scholarly journals Estimating motion between avian vertebrae by contact modeling of joint surfaces

2021 ◽  
pp. 1-9
Author(s):  
Matthieu Furet ◽  
Anick Abourachid ◽  
Christine Böhmer ◽  
Valentine Chummun ◽  
Christine Chevallereau ◽  
...  
Keyword(s):  
Contact Modeling ◽  
Joint Surfaces

3D Printing as a Way of Integrating Mathematical Models in Arthroscopic Knee Surgery

2018 ◽  
Vol 69 (9) ◽  
pp. 2501-2507
Author(s):  
Anca Plavitu ◽  
Mark Edward Pogarasteanu ◽  
Marius Moga ◽  
Mircea Lupusoru ◽  
Florentina Ionita Radu ◽  
...  
Keyword(s):  
Knee Joint ◽  
Osteochondral Defect ◽  
Surgical Intervention ◽  
Operating Time ◽  
Vascular Pathology ◽  
Osteochondral Lesions ◽  
Joint Surfaces ◽  
Novel Method ◽  
Technological Means ◽  
Arthroscopic Knee

Our objective is to develop a novel method of approaching the arthroscopic treatment of osteochondral lesions within the knee joint by using mathematics as a way of understanding the geometry involved in the knee, both in normal and degenerated knee joint surfaces. Bone and cartilage lesions are frequent, whether as a result of trauma, degenerative pathology, vascular pathology (osteocondritis dissecans) or tumoral. In all cases, a defect can be repaired arthroscopically, if it has manageable dimensions and if the surgeon has the technological means and the necessary skills, through the use of grafts (autografts or allografts). Alternatively, a lesion that may be approached arthroscopically initially could prove to be too great for repair and may need a second intervention for reconstruction with an endoprosthesis. We aim to further deepen the surgeon�s understanding of this pathology, through the use of 3D technology as a way of representing the osteochondral defect. Thus, its dimensions and position may be better understood, and the surgical intervention may be better planned out, potentially resulting in a shorter operating time and an overall superior outcome for the patient, and even potentially diminishing the number of unnecessary surgeries performed.

Evaluation of Cartilage in the Wrist using Magnetic Resonance Imaging

2020 ◽  
Vol 16 (3) ◽  
pp. 170-177
Author(s):  
Wesley N. Sivak ◽  
Joseph E. Imbriglia
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Wrist Arthroscopy ◽  
Resonance Imaging ◽  
Joint Surfaces ◽  
Articular Cartilage Surface ◽  
Small Joint ◽  
Magnetic Resonance Imaging Mri ◽  
Clinical Conditions ◽  
Accurate Imaging

Wrist pain is a common patient complaint with a myriad of clinical conditions that can explain the underlying cause. Short of wrist arthroscopy, no technique other than formal wrist arthrotomy exists for direct examination of the hyaline cartilage coating the articular surfaces of the carpal bones. Magnetic resonance imaging (MRI) has been proven accurate in evaluating joint surfaces of large joints such as the shoulder, hip, and knee with articular cartilage surface thickness is in excess of 1 mm. However, in the carpus the thickness of the cartilage and the contours present have precluded accurate imaging. Advances in MRI technology over the last several decades are now making imaging of small joint surfaces, such as the carpus, an area worth revisiting. Herein we provide a review of these efforts with a specific focus on the evaluation of the wrist.

scholarly journals Three-dimensional ultrasound for knee osteophyte depiction: a comparative study to computed tomography

2021 ◽  
Author(s):  
Valeria Vendries ◽  
Tamas Ungi ◽  
Jordan Harry ◽  
Manuela Kunz ◽  
Jana Podlipská ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Automatic Segmentation ◽  
Three Dimensional ◽  
3D Ultrasound ◽  
Surgical Interventions ◽  
Structured Light Scanner ◽  
Joint Surfaces ◽  
Operative Planning ◽  
Rms Error ◽  
Tissue Characteristics

Abstract Purpose Osteophytes are common radiographic markers of osteoarthritis. However, they are not accurately depicted using conventional imaging, thus hampering surgical interventions that rely on pre-operative images. Studies have shown that ultrasound (US) is promising at detecting osteophytes and monitoring the progression of osteoarthritis. Furthermore, three-dimensional (3D) ultrasound reconstructions may offer a means to quantify osteophytes. The purpose of this study was to compare the accuracy of osteophyte depiction in the knee joint between 3D US and conventional computed tomography (CT). Methods Eleven human cadaveric knees were pre-screened for the presence of osteophytes. Three osteoarthritic knees were selected, and then, 3D US and CT images were obtained, segmented, and digitally reconstructed in 3D. After dissection, high-resolution structured light scanner (SLS) images of the joint surfaces were obtained. Surface matching and root mean square (RMS) error analyses of surface distances were performed to assess the accuracy of each modality in capturing osteophytes. The RMS errors were compared between 3D US, CT and SLS models. Results Average RMS error comparisons for 3D US versus SLS and CT versus SLS models were 0.87 mm ± 0.33 mm (average ± standard deviation) and 0.95 mm ± 0.32 mm, respectively. No statistical difference was found between 3D US and CT. Comparative observations of imaging modalities suggested that 3D US better depicted osteophytes with cartilage and fibrocartilage tissue characteristics compared to CT. Conclusion Using 3D US can improve the depiction of osteophytes with a cartilaginous portion compared to CT. It can also provide useful information about the presence and extent of osteophytes. Whilst algorithm improvements for automatic segmentation and registration of US are needed to provide a more robust investigation of osteophyte depiction accuracy, this investigation puts forward the potential application for 3D US in routine diagnostic evaluations and pre-operative planning of osteoarthritis.

Contact modeling in forging simulation

2002 ◽  
Vol 125-126 ◽  
pp. 583-587 ◽  
Author(s):  
B Boroomand ◽  
J Parvizian ◽  
A.R Pishevar
Keyword(s):  
Contact Modeling

Contact Modeling Technique of a Flexible Piston and Cylinder Using Modal Synthesis Method

2005 ◽  
Author(s):  
W. K. Kim ◽  
S. H. Sohn ◽  
H. J. Cho ◽  
D. S. Bae ◽  
J. H. Choi
Keyword(s):  
Contact Force ◽  
Synthesis Method ◽  
Normal Modes ◽  
Modeling Technique ◽  
Mode Shapes ◽  
Dynamics Analysis ◽  
Contact Modeling ◽  
Static Correction ◽  
Modal Synthesis ◽  
Contact Surfaces

In this paper, contact modeling technique and dynamics analysis of piston and cylinder system are presented by using modal synthesis method. It is very important to select mode shapes representing a global or local behavior of a flexible body due to a specified loading condition. This paper proposes a technique to generate the static correction modes which are nicely representing a motion by a contact force between a piston and cylinder. First normal modes of piston and cylinder under a boundary condition are computed, and then static correction modes due to a contact force applied at contacted nodes are added to the normal modes. Also, this paper proposes an efficient dynamics analysis process while changing the shape of the piston and cylinder. In optimization process or design study, their geometric data can be changed a bit. The slight changes of their contact surfaces make a high variation of the magnitude of a contact force, and it can yield the different dynamic behavior of an engine system. But, since the variations of the normal and correction modes are very small, the re-computation of their normal and correction modes due to the change of contact surfaces can be useless. Until now, whenever their contact surfaces are changed at a design cycle, the modes have been recomputed. Thus, most engineers in industries have been spent many times in very tedious and inefficient design process. In this paper, the normal and correction modes from the basic geometry of the piston and cylinder are computed. If the geometry shape is changed, nodal positions of the original modal model are newly calculated from an interpolation method and changed geometry data. And then the updated nodes are used to compute a precise contact force. The proposed methods illustrated in this investigation have good agreement with results of a nodal synthesis technique and proved that it is very efficient design method.

Osteoarthritis of the Wrist: Pathology, Radiology, and Treatment

2021 ◽  
Vol 25 (02) ◽  
pp. 294-303
Author(s):  
Jan-Peter Grunz ◽  
Carsten Herbert Gietzen ◽  
Georgios Christopoulos ◽  
Jörg van Schoonhoven ◽  
Florian Goehtz ◽  
...  
Keyword(s):  
Load Distribution ◽  
Synovial Joint ◽  
Close Collaboration ◽  
Degenerative Arthritis ◽  
Specific Patient ◽  
Rapid Disease Progression ◽  
Joint Surfaces ◽  
Osteoarthritis Of The Wrist ◽  
Advanced Stages ◽  
Asymmetric Load

AbstractOsteoarthritis (OA) is a degenerative disease that can manifest in any synovial joint under certain conditions. It leads to destruction of articular cartilage and adjacent bone, as well as formation of osteophytes at the edges of afflicted joint surfaces. Regarding the wrist, typical degenerative arthritis affects particular joints at a specific patient age, due to asymmetric load distribution and repetitive microtrauma. However, in the presence of instability or systemic diseases, early-onset degeneration can also impair the range of motion and grip strength in younger patients. Although advanced stages of OA display characteristic signs in radiography, the detection of early manifestations frequently requires computed tomography or magnetic resonance imaging (in some cases with additional arthrography). If a wrist becomes unstable, timely diagnosis and precise treatment are essential to prevent rapid disease progression. Therefore, close collaboration between radiologists and hand surgeons is obligatory to preserve the carpal function of patients.

scholarly journals Evaluating the Subtalar Joint in Tibiotalocalcaneal Nail

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0040
Author(s):  
Megan Reilly ◽  
Kurosh Darvish ◽  
Soroush Assari ◽  
John Cole ◽  
Tyler Wilps ◽  
...  
Keyword(s):  
Surface Area ◽  
Subtalar Joint ◽  
Articular Surface ◽  
Joint Surface ◽  
Central Dome ◽  
Below The Knee ◽  
Joint Surfaces ◽  
Circular Surface ◽  
The Mean ◽  
Pass Through

Category: Hindfoot Introduction/Purpose: In tibiotalocalcaneal nails for arthrodesis, the path of the nail through the subtalar joint has not been well documented. Ideally, the defect caused by reaming and the nail does not pass through the joint surface so that the amount of bony contact between the talus and calcaneus is maintained in order to optimize fusion. Our hypothesis is that the TTC nail does not destroy a significant amount contact area between the talus and calcaneus. However, using larger diameter nails (which are inherently stronger) will have more of an effect on the contact surface. Methods: Five cadaveric below the knee specimens were obtained. The ankle was disarticulated on each specimen. Subsequently, a guidepin was drilled from the central dome of the talus down to the calcaneus. The 11 mm reamer was then passed over the guidepin through the calcaneus to simulate retrograde reaming of a TTC nail. Then, the subtalar joint was dissected open and the articular surface was documented in comparison with the area that was reamed out. Measurements were then made, using software that calculated two dimensional surface area to determine the percentage of actual subtalar joint area that was reamed out. The mean percentage of articular area that was removed with the reamer was then calculated. Results: Among the five specimens, in the calcaneus, the mean total articular area was 599mm2±113 and the mean drilled articular area was 21mm2±16. The percentage of the calcaneal articular surface that was removed with the reamer was 3.4%±1.9. In the talus, the mean total articular area was 782mm2±130 and the mean drilled articular area was 39mm2±18. The percentage of the talar articular surface that was removed with the reamer was 5.0%±2.3. Additionally, an 11 mm reamer makes a circular surface area of 95mm2, and the statistics above indicate that a significant portion of the reamed area is nonarticular, within the calcaneal sulcus or the talar sulcus. Conclusion: In a tibiotalocalcaneal nail the subtalar joint is typically incompletely visualized, however this anatomic study demonstrates that the 11 mm reamer eliminates about 3.4% of the calcaneal articular surface and about 5% of the talar articular surface. Therefore, the majority of the articular surface is left intact, which is ideal in optimizing arthrodesis outcomes. Furthermore, this study could extrapolate the effects of a larger nail on the availability of joint surface. It could also be used to argue for cartilage stripping of the affected joint surfaces in arthrodesis preparation, because the majority of the articular surface is, in fact, left intact.

Fast collision detection methods for joint surfaces

2009 ◽  
Vol 42 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Ehsan Arbabi ◽  
Ronan Boulic ◽  
Daniel Thalmann
Keyword(s):  
Collision Detection ◽  
Detection Methods ◽  
Joint Surfaces ◽  
Fast Collision

scholarly journals Tissue Engineering of Muscles and Cartilages Using Polyelectrolyte Hydrogels

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hyuck Joon Kwon
Keyword(s):  
Tissue Engineering ◽  
In Vivo Studies ◽  
Current Status ◽  
Polyelectrolyte Gel ◽  
Polyelectrolyte Gels ◽  
Joint Surfaces ◽  
Functional Replacement ◽  
And Cartilage

The prevalent nature of osteoarthritis that causes the erosion of joint surfaces and loss of mobility and muscle dystrophy that weakens the musculoskeletal system and hampers locomotion underlies the importance of developing functional replacement or regeneration of muscle and cartilage tissues. Polyelectrolyte gels have high potential as cellular scaffolds due to characteristic properties similar to biological matrixes. A number of in vitro and in vivo studies demonstrated that polyelectrolyte gels are useful for replacement and regeneration of muscle and cartilage tissues. In addition, it was also found that polyelectrolyte gels have high biocompatibility, durability, and resistance to biodegradation. Moreover, polyelectrolyte gels can overcome their drawbacks of mechanical behavior by introducing double network into the gel. This paper reviews the current status and recent progress of polyelectrolyte gel-based tissue engineering for repairs of muscle and cartilage tissues.

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