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- Fischer, Per, 1981-, et al.
(författare)
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Functional and kinematic analysis of a wrist radial hemiarthroplasty design
- 2017
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Konferensbidrag (refereegranskat)abstract
- Hypothesis A radial hemiarthroplasty could obviate difficulties related to distal component loosening of the total wrist arthroplasty. The aim of this study is to investigate kinematically, the feasibility of a new design for radial wrist hemiarthroplasty.Methods Six, fresh-frozen cadaveric wrist specimens were used. Testing was performed on the native wrist, after insertion of a radial hemi-arthroplasty with intact proximal carpal row (Hemi) and with proximal row carpectomy (Hemi+PRC). Each wrist was fixed to an experimental table with the tendons of the extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor carpi ulnaris (ECU), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), and abductor pollicis longus (APL) attached to the apparatus. Range of motion, axis of rotation, and muscle moment arms were recorded in manually controlled movements in wrist flexion/extension, radial/ulnar deviation, dart throwers motion, and circumduction.Results A statistically significant decrease in flexion range of motion occurred between the intact and Hemi conditions and between the intact and Hemi+PRC conditions with no significant differences in flexion range of motion occurring between the Hemi and Hemi+PRC conditions. No statistically significant changes in range of motion occurred in extension, radial deviation, ulnar deviation, flexion/ulnar deviation component of the dart throw, extension/radial deviation component of the dart throw, or circumduction functional tests.Summary Points This study indicates that the new wrist radial hemiarthroplasty can produce a stable wrist with range of motion similar to the native wrist. Overall, wrist kinematics appears to be equally acceptable in hemiarthroplasty with and without resection of the proximal row.
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| 2. |
- Hooke, Alexander W., et al.
(författare)
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An anatomic and kinematic analysis of a new total wrist arthroplasty design
- 2015
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Ingår i: Journal of wrist surgery. - New York : Thieme Medical Publishers. - 2163-3916 .- 2163-3924. ; 4:2, s. 121-127
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Total wrist arthroplasty (TWA) is a viable surgical treatment for disabling wrist arthritis. While current designs are a notable improvement from prior generations, radiographic loosening and failures remain a concern.Purpose: The purpose of this investigation is to evaluate a new total wrist arthroplasty design kinematically. The kinematic function of a native, intact cadaveric wrist was compared with that of the same wrist following TWA.Method: Six, fresh-frozen wrist cadaveric specimens were utilized. Each wrist was fixed to an experimental table and its range of motion, axis of rotation, and muscle moment arms were calculated. The following tendons were attached to the apparatus to drive motion: extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor carpi ulnaris (ECU), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), and abductor pollicis longus (APL). The wrist was then manually moved along a guide by an experimenter through a series of motions including flexion-extension, radial-ulnar deviation, and circumduction. The experiment was then performed on the specimen following implantation of the TWA.Results: Following the TWA procedure, there were statistically significant decreases in the ulnar deviation and the flexion/ulnar deviation component of dart throw ranges of motion. There were no statistically significant changes in flexion, extension, radial deviation, the extension/radial deviation component of the dart thrower motion, or the circumduction range of motion.Conclusions: Kinematic analysis of the new TWA suggests that a stable, functional wrist is achievable with this design.Clinical Relevance: While appreciating the limitations of a cadaveric study, this investigation indicates that the TWA design studied merits study in human populations.
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| 3. |
- Hooke, Alexander W., et al.
(författare)
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Mechanical Assessment of Tissue Properties During Tourniquet Application
- 2021
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Ingår i: Military medicine. - : OXFORD UNIV PRESS. - 0026-4075 .- 1930-613X. ; 186, s. 378-383
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Successful tourniquet application increases survival rate of exsanguinating extremity hemorrhage victims. Tactile feedback during tourniquet application training should reflect human tissue properties in order to increase success in the field. This study aims to understand the mechanical properties of a human limb during tourniquet application. Method: Six cadaveric extremities-three uppers and three lowers-were tested from three body mass index groups: low (<19) healthy (19-24), and overweight (>24). Each specimen donned with a tourniquet and mounted to a servo-hydraulic testing machine, which enabled controlled tightening of the tourniquet while recording the tourniquet tension force and strap displacement. A thin-film pressure sensor placed between the specimen and the tourniquet recorded contact pressure. Each limb was tested with the tourniquet applied at two different sites resulting in testing at the upper arm, forearm, thigh, and shank. Results: The load displacement curves during radial compression were found to be nonlinear overall, with identifiable linear regions. Average contact pressure under the tourniquet strap at 200N and 300N of tension force was 126.3 (sigma= 41.2) mm Hg and 205.3 (sigma = 75.3) mm Hg, respectively. There were no significant differences in tissue stiffness or contact pressure at 300N of tension force between limb (upper vs. lower) or body mass index. At 200N of tension, the upper limb had significantly higher contact pressure than the lower limb (P= 0.040). Relative radial compression was significantly different between upper (16.74, sigma = 4.16%) and lower (10.15, sigma = 2.25%) extremities at 200N tension (P= 0.005). Conclusions: Simulation of tissue compression during tourniquet application may be achieved with a material exhibiting elastic properties to mimic the force-displacement behavior seen in cadaveric tissue or with different layers of material. Different trainers for underweight, healthy, and overweight limbs may not be needed. Separate tourniquet training fixtures should be created for the upper and lower extremities.
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