scholarly journals Biomechanical study on the stress distribution of the knee joint after residual rotation deformity of tibial fracture

2020 ◽  
Author(s):  
Ming Li ◽  
Yanbin Zhu ◽  
Ning Wei ◽  
Wenli Chang ◽  
Zeyue Jin ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Knee Joint ◽  
Lower Limb ◽  
External Rotation ◽  
Biomechanical Study ◽  
Lower Limbs ◽  
Neutral Position ◽  
Lateral Stress ◽  
Significant Difference ◽  
The Difference

Abstract Objectives To investigate the effect of residual rotation deformity on the stress distribution of the knee joint after surgery to treat middle and upper tibial fractures. Methods Fourteen adult cadaver specimens that were preserved with formalin were included, and the tibias were randomly positioned at 0 degree, 5 degrees, 10 degrees, and 15 degrees from the line of force of the lower limb. These positions modeled deformities of 5 degrees, 10 degrees, and 15 degrees from the line of force. Low-pressure pressure-sensitive film technology measured the stress distribution of the knee joint under different degrees of rotation deformity. Results Under a vertical load of 400 N, the difference between the medial and lateral stress of the knee joint was significantly different between the different tibia deformities (P<0.05), and the medial stress of the knee joint was higher than the lateral stress. The current study showed that there were statistically significant differences in the medial stress on the knee joint at all angles (including the neutral position of 0 degrees) (F=89.753, P<0.001) . There was a statistically significant difference in the lateral stresses of the knee joint between different rotation deformities (including the neutral position of 0 degrees) (F=102.998, P<0.001). Conclusions Residual rotation deformity after fracture of middle and upper tibia can lead to poor alignment of lower limb force and change of articular contact characteristics of knee joint, especially external rotation of tibia.Therefore, orthopedic surgeons should correct the malalignment of lower limbs to the greatest extent and reduce the rotation deformity as far as possible.

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

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.

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

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 femur 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 femur 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 femur 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.

scholarly journals Biomechanical Study on the Stress Distribution of the Knee Joint After Distal Femoral Fracture Malunion With Residual Varus-valgus Deformity

2021 ◽  
Author(s):  
Ming Li ◽  
Pan Hu ◽  
Lijie Ma ◽  
Hao Du ◽  
Yanbin Zhu ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Knee Joint ◽  
Femoral Fracture ◽  
Femoral Fractures ◽  
Valgus Deformity ◽  
Biomechanical Study ◽  
Neutral Position ◽  
Distal Femoral Fracture ◽  
Pressure Sensitive Film ◽  
Lateral Plateau

Abstract BackgroundThis study aims to examine the biomechanical influence of residual varus and valgus deformity after malunion of distal femoral fractures on the knee joint. MethodsWe selected 14 adult cadaver specimens to establish the femoral fractures models and subsequently fixed them at neutral position and malunion positions, i.e. at 3°, 7° and 10° at valgus and varus positions, respectively. Ultra-low pressure sensitive film technology was used to quantitatively measure the stress distribution on the medial and lateral plateau of the tibia.ResultsAt neutral position, with 400 N vertical load applied, the stress values of the medial and lateral plateau of tibia were 1.162±0.114 MPa and 1.103±0.144 MPa, respectively. Compared with those measured at neutral position, the stress on the medial plateau of the valgus tibia significantly increased, while that on the lateral plateau of the valgus tibia significantly decreased (both P<0.05). In contrast, the stress on the lateral plateau of the valgus tibia significantly increased, while that on the medial plateau of the valgus tibia significantly decreased (both P<0.05). The medial plateau of tibia demonstrated significantly higher stress values than those on the lateral plateau at neutral position and 3°, 7°, 10° varus deformities, respectively (all P<0.05), but showed significantly lower values than the those on the lateral plateau at 3°, 7°, 10° valgus deformities, respectively (all P<0.05). ConclusionsThe residual varus and valgus deformities after mulunion of the distal femoral fracture resulted in significant changes of the stress distribution of the knee joint. Anatomical reduction and firm fixation of distal femoral fracture should be as possible to be obtained to avoid possible varus and valgus deformities.

scholarly journals Pressure Change Of Fixed Rotational Deformities In The Femur In Human Cadaver Knees-A Biomechanical Study

2021 ◽  
Author(s):  
Yuwen Peizhi ◽  
Hongzhi Lv ◽  
Yanbin Zhu ◽  
Wenli Chang ◽  
Ning Wei ◽  
...  
Keyword(s):  
Knee Joint ◽  
Internal Rotation ◽  
Contact Pressure ◽  
Tibial Plateau ◽  
Lower Limbs ◽  
Lateral Side ◽  
Neutral Position ◽  
Relative Pressure ◽  
Rotational Deformity ◽  
Significant Difference

Abstract Background: Closed intramedullary interlocking nailing is a standard treatment for femoral shaft fractures, but incidences of rotational malalignment after operation is really high. Poor reduction and postoperative malunion lead to many clinical symptoms and long term degenerative arthritis. It has been proved that uneven stress is the mechanical cause of knee joint degeneration, but few studies pay attention to the effect of femur rotational deformity on knee joint contact pressure.This study aim to quantitatively evaluate the relation between residual rotational deformity in femur and contact pressure of knee joint. Methods: Fourteen cadaveric Lower limbs were selected and autopsied, rotatory fixation model with different angles were then made. Connect each model on the biomechanical machine and apply a vertical load to 400N. The contact pressure was quantitatively measured using ultra-low-pressure sensitive film technology. FPD-305E density meter and FPD-306E pressure converter were used to read relative pressure values. Contact pressure on medial and lateral tibial plateau in different femoral rotational deformities were compared. Analysis were done using SPSS software.Results: The medial group show a significant difference on tibial plateau (F=92.114, P<0.01), further test showed statistically significant differences of pairwise comparisons between 0°, 5°, 10°, 15° internal rotation deformity (P<0.05). There is no significant difference in lateral group (ꭓ2=9.967, P<0.01). The medial contact pressure is 0.940±0.177 MPa and the lateral is 1.008±0.219 MPa at neutral position, no statistically significant was found, so is 5° of internal rotational deformity. But the medial contact pressure are all higher than the lateral side at 5°, 10°, 15° of external rotation, and 10°, 15° of internal rotation. Conclusion: Obvious contact pressure changes on tibial plateau were observed in rotatory deformity femur, which is closely related to the occurrence of knee osteoarthritis. Doctors should detect rotational deformity as much as possible during operation and perform anatomical reduction, for patients with residual rotational deformities, indication of osteotomy should not be too broad.

Computed tomography angiography and microsurgical flaps for traumatic wounds: What is the added value?

2021 ◽  
pp. 1-9
Author(s):  
Lucas Sousa Macedo ◽  
Renato Polese Rusig ◽  
Gustavo Bersani Silva ◽  
Alvaro Baik Cho ◽  
Teng Hsiang Wei ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Upper Limb ◽  
Computed Tomography Angiography ◽  
Lower Limb ◽  
High Energy ◽  
Lower Limbs ◽  
Added Value ◽  
Vascular Lesions ◽  
Limb Injuries ◽  
Significant Difference

BACKGROUND: Microsurgical flaps are widely used to treat complex traumatic wounds of upper and lower limbs. Few studies have evaluated whether the vascular changes in preoperative computed tomography angiography (CTA) influence the selection of recipient vessel and type of anastomosis and the microsurgical flaps outcomes including complications. OBJECTIVE: The aim of this study was to evaluate if preoperative CTA reduces the occurrence of major complications (revision of the anastomosis, partial or total flap failure, and amputation) of the flaps in upper and lower limb trauma, and to describe and analyze the vascular lesions of the group with CTA and its relationship with complications. METHODS: A retrospective cohort study was undertaken with all 121 consecutive patients submitted to microsurgical flaps for traumatic lower and upper limb, from 2014 to 2020. Patients were divided into two groups: patients with preoperative CTA (CTA+) and patients not submitted to CTA (CTA–). The presence of postoperative complications was assessed and, within CTA+, we also analyzed the number of patent arteries on CTA and described the arterial lesions. RESULTS: Of the 121 flaps evaluated (84 in the lower limb and 37 in the upper limb), 64 patients underwent preoperative CTA. In the CTA+ group, 56% of patients with free flaps for lower limb had complete occlusion of one artery. CTA+ patients had a higher rate of complications (p = 0.031), which may represent a selection bias as the most complex limb injuries and may have CTA indicated more frequently. The highest rate of complications was observed in chronic cases (p = 0.034). There was no statistically significant difference in complications in patients with preoperative vascular injury or the number of patent arteries. CONCLUSIONS: CTA should not be performed routinely, however, CTA may help in surgical planning, especially in complex cases of high-energy and chronic cases, since it provides information on the best recipient artery and the adequate level to perform the microanastomosis, outside the lesion area.

scholarly journals Unilateral and Bilateral Strength Asymmetry among Young Elite Athletes of Various Sports

Medicina ◽  
2020 ◽  
Vol 56 (12) ◽  
pp. 683
Author(s):  
Maros Kalata ◽  
Tomas Maly ◽  
Mikulas Hank ◽  
Jakub Michalek ◽  
David Bujnovsky ◽  
...  
Keyword(s):  
Lower Limb ◽  
Elite Athletes ◽  
Lower Limbs ◽  
Knee Extensors ◽  
Young Athletes ◽  
Lower Limb Muscles ◽  
Significant Difference ◽  
Strength Asymmetry ◽  
Main Factor ◽  
Objective Type

Background and objective: Type of physical activity may influence morphological and muscular asymmetries in the young population. However, less is known about the size of this effect when comparing various sports. The aim of this study was to identify the degree of bilateral asymmetry (BA) and the level of unilateral ratio (UR) between isokinetic strength of knee extensors (KE) and flexors (KF) among athletes of three different types of predominant locomotion in various sports (symmetric, asymmetric and hybrid). Material and methods: The analyzed group consisted of young elite athletes (n = 50). The maximum peak muscle torque of the KE and KF in both the dominant (DL) and non-dominant (NL) lower limb during concentric muscle contraction at an angular velocity of 60°·s−1 was measured with an isokinetic dynamometer. Results: Data analysis showed a significant effect of the main factor (the type of sport) on the level of monitored variables (p = 0.004). The type of sport revealed a significant difference in the bilateral ratio (p = 0.01). The group of symmetric and hybrid sports achieved lower values (p = 0.01) of BA in their lower limb muscles than those who played asymmetric sports. The hybrid sports group achieved higher UR values (p = 0.01) in both lower limbs. Conclusions: The results indicate that sports with predominantly symmetrical, asymmetrical, and hybrid types of locomotion affected the size of the BA, as well as the UR between KE and KF in both legs in young athletes. We recommend paying attention to regular KE and KF strength diagnostics in young athletes and optimizing individual compensatory exercises if a higher ratio of strength asymmetry is discovered.

scholarly journals Isokinetic strength of shoulder internal and external rotators in cricket bowlers

2002 ◽  
Vol 58 (2) ◽  
Author(s):  
X.M. Mabasa ◽  
A. Stewart ◽  
C. Fleishman
Keyword(s):  
External Rotation ◽  
Peak Torque ◽  
Isokinetic Strength ◽  
Neutral Position ◽  
Joint System ◽  
Rotational Strength ◽  
Significant Difference ◽  
Position Data ◽  
Torque Values ◽  
Rotation Strength

The strength of the shoulder internal and external rotators incricket bowlers, may not be sufficient to cope with the demands of bowling.As very little research has been done on cricketers, this study was done to establish the isokinetic strength profile of the shoulder internal andexternal rotators in cricket bowlers.Isokinetic, shoulder rotational strength was evaluated in thirty malecricket volunteers with a mean age of 23.9 years and mean body weight of 70.3 kgs. The Cybex 340 dynamometer multi joint system was used to collect data on shoulder rotation strength in a standing neutral position. Data were collected at four different speeds (60,90,180 and 300deg/sec) and were computed for peak torque values for internal and external ratios for both dominant and non dominant shoulders.The results showed no statistically significant difference in the mean shoulder rotational torque between the bowlingand non-bowling shoulders for external rotation (p>0.05), and indicated statistically significant differences in themean shoulder rotational torque between the bowling and non-bowling shoulders for internal rotation (p<0.05). Therewas a significant decrease in isokinetic peak torque production for the external/internal rotator muscles as the speedof contraction increased (p<0.05). The peak torque ratio for the external/internal rotator muscles of the bowling armwere significantly less than of the non-bowling arm (p<0.05). These findings suggest that the strength ratios of thebowling arm need to be considered when managing young cricketers and their injuries.

scholarly journals A kinematics analysis of the lower limb during running with different sports shoes

2018 ◽  
Vol 233 (1) ◽  
pp. 46-52
Author(s):  
Lin Fu ◽  
Yaodong Gu ◽  
Qichang Mei ◽  
Julien S Baker ◽  
Justin Fernandez
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Statistical Significance ◽  
Frontal Plane ◽  
3D Motion Analysis ◽  
Significant Difference ◽  
Running Shoes ◽  
Knee Abduction ◽  
Analysis System ◽  
Sports Shoes

The study aimed to investigate the differences in lower limb joint angles during running with three different sports shoes: basketball shoes, football shoes, and running shoes. Fifteen male subjects (age: 25 ± 2.2 years, height: 1.79 ± 0.05 m, and mass: 70.8 ± 3.4 kg) were asked to run on a treadmill at their preferred running speed. The Vicon 3D motion analysis system was used to capture the kinematics of the lower extremity during running. A one-way analysis of variance was used to determine whether any statistical significance existed between the three types of shoes (α < 0.05). Significant differences existed in the lower limb joints between the three sports shoes, particularly at the knee joint. Running shoes presented more knee flexion than basketball shoes and football shoes. In the frontal plane, basketball shoes showed less knee abduction than running shoes and football shoes. No significant difference occurred in ankle external rotation between basketball shoes and football shoes, and both of them presented greater range of motion of the ankle and knee than running shoes.

CHANGES IN THE FLEXOR AND EXTENSOR MUSCLES AT DIFFERENT SPEEDS

2021 ◽  
Vol 27 (7) ◽  
pp. 686-688
Author(s):  
Rui Ma ◽  
Wenyan Li
Keyword(s):  
Knee Joint ◽  
Peak Torque ◽  
Muscle Group ◽  
Lower Limbs ◽  
Flexor Muscle ◽  
Level Of Evidence ◽  
Isokinetic Test ◽  
Extensor Muscles ◽  
Test Velocity ◽  
The Difference

ABSTRACT Introduction: Centrifugal strength is an important element for strength quality. Developing muscle centrifugal strength can effectively increase the stability of lower limbs and reduce the risk of injury. Objective: To explore the characteristics of contractile force of flexor ahods in strength training and rehabilitation training, and the extensor muscles of the knee joint in athletes with different speeds of centripetal force. Methods: The knee joint muscle group of 8 first-level male high jumpers and 8 second-level male high jumpers were tested by isokinetic centrifugal contraction; the angular test velocity was 60 °/s, 120 °/s, 240 °/s, and the indexes included peak torque, relative peak torque (peak torque/body weight), and the peak torque flexural extension ratio. Results: With the centrifugal contraction of the knee joint muscle group (P < 0.05), the second-level high jumpers should increase the ability of the knee flexor muscle group of the take-off leg. In the case of constant velocity centrifugal contraction (P < 0.01), taking off time must be reduced, that is, taking off speed must be accelerated. Conclusions: The difference in the knee joint muscle isokinetic test results is one of the reasons for the difference in knee joint flexor and extensor muscle contractility under the different speed forces of high jumpers. Level of evidence II; Therapeutic studies - investigation of treatment results.

Design of an Orthosis for the Weight Balance of Human Lower Limbs

2012 ◽  
Author(s):  
Win-Bin Shieh ◽  
Dar-Zen Chen ◽  
Chia-Chun Wu
Keyword(s):  
Knee Joint ◽  
Lower Limb ◽  
First Generation ◽  
Lower Limbs ◽  
Gravity Effect ◽  
Normal Walking ◽  
Anthropometric Parameters ◽  
Large Power ◽  
Minimum Number ◽  
Exact Positions

Most existing lower limb orthosis use actuators and active controller to guide the motion of human lower limbs. Actuators with relatively large power are usually required to compensate the gravity effect of the human lower limbs, even for a normal walking. Hence, design of an orthosis for the weight balance of human lower limbs is desired. For the motion compatibility, the human hip joint is treated as a planar pair and the knee joint as a revolute pair. As a consequence, while the lower limb is in motion, the exact positions of the mass centers of the human lower limbs cannot be obtained. Hence, in this work, topological synthesis of the orthosis mechanisms, which can trace the mass centers of the human thigh and shank, respectively, is implemented. The weight balance of the human lower limbs is achieved by fitting a minimum number of zero-free-length springs. Based on the anthropometric parameters, dimensions of the lower limb orthosis is determined and the proposed design is justified by the simulation executed by the software of ProEngineer. Finally, a first generation prototype is built.

Sign in / Sign up

Export Citation Format

Share Document