Download Dislocation of the lunate bone

The Resting Arm…
by Vinod More
Kaan Yücel M.D., Ph.D.
30. October.2012 Tuesday
one of the most frequently fractured bones
common in children
often caused by an indirect force transmitted from an outstretched hand through
the bones of the forearm/ arm to shoulder during a fall
or
a fall directly on the shoulder
The weakest part of the clavicle
junction of its middle and lateral thirds
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usually the result of severe trauma
as occurs in pedestrian-vehicle accidents
usually also fractured ribs
mostfractures require little treatment scapula is covered on both sides by muscles.
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mostinjuries of the proximal end fractures of the surgical neck
especially common in elderly people with osteoporosis
usually result from a minor fall on the hand, with the force being
transmitted up the forearm bones of the extended limb
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usually the result of severe injury
direct injury usually produces transverse fractures at the same level
usually in the middle third of the bones
because of interosseous membrane, a fracture of one bone
associated with dislocation of the nearest joint.
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Common in adults > 50
more frequently in women osteoporosis
Colles’ fracture
complete transverse fracture of the distal 2 cm of the radius
most common fracture of the forearm
distal fragment displaced dorsally
often comminuted (broken into pieces)
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usually result of trying to ease a fall by outstretching the upper limb
the force drives the distal fragment posteriorly and superiorly
distal articular surface inclined posteriorly.
this posterior displacement produces a posterior bump
“dinner-fork deformity” forearm & wrist resemble the shape of a fork.
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Most commonly fractured carpal bone Scaphoid bone
often results from a fall on the palm when the hand is abducted
Dislocation of the lunate bone
occasionally occurs in young adults on the outstretched hand
in a way that causes hyperextension of the wrist joint.
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occur as a result of direct violence
such as the clenched fist striking a hard object.
always angulates dorsally.
Boxer’s fracture commonly produces an oblique fracture of the neck
of the fifth and sometimes the fourth metacarpal bones.
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strong costoclavicular ligament firmly holds medial end of the clavicle to
first costal cartilage.
violent forces directed along the long axis usually result in fracture
dislocation occasionally.
If the costoclavicular ligament ruptures completely,
difficult to maintain the normal position of the clavicle once reduction has been accomplished.
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.
A severe blow on the point of the shoulder
during blocking or tackling in football or any severe fall
can result in the acromion being thrust beneath the lateral end of clavicle
tearing the coracoclavicularligament
this condition shoulder separation
displaced outer end of the clavicle easily palpable
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.
A severe blow on the point of the shoulder
during blocking or tackling in football or any severe fall
can result in the acromion being thrust beneath the lateral end of clavicle
tearing the coracoclavicularligament
this condition shoulder separation
displaced outer end of the clavicle easily palpable
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Elbow joint is stable because of the
wrench-shaped articular surface of the olecranon
pulley-shaped trochlea of the humerus
strong medial and lateral ligaments
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When examining the elbow joint,
the physician must remember the normal relations of the bony points.
medial & lateral epicondyles & top of the olecranon in a straight line
bony points form the boundaries of an equilateral triangle.
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common & most posterior
posterior dislocation follows falling on the outstretched hand
posterior dislocation common in children
parts of the bones that stabilize the joint are incompletely developed
avulsion of the epiphysis of medial epicondyle common in childhood
then medial ligament stronger than bond of union between epiphysis & diaphysis
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proximal radioulnar joint communicates w/ elbow joint
distal radioulnar joint does not communicate w/ wrist joint
elbow joint infection involves proximal radioulnar joint
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Strength of proximal radioulnar joint depends on
integrity of the strong anular ligament
Rupture in cases of anterior dislocation of head of radius on capitulum of humerus
In young children head of the radius still small & undeveloped
sudden jerk on the arm– radial head pulled down through the anular ligament
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A fall on the outstretched hand strain @ anterior ligament of wrist joint
synovial effusion
joint pain
limitation of movement
Differential diagnosis fractured scaphoid /dislocation of lunate bone
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Scaphoid bone
Distal end of radius
across the interosseus membrane
Ulna
Humerus
through the glenoid fossa
Scapula
to the coracoclavicular ligament
Clavicle
Sternum
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If forces excessive, different parts of the upper limb under strain.
The area affected related to age
Young child
posterior displacement of distal radial epiphysis
Teenage
Clavicle fracture
Young adult
Scaphoid fracture
Elderly
Colles’ fracture
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