Fractures Flashcards
(36 cards)
Define fracture
Breach in continuity of bone
Why do fractures occur
Non-physiological loads applied to normal bone
Physiological loads applied to abnormal bone
Imbalance between force applied to bone and ability of bone to resit this
What are the reasons for fractures in abnormal bones
Tumour
- benign
- malignant
- metastatic
Metabolic bone disease
- osteoporosis
- Paget’s disease
- Osteogenesis imperfecta
How do you describe fractures
Site
Pattern
Displacement/angulation
Joint involvement
Skin involvement
How do you describe the site of a fracture
Bone
Part of bone
- proximal 1/3
- middle 1/3
- distal 1/3
What are the different patterns of fractures
Transverse
Oblique
Spiral
Comminuted
Segmental
Avulsed
Impacted
Torus
Greenstick
How do you describe displacement/angulation of fractures
Displacement %
Angulation - of distal part
How do you describe joint involvement in fractures
Extra-articular - does not involve the joint
Intra-articular - involves the joint (damage to the cartilage)
Fracture which involves the joint is more likely to cause a problem
What are the different types of fractures - skin involvement
Open/close
Describe open fracture
Breach in the skin with communicates with breaks (bone of the fracture is involved with the air)
- orthopaedic emergency
- required urgent treatment
- soft tissue injury determines outcome
How are fractures different in children
Epiphyses open and bone more ‘plastic’
Heal quickly
Increase deformity remodelling
What are the stages of fracture healing
Haematoma (hours)
Inflammation (days)
Repair (weeks)
Remodelling (months to years)
Describe haematoma stage
Bleeding - endosteal and periosteal vessels, muscles etc.
Decreased blood flow
Periosteal stripping
Osteocyte death
Describe inflammation stage
Fibrin clot organisation - platelets rich in chemo-attractants
Neovascularisation
Cellular invasion
Describe cellular invasion during inflammation
Haematopoietic cells
- clear debris
- express repair cytokines
Osteoclasts
- reabsorb dead bone
Mesenchymal stem cells
- building cells for repair
Describe repair stage
‘Callus’ formation
Progressive matrix mineralisation
High vascularity
Describe ‘Callus’ formation
Fibroblasts produce fibrous tissue (high strain)
Chondroblasts from cartilage (strain <10%)
Osteoblasts form osteoid (strain <1%)
Describe remodelling stage
Woven bone structure replaced by lamellar bone - osteonal remodelling
Increased bone strength
Vascularity returns to normal
Healing without scar - unique
What are the principles of fracture remodelling
Reduce (the fracture)
Immobilise (the part)
Rehabilitate (the patient)
What are the types of fracture fixation
Slings
Casts and splints
Extra-medullary device - plates and screws
Intra-medullary device - nails
External fixation
What are the three main factors which influence fracture healing
Patient
Tissue
Treatment
How does the patient effect fracture healing
Age
Nutrition
Smoking
Drugs e.g. NSAIDs, steroids
How does tissue influence fracture healing
Bone type - cancellous vs. cortical
Bone site - upper limb vs. lower limb
Vascularity/soft tissue damage
Bone pathology - breaks in metastatic deposit does not heal
Infection
How does treatment influence fracture healing
Apposition of fragments
Stability - ability to resist force without deforming
Micromotion (<1mm)
