Peds Fractures and MSK Injuries
Terms in this set (49)
What are the 3 zones of the growth plate?
- Reserve zone
- Proliferative zone
- Hypertrophic zone
What happens in the reserve zone (resting cartilage) of the growth plate?
stem cells divide to produce chondrocytes, matrix production
Where is the reserve zone found?
on epiphyseal side of growth plate
What happens in the proliferative zone of growth plate?
chondrocytes divide rapidly, cells arranged in longitudinal columns, continued matrix production
What are the 3 sections of the hypertrophic zone of growth plate?
- Maturation zone
- Degenerative zone
- Zone of provisional calcification
What happens in the maturation zone?
mature chondrocytes produce collagen matrix, cells increase in volume (providing longitudinal growth)
What happens in the degenerative zone?
cells begin to degenerate and produce chondrocalcin to prepare cartilage for mineralization
What happens in the zone of provisional calcification?
cells continue to hypertrophy and die when they reach end of growth plate. Cartilage matrix calcified.
What are the 2 zones of the metaphysis?
- Primary spongiosa
- Secondary spongia
What happens in the primary spongiosa?
vascular invasion of calcified cartilage, woven bone formation
What happens in the secondary spongiosa?
remodelling: funnelization, replacement of woven bone with lamellar bone
What is significant about the blood supply to the physis?
Physis is a barrier to intraosseous blood flow so epiphysis and metaphysis have separate blood supply in kids
- increased risk of avascular necrosis
Do bone lesions cross the physis?
Benign bone lesions DON'T cross physis! Malignant ones can
In kids, what is stronger- ligaments or physis? WHat's the significance of this?
ligaments. Trauma is more likely to cause fracture than dislocation/sprain
The __________________ anchors the epiphysis to the metaphysis
Traction injuries (e.g. child abuse) can cause _____________
Speed of healing is faster the ________________ a chid is
Permanent damage of the physis can lead to ___________________
What is the Heuter Volkmann principle? What is it important for?
In growth plate, increase pressure inhibits growth and decreased pressure stimulates growth. Important for re-orienting joint.
What is Wolff's law? What is it important for?
In diaphysis, increased pressure (compression) stimulates growth and decreased pressure (tension) inhibits growth. Important for straightening the shaft after a break.
Bone remodelling is greatest when? (3)
- Significant growth remaining
- Fracture closer to growth plate
- Deformity in plane of joint movement
Bone remodelling is not helpful for correcting? (4)
- Displacement in intra-articular fractures
- Marked shortening (>1-2cm)
- Deformity in right angles to plain of movement
What is the fastest growing growth plate?
Damage to growth plate resulting in a large central or complete growth arrest can lead to what?
Progressive limb length discrepancy
Damage to growth plate resulting in partial peripheral growth arrest can lead to what?
progressive angular deformity (bone grows valgus or varus because one side of bone stops growing)
A bony bar (fracture across growth plate) can lead to what?
joint incongruity and angular deformity
Salter harris classifications
- Type 1: straight across growth plate
- Type 2: through physis and up to metaphysis
- Type 3: through physis down the epiphysis
- Type 4: through metaphysis, physis and epiphysis
- Type 5: compression injury
What is the most common type of salter harris fracture?
Management of salter harris type 1 or 2 fracture and prognosis
Closed reduction +/- internal fixation + casting, excellent prognosis
Potential complications of SH type 1 or 2 fracture
growth arrest (rare)
Management of salter harris type 3 or 4 fracture
open reduction and internal fixation
Potential complications of SH type 3 and 4 fractures (3)
- Joint incongruity
- Growth arrest
- Progressive deformity
Management of salter harris type 5 fracture
Conservative with prolonged observation
Complications of salter harris type 5 fracture
Growth arrest-->angular deformity, +/- progressive limb length deformity
Do you need to do a closed reduction in a child with a diaphysial fracture?
What does SCFE stand for?
Slipped Capital Femoral Epiphysis
What is SCFE?
displacement of proximal femur epiphysis with respect to metaphysis (epiphysis slips posteriorly and inferiorly
Classic SCFE patient
peripubertal (age 11-14) male, obese
If a child presents with knee pain, what must you do?
Presentation of SCFE (4)
- Knee or hip pain
- Decreased hip ROM (especially flexion and internal rotation)
- Can get arthritis if you miss it
What does SCFE look like on lateral X-ray?
ice cream slipping off cone
What does SCFE look like on AP X-ray
Abnormal Klein's line.
(Klein's line: a line drawn along lateral border of femoral neck should intersect with proximal femoral epiphysis in normal person)
Treatment for SCFE
in situ screw fixation along proximal femoral physis
Complications of SCFE (2)
- Risk of contralateral slip
Majority of non-accidental injuries occur in kids of what age?
Fracture is present in ______% of non accidental injuries
Fracture in non accidental injury has ___% mortality
Management of non-accidental injury (3)
- Detailed history and precise documentation
- Expert examination
- Radiographic skeletal survey
Fractures that suggest non-accidental injury (6)
- Multiple fractures in different stages of healing
- Injury not consistent with child's mobility or described mechanism
- Rib (especially posterior)
- Spiral shaft (long bones)
- Metaphyseal bucket handle (traction injury)
- Metaphyseal corner (traction injury)