Post on 12-Feb-2016
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Orthopedic Pitfalls:Approach to Upper Limb X-rays
Yael Moussadji, PGY 3Dr. Phil UkrainetzNov 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• 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
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
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
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
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
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 HeadFractures 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
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
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 x-rays
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 7-10 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 follow-up 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 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