 6 (7_suppl4) ◽

pp. 2325967118S0015 ◽

Cited By ~ 1

Author(s):

Thomas Rudolf Pfeiffer ◽

Jan Hendrik Naendrup ◽

Calvin Chan ◽

Kanto Nagai ◽

João V. Novaretti ◽

...

Keyword(s):

Knee Kinematics ◽

Contact Forces ◽

Testing System ◽

Loading Conditions ◽

Ramp Lesion ◽

Robotic Testing ◽

Deficient Knee ◽

Robotic Testing System ◽

Intact Knee

Objectives: While recent studies showed that all inside meniscal ramp repair is able to restore knee kinematics, the effects of ramp repairs on ACL in-situ forces (ISF) and bony contact forces is still unclear. Therefore, the purpose of this study is to determine the effect of ramp lesion repair on knee kinematics, the ACL-ISF and bony contact forces using a 6-degree-of-freedom (DOF) robotic testing system. It was hypothesized that ramp repair will restore kinematics, ACL-ISF and bony contact forces comparably to the forces of the intact knee. Methods: 5 fresh-frozen human cadaveric knee specimens were tested using a 6-DOF robotic testing system (FRS2010) to continuously flex the knee from 0° to 90° and apply continuous loading conditions: 134 N anterior load + 200 N compressive load (CL), 4 Nm internal torque + 200 N CL, 4 Nm external torque + 200 N CL. Loading conditions were applied to the: 1) Intact knee 2) Arthroscopically induced 25 mm ramp lesion via posteromedial portal 3) All inside ramp repair 4) ACL deficient knee + ramp repair 5) soft tissue removal 6) Transection of the lateral condyle. To mimic an ideal ACL reconstruction the native ACL was kept intact. By replaying kinematics, ACL-ISF and bony contact forces were determined. Repeated measure ANOVAs were performed to compare knee states at each flexion angle (p<0.05). Results: Ramp repair significantly reduced anterior translation compared to the ramp deficient knee in high flexion under anterior load and CL (mean diff. -0.8 mm, range 0.6-0.9 mm) and at all flexions angles while applying internal torque and CL (mean diff. -2.3 mm, range 1.8-3.3 mm). Increased medial translation and valgus position were observed in all loading conditions at all flexion angles. Both ACL-ISF and medial bony contact forces were not significantly altered by the ramp lesion and repair under any applied loading and flexion angle. In contrast, ramp repair significantly increased lateral bony contact forces by under external torque and CL at 60° and 70° flexion compared to the ramp deficient knee, 32 N and 37 N respectively. No significant differences between intact and ramp deficient knee were detected with respect to kinematics, ACL-ISF and bony contact forces. Conclusion: In this study ramp repair decreased anterior translation, increased valgus rotation, and increased bony contact forces in the lateral compartment, disproving the hypothesis under study. The data from this study puts into question potential overconstraint when repairing ramp lesions utilizing all inside devices in 10 degrees of knee flexion. Contrasting previous literature that showed the restoration of the intact state, the results might be attributable to added CL forces and missing influence of the ACL reconstructions. The findings of this study also imply that untreated ramp lesion might not affect ACL-ISF. Future research is needed to better understand the influence of different techniques for repair of ramp lesions and the effect of chronicity on ramp lesions in patients.

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Effect of Meniscal Ramp Lesion Repair on Knee Kinematics, Bony Contact Forces, and In Situ Forces in the Anterior Cruciate Ligament

The American Journal of Sports Medicine ◽

10.1177/0363546519872964 ◽

2019 ◽

Vol 47 (13) ◽

pp. 3195-3202 ◽

Cited By ~ 10

Author(s):

Jan-Hendrik Naendrup ◽

Thomas R. Pfeiffer ◽

Calvin Chan ◽

Kanto Nagai ◽

João V. Novaretti ◽

...

Keyword(s):

External Rotation ◽

Cruciate Ligament ◽

Knee Kinematics ◽

Contact Forces ◽

Full Extension ◽

Compression Load ◽

Ramp Lesion ◽

Anterior Cruciate ◽

Intact Knee

Background: Meniscal ramp lesions are possible concomitant injuries in cases of anterior cruciate ligament (ACL) deficiency. Although recent studies have investigated the influence of ramp lesions on knee kinematics, the effect on the ACL reconstruction graft remains unknown. Purpose/Hypothesis: The purpose was to determine the effects of ramp lesion and ramp lesion repair on knee kinematics, the in situ forces in the ACL, and bony contact forces. It was hypothesized that ramp lesions will significantly increase in situ forces in the native ACL and bony contact forces and that ramp lesion repair will restore these conditions comparably with those forces of the intact knee. Study Design: Controlled laboratory study. Methods: Investigators tested 9 human cadaveric knee specimens using a 6 degrees of freedom robotic testing system. The knee was continuously flexed from full extension to 90° while the following loads were applied: (1) 90-N anterior load, (2) 5 N·m of external-rotation torque, (3) 134-N anterior load + 200-N compression load, (4) 4 N·m of external-rotation torque + 200-N compression load, and (5) 4 N·m of internal-rotation torque + 200-N compression load. Loading conditions were applied to the intact knee, a knee with an arthroscopically induced 25-mm ramp lesion, and a knee with an all-inside repaired ramp lesion. In situ forces in the ACL, bony contact forces in the medial compartment, and bony contact forces in the lateral compartment were quantified. Results: In response to all loading conditions, no differences were found with respect to kinematics, in situ forces in the ACL, and bony contact forces between intact knees and knees with a ramp lesion. However, compared with intact knees, knees with a ramp lesion repair had significantly reduced anterior translation at flexion angles from full extension to 40° in response to a 90-N anterior load ( P < .05). In addition, a significant decrease in the in situ forces in the ACL after ramp repair was detected only for higher flexion angles when 4 N·m of external-rotation torque combined with a 200-N compression load ( P < .05) and 4 N·m of internal-rotation torque combined with a 200-N compression load were applied ( P < .05). Conclusion: In this biomechanical study, ramp lesions did not significantly affect knee biomechanics at the time of surgery. Clinical Relevance: From a biomechanical time-zero perspective, the indications for ramp lesion repair may be limited.

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Effect of Meniscal Ramp Lesion Repair on Knee Kinematics, Bony Contact Forces, and In Situ Forces in the Anterior Cruciate Ligament: Letter to Editor

The American Journal of Sports Medicine ◽

10.1177/0363546519897010 ◽

2020 ◽

Vol 48 (2) ◽

pp. NP23-NP25

Author(s):

Thais Dutra Vieira ◽

William G. Blakeney ◽

Sergio Canuto ◽

Etienne Cavaignac ◽

Steven Claes ◽

...

Keyword(s):

Anterior Cruciate Ligament ◽

Cruciate Ligament ◽

Knee Kinematics ◽

Contact Forces ◽

Ramp Lesion ◽

Anterior Cruciate

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Effect of Meniscal Ramp Lesion Repair on Knee Kinematics, Bony Contact Forces, and In Situ Forces in the Anterior Cruciate Ligament: Response

The American Journal of Sports Medicine ◽

10.1177/0363546519897012 ◽

2020 ◽

Vol 48 (2) ◽

pp. NP25-NP27

Author(s):

Jan-Hendrik Naendrup ◽

Thomas R. Pfeiffer ◽

Calvin Chan ◽

Kanto Nagai ◽

João V. Novaretti ◽

...

Keyword(s):

Anterior Cruciate Ligament ◽

Cruciate Ligament ◽

Knee Kinematics ◽

Contact Forces ◽

Ramp Lesion ◽

Anterior Cruciate

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Biomechanical Comparison of Kinematic and Mechanical Knee Alignment Techniques in a Computer Simulation Medial Pivot Total Knee Arthroplasty Model

The Journal of Knee Surgery ◽

10.1055/s-0041-1740392 ◽

2021 ◽

Author(s):

Young Dong Song ◽

Shinichiro Nakamura ◽

Shinichi Kuriyama ◽

Kohei Nishitani ◽

Hiromu Ito ◽

...

Keyword(s):

Femoral Component ◽

Knee Flexion ◽

External Rotation ◽

Knee Kinematics ◽

Lateral Compartment ◽

Contact Stresses ◽

Contact Forces ◽

Medial Compartment ◽

Tibial Insert ◽

Medial Pivot

AbstractSeveral concepts may be used to restore normal knee kinematics after total knee arthroplasty. One is a kinematically aligned (KA) technique, which restores the native joint line and limb alignment, and the other is the use of a medial pivot knee (MPK) design, with a ball and socket joint in the medial compartment. This study aimed to compare motions, contact forces, and contact stress between mechanically aligned (MA) and KA (medial tilt 3° [KA3] and 5° [KA5]) models in MPK. An MPK design was virtually implanted with MA, KA3, and KA5 in a validated musculoskeletal computer model of a healthy knee, and the simulation of motion and contact forces was implemented. Anteroposterior (AP) positions, mediolateral positions, external rotation angles of the femoral component relative to the tibial insert, and tibiofemoral contact forces were evaluated at different knee flexion angles. Contact stresses on the tibial insert were calculated using finite element analysis. The AP position at the medial compartment was consistent for all models. From 0° to 120°, the femoral component in KA models showed larger posterior movement at the lateral compartment (0.3, 6.8, and 17.7 mm in MA, KA3, and KA5 models, respectively) and larger external rotation (4.2°, 12.0°, and 16.8° in the MA, KA3, and KA5 models, respectively) relative to the tibial component. Concerning the mediolateral position of the femoral component, the KA5 model was positioned more medially. The contact forces at the lateral compartment of all models were larger than those at the medial compartment at >60° of knee flexion. The peak contact stresses on the tibiofemoral joint at 90° and 120° of knee flexion were higher in the KA models. However, the peak contact stresses of the KA models at every flexion angle were <20 MPa. The KA technique in MPK can successfully achieve near-normal knee kinematics; however, there may be a concern for higher contact stresses on the tibial insert.

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In situ deformation characterization of density-graded foams in quasi-static and impact loading conditions

International Journal of Impact Engineering ◽

10.1016/j.ijimpeng.2021.103820 ◽

2021 ◽

Vol 150 ◽

pp. 103820

Author(s):

Behrad Koohbor ◽

Suraj Ravindran ◽

Addis Kidane

Keyword(s):

Impact Loading ◽

Loading Conditions ◽

In Situ Deformation

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Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽

10.1186/s42836-021-00075-7 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Toni Wendler ◽

Torsten Prietzel ◽

Robert Möbius ◽

Jean-Pierre Fischer ◽

Andreas Roth ◽

...

Keyword(s):

Soft Tissue ◽

Work Experience ◽

Soft Tissues ◽

Force Sensor ◽

Biomechanical Study ◽

Measuring System ◽

Wide Range ◽

Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

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Discrete element analysis of the punching behaviour of a secured drapery system: from laboratory characterization to idealized in situ conditions

Acta Geotechnica ◽

10.1007/s11440-020-01119-z ◽

2021 ◽

Author(s):

Antonio Pol ◽

Fabio Gabrieli ◽

Lorenzo Brezzi

Keyword(s):

Mechanical Response ◽

Steel Wire ◽

Discrete Element ◽

Wire Mesh ◽

Steel Plates ◽

Loading Conditions ◽

Element Analysis ◽

In Situ Conditions ◽

Wire Meshes

AbstractIn this work, the mechanical response of a steel wire mesh panel against a punching load is studied starting from laboratory test conditions and extending the results to field applications. Wire meshes anchored with bolts and steel plates are extensively used in rockfall protection and slope stabilization. Their performances are evaluated through laboratory tests, but the mechanical constraints, the geometry and the loading conditions may strongly differ from the in situ conditions leading to incorrect estimations of the strength of the mesh. In this work, the discrete element method is used to simulate a wire mesh. After validation of the numerical mesh model against experimental data, the punching behaviour of an anchored mesh panel is investigated in order to obtain a more realistic characterization of the mesh mechanical response in field conditions. The dimension of the punching element, its position, the anchor plate size and the anchor spacing are varied, providing analytical relationships able to predict the panel response in different loading conditions. Furthermore, the mesh panel aspect ratio is analysed showing the existence of an optimal value. The results of this study can provide useful information to practitioners for designing secured drapery systems, as well as for the assessment of their safety conditions.

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