T&O: Epiphyseal Growth Plate Fractures

Question 1

What percentage of childhood fractures involve growth plates?

Answer 1

15-30%

Question 2

What are epiphyseal growth plates and why are these vulnerable to fracture?

Answer 2

Are cartilaginous discs separating epiphysis from metaphysis, responsible for longitudinal growth of long bones.

Are last portion of child’s bone to ossify, so particularly vulnerable to fracture.

Question 3

Name the layers of the epiphyseal growth plate. Where do most physeal separations occur?

Answer 3

From epiphyseal side to diaphyseal side:

1. Resting cartilage zone - cartilage attaches to epiphysis
2. Proliferation zone - new cartilage produced via chondrocyte division
3. Hypertrophy zone - chondrocytes mature and enlarge. Most fractures occur here as is least resistant to shearing stress - lacks both collagen and calcified tissue.
4. Calcification zone - matrix is calcified and chondrocytes die

Question 4

In whom are epiphyseal growth plate fractures most likely to occur?

Answer 4

Occur 2x as often in boys as in girls (as epiphyseal fusion terminates earlier in girls).

Incidence peaks in adolescence (10-15yrs).

Question 5

Describe the Salter-Harris classification system.

Answer 5

Type I (Slipped)

• fracture through phsis (epiphyseal slip) separating bone shaft from bone end)
• no fracture fragments
• excellent prognosis, managed non-operatively

Type II (Above growth plate) - most common

• fracture extends through metaphysis
• Thurston Holland fragment
• excellent prognosis, manage non-operatively

Type III (beLow growth plate)

• fracture extends through epiphysis and into joint (intra-articular)
• often unstable - early reduction, often via open surgery, is essential for long-term outcomes
• passes through zones of proliferation and reserve so may cause premature closure of growth plate at fracture site

Type IV (Through everything)

• fracture across metaphysis, physis an epiphysis (intra-articular)
• often unstable - early reduction, often via open surgery, is essential for long-term outcomes
• prone to limb length discrepancy

Type V (ERasure of growth plate)

• crush injury to physis
• prone to limb length discrepancy

Question 6

What is a Buckle fracture?

Answer 6

• small bulge of cortex at junction of dense bone of diaphysis and more porous bone of metaphysis
• most commonly occurs after axial load injury

Question 7

Name 2 complications that can occur as a result of growth plate fractures.

Answer 7

1. bony bridge formation across fracture line, stunting growth of bone or causing bone curvature
2. growth stimulation causing injured bone to be longer than its opposite