Abstract
Introduction:
Posttraumatic elbow contracture is clinically challenging because injury often disrupts multiple periarticular soft tissues. Tissue specific contribution to contracture, particularly muscle, remains poorly understood.
Methods:
In this study we used a previously developed animal model of elbow contracture. After surgically inducing a unilateral soft tissue injury, injured limbs were immobilized for 3, 7, 21, and 42 days (IM) or for 42 IM with 42 days of free mobilization (42/42 IM-FM). Biceps brachii active/passive mechanics and morphology were evaluated at 42 IM and 42/42 IM-FM, whereas biceps brachii and brachialis gene expression was evaluated at all time points.
Results:
Injured limb muscle exhibited significantly altered active/passive mechanics and decreased fiber area at 42 IM but returned to control levels by 42/42 IM-FM. Gene expression suggested muscle growth rather than a fibrotic response at 42/42 IM-FM.
Discussion:
Muscle is a transient contributor to motion loss in our rat model of posttraumatic elbow contracture. Muscle Nerve 58:843-851, 2018.
Keywords:
contracture; elbow; fibrosis; gene expression; mechanics; muscle.
© 2018 Wiley Periodicals, Inc.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Brachial Plexus Neuropathies / complications*
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Collagen Type I / metabolism
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Connective Tissue Growth Factor / genetics
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Connective Tissue Growth Factor / metabolism
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Contracture / physiopathology*
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Disease Models, Animal
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Extracellular Matrix / metabolism
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Extracellular Matrix / pathology
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Functional Laterality
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Gene Expression Regulation / physiology*
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Immobilization
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Laminin / metabolism
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Male
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Matrix Metalloproteinase 2 / genetics
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Matrix Metalloproteinase 2 / metabolism
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Muscle Proteins / genetics
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Muscle Proteins / metabolism
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Muscle, Skeletal / physiopathology*
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Range of Motion, Articular / physiology
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Rats
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Rats, Long-Evans
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Soft Tissue Injuries / complications
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Soft Tissue Injuries / pathology*
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Time Factors
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Tissue Inhibitor of Metalloproteinase-2 / genetics
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Tissue Inhibitor of Metalloproteinase-2 / metabolism
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Transforming Growth Factor beta3 / genetics
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Transforming Growth Factor beta3 / metabolism
Substances
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CCN2 protein, rat
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Collagen Type I
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Laminin
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Muscle Proteins
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Transforming Growth Factor beta3
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Tissue Inhibitor of Metalloproteinase-2
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Connective Tissue Growth Factor
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Matrix Metalloproteinase 2
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Mmp2 protein, rat