An insight into biomechanical study for replacement of knee joint

Objective: Off-loader knee braces have traditionally focused on redistributing loads away from either the medial or lateral tibiofemoral (TF) compartments. In this article, we study the potential of a novel “tricompartment unloader” (TCU) knee brace intended to simultaneously unload both the patellofemoral (PF) and TF joints during knee flexion. Three different models of the TCU brace are evaluated for their potential to unload the knee joint.Methods: A sagittal plane model of the knee was used to compute PF and TF contact forces, patellar and quadriceps tendon forces, and forces in the anterior and posterior cruciate ligaments during a deep knee bend (DKB) test using motion analysis data from eight participants. Forces were computed for the observed (no brace) and simulated braced conditions. A sensitivity and validity analysis was conducted to determine the valid output range for the model, and Statistical Parameter Mapping was used to quantify the effectual region of the different TCU brace models.Results: PF and TF joint force calculations were valid between ~0 and 100 degrees of flexion. All three simulated brace models significantly (p < 0.001) reduced predicted knee joint loads (by 30–50%) across all structures, at knee flexion angles >~30 degrees during DKB.Conclusions: The TCU brace is predicted to reduce PF and TF knee joint contact loads during weight-bearing activity requiring knee flexion angles between 30 and 100 degrees; this effect may be clinically beneficial for pain reduction or rehabilitation from common knee injuries or joint disorders. Future work is needed to assess the range of possible clinical and prophylactic benefits of the TCU brace.

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Biomechanical study on the stress distribution of the knee joint after distal femoral fracture malunion with residual varus-valgus deformity

10.21203/rs.3.rs-24051/v2 ◽

2020 ◽

Author(s):

Ming Li ◽

Pan Hu ◽

Lijie Ma ◽

Di Zhang ◽

Wenli Chang ◽

...

Keyword(s):

Stress Distribution ◽

Knee Joint ◽

Femoral Fracture ◽

Femoral Fractures ◽

Valgus Deformity ◽

Biomechanical Study ◽

Lower Limbs ◽

Neutral Position ◽

Distal Femoral Fracture ◽

Lateral Plateau

Abstract Background: To investigate the effect of residual varus and valgus deformity on the stress distribution of knee joint after distal femoral fracture malunion. Methods: Fourteen adult cadaver specimens with formalin were selected to establish the femoral fractures models, which were fixed subsequently at neutral position (anatomical reduction) and malunion positions (at 3 degrees, 7 degrees, 10 degrees valgus positions and 3 degrees, 7 degrees, and 10 degrees varus positions). The stress distribution on the medial and lateral plateau of the tibia was quantitatively measured using ultra-low pressure sensitive film technology. The change of stress distribution of knee joint after femoral fracture malunion and the relationship between stress value and residual varus varus or valgus deformity were analyzed.Results: Under 400 N vertical load, the stress values on the medial and lateral plateau of the tibia at the neutral position were 1.162±0.114 MPa and 1.103±0.144 MPa, respectively. When compared with the stress values measured at the neutral position, the stress on the medial plateau of tibia were significantly higher at varus deformities and lower at valgus deformities, and the stress on the lateral plateau was significantly higher at valgus deformity and lower at varus deformities (all P<0.05). The stress values on the medial plateau of tibia were significantly higher than the corresponding data on the lateral plateau at neutral and 3 degrees, 7 degrees, 10 degrees varus deformities, respectively (all P<0.05), and significantly lower than the corresponding data on the lateral plateau at 3 degrees, 7 degrees, 10 degrees valgus deformities, respectively (all P<0.05). Conclusions: Residual varus and valgus deformity after femoral fracture malunion can cause obvious changes of the stress distribution of knee joint. Therefore, the distal femoral fracture should be anatomically reduced and rigidly fixed to avoid residual varus-valgus deformity and malalignment of lower limbs.

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TRANSMISSIBILITY OF WHOLE BODY VIBRATION STIMULI THROUGH HUMAN BODY IN DIFFERENT STANDING POSTURES

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519412004934 ◽

2012 ◽

Vol 12 (03) ◽

pp. 1250047 ◽

Cited By ~ 8

Author(s):

LIN YANG ◽

HE GONG ◽

MING ZHANG

Keyword(s):

Knee Joint ◽

Human Body ◽

Mechanical Vibration ◽

Whole Body Vibration ◽

Interaction Mechanism ◽

Resonant Peak ◽

Whole Body ◽

Vibration Signals ◽

Body Vibration ◽

Insight Into

This study focuses on the transmissibility of whole body vibration stimuli through human body in different standing postures to explore the mechanism in which vibration stimuli could be better used as a regimen for bone loss. Five volunteers were guided to stay at three standing postures and imposed of frequency-adjustable vibration stimuli on the plantar surfaces side-alternately. Motion capture system was used to acquire the vibration signals at head, pelvis, knee up, knee down and ankle, from which the transmissibility of vibration stimuli can be obtained. The results showed that transmissibility of vibration stimuli was closely correlated with frequency and skeletal sites. Transmissibility of vibration stimuli in head was much smaller than any other skeletal sites. Transmissibility in the ankle was always in the vicinity of unit one in all the three postures for the vibration stimuli applied side-alternately on the plantar surfaces of both feet. There was an obvious peak around 9 to 11 Hz in the transmissibility curves for knee joint and pelvis. In the resonant peak, transmissibility of vibration stimuli in knee joint and pelvis both exceeded unit one and reached 150%. As the frequency increased after 11 Hz, transmissibility of vibration stimuli decayed rapidly as a function of frequency and dropped to 25% at 30 Hz. This study may help to gain insight into the interaction mechanism between mechanical vibration stimuli and the responses of human musculoskeletal system.

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Posterolateral aspect and stability of the knee joint. I. Anatomy and function of the popliteus muscle-tendon unit: an anatomical and biomechanical study

Knee Surgery Sports Traumatology Arthroscopy ◽

10.1007/s00167-001-0268-5 ◽

2002 ◽

Vol 10 (2) ◽

pp. 86-90 ◽

Cited By ~ 45

Author(s):

Karin Ullrich ◽

Wilfried K. Krudwig ◽

Ulrich Witzel

Keyword(s):

Knee Joint ◽

Biomechanical Study ◽

And Function ◽

Popliteus Muscle

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Passive ligament stability in natural knee: a cadaveric biomechanical study

10.29007/jp61 ◽

2020 ◽

Author(s):

Thomas Paszicsnyek ◽

Edoardo Bori ◽

Bernardo Innocenti

Keyword(s):

Knee Joint ◽

Biomechanical Study ◽

Cruciate Ligaments ◽

Recent Experimental Study ◽

Ligament Tension ◽

The Stability ◽

The One ◽

Force Displacement ◽

Cadaveric Knee

Objectives: Applying the correct amount of collateral ligaments tension in the knees during surgery is a prerequisite to restore normal kinematics after TKA. It is well known that a low value of ligament tension could lead to an instable joint while a higher tension could induce over-tensioning and problems at later follow-up. In this study, an experimental cadaveric activity was performed to measure the minimum tension required to achieve stability in the knee joint.Methods: 10 cadaveric knee specimens were investigated in this study. The femur and tibia were fixed with polyurethane foam in specific designed fixtures and clamped to a loading frame.Increasing displacement was applied to the femoral clamp and the relative force was measured by a loading-frame machine up to the stability of the joint, determined by a decrease in the derivate of the force/displacement trend followed by a plateau.The force span between the slack region and the plateau was considered as the tension required to stabilize the joint.This methodology was applied for joints with intact cruciate ligaments, after ACL resection and after further PCL resection, to simulate the knee behavior prior a CR and a PS implant.The test was performed at 0, 30, 60 and 90° of flexion. Each configuration was analyzed three times for the sake of repeatability.Results and Conclusion: Results demonstrated that an overall tension of 41.2N (range 30.0-48.0 N) is sufficient to reach stability in a native knee with intact cruciate ligaments. Similar values appear to be sufficient also in an ACL resected knee (average 45.6, range 41.2-50.0 N), while higher tension is required (average 58.6N, range 40.0-77.0 N) were necessary in the case of PCL retention. Moreover, in this configuration, the tension required for stabilization was slighter higher at 30 and 60° of flexion compared to the one required at 0 and 90° of flexion.The results are in agreement to the ones found by other recent experimental study [Manning et al 2018 (KSSTA)] and shown that the tension necessary to stabilize a knee joint in different ligament conditions is way lower than the ones usually applied via tensioners nowadays.To reach functional stability, surgeons need to consider such results intraoperatively to avoid laxity, mid-flexion instability or ligament over-tension.

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Cumulative Loads Increase at the Knee Joint With Slow-Speed Running Compared to Faster Running: A Biomechanical Study

Journal of Orthopaedic and Sports Physical Therapy ◽

10.2519/jospt.2015.5469 ◽

2015 ◽

Vol 45 (4) ◽

pp. 316-322 ◽

Cited By ~ 20

Author(s):

Jesper Petersen ◽

Henrik Sørensen ◽

Rasmus Østergaard Nielsen

Keyword(s):

Knee Joint ◽

Biomechanical Study ◽

Slow Speed

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Simulation Study on Biomechanics of Knee Joint in Running

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.774-776.231 ◽

2013 ◽

Vol 774-776 ◽

pp. 231-234

Author(s):

Hui Yue

Keyword(s):

Knee Joint ◽

Simulation Study ◽

Lower Limb ◽

The Body ◽

Body Movements ◽

Running Speed ◽

Running Injuries ◽

Foot Strike ◽

Biomechanical Parameters ◽

Insight Into

The study of the forces that act on the body and the body movements during running provide an insight into how certain changes in running technique influence running performance, and how a number of biomechanical parameters can predispose a runner to injury. This paper will describe the biomechanics of running, focusing on the movement of the lower limb segments and the forces encountered during each foot strike with the ground. The effect of running speed and running surface on specific biomechanical parameters and their subsequent influence on running injuries will be reviewed, and the implications of these findings for the design of appropriate footwear disscussed.

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