Load Response of the Tarsal Bones in Patients with Flatfoot Deformity: In Vivo 3D Study

2011 ◽  
Vol 32 (11) ◽  
pp. 1017-1022 ◽  
Author(s):  
Masamitsu Kido ◽  
Kazuya Ikoma ◽  
Kan Imai ◽  
Masahiro Maki ◽  
Ryota Takatori ◽  
...  
Keyword(s):  
Load Condition ◽  
Clinical Analysis ◽  
Biomechanical Analysis ◽  
Talonavicular Joint ◽  
Level Of Evidence ◽  
Tibiotalar Joint ◽  
Talocalcaneal Joint ◽  
Load Response ◽  
Tarsal Bones

Background: The objective of this study was to evaluate the bone rotation of each joint in the hindfoot and compare the load response in healthy feet with that in flatfeet by analyzing the reconstructive three-dimensional (3D) CT image data during weightbearing. Methods: CT scans of 21 healthy feet and 21 feet with flatfoot deformity were taken in non-load condition followed by full-body weightbearing load condition. The images of the hindfoot bones were reconstructed into 3D models. The volume merge method in three planes was used to calculate the position of the talus relative to the tibia in the tibiotalar joint, the navicular relative to the talus in talonavicular joint, and the calcaneus relative to the talus in the talocalcaneal joint. Results: The talar position difference to the load response relative to the tibia in the tibiotalar joint in a flatfoot was 1.7 degrees more plantarflexed in comparison to that in a healthy foot ( p = 0.031). The navicular position difference to the load response relative to the talus in the talonavicular joint was 2.3 degrees more everted ( p = 0.0034). The calcaneal position difference to the load response relative to the talus in the talocalcaneal joint was 1.1 degrees more dorsiflexed ( p = 0.0060) and 1.7 degrees more everted ( p = 0.0018). Conclusion: Referring to previous cadaver study, regarding not only the cadaveric foot, but also the live foot, joint instability occurred in the hindfoot with load in patients with flatfoot. Clinical Relevance: The method used in this study might be applied to clinical analysis of foot diseases such as the staging of flatfoot and to biomechanical analysis to evaluate the effects of foot surgery in the future. Level of Evidence: III

scholarly journals Current status of wet lab and cadaveric simulation in urological training: A systematic review

2020 ◽  
Vol 14 (11) ◽  
Author(s):  
Ahmed Al-Jabir ◽  
Abdullatif Aydin ◽  
Hussain Al-Jabir ◽  
M. Shamim Khan ◽  
Prokar Dasgupta ◽  
...  
Keyword(s):  
Systematic Review ◽  
English Language ◽  
In Vivo Studies ◽  
Current Status ◽  
Level Of Evidence ◽  
Cadaveric Simulation ◽  
Randomized Controlled Studies ◽  
Wet Lab ◽  
Urological Training

Introduction: We undertook a systematic review of the use of wet lab (animal and cadaveric) simulation models in urological training, with an aim to establishing a level of evidence (LoE) for studies and level of recommendation (LoR) for models, as well as evaluating types of validation. Methods: Medline, EMBASE, and Cochrane databases were searched for English-language studies using search terms including a combination of surgery, surgical training, and medical education. These results were combined with wet lab, animal model, cadaveric, and in-vivo. Studies were then assigned a LoE and LoR if appropriate as per the education-modified Oxford Centre for Evidence-Based Medicine classification. Results: A total of 43 articles met the inclusion criteria. There was a mean of 23.1 (±19.2) participants per study with a median of 20. Overall, the studies were largely of low quality, with 90.7% of studies being lower than 2a LoE (n=26 for LoE 2b and n=13 for LoE 3). The majority (72.1%, n=31) of studies were in animal models and 27.9% (n=12) were in cadaveric models. Conclusions: Simulation in urological education is becoming more prevalent in the literature, however, there is a focus on animal rather than cadaveric simulation, possibly due to cost and ethical considerations. Studies are also predominately of a low LoE; more higher LoEs, especially randomized controlled studies, are needed.

Kinematics of the Ankle/Foot Complex: Plantarflexion and Dorsiflexion

Foot & Ankle ◽  
1989 ◽  
Vol 9 (4) ◽  
pp. 194-200 ◽  
Author(s):  
Arne Lundberg ◽  
Ian Goldie ◽  
Bo Kalin ◽  
Göran Selvik
Keyword(s):  
Plantar Flexion ◽  
Three Dimensional ◽  
Substantial Contribution ◽  
Neutral Position ◽  
Transverse Axis ◽  
Talocrural Joint ◽  
Foot Kinematics ◽  
Talocalcaneal Joint ◽  
Axis Rotation

In an in vivo investigation of eight healthy volunteers, three dimensional ankle/foot kinematics were analyzed by roentgen stereophotogrammetry in 10° steps of motion from 30° of plantar flexion to 30° of dorsiflexion of the foot. The study included all of the joints between the tibia and the first metatarsal, as well as the talocalcaneal joint, and was performed under full body load. Although the talocrural joint was found to account for most of the rotation around the transverse axis occurring from 30° of plantar flexion to 30° of dorsiflexion, there was a substantial contribution from the joints of the arch. This was seen particularly in the input arc from 30° of plantar flexion to the neutral position, where the dorsiflexion motion of these joints amounted to 10% to 41% of the total transverse axis rotation.

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.

scholarly journals In vivo intervertebral disc deformation: intratissue strain patterns within adjacent discs during flexion–extension

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Robert L. Wilson ◽  
Leah Bowen ◽  
Woong Kim ◽  
Luyao Cai ◽  
Stephanie Ellyse Schneider ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Biomechanical Analysis ◽  
Resonance Imaging ◽  
Tissue Architecture ◽  
Mechanical Responses ◽  
Flexion Extension ◽  
Adjacent Disc ◽  
Shear Strains ◽  
Magnetic Resonance Imaging Mri

AbstractThe biomechanical function of the intervertebral disc (IVD) is a critical indicator of tissue health and pathology. The mechanical responses (displacements, strain) of the IVD to physiologic movement can be spatially complex and depend on tissue architecture, consisting of distinct compositional regions and integrity; however, IVD biomechanics are predominately uncharacterized in vivo. Here, we measured voxel-level displacement and strain patterns in adjacent IVDs in vivo by coupling magnetic resonance imaging (MRI) with cyclic motion of the cervical spine. Across adjacent disc segments, cervical flexion–extension of 10° resulted in first principal and maximum shear strains approaching 10%. Intratissue spatial analysis of the cervical IVDs, not possible with conventional techniques, revealed elevated maximum shear strains located in the posterior disc (nucleus pulposus) regions. IVD structure, based on relaxometric patterns of T2 and T1ρ images, did not correlate spatially with functional metrics of strain. Our approach enables a comprehensive IVD biomechanical analysis of voxel-level, intratissue strain patterns in adjacent discs in vivo, which are largely independent of MRI relaxometry. The spatial mapping of IVD biomechanics in vivo provides a functional assessment of adjacent IVDs in subjects, and provides foundational biomarkers for elastography, differentiation of disease state, and evaluation of treatment efficacy.

Abstract 17070: Engineering a Novel Ex Vivo Heart Simulator for Biomechanical Analysis of the Aortomitral Junction

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Matthew H Park ◽  
Annabel Imbrie-moore ◽  
Yuanjia Zhu ◽  
Hanjay Wang ◽  
Michael J Paulsen ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Ex Vivo ◽  
Clinical Care ◽  
Biomechanical Analysis ◽  
Future Experimentation ◽  
3D Printed ◽  
Biomechanical Changes ◽  
Predictive Risk ◽  
Future Work

Introduction: Advances in ex vivo heart simulation have enabled the study of valvular biomechanics, disease pathologies, and repair strategies. However, these simulators test the valves in isolation, which does not fully replicate in vivo physiology. We hypothesize that by engineering a simulator that preserves the aortomitral junction, we can better recreate pathophysiologies such as systolic anterior motion (SAM). Here, we present a new heart simulator that preserves and manipulates the native aortomitral physiology. Methods: Our simulator is comprised of three subsystems: the ventricular chamber, atrial chamber, and aortic chamber (Fig A, B). The heart is excised at the apex to preserve the papillary muscles, and the left ventricle, atrial cuff, and aorta are fixed to their respective chambers via hemostatic suturing to 3D-printed elastomeric rings. The chambers are equipped with pressure and flow sensors, and a linear piston pump generates physiologic pressures and flows. The atrial and aortic chambers are mounted on 5-degree-of-freedom arms. To demonstrate system function, we manipulated the aortomitral angle and measured aortic cardiac output. Results: In our testing, we evaluated two unique configurations of an explanted porcine heart, of which the aortomitral angles spanned the SAM predictive risk threshold of <120° (Fig C, D). From the flow readings, we measured a 36% reduction in aortic cardiac output upon decreasing the aortomitral angle by 25°. Conclusions: This work highlights the design and development of an ex vivo heart simulator capable of modeling native aortomitral physiology. Our results point to a clear direction for future experimentation, particularly evaluating the biomechanical changes of the heart based on the aortomitral angle. Future work will utilize this platform to create new models and repair techniques to ultimately improve clinical care of valvular pathologies.

scholarly journals Identification and Determination of 1,3-Thiazinane-4-carboxylic Acid in Human Urine—Chromatographic Studies

2022 ◽  
Vol 23 (2) ◽  
pp. 598
Author(s):  
Justyna Piechocka ◽  
Natalia Litwicka ◽  
Rafał Głowacki
Keyword(s):  
Carboxylic Acid ◽  
Human Urine ◽  
Clinical Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Aqueous Environment ◽  
Limit Of Quantification ◽  
Isobutyl Chloroformate ◽  
United States Food ◽  
States Food

It is well established that homocysteine (Hcy) and its thiolactone (HTL) are reactive towards aldehydes in an aqueous environment, forming substituted thiazinane carboxylic acids. This report provides evidence that Hcy/HTL and formaldehyde (FA) adduct, namely 1,3-thiazinane-4-carboxylic acid (TCA) is formed in vivo in humans. In order to provide definitive proof, a gas chromatography–mass spectrometry (GC–MS) based method was elaborated to identify and quantify TCA in human urine. The GC–MS assay involves chemical derivatization with isobutyl chloroformate (IBCF) in the presence of pyridine as a catalyst, followed by an ethyl acetate extraction of the obtained isobutyl derivative of TCA (TCA-IBCF). The validity of the method has been demonstrated based upon United States Food and Drug Administration recommendations. The assay linearity was observed within a 1–50 µmol L−1 range for TCA in urine, while the lowest concentration on the calibration curve was recognized as the limit of quantification (LOQ). Importantly, the method was successfully applied to urine samples delivered by apparently healthy volunteers (n = 15). The GC–MS assay may provide a new analytical tool for routine clinical analysis of the role of TCA in living systems in the near future.

scholarly journals Calcaneonavicular coalition resection

2020 ◽  
Vol 14 (3) ◽  
pp. 297-300
Author(s):  
Mercedes Juncay ◽  
Rafael Sposeto ◽  
Alexandre Godoy-Santos ◽  
Túlio Fernandes
Keyword(s):  
Surgical Treatment ◽  
Surgical Technique ◽  
Conservative Treatment ◽  
Treatment Option ◽  
Expert Opinion ◽  
Tarsal Bone ◽  
Tarsal Coalition ◽  
Level Of Evidence ◽  
Calcaneonavicular Coalition ◽  
Tarsal Bones

Tarsal coalition is an abnormal connection between tarsal bones, caused by an embryogenic failure. Its most common forms are calcaneonavicular and talocalcaneal coalition, which are present in 53% and 37% of the cases, respectively. The onset of symptoms is related to tarsal bone ossification, and mean age for this event is estimated at 16 years for calcaneonavicular coalition. Surgical treatment is indicated for patients who did not improve symptoms with conservative treatment. The aim of this study is to present a surgical technique as a treatment option for resection of calcaneonavicular coalition associated with abnormal cuboid-navicular joint. Level of Evidence V; Therapeutic Studies; Expert Opinion.

Analysis of Failed Ankle Arthroplasty Components

2018 ◽  
Vol 40 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Barbara H. Currier ◽  
Paul J. Hecht ◽  
James A. Nunley ◽  
Michael B. Mayor ◽  
John H. Currier ◽  
...  
Keyword(s):  
Fatigue Cracking ◽  
Mobile Bearing ◽  
Clinical Decisions ◽  
Fixed Bearing ◽  
Level Of Evidence ◽  
Ankle Arthroplasty ◽  
Gas Plasma ◽  
Knee Replacements ◽  
End Stage

Background: Although advances in joint-replacement technology have made total ankle arthroplasty a viable treatment for end-stage arthritis, revision rates for ankle replacements are higher than in hip or knee replacements. The questions asked in this study were what can retrieved ankle devices demonstrate about ankle arthroplasty failures and how can understanding the causes of these failures inform clinical decisions for current and future ankle arthroplasty patients? Methods: An IRB-approved retrieval laboratory received retrieved components and surgeon-supplied reason for revision from 70 total-ankles (7 designs, including 5 currently marketed designs) from 2002 to 2018. These retrievals were rated for clinical wear and damage. Metal components were rated by method and effectiveness of fixation. Polyethylene inserts received by the laboratory 6 months or less after retrieval (n = 45) were analyzed for oxidation using Fourier transform infrared spectroscopy. Statistical analysis was performed using IBM SPSS, version 22. Results: The ankle implants were retrieved most commonly for loosening and polyethylene fracture. Loosening occurred more frequently in fixed-bearing designs (n = 18) than in the mobile-bearing designs (n = 4) and after shorter in vivo time (mean in vivo time to retrieval for loosening: fixed bearing 3.2 ± 2.1 years, mobile bearing 9.7 ± 4.5 years). Gamma-sterilized ankle inserts oxidized at a higher rate than non-gamma (EtO or gas-plasma) sterilized ankle inserts (gamma 0.29 ± 0.22/y, non-gamma 0.07 ± 0.05/y, mean difference=0.215, 95% CI 0.128-0.303, P < .001). The presence of clinical fatigue (cracking and/or delamination) of the polyethylene insert correlated with measured oxidation (Spearman rho = 0.685, P < .001). Nine inserts, all gamma-sterilized, fractured in vivo. Conclusions: This study suggests that loosening could be more of a problem in fixed-bearing devices than in mobile bearing devices. Gamma-sterilized polyethylene inserts were found to suffer fatigue damage or fracture in vivo, resulting in the need for revision. Retrieval analysis can provide insight into implant-related reasons for revision, with the goal of understanding the implant-related causes of these failures, informing future ankle design and clinical decisions for current and future ankle arthroplasty patients. Level of Evidence: Level III, comparative series.

scholarly journals Intra-articular Calcaneus Fractures: Current Concepts Review

2020 ◽  
Vol 5 (3) ◽  
pp. 247301142092733
Author(s):  
Paul R. Allegra ◽  
Sebastian Rivera ◽  
Sohil S. Desai ◽  
Amiethab Aiyer ◽  
Jonathan Kaplan ◽  
...  
Keyword(s):  
Tissue Injury ◽  
Soft Tissue Injury ◽  
Treatment Strategies ◽  
Late Complications ◽  
Classification Systems ◽  
Surgical Approaches ◽  
Calcaneal Fractures ◽  
Level Of Evidence ◽  
Tarsal Bones ◽  
Calcaneus Fractures

Calcaneal fractures are the most common fracture of the tarsal bones and represent 1% to 2% of all fractures. Roughly 75% of these fractures include intra-articular involvement of the posterior facet of the calcaneus. Intra-articular calcaneal fractures are challenging injuries to manage for both patients and surgeons given their association with both early and late complications. This article aims to review the management, classification systems, surgical approaches, and care regarding intra-articular calcaneal fractures. A review of the current literature yielded treatment strategies that aim to reduce complications such as soft tissue injury or loss of articular reduction while maintaining satisfactory clinical outcomes. The purpose of this article is to review these current concepts in the management of intra-articular calcaneal fractures. Level of Evidence: Level V, expert opinion.

Consensus for the Indication of Lateral Column Lengthening in the Treatment of Progressive Collapsing Foot Deformity

2020 ◽  
Vol 41 (10) ◽  
pp. 1286-1288
Author(s):  
David B. Thordarson ◽  
Lew C. Schon ◽  
Cesar de Cesar Netto ◽  
Jonathan T. Deland ◽  
Scott J. Ellis ◽  
...  
Keyword(s):  
Subtalar Joint ◽  
Consensus Statement ◽  
Talonavicular Joint ◽  
Foot Deformity ◽  
Foot Care ◽  
Level Of Evidence ◽  
Lateral Column ◽  
Fluoroscopic Imaging ◽  
Lateral Column Lengthening ◽  
Important Sign

Recommendation: Progressive collapsing foot deformity (PCFD) is a complex 3D deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot supination. Although a medial displacement calcaneal osteotomy can correct heel valgus, it has far less ability to correct forefoot abduction. More severe forefoot abduction, most frequently measured preoperatively by assessing talonavicular coverage on an anteroposterior (AP) weightbearing conventional radiographic view of the foot, can be more effectively corrected with a lateral column lengthening procedure than by other osteotomies in the foot. Care must be taken intraoperatively to not overcorrect the deformity by restricting passive eversion of the subtalar joint or causing adduction at the talonavicular joint on simulated AP weightbearing fluoroscopic imaging. Overcorrection can lead to lateral column overload with persistent lateral midfoot pain. The typical amount of lengthening of the lateral column is between 5 and 10 mm. Level of Evidence: Level V, consensus, expert opinion. CONSENSUS STATEMENT ONE: Lateral column lengthening (LCL) procedure is recommended when the amount of talonavicular joint uncoverage is above 40%. The amount of lengthening needed in the lateral column should be judged intraoperatively by the amount of correction of the uncoverage and by adequate residual passive eversion range of motion of the subtalar joint. Delegate vote: agree, 78% (7/9); disagree, 11% (1/9); abstain, 11% (1/9). (Strong consensus) CONSENSUS STATEMENT TWO: When titrating the amount of correction of abduction deformity intraoperatively, the presence of adduction at the talonavicular joint on simulated weightbearing fluoroscopic imaging is an important sign of hypercorrection and higher risk for lateral column overload. Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%. (Unanimous, strongest consensus) CONSENSUS STATEMENT THREE: The typical range for performing a lateral column lengthening is between 5 and 10 mm to achieve an adequate amount of talonavicular coverage. Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%. (Unanimous, strongest consensus)

Sign in / Sign up

Export Citation Format

Share Document