Principles of fractures
Mohammad Ararawi
Principles of fractures
Definition
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A bone fracture (sometimes abbreviated # or Fx) is a
medical condition in which a bone is cracked or broken;
it is a break in the continuity of bone.
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Fractures occur when a bone can't withstand the
physical force exerted on it.
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Bone fracture may be caused by traumatic incident, or
also can occur as a result of certain medical conditions
that weaken the bones, that may be localized or
generalized.
Principles of fractures
Classification
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In orthopedic medicine, fractures are classified as closed
or open (compound) and simple or multi-fragmentary
(formerly comminuted).
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Closed fractures are those in which the skin is intact.
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open (compound) fractures involve wounds that
communicate with the fracture and may expose bone to
contamination, may be from inside or outside.
Principles of fractures
Classification
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Simple fractures are fractures that only occur along
one line, splitting the bone into two pieces.
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multi-fragmentary fractures involve the bone
splitting into multiple pieces.
Principles of fractures
Description
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Complete Fracture- A fracture in which bone fragments separate
completely.
Transverse Fracture- A fracture that is at a right angle to the bone's
long axis.
Oblique Fracture- A fracture that is diagonal to a bone's long axis.
Spiral Fracture- A fracture where at least one part of the bone has
been twisted.
Compacted Fracture- A fracture caused when bone fragments are
driven into each other.
Comminuted Fracture.
Double or segmental Fx, occur at two levels with free segment
between them.
Principles of fractures
Description
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Incomplete Fracture- A fracture in which the bone fragments are
still partially joined.
Greenstick fractures in children, the spriny bone in childhood,
buckles on the side opposite to the causal force, where periosteum
remains intact.
a compression fracture, an example of a compression
fracture is when the front portion of a vertebra in the
spine collapses due to osteoporosis.
Reduction is not required in vertebral body fracture,But
it is necessary when the fractures are part of joint.
Greenstick fracture of radius and ulna
Principles of fractures
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A stable fracture is one which is likely to stay in a good
(functional) position while it heals.
An unstable Fx is likely to angulate or rotate before
healing and lead to poor function in the long term.
a fracture of the bony components of the joint is called
fracture-dislocation.
◦ E.g. shoulder fracture dislocation and elbow fracture
dislocation.
Burst fracture, occur in vertebra due to severe violence,
acting vertically on a straight spine.
Principles of fractures
Displacement of the fracture fragments
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The two main fragments of fracture are commonly displaced
The causes of displacement are:
• Primary impact
• Gravity
• Muscle pull
The following Displacements are recognized:
• Shift (translation) of the distal fragment.
• Angulation (alignment) of the distal fragment in
relation to proximal one or the opposite.
• Rotation (twist) one fragment may be rotated on
its longitudinal axis.
Principles of fractures
classification
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The OTA devised an elaborate classification system to
describe the injury accurately and guide treatment.
There are five parts to the code:
1-Bone: Description of a fracture starts by naming
the bone
2-Location: the part of the bone involved.
3-Type: It is important to note whether the fracture
is simple or multifragmentary and whether it is closed
or open.
4-Group: The geometry of the fracture is also
described by terms such as transverse, oblique, spiral, or
segmental.
5-Subgroup: Other features of the fracture are
described in terms of displacement, angulation and
shortening.
Principles of fractures
fractures caused by sudden injury in a normal bone.
Majority of the fractures.
 Caused by single excessive force.
 According to the force:
1-direct force:
A-Direct blow that cause a transverse Fx with
damage to skin.
B-Crushing force that cause comminuted Fx with
extensive damage to soft tissue.
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Principles of fractures
fractures caused by sudden injury in a normal bone.
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2-Indirect force.
The bone breaks at a distance from where the force is
applied.
A-Rotational force, leading to spiral fracture.
B-Bending force, leading to transverse fracture.
C-Bending with compression, leading to transverse
fracture with butterfly third segment.
D-Rotation, bending and compression combined,
leading to oblique fracture.
E-Pulling force, in which a tendon pull, causes avulsion
fracture.
Principles of fractures
Stress fracture-fatigue fracture
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Divided into two categories.
◦ fatigue fractures, is caused by the application of
abnormal stress or torque on a bone that has normal
elastic resistance, The stress placed on bone causes
resorption and microfractures.
◦ insufficiency fractures, On the other hand, occurs
when normal muscular activity stresses a bone that is
deficient in mineral or elastic resistance
Can occur any where but most commonly 2nd
metatarsal followed by Fibula and Tibia.
Principles of fractures
Stress fracture-fatigue fracture
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Clinically, Pain with gradual onset, examination will show
local tenderness after weeks there will be swelling.
X-ray, MRI and Bone scan.
Principles of fractures
pathological fracture
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Occur through a bone that is weakened by a disease.
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Fx occur either spontaneously or from trivial violence.
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Local or Generalized disorder of skeleton.
Principles of fractures
pathological fracture
Local causes
 Bone infection (osteomyelitis).
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Benign tumors (enchondroma, giant cell tumor).
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Malignant tumor (osteosarcoma , Ewing sarcoma and
metastatic carcinoma).
Principles of fractures
Generalized causes
 Congenital (osteogenesis imperfecta).
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Diffuse affection of bone (osteoporosis, rickets, uremic
osteodystrophy)
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Other causes (Polyostotic fibrous dysplasia, Paget’s
disease, Gaucher’s disease).
Principles of fractures
Growth plate injury
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Three types of injuries.
◦ Simple separation.
◦ Fractures that cross the growth plate.
◦ Crush injury.
Over 10 % of fractures in children involve the
growth plate.
Principles of fractures
Salter-Harris classification
Type I:
 The whole growth plate is
separated.
 No growth disturbances
Type II:
 The growth plate is
separated carrying with it a
triangular metaphyseal
fragment.
 No growth disturbances.
 The most common
injury.
Principles of fractures
Salter-Harris classification
Type III:
 Part of the growth plate is
separated.
 May lead to growth
disturbances.
Type IV:
 Separation of part of the
growth plate with a
metaphyseal fragment.
 May lead to growth
disturbances.
Principles of fractures
Salter-Harris classification
Type V:
 Crushing of part or all
of the growth plate.
 Growth disturbances
and growth arrest are
very common.
 The most dangerous
injury.
Principles of fractures
Fracture repair
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Fracture repair is a tissue regeneration process rather than a
healing process the injured bone is replaced by bone.
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The process of repair varies according to:
-The type of bone involved.
-The amount of movement at the fracture.
-The closeness of the fracture surfaces.
In tubular bone the pattern of repair shows striking difference
than cancellous one.
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Two types of tubular bone repair:
◦ Healing by callus
◦ Healing without callus
Principles of fractures
Healing by callus
1- Tissue destruction and
hematoma formation.
Disruption of blood vessels
 A hematoma forms around
and within fracture
 Few millimeters of the
fracture surfaces dies.
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Principles of fractures
Healing by callus
2- Inflammation and
subperiosteal and endosteal
cellular proliferation.
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Need 8 hours.
Proliferation of fibroblasts,
mesechymal cells, and
osteoproginetor cells.
New vessels formation.
Principles of fractures
Healing by callus
3- Callus formation.
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Chondrogenic and osteogenic
activity.
Cartilage in the periphery, woven
bone near the bone ends.
Marked increase in vascularity.
Osteoclast activity.
At the end the pain disappears
and the fragments are rigid w/o
movement.
Principles of fractures
Healing by callus
4- Consolidation.
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The primitive woven bone
is transformed into lamellar
bone by osteoclastic and
osteoblastic activity.
Need several months
before the bone is strong
enough to carry normal
loads.
Principles of fractures
Healing by callus
5- Remodeling.
Callus is reshaped: the bone
along the lines of stresses
are strengthened while
bone outside these lines
removed.
 The medullary canal is
reformed.
 The remodeling depends on
age that Fx remodeling in
children is so perfect.
Principles of fractures
Healing without callus
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Callus is formed as a response to movement at the
fracture side, to stabilize the fragments rigidly.
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Primary bone healing occurs directly between the 2
fragments without callus formation, when the fracture
site is absolutely immobile.
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Primary bone healing can occur in 2 instances:
◦ Naturally in impacted fractures of the cancellous
bone.
◦ In cortical fractures where the 2 fragments are in
complete contact and rigidly fixed by metal
device(plates, screws or intramedullary nails).
Principles of fractures
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Cutting cones consist of:
- Capillary bud (2)
- Osteoclasts (1)
- Osteoblasts (3)
- Osteoblasts lay down new
osteons (4)
Principles of fractures
repair of cancellous bone
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Cancelous bone has spongy texture with open
meshwork of trabeculae, allowing easier penetration by
vessels and bone forming cells.
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The broader area of contact between the fragments
with good blood supply allow healing in shorter period
of time w/o need for callus formation.
Principles of fractures
Rate of union
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Favorable factors.
◦ The age.union occur in 3-5 weeks in children while it
needs 3-5 months an adult.
◦ Type of bone.cancellous is better healer.
◦ Good blood supply.
◦ Immobilization.
◦ adequate nutrition (including calcium intake)
Principles of fractures
Rate of union
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Unfavorable factors.
◦ Impairment of blood supply.
◦ Infection
◦ Excessive movement.
◦ Presence of tumor.
◦ Synovial fluid in intraarticular Fx.
◦ Interposition of soft tissue.
◦ Any form of Nicotine.
Principles of fractures
Approach
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History.
◦ Hx of trauma, deformity, pain, inability to use the limb.
Remember:
Fx is not always at the site of impact.
Some Fx do not need severe violence.
Certain fracture will not affect the function of the limb,
like greenstick fracture or scaphoid fracture.
Principles of fractures
approach
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Examination.
General medical condition should be evaluated to
exclude shock and brain injury.
The vital signs should be observed and followed up.
Inspection.
expose the area
inspect for any swelling, bruising, colour or
deformity.
special attention is to be paid to the wound in skinif present. Is it superficial or deep.
Principles of fractures
approach
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Palpation, for tenderness, distal pulses, temperature and
crepitus on movement.
Vascular injuries are surgical emegency.
Sensation should be examined distally.
Compartment syndrom.
Movement, of the joint distal to the affected area;
crepitus and abnormal movement indicates a fracture.
Principles of fractures
approach
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Examination of the viscera.
Liver and spleen in case of rib fracture.
Bladder and urethra in case of pelvic fracture.
Neurological examination for head and spinal injury.
Principles of fractures
approach
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Investigation
Imaging.
1-X-ray criteria in fracture.
Two views, AP and lateral.
Two joints.
Two limbs.
Two injuries, like calcaneal fracture you have to
suspect vertebral fracture.
Two occasions, like stress and scaphoid fractures.
Principles of fractures
approach
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Special views,
◦ Calcaneal view, shoulder dislocation needs axial view
and acetabular fractures need 45 degree tilt view.
2-CT scan and MR.
spinal, pelvic and calcaneal fractures.
3-Radioisotope scan.
scaphoid and stress fractures.
Principles of fractures
Test of union
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Clinical and radiological tests are used to ensure that
the fracture is UNITED.
Clinical.
◦ Absence of mobility.
◦ Absence of tenderness.
◦ Absence of pain.
Radiological-X-ray criteria.
1-visible callus bridging both fragment.
2-contiuity of bone trabeculae across the fracture.
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