Lecture 14 Flashcards
(28 cards)
Causes of fractures
- trauma
- osteoporosis
- arthritis
- sarcopenia
- Parkinson’s
Endochondrial fracture repair
Initial response is blood clot formation which quickly stabilises the site and recruits immune cells. Immune cells provide granulation tissue that drives healing process. Mesenchymal stromal cells are recruited that differentiate into chondrocytes which replace blood clot and granulation tissue with cartilage. It gets replaced by bone through endochondrial ossification. It is remodelled into cortical bone. Macrophages, T-cells, monocytes and mesenchymal stromal cells. Osteoblasts form bone at the periphery of the fracture site and chondrocytes proliferate at the fracture sity for stability. Osteoclasts come to remodel cartilage to bone. Also work to shape bone.
cause of impaired healing
open fractures increase infection risk. Too much/too little stability can hinder healing.
Non-union
fracture that won’t heal on its own. Needs medical intervensions. Filled with fibrous tissue that doent fuse with bone.
Hypertrophic
blood supply, but, lack of mechanical stability
atrophic
poor vasculature. not mounting an immune response.
surgical correction of impaired fracture
rod implaced or exernal fixator which facilitates union of fracture site by moving it at rate that stimulates bone healing and straightens the bone. High trauma has extensive soft-tissue damage. can be pinned.
increase fracture with age
In vertebral fractures, fracture risk increases with age. Due to aging population, burden projected to nearly double by 2032.
Physical health
decreases due to chronic pain, decreases mobility. increases dependency on others.
Emotional well-being
Pain and physical = stress incl. anxiety and depression
overall health
decrease overall health
Mortality after hip fracture
mortality in 1st year following hip f is 20%
MSK disease
Affects >1.7B people globally (>7million Aussies) #1 healthcare cost.
osteoarthritis
Greatest contributer to MSK burden. 25% affected struggle with everyday living. No cure or symptom management treatments. Only with increased understanding of the pathophysiology of the disease and its symptomatology can we develop effective-evidence based therapeutics.
Synovial joints
Joint functions through the collaboration of different tissue types. They provide a low friction bearing surface between the bones enabling movement and ambulation while bearing load. Joints are biological systems that allows adaptations to loads and exercises along with the neurological feedback and proprioception in joint provides normal function that cannot be replaced.
bone
rigid, mineralised element that supports load and are moved by muscles in a controlled manner to enable ambulation. Represents continuum for diaphysis -> metaphysis -> subchondrial plate. Very adaptable in response to mechanical loading and systemic Ca2+ P balance and is rapidly remodelled
Cartilage
Lines ands of bones. Resists compressive loads and facilitates low friction movement between bones. Achieved via composition where it is rich in a proteoglycan that absorbs water to form hydrated cushion. It is also plastic, allowing it to return to og shape and gives topographical variation. Avascular and a neural.
synovium/synovial fluid
No basement membrane. Single layer of cells with tight junction (mix of macrophage-like cells therefore, regulate inflammation and fibroblast-like cells that secrete hyleronic acid and lubricin for lubrication). Cells sit on a sub-internal stromal and adipose tissue matrix which is vascularised and has neural input. Layer acts as filtration system. Secretions compose synovial fluid.
joint capsule ligaments
Fibrous layer that defines joint space. Has proximal and distal reflections that accomodate joint movements. Has vessels and nerves. They constrain and regulate range of motion and nerves involved in proprioception and noiciception.
menisci
sit between the tibia and femoral chondyle. Fibrocartilaginous with distinct with distinct regional composition. Inner is certilage-likke (resists compression) and outer is T1 collagen fibres allowing stretch for load. Bone anchorage regulates bone movement and lubricates it.
Nerves
Found in synovial fat-pad capsule, outer meniscus, ligament and bone. Not cartilage. Autonomic and sensory. Provide proprioception and nociception
Muscles
Promotes movement. Feedback through myokines to bone and other fibres.
Osteoarthritus in bone
Increase: bone formation, thickness of subchondrial bone, bone turnover causing decrease in bone mineral density, valculature = pain
areas of necrosis and inflammation. Change load-transmission where cytokines can degrade cartilage.
Osteoarthritus in cartilage
decrease in aggrecan. Collagen breakdown through enzymes which are produced by chondrocytes. Decrease mechanical function and lead-transmission. Break-down products are inflammatory
