Download Approach to Upper Limb X-rays

Orthopedic Pitfalls:
Approach to Upper Limb X-rays
Yael Moussadji, PGY 3
Dr. Phil Ukrainetz
Nov 2, 2006
Objectives
 To review diagnosis and management of upper
extremity orthopedic injuries
 To highlight injuries that are frequently missed or
mismanaged
 To review, in detail, orthopedic “pitfalls”
including
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Posterior shoulder dislocations
Elbow fractures
Forearm fractures
Wrist injuries
Anterior Shoulder Dislocations
 Classified according to the
final position of the
humeral head
 Subcoracoid dislocations
are most common (70%),
followed by subglenoid
(30%)
 Subclavicular and
intrathoracic are
associated with violent
forces, fractures, and are
extremely rare
Clinical Features
 Arm held in slight abduction and external rotation
by other extremity
 Shoulder may have a squared off appearance, with
fullness of anterior shoulder
 Patient cannot adduct of internally rotate without
severe pain
 5-54% may have axillary nerve injury, assessed by
testing for sensation over lateral shoulder and
motor function of deltoid (more accurate)
Associated Fractures
 Associated fractures in
50%
 Most common is the Hill
Sachs deformity,
compression fracture of
the posterolateral humeral
head
 Bankart’s lesions may be
present in up to 5%
 Avulsion fractures of the
greater tuberosity account
for 10-15%
Selective radiology in 100 patients with suspected
shoulder dislocation. The Journal of Emergency Medicine.
Hendey et al, 2006.
 Prospective validation of a previously derived clinical decision rule for
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selective radiography of patients with suspected shoulder dislocation in
the ED
Pre and post reduction radiographs were ordered based on the
algorithm incorporating mechanism of injury, previous dislocations,
and physicians clinical certainty of joint position
94 of 100 patients had shoulder dislocations, of which 59% were
recurrent
30% had both pre and post films, 45% had either pre or post, and 25%
had none
There was a 46% reduction in x-ray utilization, with no missed
fractures or dislocations, with the greatest potential for saving noted in
the subset of patients with recurrent atraumatic dislocations
Previous studies have indicated that fracture dislocations can be
predicted by 3 variables: first time dislocations, blunt traumatic
mechanism (fall > 1 flight stairs, assult, MVC), age >40
Algorithm for Shoulder Radiography in the ED
Shoulder Reduction
 Traction-counter traction
 Stimson technique
• Patient is placed prone with the affected limb hanging
downwards in forward flexion at the shoulder; patient remains
in that position with 5-10 pound weights suspended from the
wrist; can take 15-20 min
 External rotation
• Slow gentle external rotation of the adducted arm; reduction
occurs between 70 and 110 degrees
• Can be done supine or sitting (80% successful) over 5-10 min
 Scapular manipulation
• Focus is on repositioning the glenoid fossa (85% successful)
• Arm held at forward flexion with slight traction
• Superior aspect of scapula is stabilized, while the inferior tip is
adducted with the thumb
 Others (Milch, Spaso
etc) all employ some
degree of traction and
external rotation to
simulate the
mechanism in which
dislocation occurred
Posterior Shoulder Dislocation
 The most commonly missed joint
dislocation in the body
 Incidence of 1-4% of all shoulder
dislocations
 79% are incorrectly diagnosed
 Must have a high index of suspicion in
order to seek out the classic physical
findings
History
 Occurs when the arm is forward flexed and slightly
internally rotated with axial load applied, eg hitting a
heavy punching bag or striking the dash with arm extended
to the front
 Classic history is a significant blow to the front of the
shoulder, or a FOOSH with the elbow extended and
humerus internally rotated
 Posterior dislocations are the result of indirect forces
producing a combination of internal rotation, adduction,
and flexion
 Can also be encountered in patients with seizures, alcohol
withdrawal, or electrocution
Physical Exam
 Generally, patients complain of severe pain (more painful
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than anterior dislocations)
Patient will usually be sitting with arm held tightly across
front of trunk, fixed in a position of adduction and internal
rotation
External rotation is blocked and abduction is severely
limited
The posterior aspect of the shoulder is rounded and more
pronounced, and the anterior portion will be flattened with
a prominent coracoid process
Clinical pearl: Patients will be unable to supinate the
palm (always present)
Radiographs: AP view
AP view
 Absence of the normal elliptical shadow
• On a routine AP view there is usually an overlap shadow created by
the head of the humerus imposed on the glenoid fossa; in a posterior
dislocation, the articular surface of the humeral head is posterior to
the glenoid, distorting the elliptical overlap shadow; the inferior third
of the glenoid fossa usually has no contact with the humeral head
 Vacant glenoid sign
• The humeral head normally occupies the majority of the glenoid
cavity; in posterior dislocations the head rests behind the glenoid,
producing a positive rim sign; if the space between the anterior rim
and the humeral head >6mm, posterior dislocation is likely
 The “trough line”
• An impaction fracture of the humeral head caused by posterior rim of
glenoid resulting in two parallel lines of cortical bone on the medial
cotext of the humeral head
 “Hollowed out” or “cystic” humeral head
• Arm locked in internal rotation, aligning the greater and lesser
tuberosities
Shoulder radiographs
 Caution: the AP view does not represent a
true AP of the glenohumeral joint (scapula
lies at 45 degrees, angulating the
glenohumeral joint space anteriorly at 45
degrees)
 Therefore loss of the joint space in a
posterior dislocation may not be visualized
on a normal AP of the shoulder
 An axillary or scapular view is required
Scapular lateral
 Most clinically useful AND
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patient friendly
Virtually diagnostic of posterior
shoulder dislocation
Taken sitting or standing or
supine with arm left
undisturbed
Anterolateral portion of
shoulder placed against the
cassette
X-ray beam passes tangentially
across posterolateral chest
parallel to and down from spine
of scapula onto cassette
This represents a true lateral of
the scapula, and therefore the
glenohumeral joint
Scapular lateral
 In the lateral view, the
scapula projects as the
letter Y
 The vertical stem of the Y
is the body of the scapula;
the upper fork is formed
by the juncture of the
coracoid and the acromion
process
 The glenoid is located at
that junction
 In a posterior dislocation,
the humeral head will be
posterior to the glenoid
Axillary lateral
 Requires the patient to
lie supine and abduct
the arm 70-90 degrees
with cassette above
shoulder and tube near
hip
 2 modified axillary
views available in
patients who are in too
much pain to tolerate
Axillary lateral
 Humeral head
posterior to glenoid
fossa
 Dots and arrows
indicate trough lines
(reverse Hill Sack’s
lesions)
 B = Bankhart fracture
fragment
Management
 Management depends on the presence of and size of the anterior
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impression fracture; incidence of co-existent fractures is 50%
When humeral head lesion <20% of articular surface, closed reduction
may be attempted
Many may go on to need general anesthetic
Place patient supine and apply traction to the adducted arm in the line
of deformity
While applying traction, gently lift the humeral head back into the
glenoid fossa
If the head remains locked on the glenoid rim, apply lateral traction on
the upper arm using a folded towel
Traction is maintained while the arm is then slowly externally rotated
Do not force the arm into external rotation; this may fracture the
humerus
The arm is then immobilized in external rotation and slight abduction
Luxatio Erecta
(a.k.a. inferior shoulder dislocation)
 Comprises 0.5% of all shoulder dislocations, and
can be misdiagnosed as an anterior dislocation
 Mechanism is injury involves hyperabduction of
arm at shoulder with extension at elbow while
forearm pronated
 Direct violent force applied to superior shoulder,
causing inferior movement of humeral head
relative to glenoid fossa disrupting the inferior
glenohumeral capsule
Clinical presentation
 Patients usually present
with arm hyperabducted at
shoulder and flexed at
elbow with forearm
resting behind the head
 Glenoid fossa is empty
and humeral head is
palpated in axilla
 AP view demonstrates
inferior displacement of
humeral head
 Axillary view
Management
 Closed reduction with muscle relaxation and anesthesia
 In-line traction to the fully abducted arm with firm
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cephalad pressure on humeral head
Counter-traction using rolled bed sheet placed superior to
shoulder
Once humeral head reduced, arm adducted towards body
and forearm supinate
Outpatient orthopedic referral
Associated injuries include rotator cuff injuries, fractures
of the clavicle, coracoid, acromion, inferior glenoid,
greater tuberosity of humerus (80% of cases)
60% suffer axillary nerve injury
Supracondylar fractures
 Bony injury of distal humerus proximal to the
epicondyles
 Mean age of 7 years, rare beyond 15
 Similar injury mechanisms in adults produce
posterior elbow dislocations
 Classified as flexion type or extension type (95%)
 Extension type supracondylar fractures result from
FOOSH with elbow fully extended; force of
impact directed forward fracturing the anterior
aspect of the distal humerus; contraction of the
triceps pulls the distal fragment posteriorly and
proximally
Radiography
 Type I
• Minimal to no displacement
 Type II
• Incomplete injury, minimal to moderate
displacement and/or intact posterior cortex
 Type III
• Complete displacement of fragment with posterior
cortical disruption
Occult fracture
 Anterior humeral line
should bisect the middle
of the capitellum; in a
supracondylar fracture, the
line will strike the anterior
third or miss it entirely
 Fat pad sign results from
swelling adjacent to the
distal humerus; the
posterior fat pad is never
seen in an uninjured
patient and is associated
with fracture in 90%
Management
 Type I
• Mechanically stable; splint for pain control and comfort
 Type II
• Reduction, preferably by ortho (yeah right)
• Cast at 120 degrees of flexion
 Type III
• ED reduction
• Associated with loss of arm length, deformity, neurovascular
compromise
• Apply traction at wrist in line with upper extremity with thumb
in up position while correcting any medial or lateral deformity
• When arm length restored, slowly and gently flex elbow to 100
degrees
• Immobilize medially displaced fractures with forearm pronated
and laterally displaced fractures with forearm supinate
Radial Head
Fractures
 Usually results from
FOOSH in adults
 Impact transmitted axially,
forcing radial head against
capitellum
 X-ray may detect fracture
or only pathological fat
pads suggestive of occult
fracture
 Any irregularity in radial
head, especially in
association with fat pads is
a radial head fracture until
proven otherwise
Radial Head #
Mason Classification
 Type I
• undisplaced
 Type II
• Minimally displaced
 Type III
• comminuted
 Type IV
• Fracture-dislocation
Management
 Type I
• Treat symptomatically with sling and early ROM
 Type II
• Treat as Type I; patients may require radial head
excision if fails ROM maneuvering
 Type III
• Early ortho follow-up for excision of radial head
 Type IV
• Reduction and early surgical excision
• Outcomes excellent
Galeazzi and Monteggia fracture dislocations
 Dislocation at the elbow or wrist may
accompany any forearm fracture
 Monteggia pattern of injury consists of a
fracture of proximal third of ulna with
dislocation of radial head
 Galeazzi pattern of injury consists of radius
fracture, most often at junction of middle
and distal third, with dislocation at DRUJ
Monteggia
 Proximal dorsally
angulated ulna fracture
 Radiocapetellar line
misses the capitellum
indicating a proximal
radial head dislocation
Galeazzi
 Comminuted distal
radius fracture
 Subtle disruption of
DRUJ evident by
shortened radius and
loss of overlap
between radius and
ulna
Mechanism
 Can be caused by low energy (FOOSH) while
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hyperpronated or high energy (MVC)
Galeazzi is three times more common; miss rate of up to
50% in diagnosis quoted in some studies
Monteggia fractures result in an ulnar shaft fracture with
an anterior radial head dislocation in 60%
Galeazzi fractures usually occur distal to biceps tuberosity
and proximal to 4cm from distal radius; with displaced
radial shaft fracture, DRUJ disruption is common but
frequently subtle
May be purely ligamentous, or may involve fracture of
ulnar styloid
Presentation
 Monteggia
• Extremely limited ROM of elbow, especially flexion
and supination
• Dislocated radial head may be palpable
• Deep branch of radial nerve may be affected
resulting in weakness of extension of fingers/thumb
 Galeazzi
• Resist any attempts at pronation and supination
• Ulnar styloid process may be prominent
• However, in nondisplaced fractures the patient may
not complain of any wrist pain
Radiography: Monteggia
 Ulna fracture usually
clearly evident
 ALWAYS measure the
radiocapitellar line to
avoid missing a radial
head dislocation
 If the ulnar fracture is
angulated, the apex of
angulation points in
the same direction as
the dislocation
Radiography: Galeazzi
 Radius fractured and
shortened
 Increased space between
distal radius and ulna on
PA (should not be wider
than 1-2mm)
 On lateral, fractured radius
angulated dorsally and
ulna appears dorsally
displaced (normally
overlies the radius)
 Inability of the tech to get
a true lateral should raise
suspicion of injury
Management
 Monteggia fractures can be successfully
treated in children with closed reduction
and supinated long arm splinting
 More severe injury in adults, required ORIF
 Galeazzi in particular is prone to poor
outcome if missed (>90%)
 Treated with ORIF of fracture and pin or
open fixation of DRUJ
Wrist Sprain?
Wrist Injuries
 The most common but inaccurate diagnosis
made in wrist injuries is wrist sprain
 This should be a diagnosis of exclusion
 Commonly missed injuries include scaphoid
fractures, scapholunate dissociations, lunate
and perilunate injuries, DRUJ dislocations,
hamate hook fractures, and triquetral
avulsion fractures
Clinical Approach
 Demonstration of specific point tenderness is the most
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important diagnostic test, so know your anatomy
Anatomic snuffbox sits between the extensor pollicus
longus and extensor pollicus brevis when the thumb is
radially abducted; body of scaphoid is palpated here
Scaphoid tuberosity palpable at the base of the thenar
muscles on palmar aspect of wrist
Pisiform palpable at the junction of the flexor carpi ulnaris
and volar wrist crease; just distal to this lies the hook of the
hamate
On dorsal wrist palpate Lister’s tubercle; the scapholunate
ligament is just distal to this
Just distal to ulnar head and radial to its styloid lies the
lunotriquetral junction
Scaphoid fractures
 Accounts for 60-70% of all wrist fractures, and is
the most commonly missed injury
 Scaphoid links the proximal and distal carpal rows
and is the principle bony block to wrist extension
 Classic history is a FOOSH with hyperextension
at the wrist in 97% of cases
 Immediate pain, minimal swelling, and patient is
able to continue on with daily activities
 Palpation in the anatomic snuffbox is the most
reliable diagnostic maneuver
Scaphoid fractures
 Fracture of the middle third is most common
(80%), followed by proximal third (15%), distal
third (4%) and distal tubercle (1%)
 Propensity for nonunion and AVN caused by
blood supply which arises distally
 Proximal bone is completely dependent on this
blood supply and most at risk
 Common associated injuries include fractures of
distal radius, lunate, or radial head; median nerve
injury has also been described
 10-20% of fractures are not visible on initial xrays
X-rays
 Scaphoid view
positions wrist in ulnar
deviation, placing
scaphoid in extended
position, allowing you
to view the entire
length of the scaphoid
 Also accentuates any
scapholunate
dissociation
Management
 Treat all suspected fractures as though one
exists, with thumb spica splint and f/u in 710 days for reassessment and repeat X-rays
• 15% are ultimately shown to have a fracture
 For confirmed fractures, treat with long arm
thumb spica splint with hand clinic followup in 7 days
• Consult a hand surgeon on presentation if any
significant angulation, displacement, or
comminution
Lunate and Perilunate Injuries
 Results from similar hyperextension mechanisms
 Perilunate dislocations are more common, and
lunate dislocations are more severe
 Most common mechanism is a high energy
FOOSH, followed by MVC and motorcycle
crashes
 Accounts for 10% of all carpal injuries
 Associated injuries include fractures of the radial
styloid, scaphoid, capitate and triquetrum; the
presence of theses should alert you to the
possibility of an occult perilunate injury
Lunate and Perilunate Injuries
 The hallmark of perilunate dislocation is a dislocation of
the head of the capitate from the the distal surface of the
lunate, most often dorsally
 The defining feature of a lunate dislocation is disruption
between the lunate and lunate fossa of the distal radius
 All are a progression of the same pathologic process
 The mechanism is a progressive pattern of carpal
ligamentous injury caused by wrist hyper-extension and
ulnar deviation causing 4 distinct stages of injury
beginning with a scapholunate joint disruption and
proceeding around the lunate
Stage I
 Scapholunate dissociation,
resulting in widening of
scapho-lunate joint (most
common injury), which
can be seen better on a
clenched fist view
 A gap of 2mm of less is
considered normal
 Can be associated with
rotary subluxation of
scaphoid resulting in
“signet ring sign”
 Terry Thomas sign
Stage II
 Perilunate dislocation,
best seen on lateral wrist
 Capitate is dislocated
dorsally
 PA usually demonstrates
overlap of distal and
proximal carpal rows and
may demonstrate an
associated scaphoid
fracture
Stage III
 Similar to stage II, but
with dislocation of
triquetrum, best seen
on PA view with
overlap of the
triquetrum on the
lunate (due to
scaphoid and triquetral
malrotation)
Stage IV
 Lunate dislocation
 Triagular “piece of pie
sign” on PA view as lunate
rotates volarly
 Laterally, this appears
“spilled teacup”
 The capitate lies
posteriorly to the lunate,
which is no longer
articulating with the radius
Approach to the Wrist X-ray: PA view
 On the PA view, identify
the three arcs
 First is the radiocarpal arc;
disruption here suggests a
lunate dislocation
 Second is the midcarpal
row; disruption suggests a
perilunate dislocation
 Third is the proximal arc
of the distal carpal row;
disruption here suggests a
carpal dislocation or
fracture
The Lateral Wrist
 The radius, lunate and
capitate should all line
up in a row
Distal Radioulnar Joint Disruption
 Isolated injuries occur from falls, twisting injuries, or suddenly lifting
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heavy loads with wrist outstretched, either in hyperpronation or
hypersupination
The radius and carpus dislocate about the ulna; injuries are classified
according to position of ulna relative to radius
Patients complain of a painful loss of forearm rotation
Presents with an asymmetrically prominent distal ulna dorsally
dislocated with loss of supination, or wrist narrowed in AP diameter
with fullness of palmar aspect, dorsal sulcus, and limited pronation
Primarily a clinical diagnosis
Ulnar head should be reduced and forearm immobilized in full
supination with above elbow sugar tong splints if dorsally dislocated;
volar dislocations also require reduction and immobilization in
pronation, but are more mechanically stable
Hamate Hook Fractures
 Occurs from fall on dorsiflexed wrist or through
direct forces applied to the hypothenal eminence
by a raquet or bat
 Patients complain of a weak or painful grip, and
be maximally tender just distal and radial to the
pisiform
 Carpal tunnel view is the best way to visualize the
fracture, but if suspected, may need CT scan
 Treat with short arm cast for 4-6 weeks (short arm
volar splint is appropriate) and ortho referral
Triquetral Fractures
 Usually from a direct blow to the hand or a
FOOSH (ulnar styloid hits the triquetrum,
resulting in a dorsal chip fracture)
 Localized tenderness over dorsal wrist distal
to ulnar styloid
 Seen best on the lateral wrist as a drosal
chip fragment
 Heals well in short arm splint for 3-4 weeks