|
https://upload.orthobullets.com/topic/4002/images/salter_2.jpg
https://upload.orthobullets.com/topic/4002/images/Histology of zones_moved.jpg
https://upload.orthobullets.com/topic/4002/images/forearm greenstick fx (medcyclopaedia.com).jpg
https://upload.orthobullets.com/topic/4002/images/wrist move (midfordathleticclub.org).jpg
https://upload.orthobullets.com/topic/4002/images/ring.jpg
https://upload.orthobullets.com/topic/4002/images/perichondral artery.jpg

Introduction
  • Always look to see if physis is open
  • Unique principals in pediatric bone
    • elasticity
      • more elastic which leads to unique fracture patterns
        • buckle fractures
        • greenstick fractures
    • remodeling potential
      • open physes (growth plates) can allow extensive bone deformity remodeling potential
      • occurs more rapidly in plane of joint motion
        • sagittal plane in wrist, due to primarily extension/flexion
      • occurs more at the most active physes, due to most growth and potential for remodeling
        • most active physes in upper extremity
          • proximal humerus 
          • distal radius
        • most active physes in lower extremity
          • distal femur 
          • proximal tibia
  • Same principles as adult bone
    • intra-articular fractures must be reduced
 Physeal Anatomy
 
Physeal Growth Plate
(letters on left correspond to histology in top right)
B. Reserve zone
  • Cells store lipids, glycogen, and proteoglycan aggregates for later growth and matrix production
  • Low oxygen tension


  • Gaucher's
  • diastrophic dysplasia
  • Kneist
  • pseudoachondroplasia
C. Proliferative zone
  • Proliferation of chondrocytes with longitudinal growth and stacking of chondrocytes.
  • Highest rate of extracellular matrix production
  • Increased oxygen tension in surroundings inhibits calcification


  • Achondroplasia
  • Gigantism
  • MHE
D. Hypertrophic zone
  • Zone of chondrocyte maturation, chondrocyte hypertrophy, and chondrocyte calcification.
  • Three phases occur in the hypertrophic zone
    • Maturation zone: preparation of matrix for calcification, chondrocyte growth
    • Degenerative zone: further preparation of matrix for calcification, further chondrocyte growth in size (5x)
    • Provisional calcification zone: chondrocyte death allows calcium release, allowing calcification of matrix
  • Chondrocyte maturation regulated by local growth factors (parathyroid related peptides, expression regulated by Indian hedgehog gene)
  • Type X collagen produced by hypertrophic chondrocytes important for mineralization


  • SCFE (not renal)
  • Rickets (provisional calcification zone)
  • Enchondromas
  • Mucopolysacharide disease
  • Schmids
  • Fractures most commonly occur through hypertrophic zone


E. Primary spongiosa
(metaphysis)
  • Vascular invasion and resorption of transverse septa.
  • Osteoblasts align on cartilage bars produced by physeal expansion. 
  • Primary spongiosa mineralized to form woven bone and then remodels to become secondary spongiosa (below)
  • Metaphyseal "corner fracture" in child abuse
  • Scurvy
Secondary spongiosa
(metaphysis)
  • Internal remodeling (removal of cartilage bars, replacement of fiber bone with lamellar bone) 
  • External remodeling (funnelization)
  • Renal SCFE
Physis Periphery
Groove of Ranvier
  • During the first year of life, the zone spreads over the adjacent metaphysis to form a fibrous circumferential ring bridging from the epiphysis to the diaphysis. 
  • This ring increases the mechanical strength of the physis and is responsible for appositional bone growths
    • supplies chondrocytes to periphery

 

  • Osteochondroma

 

Perichondrial fibrous ring of La Croix

  • Dense fibrous tissue that is the primary limiting membrane that anchors and supports the physis through peripheral stability
 

 

  • Perichondrial artery 
    • major source of nutrition to physis 
Injury Classification
  • Salter-Harris classification
    • Type 1-  physeal separation
    • Type 2- fracture traverses physis and exits metaphysis
      • most common type
      • Thurston Holland fragment
    • Type 3- fracture traverses physis and exits epiphysis
    • Type 4- fracture passes through epiphysis, physis, metaphysis
      • Thurston Holland fragment
    • Type 5- crush injury to physis
Treatment
  • Closed reduction vs. CRPP vs Open reduction
    • depends on injury pattern
    • intra-articular fractures must be reduced
Complications
  • Growth arrests
    • overview
      • complete arrest leads to shortening
        • see Leg Length Discrepancy topic
      • partial arrest leads to angulation
    • treatment
      • bar resection with interposition
        • indications
          • < 50% physeal involvement
          • > 2 years or 2cm growth remaining
      • ipsilateral completion of arrest
        • indications
          • > 50% physeal involvement
          • can combine with contralateral epiphysiodesis and/or ipsilateral lengthening
 

Please rate topic.

Average 3.6 of 33 Ratings

Questions (9)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(OBQ04.234) Growth at the distal humerus physis accounts for what percentage of humeral length? Review Topic

QID: 1339
1

20%

77%

(857/1106)

2

40%

9%

(97/1106)

3

50%

1%

(8/1106)

4

60%

6%

(69/1106)

5

80%

6%

(69/1106)

Select Answer to see Preferred Response

PREFERRED RESPONSE 1
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
ARTICLES (10)
VIDEOS (2)
GROUPS (1)
Topic COMMENTS (16)
Private Note