General Trauma Master Deck Flashcards
Different classifications of fractures?
Direct trauma, e.g: direct blow, OR indirect trauma (majority), e.g: twisting/bending forces
Partial/incomplete OR complete
High-energy OR low-energy
Describe primary bone healing and when it occurs
Occurs where there is minimal fracture gap (< 1mm), e.g: hairline fractures and when fractures are fixed with compression screws and plates
Bone bridges the gap with new bone
Describe secondary bone healing and when it occurs
Majority of fractures have a gap that needs to be temp. filled to act as a scaffold for new bone
Inv. an inflammatory response with recruitment of pluripotential stem cells, which differentiate
Fracture process of secondary bone healing?
- Fracture occurs and haematoma forms, with inflammation from damaged tissues
- Macrophages and osteoclasts remove debris and resorb the bone ends
- Granulation tissue forms from fibroblasts and new blood vessels
- Chondroblasts form cartilage (soft callus) and osteoblasts lay down bone matrix (collagen type 1)– enchondral ossification
- Calcium mineralisation produces immature woven bone (hard callus)
- Remodelling occurs with organization along lines of stress into lamellar bone
Time period in which soft and hard callus appear?
Soft callus usually forms by 2nd-3rd week
Hard callus takes approx. 6-12 weeks
Requirements for secondary bone healing?
Good blood supply for oxygen, nutrients and stem cells
A little movement/stress (compression or tension)
What factors may result in atrophic non-union?
Lack of blood supply
No movement (internal fixation with fracture gap)
Too large a fracture gap
Tissue trapped in the fracture gap
Smoking may severely impair fracture healing due to vasospasm; vascular disease, chronic ill health and malnutrition also impair fracture healing
Cause of hypertrophic non-union?
Occurs due to excessive movement at the fracture site; there is abundant hard callus formation too much movement gives the fracture no chance to bridge the gap
5 fracture patterns?
- Transverse fractures
- Oblique fractures
- Spiral fractures
- Comminuted fractures
- Segmental fractures
Describe a transverse fracture
Occur with PURE BENDING force (cortex on one side fails in compression and the cortex on the other side in tension)
May not shorten (unless completely displaced) but may angulate or result in rotational malalignment
Describe an oblique fracture
Occurs with a SHEARING force, e.g: fall from height, deceleration; they tend to shorten and may angulate
They can be fixed with an interfragmentary scews
Describe a spiral fracture
Occurs due to TORSIONAL forces; they are most unstable to rotational forces but they can also angulate
Interfragmentary screws can be used
Describe a comminuted fracture
Fracture with 3/more fragments and tend to occur with HIGH-ENERGY injuries (or POOR BONE quality); very unstable and tend to be surgically stabilised
There may be soft tissue damage and periosteal damage with reduced blood supply to the fracture site which may impair healing
How to describe a fracture of long bone?
According to the site of the bone inv.:
• Proximal, middle or distal 1/3rd
OR
• Diaphyseal (shaft), metaphyseal or epiphyseal
How to describe a fracture at the end of a long bone (metaphyseal/epiphyseal)?
Can be:
• Intra-articular - greater risk of stiffness, pain and post-traumatic OA, part. if there is residual displacement resulting in an uneven articular surface
• Extra-articular
What is displacement?
Direction of translation of the distal fragment; described as:
• Anteriorly or posteriorly displaced (in the forearm and hand, volar/palmar and dorsal
• Medially or laterally displaced (ulnar and radial)
Can be estimated with reference to the width of the bone, e.g: 25%; 100% displacement means “off-ended” bone
What is angulation?
Direction in which the distal fragment points towards and the degree of this deformity:
• Medial or lateral (radial or ulnar; in the lower limb, varus and valgus are used)
• Anterior or posterior (volar or dorsal)
Clinical signs of a fracture?
- Localised bony tenderness that is marked (not diffuse mild tenderness)
- Swelling
- Deformity
- Crepitus (bone ends grate in an unstable fracture)
Useful rule when deciding whether to X-ray the lower limb for a fracture?
Inability to weight-bear
Steps in the assessment of an injured limb?
- Open/closed
- Distal neurovascular status (pulses, CRT, temp, colour, sensation, motor power)
- Check for compartment syndrome
- Assess the status of the skin and soft tissue envelope
Methods of Ix for a fracture?
X‐ray (must have 2 views) - usually an AP and lateral view; oblique views can be useful for complex shaped bones (e.g: scaphoid, acetabulum, tibial plateau)
Tomogram (historic)
CT scan - for complex bones and for assessment of articular damage
MRI - for occult fractures that are suspected despite a normal X-ray
Technetium bone scans - to detect stress fractures that may not show up on X-ray until a hard callus forms
Initial Mx of a long bone fracture?
Analgesia (IV morphine), splintage/immobilisation of the limb and Ix (X-rays)
Reduction is performed before X-ray if:
• Fracture is obviously grossly displaced
• Obvious fracture-dislocation
• Risk of skin necrosis from excessive pressure
What does splintage or immobilisation involve?
- Temporary plaster slab (AKA backslab)
- Sling
- Orthosis
- Thomas splint (for femoral shaft fractures)
Definitive fracture Mx for different types of fractures?
Undisplaced, minimally displaced and minimally angulated fractures that are stable:
• Non-operative Mx with a period of splintage/immobilisation followed by rehab
Displaced OR angulated fractures where the position is unacceptable:
• Reduction under anaesthetic; closed reduction and cast application can be used with serial X-rays to ensure no loss of position
• Unstable injuries can have surgical stabilisation
Tools used for surgical stabilisation of an unstable injury?
- Small percutaneous wires (K-wires) for small fragments
- Screws OR plates and screws
- IM nails
- External fixation
Definitive Mx of an extra-articular diaphyseal fracture?
Open reduction and internal fixation (ORIF) using plates and screws
Aim is primary bone healing
When should ORIF be avoided?
- Too much soft tissue swelling
- Blood supply to the fracture site is tenuous (high-energy)
- If ORIF may cause extensive blood loss, e.g: femoral shaft
- Where plate fixation may be prominent, e.g: tibia
Alternative to ORIF?
Closed reduction and indirect internal fixation, with an IM nail; aim is functional reduction and stable fixation allowing micromotion required for secondary bone healing
Another alternative is external fixation; aim is secondary bone healing
Risks of external fixation?
Pin site infection and loosening
Definitive Mx of a displaced intra-articular fracture?
Anatomic reduction with rigid fixation with ORIF
Fractures of a joint with a predictable poor outcome can undergo joint replacement or arthroidesis
Problems with treatment of fractures in elderly patient?
May have co-morbidities, osteoporosis and dementia; they have a higher risk of surgical complications, failure of fixation and failure to rehab satisfactorily
Tend not to have as high a functional demand and so more likely to be treated non-operatively
Early local complications of fractures?
- Compartment syndrome
- Vascular injury with ischaemia
- Nerve compression/injury
- Skin necrosis
Early systemic complications of fractures?
- Hypovolaemia and shock
- Fat embolism
- Acute renal failure
- ARDS, SIRS and MODS
Late local complications of fractures?
- Stiffness and loss of function
- Chronic Regional Pain Syndrome (CRPS)
- Infection
- Non-union
- Malunion
- Volkmann’s ischaemia contracture
- Post-traumatic OA
- DVT
Late systemic complications of fractures?
PE (tends to occur several days-weeks after injury but may occur within a day)
Describe compartment syndrome
Groups of muscles are bound in tight fascial compartment with limited capacity for swelling
Bleeding and inflammatory exudate cause pressure rise and compression of the venous system, resulting in congestion within the muscle; secondary ischaemia occurs as arterial blood cannot supply the congested muscle, so muscle ischaemia occurs
Symptoms and signs of compartment syndrome?
Pressure can compress nerves, causing paraesthesiae and sensory loss
Cardinal clinical signs:
- Increased pain on passive stretching of the inv. muscle
- Severe pain outwith the anticipated severity in the clinical context (disproportionate)
Limb is tensely swollen and muscle is tender to touch
Loss of pulses is a feature of end-stage ischaemia (late diagnosis)
Treatment of compartment syndrome?
Removal of any tight bandages can cause temporary relief
Emergency fasciotomy; the open wound is left for a few days before secondary closure (may require split skin grafting)
Complications of untreated ischaemic muscle in compartment syndrome?
Necrosis occurs, resulting in fibrotic contracture (AKA Volkmann’s ischaemia contracture) and poor function
Types of nerve injury?
- Neurapraxia
- Axonotmesis
- Neurotmesis
What is neurapraxia?
Nerve has a temporary conduction defect from compression/stretch and resolve over time with full recovery (up to 28 days)