scholarly journals Laminectomy and functional impairment of the lumbar spine: the importance of muscle forces in flexible and rigid instrumented stabilization – a biomechanical study in vitro

1998 ◽  
Vol 7 (3) ◽  
pp. 229-238 ◽  
Author(s):  
U. Quint ◽  
H.-J. Wilke ◽  
F. Löer ◽  
L. Claes
Keyword(s):  
Lumbar Spine ◽  
Functional Impairment ◽  
Biomechanical Study ◽  
Muscle Forces

Lateral Translation of the Lumbar Spine: In Vitro Biomechanical Study

2006 ◽  
Vol 22 (2) ◽  
pp. 83-92 ◽  
Author(s):  
Yuichiro Okushima ◽  
Nobutoshi Yamazaki ◽  
Morio Matsumoto ◽  
Kazuhiro Chiba ◽  
Takeo Nagura ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Three Dimensional ◽  
Shear Loading ◽  
Biomechanical Study ◽  
Facet Joints ◽  
Lateral Translation ◽  
Natural Movement ◽  
Human Cadavers ◽  
Position Sensitive Detectors

A biomechanical study of lateral translation in lumbar spine with human cadavers was performed in order to explore the direction of the force increasing lateral translation and the contributions of discs and facet joints to lateral translation. Whole lumbar spines from 12 fresh cadavers were attached to a specially designed loading apparatus whose five cables simulated the muscles of the trunk without restricting natural movement. Three-dimensional positions of each vertebra were recorded with position-sensitive detectors. Force in the anterolateral direction increased the lateral translation more than force in the posterolateral direction. Lateral translation was increased to a significantly greater extent when the facet joints were removed than when the discs were removed at L4-5 at the levels of shear loading applied in this study.

The Effect of Volarly Angulated Distal Radius Fractures on Forearm Rotation: In Vitro Biomechanical Study

2015 ◽  
Vol 04 (S 01) ◽  
Author(s):  
Masao Nishiwaki ◽  
Mark Welsh ◽  
Louis Ferreira ◽  
James Johnson ◽  
Graham King ◽  
...  
Keyword(s):  
Distal Radius ◽  
Biomechanical Study ◽  
Distal Radius Fractures ◽  
Radius Fractures ◽  
Forearm Rotation

Role of the anconeus in the stability of a lateral ligament and common extensor origin–deficient elbow: an in vitro biomechanical study

2019 ◽  
Vol 28 (5) ◽  
pp. 974-981 ◽  
Author(s):  
Armin Badre ◽  
David T. Axford ◽  
Sara Banayan ◽  
James A. Johnson ◽  
Graham J.W. King
Keyword(s):  
Biomechanical Study ◽  
Lateral Ligament ◽  
The Stability

scholarly journals Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Toni Wendler ◽  
Torsten Prietzel ◽  
Robert Möbius ◽  
Jean-Pierre Fischer ◽  
Andreas Roth ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Work Experience ◽  
Soft Tissues ◽  
Force Sensor ◽  
Biomechanical Study ◽  
Measuring System ◽  
Wide Range ◽  
Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

scholarly journals Whether sutures reduce the graft laceration caused by interference screw in anterior cruciate ligament reconstruction? A biomechanical study in vitro

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yuanjun Teng ◽  
Xiaohui Zhang ◽  
Lijun Da ◽  
Jie Hu ◽  
Hong Wang ◽  
...  
Keyword(s):  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Interference Screw ◽  
Biomechanical Study ◽  
Interference Screws ◽  
Suture Group ◽  
Anterior Cruciate ◽  
Biomechanical Tests ◽  
Single Insertion

Abstract Background Interference screw is commonly used for graft fixation in anterior cruciate ligament (ACL) reconstruction. However, previous studies had reported that the insertion of interference screws significantly caused graft laceration. The purposes of this study were to (1) quantitatively evaluate the graft laceration from one single insertion of PEEK interference screws; and (2) determine whether different types of sutures reduced the graft laceration after one single insertion of interference screws in ACL reconstruction. Methods The in-vitro ACL reconstruction model was created using porcine tibias and bovine extensor digitorum tendons of bovine hind limbs. The ends of grafts were sutured using three different sutures, including the bioabsorbable, Ethibond and ultra-high molecular weight polyethylene (UHMWPE) sutures. Poly-ether-ether-ketone (PEEK) interference screws were used for tibial fixation. This study was divided into five groups (n = 10 in each group): the non-fixed group, the non-sutured group, the absorbable suture group, the Ethibond suture group and the UHMWPE suture group. Biomechanical tests were performed using the mode of pull-to-failure loading tests at 10 mm/min. Tensile stiffness (newtons per millimeter), energy absorbed to failure (in joules) and ultimate load (newtons) were recorded for analysis. Results All prepared tendons and bone specimens showed similar characteristics (length, weight, and pre-tension of the tendons, tibial bone mineral density) among all groups (P > 0.05). The biomechanical tests demonstrated that PEEK interference screws significantly caused the graft laceration (P < 0.05). However, all sutures (the bioabsorbable, Ethibond and UHMWPE sutures) did not reduce the graft laceration in ACL reconstruction (P > 0.05). Conclusions Our biomechanical study suggested that the ultimate failure load of grafts was reduced of approximately 25 % after one single insertion of a PEEK interference screw in ACL reconstruction. Suturing the ends of the grafts using different sutures (absorbable, Ethibond and UHMWPE sutures) did not decrease the graft laceration caused by interference screws.

The Effectiveness of a Hinged Elbow Orthosis in Medial Collateral Ligament Injuries: An In Vitro Biomechanical Study

2019 ◽  
Vol 47 (12) ◽  
pp. 2827-2835
Author(s):  
Ranita H.K. Manocha ◽  
James A. Johnson ◽  
Graham J.W. King
Keyword(s):  
Medial Collateral Ligament ◽  
Muscle Activation ◽  
Mechanical Stability ◽  
Biomechanical Study ◽  
Return To Play ◽  
Collateral Ligament ◽  
Valgus Stress ◽  
Active Motion ◽  
Early Return

Background: Medial collateral ligament (MCL) injuries are common after elbow trauma and in overhead throwing athletes. A hinged elbow orthosis (HEO) is often used to protect the elbow from valgus stress early after injury and during early return to play. However, there is minimal evidence regarding the efficacy of these orthoses in controlling instability and their influence on long-term clinical outcomes. Purpose: (1) To quantify the effect of an HEO on elbow stability after simulated MCL injury. (2) To determine whether arm position, forearm rotation, and muscle activation influence the effectiveness of an HEO. Study Design: Controlled laboratory study. Methods: Seven cadaveric upper extremity specimens were tested in a custom simulator that enabled elbow motion via computer-controlled actuators and motors attached to relevant tendons. Specimens were examined in 2 arm positions (dependent, valgus) and 2 forearm positions (pronation, supination) during passive and simulated active elbow flexion while unbraced and then while braced with an HEO. Testing was performed in intact elbows and repeated after simulated MCL injury. An electromagnetic tracking device measured valgus angulation as an indicator of elbow stability. Results: When the arm was dependent, the HEO increased valgus angle with the forearm in pronation (+1.0°± 0.2°, P = .003) and supination (+1.5°± 0.0°, P = .006) during active motion. It had no significant effect on elbow stability during passive motion. In the valgus position, the HEO had no effect on elbow stability during passive or active motion in pronation and supination. With the arm in the valgus position with the HEO, muscle activation reduced instability during pronation (–10.3°± 2.5°, P = .006) but not supination ( P = .61). Conclusion: In this in vitro study, this HEO did not enhance mechanical stability when the arm was in the valgus and dependent positions after MCL injury. Clinical Relevance: After MCL injury, an HEO likely does not provide mechanical elbow stability during rehabilitative exercises or when the elbow is subjected to valgus stress such as occurs during throwing.

Osteochondral Lesions of the Capitellum Do Not Affect Elbow Kinematics and Stability With Intact Collateral Ligaments: An In Vitro Biomechanical Study

2011 ◽  
Vol 36 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Marlis T. Sabo ◽  
Colin P. McDonald ◽  
Louis M. Ferreira ◽  
Jim A. Johnson ◽  
Graham J. King
Keyword(s):  
Biomechanical Study ◽  
Osteochondral Lesions ◽  
Collateral Ligaments

Evaluation of BioCorkscrew and Bioknotless RC suture anchor rotator cuff repair fixation: an in vitro biomechanical study

2007 ◽  
Vol 15 (11) ◽  
pp. 1375-1381 ◽  
Author(s):  
Jennifer Tucker Ammon ◽  
John Nyland ◽  
Haw Chong Chang ◽  
Robert Burden ◽  
David N. M. Caborn
Keyword(s):  
Rotator Cuff ◽  
Rotator Cuff Repair ◽  
Suture Anchor ◽  
Biomechanical Study ◽  
Cuff Repair
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