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Flashcards in MSK Deck (359)
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1

Epiphysis are initially ______

Cartilaginous, converting to bone with development of secondary ossification center

2

Primary physis is responsible for

Longitudinal growth of the bone

3

Secondary physis is responsible for

Spherical growth of epiphysis

4

What are the characteristics of pediatric bone as compared to adults

Less dense, more porous and have lower mineral content compared with adults

5

Due to pediatric bones characteristics, it can undergo a greater degree of deformation before breaking. Therefore, what fractures are common in pedia population

Greenstick (unicortical) and torus (buckle) fractures, as well as plastic deformation, complete fractures and physeal injuries

6

In newborn, bone marrow is entirely

Hematopoietic (red marrow)

7

Bone marrow transformation to fatty (yellow) marrow begins when

Within the first year of life and occurs in a predictable manner

8

In the body as a whole, marrow transformation begins where

In the periphery, first occurring in the phalanges of the fingers and toes and progressing centrally

9

Order of fatty marrow conversion of epiphysis, metaphysis and diaphysis

Epiphyses are first to convert, occurring within 6 months of radiologic appearance of secondary ossification center, continues within diaphysis, followed by metaphysis, with the proximal metaphysis the last to convert

10

On MR, the physis has a ______ appearance

Trilaminar appearance

11

The trilaminar appearance of physis in MRI consists of:

Zone of cartilage- active chondrocytes;
Zone of provisional calcification- cartilage matrix become calcified;
Primary spongiosa- where woven bone is formed

12

Fibrocartilaginous structure that surrounds the physeal cartilage, low signal on all sequences. This is tightly tethered to the physis and acts as a barrier to disease

Perichondrium

13

A thin low SI structure that parallels bone cortex and is loosely attached to the shaft and tightly attached to the perichondrium. Deep to this structure is a rich vascular network that helps to feed the growing metaphyses

Periosteum

14

This fracture occurs from longitudinal stress and results in bowing of the bones, with an intact periosteum

Plastic deformation

15

Plastic deformation are common in

Forearm, tibia, fibula

16

Fractures that results from axial loading on an extremity, occurring at the metaphysis or metadiaphysis. The cortex is compressed and bulges without extension of the fracture to the cortex

Buckle or torus fracture

17

Represent 50% of pediatric wrist fractures

Buckle fracture

18

Incomplete fractures resulting from perpendicular forces that break one cortex, the side opposite the site of stress

Greenstick fractures

19

Most vulnerable to injury during periods of active growth, such as during early adolescence

Cartilage

20

Weakest portion of the physeal cartilage

Zone of provisional calcification

21

Pathophysiology of chronic physeal trauma

Repetitive loading can alter metaphyseal perfusion and interfere with the mineralization of hypertrophied chondrocytes

22

In high intensity runners, chronic physeal injury are common in _____, while in baseball players its common in the ______ which is called little league shoulder and in the _______ in gymnasts (gymnast wrist)

Knees- runners
Proximal humerus- baseball players
Distal radiu- gymnast

23

Manifests radiographically as widening of the primary physis, with sclerosis at the margins of adjacent metaphysis

Chronic physeal trauma

24

A subset of physeal injuries (either sequela of trauma, infection or ischemia) can lead to cellular disruption and ischemia, giving rise to the development of abnormal osseous connection (bone bridge or bar) between epiphysis and metaphysis. These bone bars can result in limb length discrepancy, angular deformity, or altered joint mechanics

Physeal bars

25

The incidence of physeal bar formation is higher after injuries to the

Distal femur, proximal tibia and distal tibia

26

These areas contribute to the greatest proportion of limb growth, and therefore, bars in these regions have the biggest impact on limb length discrepancies

Distal femur and proximal tibia

27

Salter harris type: separation thru the physis, usually thru areas of hypertrophic and degenerating cartilage cell columns

1

28

Salter harris type: fracture thru a portion of the physis that extends thru the metaphyses

2

29

Salter harris type: fracture theu a portion of the physis that extends thru the epiphysis

3

30

Salter harris: fracture across the metaphysis, physis and epiphysis

4