Skeletal Trauma Flashcards
complete or incomplete disruption in continuity and structure of
the bone and/or cartilage.
Fracture
bone is ______,
(unequal in strength) and can withstand
mechanical forces differently
anisotropic
Cortical bone is stronger on
compression
Cortical bone is less resilient to
distraction
Cortical bone is most vulnerable to
shearing forces
situations that increase risk of fracture?
- repeated loading and the resulting fatigue
- local/systemic pathology
- surgical pin holes or bone resection
Surgical pin holes or a site of bone resection may weaken the bone, known
as a?
stress raiser
seen in children as 3-types
incomplete fracture
3-types of incomplete fracture
- Torus
- Green stick
- Plastic deformity
- cortical buckling on compression
Torus
incomplete fracture on tension
Green stick
bending of the bone without angular break and
remodeling
Plastic deformity
transverse, oblique and spiral
Complete fracture
fragment of bone being detached by the tension from
muscles or ligaments
Avulsion fracture
typically corner fracture that is chipped rather than avulsed
Chip fracture
results in telescoping of osseous
trabeculae
Impaction (compression)
No typical radiolucent line is seen on radiographs and instead
a zone of sclerosis or condensation may be present describes what type of fracture?
Impaction (compression)
typically in the calvaria (cranial vault) and
occasionally in Tibial plateau
Depression fracture
repeated stress applied to normal bone –> marrow hyperemia and resorption
Stress (fatigue) fracture
examples of Stress (fatigue) fracture
March fracture of 2nd
or 3d Metatarsal bone, Tibial stress fractures in runners etc
normal stresses i.e. normal weight bearing, walking
applied to osteoporotic (involuted/insufficient) bone.
Insufficiency fracture
vertebral
osteoporotic fracture is an example of an Insufficiency OR pathologic fracture?
Insufficiency fracture
bone weakened by things such as neoplasms,
infection, congenital defect of collagen?
Pathologic fracture
more than 2-segments
Comminution (comminuted) fracture
2-subtypes of comminuted fracture
Segmental fracture and Butterfly fragment-
two separate fracture lines producing an isolated
segment of bone
Segmental fracture
wedge shaped fragment produced at the apex of the
maximum force
Butterfly fragment
Fx due to trabecular
telescoping and buckling
Torus fracture
deminiralised
bone is unable to adequately respond to normal mechanical stresses
insufficiency fracture
impaction/compression fracture of the anterior humeral head due to
posterior shoulder dislocation and compression by the posterior glenoid rim, so-called…
“trough sign”
during posterior GHJ dislocation
Depressed fracture most seen in what bones?
flat
skin intact and no exposure to outside aire = Closed fracture
Closed fracture
Position of fractures based on?
regions of the bone (metaphysis vs
diaphysis
Intra-articular fracture extension can lead to what type of complications?
- delayed/abnormal healing
- chondrolysis
- secondary osteoarthritis
bone ends are not aligned is loss of?
apposition
overlap of one fragment over another
Bayonet apposition
complete loss of apposition
Distraction
classification of pediatric growth plate injury
Salter-Harris classification
classification of pediatric growth plate injury
Salter-Harris classification
most vulnerable regions in the pediatric
skeleton
epiphyseal growth
plate and growth apophysis
Why are the epiphyseal growth
plate and growth apophysis most vulnerable?
from the cartilagenous nature and metabolic activity
fracture through growth plate itself often unrecognized
because of minimal displacement
Salter-Harris 1
most common (>75%), fracture through physis and a part
of metaphysis forming a Thurston-Holland fragment. Good healing
prospects.
Salter-Harris 2-
through the plate and into epiphysis
Salter-Harris 3
fracture traverses metaphysis, physis and into epiphysis
Salter-Harris 4
crush injury to growth plate, often unrecognized or
confused with type 1 but essentially damages physeal blood supply.
Salter-Harris 5
which Slater-harris types are rare but show highest complications?
4 & 5
Salter-Harris type 4 and 5 can lead to…
premature
plate closure, limb deformities, shortening and other sequela
subtype of insufficiency fracture that develops
in bones with insufficient osteoid
Pseudo-fracture
Fracture most seen in Rickets & Osteomalacia
Pseudo-fracture
which type of fracture show very characteristic appearance on x-rays as
widened transverse radiolucent lines oriented at the right angle typically
to the medial cortex?
Pseudo-fracture
Pseudo-fractues are also referred to as…
- Looser zones
- Milkman lines
- umbau zones
Typically found along the medial aspect of the cortex of long bones
Pseudo-fractues
intra-osseous edema
bone bruise
not detected by conventional radiographs and best
seen on MR imaging
bone bruise
when injury and intra-osseous edema have
occurred
(Osteoclasts will become activated)
Occult fractures
Best example of an occult fracture is Injuries to
carpal navicular or
scaphoid bone
Occur in bones due to a mismatch of bone strength and chronic mechanical
stress
stress fracture
complete loss of articular contact/alignment with resultant injury
to periarticular restraints
Dislocation
partial loss of articular alignment
Subluxation
separation of fibrous joints or fibrocartilagenous joints often seen
as suture diastasis in the scull and symphysis pubis
Diastasis
Develops prior closure
of skull sutures (<3 y.o) as a result of tear in the dura
Growing skull fracture or leptomeningeal cyst (not true cyst)
traumatic disruption of bone and periosteum causes
significant hemorrhage that initiates
fracture healing
3-main phases of fracture healing:
1) Inflammatory (48-hours)
2) Repair (7-14-days)
3) Remodeling (9-24 months)
Requirements for fracture healing:
a) good fragments apposition and normal blood supply
b) sufficient immobilisation with adequate physiological stress
c) absence of infection
d) absence of systemic factors
hematoma and inflammatory mediators within first
48-hours initiate chemotaxis with phagocytes and repair cells being drawn
to fracture site (shortest phase)
Inflammatory phase
cells involved during initial inflammation will gradually begin
to form granulation tissue and remove unwanted material and damaged
cell.
Repair phase
During this phase within 7-14 days hematoma becomes vascularised
and may appear more translucent on x-rays.
Repair phase
Damaged tissue will gradually become populated by fibroblasts and
chondrocytes and bone remodeling will begin
Repair phase
Fracture callus still remains very vulnerable to shearing forces but may
be better stimulate if limited axial forces are applied.
Repair phase
when population of cells will sufficiently evolve into
fibroblasts, chondrocytes and osteoblasts the osteoid and bone
mineralisation will continue.
Remodeling phase
Remodeling phase on average may take
9-24
months
pediatric fractures heal quicker due to _______ of the periosteum.
vascularity
takes twice as long as physiologically expected
Delayed union
no healing for >9-months:
Non-union (pseudoarthrosis
2 types of Disturbed fracture healing
- Delayed union
2. Non-union
3 types of non-union
a. hypertrophic
b. Hypotrophic
c. atrophic
- abnormal exuberant callus
hypertrophic non-union
week callus with insufficient vascularisation and new bone
formation
Hypotrophic non-union
absent callus often with synovial fluid or infected exudate
intervening between fracture ends
atrophic non-union
healing occurred in abnormally positioned fracture ends
Malunion
- neurological and vascular injury
- acute compartment
syndrome and renal failure - pulmonary fat embolism
- gas gangrene
IMMEDIATE complications of fracture
- osteomyelitis
- sepsis
- complex regional pain syndrome
formerly known as RSDS - non-union/malunion
INTERMEDIATE complications of fracture
- ischemic necrosis (AVN)
- secondary osteoarthritis
LATE complications of fracture
What type of fracture may sometimes cause
lead toxicity
Gun shot wound (GSW)
if bullet was lodged in peritoneal cavity
