..... Forearm Injuries

A nightstick fracture is an isolated fracture of the ulnar shaft

that occurs when a patient is protecting the body from a

blunt force to the upper torso or head. Both bone forearm

fractures (radius and ulna) are common in children after a

fall. In both children and adults, these are highly unstable

fractures that require early orthopedic consultation. Galeazzi

fracture-dislocation is a distal radius fracture with dislocation

of the ulna at the distal radioulnar joint (wrist). Monteggia

fracture-dislocation is a proximal ulna fracture with dislocation of the radial head at the proximal radioulnar joint

(elbow). Both of these injuries require surgical reduction .

..... Wrist and Hand Injuries

Distal radius fractures account for up to 15% of upper

extremity fractures and are classified by the pattern of

injury. They are most commonly caused by a fall on an

outstretched hand (FOOSH). A Colles fracture is an extraarticular metaphyseal fracture with dorsal angulation, as

opposed to a Smith fracture, which is an extra-articular

metaphyseal fracture with volar angulation (Figure 90-3).

A Barton fracture involves the volar or dorsal rim of the

distal radius with subluxation of the carpals. A Hutchinson

fracture is an isolated fracture of the r adial styloid.

Of the 8 carpal bones, the scaphoid accounts for 60--80%

of all fractures (Figure 90-4). These fractures have a significant

A. Figure 90-3. Distal radius fracture is an example of a

Calles fracture.

UPPER EXTREMITY INJURIES

Figure 90-4. Scaphoid fracture (arrow).

risk of avascular necrosis due to the pattern of blood supply

in this area, and this risk increases with more proximal frac ­

tures. The false-negative rate of plain radiographs is as high as

20%, making conservative treatment in patients with tenderness over the scaphoid (anatomical snuffbox) appropriate.

Metacarpal fractures may occur in the base, shaft, neck,

or head of the bone. The most common is a fracture to the

neck of the fourth and/or fifth metacarpal, called a boxer's

fracture (Figure 90-5). Angulation is acceptable if it is

Figure 90-5. Fracture of the neck of the fourth and

fifth metacarpa ls-boxer's fracture (a rrows).

<40 degrees. For fractures of the metacarpal shafts of the

second and third metacarpal necks, less angulation

( 10-20 degrees) is acceptable because healing with significant angulation in these more anatomically fixed metacarpals may inhibit function.

Injury to the ligaments of the wrist produces several

patterns of injury observed on plain radiographs.

Progressive ligamentous injury results in a characteristic

sequence of injuries, from scapholunate dissociation, to

perilunate dislocation and, finally, lunate dislocation.

Scapholunate dissociation occurs when the interosseous

ligament between the scaphoid and lunate is disrupted. On

the anteroposterior (AP) radiograph, the joint space

between the scaphoid and lunate is 2':3 rom, a finding

termed the Terry Thomas sign. The other 2 patterns are

best seen on the lateral radiograph. On this view, a

line drawn through the center of the radius should transect

the lunate and capitate. In a perilunate dislocation, the

capitate is malaligned, usually dorsally (Figure 90-6A). In a

lunate dislocation, the lunate is in an anterior position and

is tipped over like a "spilled teacup" (Figure 90-6B).

Tendon lacerations are common after lacerations of

the hand. Examination should include testing the movement and strength of the digit, as well as inspection of

the tendon through its full range of motion. Flexor

tendons are tested by noting flexion at the distal

interphalangeal joint ( flexor digitorum profundus) and

the proximal interphalangeal joint ( flexor digitorum

superficialis ). Mallet finger is a closed extensor tendon

injury due to forced flexion of an extended distal phalangeal joint. It may be associated with an avulsion fracture.

This injury occurs commonly when a person attempts to

catch a ball.

CLINICAL PRESENTATION

� History

The patient presenting with upper extremity injury must

be assessed for other more urgent or life-threatening injuries such as head or torso trauma before focusing attention on the extremity. A detailed history should attempt

to identify the mechanism of injury, as this is often help ­

ful in determining the type of injury sustained. Careful

attention should be paid to injuries associated with sig ­

nificant swelling and pain unresponsive to narcotic medications, as these may be signs of limb-threatening

compartment syndrome.

� Physical Examination

A thorough neurovascular assessment will help characterize the urgency of a patient's injury. This includes

assessing pulses, skin color, capillary refill, and nerve

function. The radial nerve performs wrist extension and

provides sensation to the dorsal web space between the

first and second digits and may be damaged by mid-shaft

CHAPTER 90

A

8

.A. Figure 90-6. A. Peri lunate dislocation. Note that the

lunate sti ll articulates with the radius (horizontal arrow)

but the capitate is dislocated dorsally (vertical arrow).

B. Lunate dislocation. The lunate (arrow) is volarly

dislocated and no longer articulates with the radius.

humerus fractures. The ulnar nerve travels posterior to

the medial epicondyle of the elbow and abducts, or

spreads apart, the digits, and provides sensation to the

fifth digit. The median nerve allows opposition of the

thumb and fifth digit and supplies sensation to the first

3 digits. It is most frequently injured in supracondylar

humerus fractures.

After assessing for neurovascular integrity, evaluate for

any gross deformities or swelling as well as any tenderness

or "tenseness" that might suggest compartment swelling.

Lacerations are noted, as these could represent open fractures. The entire extremity must be evaluated for secondary injuries that may be overlooked by a more "obvious"

source of pain, paying particular attention to adjacent

joints.

DIAGNOSTIC STUDIES

� Laboratory

Laboratory studies are usually unnecessary in the

evaluation and management of extremity injuries.

IMAGING

In most cases, plain radiographs are sufficient to diagnose

upper extremity trauma. Both an AP and lateral view of the

bone must be viewed to fully understand and describe a

fracture. Imaging the joint above and below the fracture is

helpful to identify associated injuries.

Fractures must be described with a consistent language

to properly manage and effectively communicate with

consulting specialists. Common patterns include spiral,

transverse, and oblique fractures. The degree of angulation,

displacement, and level of comminution (see Figure 90-2)

must be noted, in addition to the presence of intraarticular involvement, as these features frequently impact

the definitive treatment plan.

Shoulder radiographs include AP films in internal and

external rotation, a scapular "Y" view, and an axillary view.

The axillary and "Y" view are especially helpful in diagnos ­

ing the posterior dislocation. Wrist radiographs consist of

AP, lateral, and oblique views. The carpal bones are best

scrutinized on the AP radiograph. Overlap of the bones

suggests a carpal dislocation (ie, lunate or perilunate). The

lateral view is best for detecting carpal dislocations and

fractures of the distal radius and triquetrum. The oblique

view allows for better visualization of the first metacarpal

and the distal scaphoid. The scaphoid view, an AP view

with ulnar deviation of the wrist, will increase the sensitivity for detecting scaphoid fractures .

Computed tomography ( CT) and magnetic resonance

imaging are not routinely ordered but have an improved

sensitivity over plain radiographs for detecting occult

fractures (eg, scaphoid fractures). CT scans can also better

characterize complicated fractures seen on plain radiographs.

UPPER EXTREMITY INJURIES

PROCEDURES

� Shoulder Dislocation Reduction

An anterior shoulder dislocation can be reduced by several

techniques. The external rotation maneuver places the patient

sitting upright or at 45 degrees. The patient's elbow is

supported in adduction by one hand while the other hand is

used to slowly and gently externally rotate the arm. The

shoulder may reduce spontaneously. If not, the arm is slowly

abducted and the humeral head is lifted into the socket.

Scapular manipulation involves pushing the inferior portion

of the scapular tip medially while the superior aspect is

rotated laterally. This movement shifts the glenoid inferiorly

toward the humeral head, allowing it to reduce spontaneously.

The Stimson technique relies on gravity to slowly fatigue the

shoulder musculature and allow spontaneous reduction of

the humerus in 20-30 minutes. The patient is placed in the

prone position with the arm hanging over the side of the bed

with 10- to 15-lb weights suspended from the wrist.

MEDICAL DECISION MAKING

Most upper extremity injuries can be clinically diagnosed

by a thorough history and physical exam. An accurate

neurovascular exam is invaluable in rapidly identifying

potentially limb-threatening injuries such as a vascular

injury or compartment syndrome. When a fracture is

suspected, radiographs are necessary to properly characterize fracture patterns, which will often dictate both the

acute management and overall disposition of a patient

(Figure 90-7).

Extremity pain

or trauma

Pulses present; good

perfusion

Thorough h istory and

examination

Assess need for

radiog raphs and pain

control

Thorough

neurovascular

examination

Pulses absent; poor

perfusion

Reduce fractures/

dislocations and

reassess pulses

• Reduce dislocations/fractures and repeat radiographs

• Splint fractures or suspected fractures, as appropriate

• Discharge instructions

• Prescribe pa in medications

• Give appropriate follow-up

Figure 90-7. Upper extremity injuries diag nostic algorithm.

CHAPTER 90

TREATMENT

The general treatment of most orthopedic injuries involves

rest, ice, compression, and elevation (RICE). Most fractures

should be immobilized with a splint that supports the joint

above and below the injury. Ice should be applied 3-4 times

daily for no more than 20 minutes at a time during

the first 72 hours. Elevation of the injury will also help

reduce swelling and pain. Gentle compression with elastic

bandages can provide additional support to soft tissue

injuries, though tight wrapping can induce compartment

syndrome. Narcotic medications are preferred for fractures.

Nonsteroidal anti-inflammatory drugs may inhibit bone

healing and are therefore recommended only for soft-tissue

injuries without underlying fractures.

..... Shoulder Dislocation

After successful reduction, apply a sling or shoulder immobilizer. The patient should be instructed to avoid external

rotation of the arm, although early range of motion is

often recommended for patients with shoulder injuries,

especially in the elderly.

..... Shoulder Separation

Initial treatment of a first-, second-, or third-degree injury

is a sling and pain control.

..... Humerus Fracture

A coaptation splint is applied for humeral shaft fractures,

whereas a shoulder sling alone suffices for proximal fractures. Both injuries must be referred to an orthopedist for

follow-up. Radial nerve injuries should be documented

and are often managed conservatively.

..... Distal Radius Fracture

Closed reduction is recommended for displaced fractures

with immobilization in a sugar tong splint.

..... Scaphoid Fracture

Because of the high risk of avascular necrosis with these

fractures, a patient with wrist pain and anatomical

snuffbox tenderness should be assumed to have a scaphoid fracture and immobilized with a thumb spica splint

and referred for follow-up, even if radiographs are

negative.

..... Metacarpal Fracture

These fractures will require reduction if significant angulation is present, followed by a radial or ulnar gutter

splint.

..... Carpal Dislocation

Placement in a volar splint and orthopedic consultation for

reduction and operative repair.

..... Mallet Finger

This injury must be splinted in extension for 6 weeks to

allow for proper tendon healing.

..... Tendon Injury

Treatment of open tendon injuries in the ED includes thorough wound irrigation, laceration repair of skin wounds if

indicated, and prophylactic antibiotics. Extensor tendon

injuries should be splinted in extension, whereas flexor

tendon injuries are splinted in flexion. Complete open

tendon injuries require referral to a hand surgeon for tendon repair within a 7 -day period.

DISPOSITION

..... Admission

Admission is indicated after orthopedic consultation for

irreducible fractures or dislocations, open fractures,

suspected compartment syndrome, or planned surgical

repair. Admission for observation should also be considered

for any injuries that are at high risk for early complications

such as infection or compartment syndrome, or those that

render patients unable to care for themselves.

..... Discharge

Most patients with upper extremity injuries are appropriate to

discharge home after proper splinting and analgesia. Specific