Assessment of the Effects of Diabetes on Midfoot Joint Pressures Using a Robotic Gait Simulator

2009 ◽  
Vol 30 (8) ◽  
pp. 767-772 ◽  
Author(s):  
Dong Gil Lee ◽  
Brian L. Davis
Keyword(s):  
Stance Phase ◽  
Walking Speed ◽  
Normal Population ◽  
Human Gait ◽  
Diabetic Patients ◽  
Foot Deformity ◽  
Charcot Neuroarthropathy ◽  
Joint Contact ◽  
Peak Pressures ◽  
Contact Pressures

Background: One of the more serious diabetic complications is Charcot neuroarthropathy (CN), a disease that results in arch collapse and permanent foot deformity. However, very little is known about the etiology of CN. From a mechanical standpoint, it is likely that there is a “vicious circle” in terms of (i) arch collapse causing increased midfoot joint pressures, and (ii) increased joint contact pressures exacerbating the collapse of midfoot bones. This study focused on assessment of peak joint pressure difference between diabetic and non-diabetic cadaver feet during simulated walking. We hypothesized that joint pressures are higher for diabetics than normal population. Materials and Methods: Sixteen cadaver foot specimens (eight control and eight diabetic specimens) were used in this study. Human gait at 25% of typical walking speed (averaged stance duration of 3.2s) was simulated by a custom-designed Universal Musculoskeletal Simulator. Four medial midfoot joint pressures (the first metatarsocuneiform, the medial naviculocuneiform, the middle naviculocuneiform, and the first intercuneiform) were measured dynamically during full stance. Results: The pressures in each of the four measured midfoot joints were significantly greater in the diabetic feet ( p = 0.015, p = 0.025, p < 0.001, and p = 0.545, respectively). Conclusion: Across all four tested joints, the diabetic cadaver specimens had, on average, 46% higher peak pressures than the control cadaver feet during the simulated stance phase. Clinical Relevance: This finding suggests that diabetic patients could be predisposed to arch collapse even before there are visible signs of bone or joint abnormalities.

Contact mechanics of the ovine stifle during simulated early stance in gait

2007 ◽  
Vol 20 (01) ◽  
pp. 70-72 ◽  
Author(s):  
N. K. Lee-Shee ◽  
M. B. Hurtig ◽  
J. P. Dickey
Keyword(s):  
Stance Phase ◽  
Unique Contribution ◽  
Worst Case ◽  
Stifle Joint ◽  
Mean Pressure ◽  
Joint Contact ◽  
Six Degree Of Freedom ◽  
Joint Loads ◽  
Contact Pressures

SummaryOvine stifle joint contact pressures and contact areas were measured in vitro using a six degree-of-freedom (DOF) robotic system. The robot generated static joint loads of 1.875 times body weight (BW) compression, 0.15 BW medial shear and 0.625 BW cranial shear at 6.5o of flexion for four specimens, simulating the early stance phase of gait (walking). This condition represents a period of intense loading and was implemented as a worst-case loading scenario for the joint at this gait. We determined that the medial and lateral compartments bore 5.5 ± 0.9 MPa and 4.4 ± 1.1 MPa of mean pressure, respectively, on 107.7 ± 28.7 mm2 and 60.8 ± 56.3 mm2 of area, respectively. The unique contribution of this study is that stifle contact pressures and areas were determined during loading which simulated physiological levels (early stance phase of gait). This information is important to our understanding of the stresses that must be borne by repair tissues/constructs that are implanted into human and animal tibio-femoral joints.

scholarly journals Computationally Efficient Magnetic Resonance Imaging Based Surface Contact Modeling as a Tool to Evaluate Joint Injuries and Outcomes of Surgical Interventions Compared to Finite Element Modeling

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Joshua E. Johnson ◽  
Phil Lee ◽  
Terence E. McIff ◽  
E. Bruce Toby ◽  
Kenneth J. Fischer
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Joint Mechanics ◽  
Computationally Efficient ◽  
Efficient Manner ◽  
Element Modeling ◽  
Joint Injuries ◽  
Surface Contact ◽  
Joint Contact ◽  
Contact Pressures

Joint injuries and the resulting posttraumatic osteoarthritis (OA) are a significant problem. There is still a need for tools to evaluate joint injuries, their effect on joint mechanics, and the relationship between altered mechanics and OA. Better understanding of injuries and their relationship to OA may aid in the development or refinement of treatment methods. This may be partially achieved by monitoring changes in joint mechanics that are a direct consequence of injury. Techniques such as image-based finite element modeling can provide in vivo joint mechanics data but can also be laborious and computationally expensive. Alternate modeling techniques that can provide similar results in a computationally efficient manner are an attractive prospect. It is likely possible to estimate risk of OA due to injury from surface contact mechanics data alone. The objective of this study was to compare joint contact mechanics from image-based surface contact modeling (SCM) and finite element modeling (FEM) in normal, injured (scapholunate ligament tear), and surgically repaired radiocarpal joints. Since FEM is accepted as the gold standard to evaluate joint contact stresses, our assumption was that results obtained using this method would accurately represent the true value. Magnetic resonance images (MRI) of the normal, injured, and postoperative wrists of three subjects were acquired when relaxed and during functional grasp. Surface and volumetric models of the radiolunate and radioscaphoid articulations were constructed from the relaxed images for SCM and FEM analyses, respectively. Kinematic boundary conditions were acquired from image registration between the relaxed and grasp images. For the SCM technique, a linear contact relationship was used to estimate contact outcomes based on interactions of the rigid articular surfaces in contact. For FEM, a pressure-overclosure relationship was used to estimate outcomes based on deformable body contact interactions. The SCM technique was able to evaluate variations in contact outcomes arising from scapholunate ligament injury and also the effects of surgical repair, with similar accuracy to the FEM gold standard. At least 80% of contact forces, peak contact pressures, mean contact pressures and contact areas from SCM were within 10 N, 0.5 MPa, 0.2 MPa, and 15 mm2, respectively, of the results from FEM, regardless of the state of the wrist. Depending on the application, the MRI-based SCM technique has the potential to provide clinically relevant subject-specific results in a computationally efficient manner compared to FEM.

The Effect of Tibiotalar Fixation on Foot Biomechanics

1997 ◽  
Vol 18 (12) ◽  
pp. 792-797 ◽  
Author(s):  
Jennifer S. Wayne ◽  
Keith W. Lawhorn ◽  
Kenneth E. Davis ◽  
Karanvir Prakash ◽  
Robert S. Adelaar
Keyword(s):  
Subtalar Joint ◽  
Sagittal Plane ◽  
Lower Limbs ◽  
Coronal Plane ◽  
Neutral Position ◽  
Talonavicular Joint ◽  
Tibiotalar Joint ◽  
Contact Areas ◽  
Joint Contact ◽  
Peak Pressures

Contact areas and peak pressures in the posterior facet of the subtalar and the talonavicular joints were measured in cadaver lower limbs for both the normal limb and after fixation of the tibiotalar joint. Six joints were fixed in neutral, in 5–7° of varus and of valgus. Ten degrees of equinus angulation was also studied. Each position of fixation was tested independently. Neutral was defined as fixation without coronal or sagittal plane angulation compared with prefixation alignment of the specimen. When compared with normal unfused condition, peak pressures increased, and contact areas decreased in the subtalar joint for specimens fixed in neutral, varus, and valgus. However, the change in peak pressure for neutral fusion compared with normal control was not statistically significant ( P > 0.07). Peak pressures for varus and valgus fixation were significantly different from normal ( P < 0.001). Contact areas for all positions of fixation were significantly different from normal ( P < 0.001). Coronal plane angulation, however, also resulted in significantly lower contact areas compared with neutral fixation ( P < 0.001). Contact areas and peak pressures in the talonavicular joint did not appear to be substantially affected by tibiotalar fixation with coronal plane angulation. Equinus fixation qualitatively increased contact areas and peak pressures in the talonavicular and posterior facet of the subtalar joint. Neutral alignment of the tibiotalar joint in the coronal and sagittal planes altered subtalar and talonavicular joint contact characteristics the least compared with normal controls. Therefore, ankle fusion in the neutral position would be expected to most closely preserve normal joint biomechanics and may limit the progression of degenerative arthrosis of the subtalar joint.

Can the Hip Joint be Modeled Accurately Using Simplified Geometry?

2008 ◽  
Author(s):  
Andrew E. Anderson ◽  
Steve A. Maas ◽  
Benjamin J. Ellis ◽  
Jeffrey A. Weiss
Keyword(s):  
Contact Pressure ◽  
Hip Joint ◽  
Spherical Geometry ◽  
Model Complexity ◽  
Hip Morphology ◽  
Joint Contact ◽  
Analytical Approaches ◽  
Contact Pressures ◽  
In Vitro Data

Simplified analytical approaches to estimate hip joint contact pressures using perfectly spherical geometry have been described in the literature (rigid body spring models); however, estimations based on these simulations have not corresponded well with experimental in vitro data. Recent evidence from our laboratory suggests that finite element (FE) models of the hip joint that incorporate detailed geometry for cartilage and bone can predict cartilage pressures in good agreement with experimental data [1]. However, it is unknown whether this degree of model complexity is necessary. The objective of this study was to compare cartilage contact pressure predictions from FE models with varying degrees of simplicity to elucidate which aspects of hip morphology are required to obtain accurate predictions of cartilage contact pressure. Models based on 1) subject-specific (SS) geometry, 2) spheres, and 3) rotational conchoids were analyzed.

scholarly journals Phase resetting behavior in human gait is influenced by treadmill walking speed

2016 ◽  
Vol 43 ◽  
pp. 187-191 ◽  
Author(s):  
Jeff A. Nessler ◽  
Tavish Spargo ◽  
Andrew Craig-Jones ◽  
John G. Milton
Keyword(s):  
Walking Speed ◽  
Treadmill Walking ◽  
Human Gait ◽  
Phase Resetting

scholarly journals Biomechanics of a novel extra-articular implant for younger patients with knee osteoarthritis

2018 ◽  
Vol 4 (1) ◽  
pp. 203-205
Author(s):  
Mehdi Saeidi ◽  
Maziar Ramezani ◽  
Piaras Kelly ◽  
Mohd Sabri Hussin ◽  
Thomas Neitzert
Keyword(s):  
Knee Joint ◽  
Cartilage Regeneration ◽  
Stress Distributions ◽  
Element Analysis ◽  
Medial Side ◽  
Pressure Distributions ◽  
Joint Contact ◽  
As Stress ◽  
Joint Contact Pressure ◽  
Contact Pressures

AbstractThis research aimed to study the efficacy of a novel implant for osteoarthritic knees. This implant is designed to eliminate excessive loads through the knee and to provide suitable conditions for possible tibiofemoral cartilage regeneration. The implant was designed for the medial side of the knee joint. Finite Element Analysis (FEA) was performed for an extended knee position of the knee joint. Contact pressure distributions on the medial and lateral compartments were investigated as well as stress distributions throughout the implant’s plates. Results with and without the implant were compared, and it was seen that the contact pressures on the surface of the distal femur were reduced by more than 90% after the introduction of the implant.

scholarly journals Osteoporosis and diabetes mellitus

2013 ◽  
pp. 63-69
Author(s):  
Andrea Montagnani ◽  
Massimo Alessandri
Keyword(s):  
Diabetes Mellitus ◽  
Bone Resorption ◽  
Bone Tissue ◽  
Close Association ◽  
Normal Population ◽  
Diabetic Patients ◽  
Mineral Density ◽  
Apparent Paradox ◽  
Mortality And Morbidity ◽  
Positive Effects

Introduction: Diabetes mellitus (DM) and osteoporotic fractures are major causes of mortality and morbidity in older subjects. Recent reports have revealed close association between fracture risk and DM types 1 and 2 (DM1 and DM2, respectively). Aim of this review is to highlight the importance of these diseases in the elderly and examine certain etiopathogenetic aspects of DM associated osteoporosis, which could be useful in management of diabetic patients. Materials and methods: We searched the Embase and PubMed databases using diabetes, osteoporosis, and bone mineral density (BMD) as search terms and 1989-2009 as publication dates. Discussion: The risk of fractures seems to be increased in both types of DM although DM2 seems to be associated with normal-high BMDs compared with the normal population. This apparent paradox could reflect greater bone frailty in diabetic patients that are unrelated to adipose tissue, hyperinsulinemia, deposition of advanced glycosylation end products in collagen, reduced serum IGF-1 levels, hypercalciuria, renal failure, microangiopathy, and/or inflammation. Diabetic patients’ propensity to fall and multiple comorbidities might also explain their higher fracture rates. The effects of drugs that inhibit bone resorption in diabetic patients are probably similar to those obtained in nondiabetics although there is little information on this issue. In general, effective treatment of diabetes has positive effects on bone metabolism. Metformin acts directly on bone tissue, reducing AGE accumulation, and insulin has direct effects on osteoclast activity. In contrast, the thiazolidinediones seem to have negative effects since they orient mesenchymal progenitor cell differentiation toward adipose rather than bone tissue. Incretin therapy is a newer approach that appears to modify interactions between nutrition and bone turnover (e.g., postprandial suppression of bone resorption). Conclusions: Better understanding of how diabetes and its treatment influence bone tissue could lead to more effective strategies for preventing fractures in diabetic patients. More investigation is needed to determine whether conventional osteoporotic therapy is fully effective in patients with DM.

scholarly journals Stability-normalised walking speed: A new approach for human gait perturbation research

2019 ◽  
Vol 87 ◽  
pp. 48-53 ◽  
Author(s):  
Christopher McCrum ◽  
Paul Willems ◽  
Kiros Karamanidis ◽  
Kenneth Meijer
Keyword(s):  
Walking Speed ◽  
Human Gait ◽  
New Approach
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