O&T: Childhood Injuries Flashcards
Childhood injury and Paediatric fractures
Childhood injuries:
- Common
- Related to socioeconomic factors:
1. Low family income
2. Poor education level
3. Big family structure
4. Poor accommodation
Paediatric fractures:
- 50% death in children <14 are related to trauma
- 15% childhood injuries involve musculoskeletal system
- most paediatric trauma are **single limb, **low energy injuries
- ***Upper limb fracture > Lower limb fracture
- basic principles of fracture treatment ~ adults
- differences in
1. Anatomy
2. Biomechanical properties of bone
3. Physiology of bone healing
- Anatomical difference
-
**Bone less dense, more porotic, more vascular, thinner cortex, presence of physis
- **less force required for fracture to occur
- fracture more common than dislocation
- fracture heals ***faster -
**Periosteum is thicker, stronger, more vascular (periosteum: contain osteoprogenitor cells —> osteoblasts for growth, remodeling, repairing of bone —> diameter growth of bone)
- form **callus quicker
- good soft tissue ***splintage - Presence of **growth centres (physis + secondary ossification centres)
- physeal injury —> growth arrest resulting in shortening / angular deformity
- ossification centres in elbow (temporal appearance sequence: **CRITOE) (2, 4, 6, 8, 10, 12 (SpC C Fang Revision))
—> Capitellum (1 yo) (2 yo)
—> Radial head (3 yo) (4 yo)
—> Internal (Medial) epicondyle (5 yo) (6 yo)
—> Trochlea (7 yo) (8 yo)
—> Olecranon (9 yo) (10 yo)
—> External (Lateral) epicondyle (11 yo) (12 yo)
- Biomechanical differences
- **Weaker bone —> **Less energy needed to cause a fracture
- Bone more **elastic with thick periosteum resulting in
- **Greenstick fracture (bone bends and cracks, instead of breaking completely into separate pieces)
- **Plastic deformation (deform without fracture)
- **Torus (Buckle) fracture (incomplete fractures of shaft of a long bone that is characterised by bulging of the cortex) - Ligament injury less common
- Physiological differences
- More ***rapid healing of fractures
- physis > metaphysis > diaphysis - May result in **growth acceleration
- more obvious in proximal tibia + femur
- **shortening allowed during treatment of fractures to prevent overgrowth phenomenon - Good **remodeling power according to the **plane of adjacent joint (e.g. flexion deformity in distal femur —> can be corrected, but valgus deformity cannot be corrected ∵ not in same plane as knee joint)
- allow deformed bone to remodel itself into normal shape
Growth centres / plate
- Special piece of cartilage
- At 2 ends of bones
- Appear at different time point of age
- Each growth centres contribute to different degrees to bone growth
—> e.g. 80% of humerus growth from proximal growth centre, 20% from distal growth centre
—> e.g. 30% of femur growth from proximal growth centre, 70% from distal growth centre
4 zones:
1. Reserve / Resting zone
- cells remain dormant until they divide + proliferate
- tissue bank: growth plate retain ability to divide + grow
- damage —> non-functional growth plate —> ***grow arrest / deformity / leg-length discrepancy
- Proliferative zone (new cell production)
- Hypertrophic zone (chondrocytes enlargement in growth direction)
- **most commonly injured (∵ **transition point between most mobile segment of growth plate and most rigid area of zone of endochondral ossification)
—> but resting zone not damaged
—> not affect bone growth - Calcification zone (endochondral ossification)
Physeal injury: ***Salter-Harris classification
- Resting zone located near to epiphysis than metaphysis
Type 1:
- Separation of epiphysis from metaphysis
- Mild displacement
- Intact periosteum
- ***Resting zone untouched —> Good prognosis
Type 2:
- Epiphysis-metaphysis separation
- Intact epiphysis, fragment of metaphysis attached
- Strain / Torn epiphyseal periosteum
- ***Resting zone untouched —> Good prognosis
Type 3:
- Physeal separation associated with epiphyseal fracture
- Intra-articular fracture
- Fracture through germinal layer (resting zone)
- ***Resting zone damaged —> Good prognosis with treatment
Type 4:
- Extended from metaphysis across growth plate into epiphysis
- ***Resting zone damaged —> Good prognosis with treatment
Type 5:
- Crush fracture of a part / whole physis from compression
- ***Resting zone damaged —> Poor prognosis
End result of physeal injury:
- Resting zone damaged (**Type 3-5: injury extending to epiphysis)
—> scarring in growth plate
—> formation of vertical septa
—> structural disorganisation
—> **bone bridge / **bone bar formation (depend on location + size: **eccentric location + large size —> deformity)
—> growth arrest / deformity / leg-length discrepancy
- Resting zone undamaged
—> great remodeling potential
**Remodeling of bone + **Consideration of fracture management in children
Complex process involving balance between bone formation + resorption
Depends on:
1. Endochondral
2. Periosteal bone formation
3. Integrated resorption
Paediatric fractures have high remodeling ability
—> Acceptable limit of deformities is based on anticipated remodeling
1. **Child’s age / growth potential remaining
2. **Distance of fracture from end of bone / physis —> closer to physis —> better remodeling
3. **Longitudinal growth potential of that physis (e.g. proximal humerus growth centre)
4. **Angulation amount + direction
—> When closer to skeletal maturity —> require Better anatomical reduction + More stable fixation
Diagnosis of fracture in children
- Difficult
- X-ray require 2 views
- may need MRI
Management of fracture in children
Difficult:
1. Nervous child
2. Unable to give good history
3. Uncooperative in P/E
4. Anxious parents
Initial assessment:
1. ABCDE (beware of differences in vitals in different age group: faster HR, lower BP, higher RR)
2. Investigations
3. Fracture assessment
- Adequate exposure of fracture site
- Look out for associated soft tissue injuries
—> Rule out **open fracture / open wound
—> Skin blistering / abrasions / necrosis
—> **Skin impingement by bone ends
—> Subcutaneous swelling
—> **Neurovascular injury
—> **Compartment syndrome
- Reduction if necessary (Pain control + Anaesthesia)
- Open / Closed reduction - Immobilisation if necessary
- Cast / External / Internal fixation - Rehabilitation always
X-ray examination
- Confirm fracture
- Configuration of fracture
- Low energy trauma: Spiral / Oblique / Transverse
- High energy trauma: Butterfly / Comminuted
- Greenstick / Torus / Plastic deformation - Alignment of fracture
Fixation methods in children
More conservative treatment ∵
- Good healing + remodeling potential
- Relatively less post-op contracture
Smaller deformities:
1. **Traction
2. **Plaster
Larger deformities / Skeletal more mature:
3. K-wire fixation
4. Plate
5. External fixator
6. Intramedullary devices
Supracondylar fracture of humerus
- Often 6-7 yo
- Involves thin bone between **coronoid fossa and **olecranon fossa of distal humerus (Dumbbell shape shown in cross section)
—> ***Dumbbell configuration make fracture unstable
—> Very often have deformity in displaced fracture
Complications:
1. **Vascular injuries
2. **Neurologic deficits (esp. **Anterior interosseous nerve)
3. **Cubitus varus / Recurvatum
4. **Volkmann’s contracture
5. **Compartment syndrome
Classification:
1. Extension (95%) (i.e. distal humerus向後彎)
- fall on outstretched hand —> ∵ laxity of elbow —> hyperextend
- associated with more complications (e.g. neurovascular injuries ∵ most are located **anterior to humerus —> impinged by fracture ends)
- most displaced fractures (Type 3) are extension type (97%)
- **Gartland classification
—> **Undisplaced (type 1): Conservative with cast
—> **Displaced with intact posterior cortex (Type 2): Surgery needed
—> ***Displaced with no cortical contact (Type 3): Surgery needed
- Flexion
- fall on flaccid elbow
Assessing whether fracture is displace or not:
1. ***Baumann angle (~10o)
- angle made by capitellum and horizontal plane of distal humerus —> normal carrying angle of forearm
- ***Anterior humeral line
- line along anterior cortex of humerus —> should intersect with capitellum
Neurological injury
E.g. assess by paper, scissors, stones —> assess flexors innervated by median nerve, extensors by radial nerve
- MUST before operation
- Difficult to examine
- May not be able to identify
- Detailed documentation
- Majority due to ***neurapraxia (~ several weeks to recover)
- Generally not considered an indication for open reduction / exploration
Deformities: Cubitus varus, Cubitus recurvatum, Volkmann’s contracture
Malalignment:
- Although rotational deformity can be compensated by shoulder
—> Remodeling is usually suboptimal
—> NOT acceptable
Deformity due to ***Poor remodeling power:
1. Physis in distal humerus only contribute 20% of growth
2. Hinge joint —> most Supracondylar fracture of humerus will lead to Cubitus varus —> direction of deformity not favour remodeling
Cubitus varus:
- Most common complication
- Resulted from:
1. Physeal damage
2. Malreduction —> Malunion
- Cosmetic deformity but little functional deficit
Cubitus recurvatum:
- Result from **residual dorsal angulation of fracture —> **Hyperextension deformity of elbow
Volkmann’s contracture:
- A form of Compartment syndrome
- Loss of motor / sensory function, claw hand deformity
Causes:
- **Brachial artery injury usually associated with supracondylar fracture of humerus
- **Hyperflexion of cast —> now if need to hyperflex elbow for immobilisation —> use internal fixation instead of hyperflexion of cast
(Claw hand: (from web)
- Ischaemia + necrosis of forearm muscles —> contracture
—> Wrist flexed ∵ bulkier flexors —> more contracture
—> MCP extended ∵ Insertion of extensor tendons
—> IP joints flexed ∵ insertion of long flexor tendons)
P/E of Supracondylar fracture of humerus
- Swelling + Tenderness of forearm compartments (potential site of compartment syndrome)
- ***“Dimple sign”
- occurs when a spike of bone penetrates brachialis muscle + anterior SC tissues —> catches on skin -
**Neurovascular injuries
- need to rule out
- check + check + check **radial pulse repeatedly —> Intimal arterial injury can occur slowly over several hours - ***Compartment syndrome
- need to rule out - Associated injury
