15. Musculoskeletal Injury Flashcards
What is required for a tissue to regenerate?
An intact connective tissue scaffold. Will not regenerate properly if the matrix and cells are damaged
What are the three types of cells?
Labile - change often
Stable - may become labile
Permanent
What makes labile cells suitable for regeneration?
Have a high rate of loss and replacement
When do stable cells become labile?
When they are stimulated to regenerate after damage, ie fibroblasts
What are examples of permanent cells?
Neurons, cardiac and skeletal muscle
What signalling methods are used in minor injury?
What signalling methods are used in larger injury?
Paracrine - extracellular signal acts on adjacent cell
Endocrine - hormone secreted into blood to distant target cells
Where do inflammatory cells originate?
In the epitendinous tissues (sheath, periosteum, soft tissues) and epitendon and endotendon
What occurs during the inflammatory response of tissue healing?
Granulation tissue, haematoma, and tissue debris fills defect. Fibronectin laid as scaffold for collagen synthesis
What is the function of platelet derived growth factor in the inflammatory response?
Pull adjacent inflammatory cells into the site of injury
How does a healing tendon differ from a normal tendon?
Fibroblasts synthesise type III collagen which is laid down randomly, not in lines like normal
How is type I collagen created in injured sites?
Intrinsic fibroblasts take over healing process. Make collagen I and reabsorb collagen III. Get vascular in growth
What occurs during the organisation phase of wound healing?
Final stability acquired by normal use of the structure. Cross linking occurs to further increase strength
Why is complete regeneration of a wound never achieved?
The defect remains hyper cellular with thinner collagen fibrils
What are the advantages and drawbacks of early mobilisation of an injury?
Increase ROM, but decrease repair strength
Immobilisation causes increased strength but less ROM
Why are fractures more common in children?
Bones are not as brittle so tend to fracture instead of break
