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

Author(s):  
Joshua D. Roth ◽  
S. M. Howell ◽  
M. L. Hull

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.

2017 ◽  
Vol 11 (1) ◽  
pp. 1165-1172
Author(s):  
Philippe Van Overschelde ◽  
Vera Pinskerova ◽  
Peter P. Koch ◽  
Christophe Fornasieri ◽  
Sandro Fucentese

Background: To date, there is still no consensus on what soft tissues must be preserved and what structures can be safely released during total knee arthroplasty (TKA) with a medially stabilized implant. Objective: The aim of this study was to analyze the effect of a progressive selective release of the medial and lateral soft tissues in a knee implanted with a medially stabilized prosthesis. Method: Six cadaveric fresh-frozen full leg specimens were tested. In each case, kinematic pattern and mediolateral laxity were measured in three stages: firstly, prior to implantation; secondly, after the implantation of the trial components, but before any soft tissue release; and thirdly, progressively as soft tissue was released with the trial implant in place. The incremental impact of each selective release on knee balance was then analyzed. Results: In all cases sagittal stability was not affected by the progressive release of the lateral soft tissue envelope. It was possible to perform progressive lateral release provided the anterior one-third of the iliotibial band (ITB) remained intact. Progressive medial release could be performed on the medial side provided the anterior fibers of the superficial medial collateral ligament (sMCL) remained intact. Conclusion: The medially conforming implant remains stable provided the anterior fibers of sMCL and the anterior fibers of the ITB remain intact. The implant’s sagittal stability is mainly dependent on its medial ball-in-socket design.


1997 ◽  
Vol 18 (5) ◽  
pp. 277-283 ◽  
Author(s):  
Zong-Ping Luo ◽  
Harold B. Kitaoka ◽  
Horng-Chaung Hsu ◽  
Hideji Kura ◽  
Kai-Nan An

Ligaments surrounding the hindfoot joints play an important role in hindfoot stability. This in vitro study investigated anatomical and biomechanical characteristics of nine major ligamentous structures, including length and orientation at neutral position and physiological elongation with the foot in five different positions relative to the neutral position. The results showed that ligament elongation depended on the ligament length, orientation in neutral position, and movement of bones to which they were attached.


2015 ◽  
Vol 24 (8) ◽  
pp. 2395-2401 ◽  
Author(s):  
Arnd Steinbrück ◽  
Christian Schröder ◽  
Matthias Woiczinski ◽  
Tatjana Müller ◽  
Peter E. Müller ◽  
...  

2011 ◽  
Vol 44 (5) ◽  
pp. 877-884 ◽  
Author(s):  
C. Belvedere ◽  
A. Leardini ◽  
S. Giannini ◽  
A. Ensini ◽  
L. Bianchi ◽  
...  

Author(s):  
Kavinaya C ◽  
Ashuthoshkumar L

Computation of knee modeling is a subject-specific techniquethatdefining the zero-load measurements of the cruciate and indemnity ligaments.The dynamic knee simulator was used to test the three carcass knees. The carcass knees also experiencedphysicalsachet of motion testing to discovery their inactivesort of motion in order to regulate the zero-load measurements for everymuscle bundle. Compotation multibody knee representations were shaped for each knee and classical kinematics were likened to investigational kinematics for a replicated walk series. Simple-minded non-linear mechanisminhibition elements were used to characterize cruciate and deposited particles in musclepackages in the knee representations. This learningoriginate that knee kinematics was enormously sensitive to changing of the zero-load measurement. The domino effects also recommendoptimum methods for describing each of the muscle bundle zero-load measurements, irrespective of the subject. These consequencesvalidate the significance ofthe zero-load length when modeling the knee united and verify that physicalcloak of motion dimensions can be usedto determine the passive range of motion of the knee joint. It is also supposed that the method defined here forresponsible zero-load measurement can be used for in vitro or in vivo subject-specific computational models.


2020 ◽  
Vol 48 ◽  
Author(s):  
Cristiane Alves Cintra ◽  
Luís Gustavo Gosuen Gonçalves Dias ◽  
Fernanda Gosuen Gonçalves Dias ◽  
Danyelle Rayssa Cintra Ferreira ◽  
Lucas De Freitas Pereira ◽  
...  

Background: Coxofemoral luxation is the most common traumatic luxation in dogs and the iliotrochanteric suture is one of the surgical treatment options. The orthopedic suture aimed at surgically restoring joint movement should be employed in an isometric manner in order to maintain adequate tension throughout the arc of motion. This study aimed to determine the isometric points for the iliotrochanteric suture in dogs during the joint extension and flexion movements. This evaluation was performed both in the intact hip joint and in the luxation model, establishing the best combination, among the determined points, for the reestablishment of normal joint movement.Materials, Methods & Results: Radiographic analyses of 12 canine cadaveric hips, both intact and in craniodorsal luxation model, were performed in a neutral position, flexion at 50°, and extension at 150°. In the trochanteric segment, two parallel lines were drawn, creating the central vertical axis and the secondary vertical axis. Three points were then determined on each axis, from proximal to distal, corresponding to 25, 50, and 75% of the height of the axis, and were labelled as T1, T2, and T3 and T4, T5, and T6, respectively. In the iliac segment, a line perpendicular to the longitudinal axis of the ilium was drawn, and 25, 50, and 75% of this height corresponded to points I1, I2, and I3, respectively. The lengths between the points were measured, with the objective of evaluating which combination of points presented less variation in the joint positions. The central location of the iliac and trochanteric segments, determined respectively by I2 and T2, provided smaller variations during the maximal movements of hip flexion and extension.Discussion: The surgical techniques of iliotrochanteric suture target to maintain the internal rotation of the femoral head inside the acetabulum and abduction of the femur until the soft tissues have healed. The described techniques for the iliotrochanteric suture present a great anatomical variety in the arrangement of the anchor points of the suture. It is known that if during motion, the attachment sites move closer to one another, the suture will become lax and, if the attachment sites move away from one another, the suture will tighten. Therefore, the implantation in isometric sites assists in reducing the variation of the distance between the points of origin and insertion of the suture during joint movement, keeping the suture tension constant and allowing the functional recovery of the joint. This study demonstrates that there are some locations for the origin and insertion of an iliotrochanteric suture that are associated with less length change than others. I2-T2 combination is the point closest to isometry for the iliotrochanteric suture during hip extension and flexion, so that, T2 is the most central point of the greater trochanter, corresponding to 50% of the height of its central vertical axis, as well as I2, which corresponds to the most central point of the ilium, representing 50% of the height of the most caudal portion of its body. The isometric point found by us details the exact location of perforation in all aspects (height and length), both in the ilium and the trochanter. In addition, it is a personalized point created for each patient from its radiographic examination and taking into consideration its anatomical variations, so that there is no damage to the suture during hip extension and flexion movements.


Author(s):  
Nicole A. DeVries ◽  
Anup A. Gandhi ◽  
Douglas C. Fredericks ◽  
Joseph D. Smucker ◽  
Nicole M. Grosland

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.


2021 ◽  
Vol 10 (30) ◽  
pp. 2305-2309
Author(s):  
Sahana Selvaganesh ◽  
Subhasree R. ◽  
Thiyaneswar Nessapan ◽  
Abhinav R.P. ◽  
Dimple S.

BACKGROUND Peri-implantitis is an inflammatory reaction surrounding the hard and soft tissues of the implant that is functional in the patient's mouth. If left untreated, this might lead to further bone loss, loosening of the implant and the ultimate failure of the implant. There are many treatment modalities that have been suggested to treat periimplantitis, but there are no set guidelines or protocols for the same. Implantoplasty seems to be a viable option for treating peri-implantitis, as it involves the smoothening of the macro geometry of the supracrestal exposed implant surface thus reducing the plaque accumulation and ultimately preventing the bacterial recolonization and preventing the implant from failure. This study was done to evaluate the smoothness and the fracture resistance of the implants treated by implantoplasty and as an effective treatment for peri-implantitis. METHODS This in-vitro study was done on 5 failed implants, in which 4 were subjected to a sequence of dental burs and prophy paste and 1 implant was kept as a control. They were subjected to laser topography analysis to determine the smoothness after implantoplasty, and their fracture resistance was also checked in Instron. RESULTS Implant no. 4 subjected to both dental burs and prophy paste was considered to be the smoothest with the laser topography of 2.049 mm compared to the control that was 3.132 mm. Also, the fracture resistance between the implants and the control was similar. CONCLUSIONS In conclusion implantoplasty is a suggested treatment option for patients with periimplantitis keeping in mind the practical difficulties of the procedure. KEY WORDS Peri-Implantitis, Implantoplasty, Dental Burs, Surface Analysis


2004 ◽  
Vol 12 (2) ◽  
pp. 108-112 ◽  
Author(s):  
Vânia Portela Ditzel Westphalen ◽  
Ivaldo Gomes de Moraes ◽  
Fernando Henrique Westphalen

This in vitro study evaluated and compared the efficacy of conventional (Kodak F-speed (Insight), Kodak) and a digital (DRS Gnatus System, Gnatus) radiographic imaging for diagnosis of simulated external root resorption cavities. Human mandibles containing teeth were covered with bovine muscle slices in order to simulate the soft tissues. Nine teeth out of each group of teeth were investigated. Initially, three periapical radiographs of each tooth were taken using a tube shift technique with mesial and distal angulations in both methods. All teeth were subsequently extracted and had 0.7 and 1.0-mm deep cavities prepared on their buccal, mesial and distal surfaces at the cervical, middle and apical thirds. Steel cylinder burs (DORMER® - HSS) with 0.7 and 1.0-mm diameter were used. Each tooth was replaced on its socket and new radiographs were taken. Three examiners, an endodontist (1), a radiologist (2) and a general dentist (3), evaluated the images. Results were compared by z-test and showed a higher number of cavities detected by the digital method compared to the conventional, regardless of the deepness of the cavity. In decreasing order, examiners 2, 3 and 1 exhibited different potentials of detection of cavities with the conventional method. Examiners 1 and 3 exhibited superior potential than examiner 2 for detection of cavities of different sizes with the digital method.


2010 ◽  
Vol 25 (4) ◽  
pp. 539-543 ◽  
Author(s):  
Umberto Romeo ◽  
Gaspare Palaia ◽  
Alessandro Del Vecchio ◽  
Gianluca Tenore ◽  
Gianluca Gambarini ◽  
...  

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