Article
Role of an Adjustable Hinged Elbow Orthosis in the Rehabilitation of a Lateral Collateral Ligament Deficient Elbow: An In Vitro Biomechanical Study
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Authors
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Armin Badre
- Roth-McFarlane Hand & Upper Limb Centre, St. Joseph's Health Care, London, Canada
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Sara Banayan
- Roth-McFarlane Hand & Upper Limb Centre, St. Joseph's Health Care, London, Canada
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David Axford
- Roth-McFarlane Hand & Upper Limb Centre, St. Joseph's Health Care, London, Canada
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Jim Johnson
- Roth-McFarlane Hand & Upper Limb Centre, St. Joseph's Health Care, London, Canada
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Graham King
- Roth-McFarlane Hand & Upper Limb Centre, St. Joseph's Health Care, London, Canada
| Published: | February 6, 2020 |
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Outline
Text
Objectives/Interrogation: Hinged elbow orthoses (HEO) are often used to allow protected motion of the unstable elbow. However, previous biomechanical studies have not shown HEO to improve the stability of an LCL deficient elbow. This lack of effectiveness may be due to the straight hinge of current HEO designs which do not account for the native carrying angle of the elbow.
The aim of this study was to determine the effectiveness of a custom-designed HEO with an adjustable carrying angle on stabilizing the LCL deficient elbow.
Methods: Eight cadaveric arms were mounted in an elbow motion simulator with the arm in the varus position. An LCL injured (LCLI) model was created by sectioning of the common extensor origin, and the LCL. The adjustable HEO was secured to the arm and its effect with 0°, 10°, and 20° (BR00, BR10, BR20) of valgus carrying angle was investigated.
Varus-valgus angles and ulnohumeral rotations were recorded using an electromagnetic tracking system during simulated active elbow flexion with the forearm pronated and supinated.
Results and Conclusions: There were significant differences in varus and ER angulation between different elbow states with the forearm both pronated and supinated (P=.000 for all). The LCLI state with or without the brace resulted in significant increases in varus and ER of the ulnohumeral articulation compared to the intact (P< 0.05). The difference between each of the LCLI, BR00, BR10, BR20 states and the intact ranged from 3.8-6.2° for varus and 3.6-5.2° for ER. However, there were no significant differences in varus or ER of the ulnohumeral articulation between any of the brace angles and the LCLI state (P >0.05). The difference between each of the brace angles and the LCLI state ranged from 1.1-2.4° for varus and 0.5-1.6° for ER.
Although there was a trend toward decreasing varus and ER of the ulnohumeral articulation with the application of this adjustable HEO, none of the brace angles examined was able to restore the stability of the LCL deficient elbow. This lack of stabilizing effect may be due to the weight of the brace exerting unintentional varus and torsional forces on the unstable elbow. Previous investigations have shown that the varus arm position is highly unstable in the LCL deficient elbow. Our results demonstrate that the application of an HEO with an adjustable carrying angle does not stabilize the LCL deficient elbow in this unstable position. Varus arm positioning should be avoided in the rehabilitation programs of an LCL deficient elbow.
