scholarly journals The Cadaveric Studies and the Definition of the Antero-Lateral Ligament of the Knee: From the Anatomical Features to the Patient-Specific Reconstruction Surgical Techniques

2021 ◽  
Vol 18 (23) ◽  
pp. 12852
Author(s):  
Giacomo Dal Fabbro ◽  
Piero Agostinone ◽  
Gian Andrea Lucidi ◽  
Nicola Pizza ◽  
Nicolò Maitan ◽  
...  
Keyword(s):  
Knee Joint ◽  
Surgical Techniques ◽  
In Vitro Study ◽  
Joint Disease ◽  
Surgical Reconstruction ◽  
Patient Specific ◽  
Lateral Ligament ◽  
Joint Biomechanics ◽  
Cadaver Studies

Cadaver studies represented a milestone in surgical orthopaedic research, and still today they play a crucial role in the achievement of new knowledge about joint disease behaviour and treatment. In this review, an overview of the cadaver studies available in the literature about the anatomy, role, and treatment of the antero-lateral ligament (ALL) of the knee was performed. The aim of the review was to describe and gain more insight into the part of in vitro study in understanding knee joint anatomy and biomechanics, and in developing surgical reconstruction techniques. The findings of the review showed that cadaver studies had, and will continue to have, a key role in the research of knee joint biomechanics and surgical reconstruction. Moreover, they represent a powerful tool to develop and test new devices which could be useful in clinical and surgical practice.

Quantifying Achievable Levels of Improvement in Knee Joint Biomechanics During Gait After Total Knee Arthroplasty Relative to Osteoarthritis Severity

2020 ◽  
pp. 1-9
Author(s):  
Jereme B. Outerleys ◽  
Michael J. Dunbar ◽  
Glen Richardson ◽  
Cheryl L. Hubley-Kozey ◽  
Janie L. Astephen Wilson
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Joint ◽  
Knee Arthroplasty ◽  
Frontal Plane ◽  
Knee Adduction Moment ◽  
Patient Specific ◽  
Knee Biomechanics ◽  
Knee Oa ◽  
Joint Biomechanics ◽  
Total Knee

Total knee arthroplasty (TKA) surgery improves knee joint kinematics and kinetics during gait for most patients, but a lack of evidence exists for the level and incidence of improvement that is achieved. The objective of this study was to quantify patient-specific improvements in knee biomechanics relative to osteoarthritis (OA) severity levels. Seventy-two patients underwent 3-dimensional (3D) gait analysis before and 1 year after TKA surgery, as well as 72 asymptomatic adults and 72 with moderate knee OA. A combination of principal component analysis and discriminant analyses were used to categorize knee joint biomechanics for patients before and after surgery relative to asymptomatic, moderate, and severe OA. Post-TKA, 63% were categorized with knee biomechanics consistent with moderate OA, 29% with severe OA, and 8% asymptomatic. The magnitude and pattern of the knee adduction moment and angle (frontal plane features) were the most significant contributors in discriminating between pre-TKA and post-TKA knee biomechanics. Standard of care TKA improves knee biomechanics during gait to levels most consistent with moderate knee OA and predominately targets frontal plane features. These results provide evidence for the level of improvement in knee biomechanics that can be expected following surgery and highlight the biomechanics most targeted by surgery.

Biomechanical In Vitro Study on the Stability of Patient-Specific CAD/CAM Mandibular Reconstruction Plates: A Comparison Between Selective Laser Melted, Milled, and Hand-Bent Plates

2020 ◽  
pp. 194338752095268
Author(s):  
Robin Kasper ◽  
Karsten Winter ◽  
Sebastian Pietzka ◽  
Alexander Schramm ◽  
Frank Wilde
Keyword(s):  
In Vitro Study ◽  
Mandibular Reconstruction ◽  
Patient Specific ◽  
Plate Fracture ◽  
Computer Aided ◽  
Cad Cam ◽  
Number Of Cycles ◽  
Bent Plates ◽  
Cam Systems

Study Design: An experimental in vitro study. Objective: Plate fractures are a recurrent problem in alloplastic mandibular reconstruction. Hypothetically it can be assumed that computer-aided design (CAD)/computer-aided manufacturing (CAM) reconstruction plates have a higher stability than conventional hand-bent plates. The aim of the study was to compare additive and subtractive fabricated CAD/CAM mandibular reconstruction plates as well as conventional plates with regard to their biomechanical properties. Methods: In a chewing simulator, plates of 2 conventional locking plate systems and 2 CAD/CAM-fabricated plate systems were compared. The plates were loaded in a fatigue test. The maximum number of cycles until plate fracture and the plate stiffness were compared. Results: While all conventional plates fractured at a maximum load between 150 and 210 N (Newton) after a number of cycles between 40 000 and 643 000, none of the CAD/CAM plates broke despite a nearly doubled load of 330 N and 2 million cycles. Both CAD/CAM systems proved to be significantly superior to the hand-bent plates. There was no difference between the 2 CAD/CAM systems. Conclusions: Concerning the risk of plate fracture, patient-specific CAD/CAM reconstruction plates appear to have a significant advantage over conventional hand-bent plates in alloplastic mandibular reconstruction.

A patient-specific guide for optimizing custom-made glenoid implantation in cases of severe glenoid defects: an in vitro study

2016 ◽  
Vol 25 (5) ◽  
pp. 837-845 ◽  
Author(s):  
Koen Eraly ◽  
Danny Stoffelen ◽  
Jos Vander Sloten ◽  
Ilse Jonkers ◽  
Philippe Debeer
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Patient Specific ◽  
Custom Made

Envelopes of Passive Motion in the Intact Tibiofemoral Joint: An In Vitro Study

2013 ◽  
Author(s):  
Joshua D. Roth ◽  
S. M. Howell ◽  
M. L. Hull
Keyword(s):  
Computational Models ◽  
Soft Tissues ◽  
Surgical Techniques ◽  
Knee Kinematics ◽  
In Vitro Study ◽  
Neutral Position ◽  
Tibiofemoral Joint ◽  
Passive Motion ◽  
Posterior Translation

The kinematics (i.e. passive motions) of the knee are determined and constrained by the articular surfaces and soft tissues of the tibiofemoral joint [1]. Knee kinematics may be characterized by measuring the envelopes of passive motion which are described, for each DOF over a range of flexion, by the positive and negative limits of displacement about a neutral position, under a prescribed load. It is crucial to understand the kinematics of the intact tibiofemoral joint because the envelopes of passive motion could serve as a gold standard for validating computational models of the knee as well as evaluating the effectiveness of innovative and established surgical techniques. Therefore, the objective of this study was to define the envelopes of passive motion for internal-external (I-E) rotation, varus-valgus (V-V) rotation, anterior-posterior translation (A-P), and distraction (D) translation of the intact tibiofemoral joint.

scholarly journals Fresh Osteochondral Allograft Transplants in the Knee: Bipolar and Beyond

2020 ◽  
Vol 33 (12) ◽  
pp. 1172-1179
Author(s):  
James P. Stannard ◽  
James T. Stannard ◽  
Anna J. Schreiner
Keyword(s):  
Surgical Techniques ◽  
Treatment Strategies ◽  
Treatment Method ◽  
Joint Disease ◽  
Osteochondral Allograft ◽  
Patient Specific ◽  
Osteochondral Lesions ◽  
Fresh Osteochondral Allograft ◽  
Total Knee ◽  
Spectrum Of Patients

AbstractKnee patients who have sustained chondral and osteochondral lesions suffer from debilitating pain, which can ultimately lead to posttraumatic osteoarthritis and whole-joint disease. Older, nonactive patients are traditionally steered toward total knee arthroplasty (TKA), but younger, active patients are not good candidates for TKA based on implant longevity, complications, morbidity, and risk for revision, such that treatment strategies at restoring missing hyaline cartilage and bone are highly desired for this patient population. Over the past four decades, fresh osteochondral allograft (OCA) transplantation has been developed as a treatment method for large (> 2.5 cm2) focal full-thickness articular cartilage lesions. This article documents our own institutional OCA journey since 2016 through enhanced graft preservation techniques (the Missouri Osteochondral Preservation System, or MOPS), technical improvements in surgical techniques, use of bone marrow aspirate concentrate, bioabsorbable pins and nails, and prescribed and monitored patient-specific rehabilitation protocols. Further follow-up with documentation of long-term outcomes will provide insight for continued optimization for future applications for OCA transplantation, potentially including a broader spectrum of patients appropriate for this treatment. Ongoing translational research is necessary to blaze the trail in further optimizing this treatment option for patients.

scholarly journals Sinus Hemodynamics in Representative Stenotic Native Bicuspid and Tricuspid Aortic Valves: An In-Vitro Study

Fluids ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 56 ◽  
Author(s):  
Hoda Hatoum ◽  
Lakshmi Prasad Dasi
Keyword(s):  
Aortic Valve ◽  
In Vitro Study ◽  
Patient Specific ◽  
Shear Stresses ◽  
Flow Shear ◽  
Aortic Sinus ◽  
Image Velocimetry ◽  
3D Printed ◽  
Sinus Flow

(1) The study’s objective is to assess sinus hemodynamics differences between stenotic native bicuspid aortic valve (BAV) and native tricuspid aortic valve (TrAV) sinuses in order to assess sinus flow shear and vorticity dynamics in these common pathological states of the aortic valve. (2) Representative patient-specific aortic roots with BAV and TrAV were selected, segmented, and 3D printed. The flow dynamics within the sinus were assessed in-vitro using particle image velocimetry in a left heart simulator at physiological pressure and flow conditions. Hemodynamic data calculations, vortex tracking, shear stress probability density functions and sinus washout calculations based on Lagrangian particle tracking were performed. (3) (a) At peak systole, velocity and vorticity in BAV reach 0.67 ± 0.02 m/s and 374 ± 5 s−1 versus 0.49 ± 0.03 m/s and 293 ± 3 s−1 in TrAV; (b) Aortic sinus vortex is slower to form but conserved in BAV sinus; (c) BAV shear stresses exceed those of TrAV (1.05 Pa versus 0.8 Pa); (d) Complete TrAV washout was achieved after 1.5 cycles while it was not for BAV. 4) In conclusion, sinus hemodynamics dependence on the different native aortic valve types and sinus morphologies was clearly highlighted in this study.

Knee Joint Motion and Ligament Forces Before and After ACL Reconstruction

1989 ◽  
Vol 111 (2) ◽  
pp. 97-106 ◽  
Author(s):  
J. L. Lewis ◽  
W. D. Lew ◽  
J. A. Hill ◽  
P. Hanley ◽  
K. Ohland ◽  
...  
Keyword(s):  
Knee Joint ◽  
Cruciate Ligament ◽  
In Vitro Study ◽  
Test Series ◽  
Poor Correlation ◽  
Consistent Difference ◽  
Joint Motion ◽  
Mechanical State ◽  
Control Series

The goal of this in vitro study was to investigate the initial postoperative mechanical state of the knee with various types of anterior cruciate ligament (ACL) reconstructions. An experimental knee testing system was developed for the in vitro measurement of ligament forces and three-dimensional joint motion as external loads were applied to fresh knee specimens. Two groups of knee specimens were tested. In test series #1, two intraarticular reconstructions were performed in each of five specimens using semifree and free patellar tendon grafts with bone blocks. In test series #2, a more carefully controlled intraarticular reconstruction was performed in five specimens using a semifree composite graft consisting of the semitendinosus and gracilis tendons augmented with the Ligament Augmentation Device. Ligament force and joint motion data were collected as anteriorly directed tibial loads were applied to the normal joint, the joint with a cut ACL and the reconstructed joint. These knee joint states were compared on the basis of ACL or graft forces, joint motion and load sharing by the collateral ligaments. The dominate result of the study was that the forces and motions defining the mechanical state of the knee after the ACL reconstructions in both test series were highly variable and abnormal when compared to the normal knee state. The higher level of surgical control series #2 did not decrease this variability. There was a poor correlation between motion of the reconstructed knee relative to normal, and the ACL graft force. There was little consistent difference in force and motion results between the surgical procedures tested.

In Vitro Study of the C2-C7 Sheep Cervical Spine

2011 ◽  
Author(s):  
Nicole A. DeVries ◽  
Anup A. Gandhi ◽  
Douglas C. Fredericks ◽  
Joseph D. Smucker ◽  
Nicole M. Grosland
Keyword(s):  
Cervical Spine ◽  
Surgical Techniques ◽  
In Vitro Study ◽  
Axial Rotation ◽  
Lateral Bending ◽  
Disc Space ◽  
Flexion Extension ◽  
Biomechanical Responses ◽  
Experimental Biomechanics

Due to the limited availability of human cadaveric specimens, animal models are often utilized for in vitro studies of various spinal disorders and surgical techniques. Sheep spines have similar geometry, disc space, and lordosis as compared to humans [1,2]. Several studies have identified the geometrical similarities between the sheep and human spine; however these studies have been limited to quantifying the anatomic dimensions as opposed to the biomechanical responses [2–3]. Although anatomical similarities are important, biomechanical correspondence is imperative to understand the effects of disorders, surgical techniques, and implant designs. Some studies [3–5] have focused on experimental biomechanics of the sheep cervical functional spinal units (FSUs). Szotek and colleagues [1] studied the biomechanics of compression and impure flexion-extension for the C2-C7 intact sheep spine. However, to date, there is no comparison of the sheep spine using pure flexion-extension, lateral bending, or axial rotation moments for multilevel specimen. Therefore, the purpose of this study was to conduct in vitro testing of the intact C2-C7 sheep cervical spine.

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