T&O - Bone And Fracture Pathophysiology Flashcards
Outline the 5 phases of fracture healing
Reactive Phase (injury – 48hrs)
- Bleeding into fracture site → Haematoma
- Inflammation → cytokine, GF and vasoactive mediator release → recruitment of leukos and fibroblasts → Granulation Tissue
Reparative Phase (2 days – 2 wks)
- Proliferation of osteoblasts and fibroblasts → cartilage and woven bone production → Callus Formation. (fibrocartilagionous + osteocallus)
- Consolidation (endochondral ossification) of woven bone → Lamellar bone
Remodelling Phase (1wk – 7yrs)
- Remodelling of lamellar bone to cope with mechanical forces applied to it (Wolff’s Law: “form follows function”)
Outline healing time for different fractures/locations
- Closed, paediatric, metaphyseal, upper limb: 3 weeks
- “Complicating factor” doubles healing time: Adult, Lower limb, Diaphyseal, Open
Outline the fracture classification (3 main types)
Traumatic fracture
- Direct: e.g. assault withmetal bar
- Indirect: e.g. FOOSH → clavicle fracture
Avulsion Stress Fracture
- Bone fatigue due to repetitive strain g.g. foot fractures in marathon runners
Pathological #
- Normal forces but diseased bone
- Local: tumours
- General: osteoporosis, Cushing’s, Paget’s
Describing a fracture: Demographics, pattern and anatomical location
Must always state:
- Radiographs must be orthogonal: request AP and lat. films.
- Need images of joint above and joint below for fractures.
- Demographics:
- Pt details
- Date taken
- orientation and content of image
- Anatomical location
- What are you looking at?
Describing a fracture: intra/extra articular, deformity, soft tissues
- Intra/extra articular: dislocation or subluxation?
- Deformity (distal relative to proximal): translation, angulation or tilt, rotation, impaction
- Soft tissues: open or closed (can’t always tell), neurovascular status, compartment syndrome
Describing a fracture: specific fracture classification type
- Salter Harris
- Garden
- Colle’s
- Smith’s
- Galeazzi
- Monteggia
- Weber
Fracture management: what are the 4 Rs?
- Resuscitation
- Reduction
- Restriction
- Rehabilitation
Resuscitation: principles
- Deal with associated life threatening injuries first
- Assess neurovascular status
- ABX started
- Wound washed out/dead tissue debriefed
- Fractures that need urgent treatment: life threatening, fracture dislocations, open fractures
Reduction: principles
- Not all fractures require reduction (eg no displacement or displacement unlikely to affect final result)
- Decision is based on balance between function and acceptable appearance
- Manipulation (closed reduction): local/GA
- Distal fragment pulled in line
- Traction: need to overcome large forces of muscle, can be skin or skeletal
- Open reduction: usually after failure of above methods
- usually needs ORIF (open reduction and internal fixation)
Restriction: principles
Must be held in right position to heal. Unstable require much splinting + stable usually splinted anyway
- Plaster fixation: most common is Plaster of Paris - first 24-48h have back slab to accommodate for any early swelling - can then complete it or put initial split plaster
- Functional bracing: joints can move (with hinges) but upper and lower segments casted
- Continuous traction: not really used anymore b/c significantly reduced mobility
- Ex-fix: bones held in place by pins inserted through skin and bone - joined together with external mechanical support (high infection risk)
- Internal fixation: pins, plates, screws or large intramuscular nails hold bony fragments in position
Restriction: principles and methods
Principles
- Immobility → ↓ muscle and bone mass, joint stiffness
- Need to maximise mobility of uninjured limbs
- Quick return to function decreases later morbidity
Methods
- Physiotherapy: exercises to improve mobility
- OT: splints, mobility aids, home modification
- Social services: meals on wheels, home help