Download 16-Clinical Anatomy of The Upper Limb

Clavicle
It is the most commonly fractured bone
in the body.
The fracture occurs due to falling on
the shoulder or the outstretched hand.
It is most commonly fractured at the
junction of the middle and outer thirds
(weakest point).
The lateral fragment :
 Depressed by the weight of the
arm
 Pulled medially and forwards by
the adductors of arm (especially
pectoralis major).
The medial fragment :
 Pulled upward by the
sternomastoid.
 Involvement of supraclavicular
nerves can be the cause of
persistent pain over the side of the
neck.
Humerus
Fractures of the proximal end:
 Humeral head fracture:
 may occur in anterior or posterior
dislocations of shoulder
 Greater tuberosity fracture:
 It is due to direct trauma,
dislocation of the shoulder joint or
due to violent contraction of
supraspinatus muscle.
 The bone fragment will have the
attachments of the rotator cuff
muscles
 Severe tearing of the rotator cuff
with the dislocation can result in the
greater tubercle remaining
displaced posteriorly even after the
joint is reduced.
 Lesser tuberosity fracture
 Surgical neck fractures: may result in
injury to axillary nerve
Humerus
Fractures of the shaft:
 Are common
 The displacement of the fragments
depends on the relation of the site of
fracture to the insertion of the deltoid.
muscle
If the fracture line is proximal to the
deltoid insertion:
 The proximal fragment is adducted by
the pectoralis major, latissimus dorsi
and teres major.
 The distal fragment is pulled proximally
by deltoid, biceps & triceps.
If the fracture line is distal to the deltoid
insertion:
 The proximal fragment is abducted by
deltoid.
 The distal fragment is pulled proximally
by the biceps & triceps.
 The radial nerve can be injured.
Humerus
Fractures of the lower
end:
 Supracondylar fracture:
 Common in children
 May injure median
nerve and brachial
artery
 Medial epicondyle
fracture:
 May injure the ulnar
nerve
Radius
Fracture of the distal end
(Colle’s fracture):
It is due to a fall on the outstretched
hand in patients over (50) years.
The distal fragment of the radius is
pulled posteriorly and superiorly
The distal articular surface is
directed posteriorly.
The posterior displacement
produces a posterior bump.
The deformity is referred to as,
‘dinner-fork deformity’ because the
forearm and wrist resemble the
shape of a dinner fork.
Smith’s fracture is a reversed
Cole’s as the distal segment is
displaced anteriorly
Fracture of the Scaphoid Bone
Common in young adults
Fracture line passes through the narrowest
part of the bone
The blood supply to scaphoid may come from
its distal end and the only way the proximal
pole can receive any blood supply and
nutrients is through the rest of the bone. Thus
a fracture of the scaphoid in the proximal pole
or waist, deprives the proximal fragment of its
arterial supply, and this fragment undergoes
avascular necrosis.
If the fragments will not unite properly, there
will be permanent pain and weakness at the
wrist
Deep tenderness in the anatomical snuff box
after a fall on an outstretched hand in a young
adult is an indication of fracture of scaphoid
bone
Sternoclavicular Joint
Occasionally dislocated
because of strong ligaments
around
 Anterior dislocation:
medial end of clavicle
pulled forward and upward
 Posterior dislocation:
medial end of clavicle
pulled backward, which
may press trachea,
esophagus & great
vessels in the root of the
neck
Anterior
dislocation
Acromioclavicular Joint
The stability of the
acromioclavicular joint depends
on the strong coracoclavicular
ligament
The joint may get injured by a
severe blow such as a hard fall
on the shoulder.
The acromian thrusts beneath
the lateral end of the clavicle
tearing the coracoclavicular
ligament. This condition is
called shoulder separation, as
the shoulder separates (falls
away) from the clavicle because
of the weight of the upper limb.
The displaced lateral end of
clavicle is easily palpable
Shoulder Joint
It is the most commonly
dislocated large joint.
Dislocations happen when a
force overcomes the strength of
the rotator cuff muscles and the
ligaments of the shoulder.
Nearly all dislocations are
anterior inferior dislocations,
meaning that the humerus slips
out of the front of the glenoid.
Only three percent of
dislocations are posterior
dislocations, or out the back.
Anterior inferior dislocation
 Sudden violence applied to the
humerus when the joint is fully
abducted. The humeral head
moves downward onto the
inferior weak part of the capsule
which tears.
 The humeral head comes to lie
inferior to the glenoid fossa
 The acromion acts as a fulcrum
and the head of the humerus is
pulled upward and forwards by
the strong flexors and adductors.
Posterior displacement
 It is due to direct violence to the
front of the joint.
 The shoulder loses its rounded
appearance as the greater
tuberosity is no more bulging
laterally.
 The axillary nerve can be
damaged.
Elbow Joint
Dislocations are common and
most are posterior. Are more
common in children, due to a
fall on outstretched hand. The
distal end of humerus is
pushed anteriorly through
weak part of the capsule
Pulled Elbow: occurs in
children, when the child is
lifted by the upper limb. The
radial head is pulled out of the
annular ligament
Rotator Cuff Tendinitis
Results due to excessive
overhead activity of the upper
limb.
It is a common cause of pain in
the shoulder region
Normally during abduction of the
shoulder joint, friction between
the supraspinatus tendon and
the acromion is minimized by the
subacromial bursa.
Degenerative changes in the
bursa are followed by
degenerative changes in the
tendon of supraspinatus that
may extend to the tendons of the
other rotator cuff
There is a spastic pain in the
middle range of abduction.
Rupture of the Supraspinatus Tendon
In advanced cases of
tendinitis, the necrotic
supraspinatus tendon
may become calcified
and rupture
The patient is unable to
initiate abduction of the
arm
Tennis Elbow
Caused by partial tear or
degeneration of the origin of
superficial extensor muscles
attached to the lateral
epicondyle
It results due to excessive
use of these muscles as in
tennis, violinists and
housewives.
Results in pain and
tenderness over the lateral
epicondyle that radiates to
the lateral side of the
forearm
Golfer’s Elbow (Medial Epicondylitis)
Caused by partial tear or
degeneration of the origin
of superficial flexor
muscles attached to the
medial epicondyle
It results due to excessive
use of these muscles as in
playing golf
Results in pain and
tenderness over the medial
epicondyle that radiates to
the medial side of the
forearm
Biceps Brachii & Osteoarthritis of the
Shoulder Joint
Advanced
osteoarthritic changes
in the shoulder joint
can cause erosion of
the tendon of the long
head of biceps by
osteophytic changes.
The tendon may be
reptured.
Volkmann’s Ischaemic Contracture
It is the contractures of the muscles of the
forearm that follows fractures of the distal end of
the humerus or fractures of the radius and ulna.
Spasm of a localized segment of the brachial
artery reduces the blood flow to the flexors and
extensor muscles so that they under go ischemic
necrosis.
The flexor muscles are mostly affected
The muscles are replaced by fibrous tissue,
which contract and result in the deformity
3 types of deformity exists:
 The long flexors of the carpals
and fingers are more contracted
than extensors. The wrist joint
is flexed and the fingers are
extended.
 The long extensors of the
fingers are greatly contracting
The wrist and metacarpophalngeal joints are extended.
The interphalngeal joints are
flexed.
 Both the flexor and extensor
are contracted:
 The wrist joint and the
interphalangeal joints are
flexed. The metacarpophalangeal joints are extended.
Dupuytren’s Contracture
It is a localized thickening and
contracture of the palmar
aponeurosis.
It commonly starts near the root of
the ring finger pulling it to the palm
and flexing it at the metacarpophalngeal joint. Later the little finger
is involved.
In long standing cases prolonged
pulling of the fibrous sheaths of
these two fingers would flex their
proximal interphalangeal joints
Their distal interphalangeal joints
are not involved and they actually
become extended
Dupuytren's disease is familial, and
may be associated with cigarette
smoking, vascular disease, epilepsy,
and diabetes.
Compartment syndromes of the forearm
The deep facial sheath, the
interosseous membrane &
the fibrous intermuscular
septae divide the forearm into
compartments, that contain
muscles, vessels and nerves
There is very little room within
each compartment, and any
edema will cause secondary
vascular compression.
The veins are affected first
and later the arteries
Tenosynovitis & Infection of the Fascial
Spaces of Palm
May get infected
and distended with
pus, after
penetrating
wounds of the
palm
Pulp-Space Infection (Felon)
This is the commonest hand
infection. Pus more often gathers in
the finger tips than anywhere else in
the hand.
It is more common in the thumb and
index fingers.
Bacteria enter the space through
needles or nails.
Accumulation of inflammatory
exudate within the small
compartments of the pulp would
rapidly increase its pressure. There
is little room for swelling, so that
infection causes a throbbing pain
early.
If infection is not decompressed, it
can extend into the terminal
phalanx.
Pus from the pulp can track:
 through to the skin outside
 through the periosteum,
causing osteomyelitis of the
distal phalanx.
Since the blood supply of the
diaphysis of the phalanx passes
through the pulp space (in
children), the infection would
result in necrosis of the
diaphysis. Its epiphysis is
supplied by a separate artery, so
this usually survives the
infection.
The synovial sheaths of the
affected fingers can be involved
because of their close
relationships to the proximal part
of the pulp space.
Venipuncture
The superficial veins of the upper limb
are used for venipuncture, transfusion
and cardiac cathetrization.
When a patient is in shock, the
superficial veins are not always visible. It
is very important to know their course
and the relations to important landmarks.
The cephalic vein:
 At the wrist, it passes posterior to the
styloid process of the radius.
 In the cubital fossa it is separated
from the brachial artery by the
bicipital aponeurosis which protects
the artery from irritating drugs.
 In the deltopectoral groove, it
communicates with the external
jugular vein by a small vein that
passes in front of the clavicle.
Fracture of the clavicle can tear this
communicating vein and causes a
large hematoma.
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