| 1. |
- Beumer, Annechien, et al.
(författare)
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Effects of ligament sectioning on the kinematics of the distal tibiofibular syndesmosis - A radiostereometric study of 10 cadaveric specimens based on presumed trauma mechanisms with suggestions for treatment
- 2006
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 77:3, s. 531-540
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Tidskriftsartikel (refereegranskat)abstract
- Background Syndesmotic injuries of the ankle without fractures can result from external rotation, abduction and dorsiflexion injuries. Kinematic studies of these trauma mechanisms have not been performed. We attempted to describe the kinematics of the tibiofibular joint in cadaveric specimens using radiostereometry after sequential ligament sectioning, and resulting from different trauma mechanisms and axial loading, in order to put forward treatment guidelines for the different types of syndesmotic injuries. Methods We assessed the kinematics of the distal tibiofibular joint in fresh-frozen cadaveric specimens using radiostereometry in the intact situation, and after alternating and sequential sectioning of the distal tibiofibular and anterior deltoid ligaments. To assess which of the known trauma mechanisms would create the largest displacements at the syndesmosis, the ankle was brought into the following positions under an axial load that was comparable to body weight (750 N): neutral, dorsiflexion, external rotation, abduction, and a combination of external rotation and abduction. Results In the neutral position, the largest displacements of the fibula consisted of external rotation and posterior translation. Loading of the ankle with 750 N did not apparently increase or decrease the displacements of the fibula, but gave a larger variety of displacements. In every position, sectioning of a ligament resulted in some fibular displacement. Sectioning of the anterior tibiofibular ligament (ATiFL) invariably resulted in external rotation of the fibula. Additional sectioning of the anterior part of the deltoid ligament (AD) gave a larger variety of displacements. In general, sectioning of the posterior tibiofibular ligament (PTiFL) gave the smallest displacements. Combined sectioning of the ATiFL and the PTiFL resulted in a larger variety of displacements in the neutral position. Sectioning of the AD together with the ATiFL and PTiFL resulted in tibiofibular displacements in the neutral situation exceeding the maximum values found in the intact situation, the most important being fibular external rotation. Interpretation Sectioning of the ATiFL results in mechanical instability of the syndesmosis. Of all trauma mechanisms, external rotation of the ankle resulted in the largest and most consistent displacements of the fibula relative to the tibia found at the syndesmosis. Based on our findings and the current literature, we recommend that patients with isolated PTiFL or AD injuries should be treated functionally when no other injuries are present. Patients with acute complete ATiFL ruptures, or combined ATiFL and AD ruptures should be treated with immobilization in a plaster. Patients with combined ruptures of the AWL, AD and PTiFL need to be treated with a syndesmotic screw.
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| 2. |
- Koning, Olivier H. J., et al.
(författare)
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Fluoroscopic Roentgen stereophotogrammetric analysis (FRSA) to study three-dimensional stent graft dynamics
- 2009
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 1097-6809 .- 0741-5214. ; 50:2, s. 407-412
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Tidskriftsartikel (refereegranskat)abstract
- We report the clinical feasibility of fluoroscopic Roentgen stereophotogrammetric analysis (FRSA), a validated method to quantify, real time three-dimensional (3D) dynamic motion of stent grafts and the first clinical results after abdominal and thoracic endovascular repair (EVAR). Stent graft motion was measured at 30 (stereo) frames per second, during the cardiac cycle and in the patient after abdominal EVAR, due to respiratory action. Translational motions of the center of mass, diameter change, and rotational and axial motion could be measured. Quantification of 3D motion was not available until now. FRSA can provide crucial information on the forces exerted oil stent grafts and will, therefore, provide essential information for improvements in stent graft design. (J Vasc Surg 2009;50:407-12.)
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| 3. |
- Nelissen, Rob G H H, et al.
(författare)
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RSA and registries: the quest for phased introduction of new implants.
- 2011
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Ingår i: The Journal of bone and joint surgery. American volume. - 1535-1386. ; 93 Suppl 3, s. 62-5
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Tidskriftsartikel (refereegranskat)abstract
- Although the overall survival of knee and hip prostheses at ten years averages 90%, recent problems with several hip and knee prostheses have illustrated that the orthopaedic community, industry, and regulators can still further improve patient safety. Given the early predictive properties of roentgen stereophotogrammetric analysis (RSA) and the meticulous follow-up of national joint registries, these two methods are ideal tools for such a phased clinical introduction. In this paper, we elaborate on the predictive power of RSA within a two-year follow-up after arthroplasty and its relationship to national joint registries. The association between RSA prosthesis-migration data and registry data is evaluated.The five-year rate of revision of RSA-tested total knee replacements was compared with that of non-RSA-tested total knee replacements. Data were extracted from the published results of the national joint registries of Sweden, Australia, and New Zealand.There was a 22% to 35% reduction in the number of revisions of RSA-tested total knee replacements as compared with non-RSA-tested total knee replacements in the national joint registries. Assuming that the total cost of total knee arthroplasty is $37,000 in the United States, a 22% to 35% reduction in the number of revisions (currently close to 55,000 annually) could lead to an estimated annual savings of over $400 million to the health-care system.The phased clinical introduction of new prostheses with two-year RSA results as a qualitative tool could lead to better patient care and could reduce the costs associated with revision total knee arthroplasty. Follow-up in registries is necessary to substantiate these results and to improve post-market surveillance.
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