PEM Board Review
Chapter 19: Trauma: Orthopedic & Hand
A nondisplaced supracondylar fracture: although there is no obvious bony abnormality,
the presence of a displaced anterior fat pad and a visible posterior fat pad suggest
distention of the joint capsule:
In the setting of a traumatic injury, this is likely a hemarthrosis due to an intra-articular
fracture. Although an anterior fat pad may be normal, if present, as a thin radiolucency
just anterior to the distal humerus, anterior displacement (“sail sign”) or the visible
presence of the posterior fat pad are pathologic and suggest an underlying fracture.
Appropriate management for such a fracture includes application of a posterior long-arm
splint or long-arm cast and orthopedic follow-up care.
Supracondylar fractures are the most common elbow fractures in children, with a peak
incidence seen between the ages of 4 and 7 years. The most common causative
mechanism is a fall onto an outstretched hand with the elbow in extension. Due to the
position of the olecranon relative to the distal humerus when the elbow is extended,
fracture through the supracondylar region with varying degrees of (most commonly)
posterior displacement of the distal humerus results.
Subtle displacement can be appreciated using the anterior humeral line; a line drawn
along the anterior cortex of the humerus should intersect the middle third of the
capitellum. If it crosses the anterior third, posterior displacement is present & vice versa.
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If there is incomplete reduction or persistent neurovascular compromise, open reduction
and fixation is performed. Diminished pulses or decreased perfusion that does not
improve after reduction requires further evaluation with either surgical exploration or
angiography. Volkmann ischemic contracture can result from unrecognized vascular
compromise due to the fracture itself, vessel injury during reduction, or compartment
syndrome.
Orthopedic consultation is appropriate for a displaced supracondylar fracture, an open
fracture, or a fracture with neurovascular compromise. Displaced fractures with
neurovascular compromise require sedation and emergent reduction. Displaced fractures
with intact neurovascular status can be reduced on a nonemergent basis.
The estimated incidence of neurovascular injury in supracondylar fracture is 8% to 12%,
which increases substantially if the fracture is displaced. The absence of a radial pulse is
reported in 7% to 12% of all supracondylar fractures and 19% of displaced fractures. The
most common nerve injured is the median (28% to 60%), followed by the radial (26% to
61%) and ulnar (11% to 15%). The brachial artery is the most commonly injured vascular
structure in posteriorly displaced fractures. Thus, a detailed neurovascular examination is
critical, including palpation of distal pulses and assessment of skin color, temperature,
and capillary refill as well as sensory and motor aspects of the median, ulnar, and radial
nerves. If the pulse is weak, Doppler ultrasonography should be undertaken. One of the
earliest signs of ischemia is pain on passive flexion of the fingers, but such a finding is
not possible to elicit in a comatose or an anxious child. Vascular injury can lead to
compartment syndrome, with associated necrosis and fibrosis of the involved
musculature.
Some controversy surrounds whether a supracondylar fracture should be reduced
immediately in the emergency department or be reduced in the operating room. A cool,
pulseless hand that is still pink suggests some limb perfusion, and reduction in the
emergency department might cause more harm and further impair flow. Radiography in a
splinted position is needed to determine the extent of displacement. If the hand is cold,
white, and pulseless, the clinician should perform gentle, inline traction in the emergency
department to determine whether flow can be re-established prior to obtaining a
radiograph.
Application of a volar splint is appropriate for a distal forearm buckle fracture. This
injury results most commonly from a forward fall onto an outstretched hand. Focal pain,
tenderness, and swelling are present in the distal forearm.
Supination of the forearm and flexion of the elbow while palpating over the radial head is
one of two accepted methods for reducing radial head subluxation (nursemaid's elbow).
Affected patients typically present with a history of being pulled by the involved arm.
The injured arm is held in a pronated, slightly flexed, and adducted position, and there is
generally no swelling or focal tenderness.
Felon: an abscess of the digital pulp that is characterized by severe pain, swelling, and
erythema of the pad of the fingertip. The distal phalanx encloses a connective tissue
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framework in which multiple trabecula divide the pulp, which is composed of fat
globules and eccrine sweat glands. The sweat glands open to the epidermis, providing a
portal of entry for bacteria. Felon often is associated with a history of preceding minor
penetrating trauma, such as a minor cut, splinter, or sliver. This closed compartment
abscess requires urgent incision and drainage to prevent complications of osteomyelitis
and necrosis of the finger tip.
Local anesthesia should be achieved with a digital block. The preferred incision for
drainage of a felon is parallel to the long axis of the digit and over the site of maximal
fluctuance (volar longitudinal incision). The incision should not cross the distal
interphalangeal joint, which could cause the complication of flexion contracture. In
addition, probing proximal to the incision may cause extension of infection into the flexor
tendon sheath. Lateral incisions are less preferred because of the potential for inadvertent
injury to the digital nerves, which run along the radial and ulnar border of the digit. The
“hockey stick” and “fishmouth” incisions (transverse incision at the distal tip of the
finger) are associated with an increased risk of iatrogenic complications, which include
permanent anesthesia, unstable fat pads, pain, and unacceptable scarring.
After successful I&D of a felon, the wound should be packed with petrolatum gauze and
the finger immobilized. A relative contraindication to drainage of a felon is more
extensive finger and hand involvement, such as flexor tenosynovitis, which requires
management by a hand surgeon. Administration of oral antibiotics to cover staph and
strep is appropriate. IV ABX are not necessary if the wound is drained adequately.
Paronychia is an inflammation or abscess of the lateral or posterior nailfolds. Occurs after
minor local trauma, such as nail-biting, that disrupts the eponychial fold (cuticle),
allowing bacteria to enter. Treated with warm soaks and antistaphylococcal oral ABX. If
an abscess has formed, I&D is performed with an 11-blade scalpel along the cuticle of the
involved nail margin, followed by warm soaks. Oral antibiotics also may be prescribed.If
herpetic Whitlow is suspected, antibiotics are not indicated, and incision and drainage is
contraindicated.
The patient described in the vignette has suffered major trauma and has multiple areas of
injury that require prompt care. The first priority, after initial stabilization, is to salvage
the left hand, which is showing signs of neurovascular compromise (absent radial pulse,
pale and cool extremity). The patient likely has a supracondylar fracture of the left
extremity. The presence of signs of ischemia is an indication for immediate consultation
with orthopedic surgery for reduction of the fracture.
The injury sustained by the boy described in the vignette is suggestive of a fracture of the
scaphoid (navicular) bone. The typical mechanism for this fracture is a fall onto an
outstretched arm. Despite the lack of radiographic abnormality, he should be assumed to
have a nondisplaced fracture until proven otherwise. Approximately 10% to 20% of
patients who have scaphoid fractures do not have visible fracture lines on any
radiographic view in the acute setting. Therefore, in the presence of a clinical suspicion
(tenderness at the anatomic snuff box or pain on axial loading of the thumb),
immobilization in a thumb spica splint is recommended, followed by repeat radiographs
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and physical examination in 2 weeks. If the patient is pain-free and radiographs are
negative at the time of follow-up, he or she may return to usual activities. If the
radiographs are negative but pain persists on physical examination, the patient should
undergo further imaging, such as magnetic resonance imaging. Because elastic bandages,
commercial air splints, short arm volar splints, and slings allow mobility of the scaphoid
bone, they should not be used when scaphoid fracture is suspected. Nonunion is rare in
pediatric patients (<5%), but delayed diagnosis and improper or inadequate
immobilization increase this likelihood.
Most pediatric scaphoid fractures occur in teenage patients who sustain a fall on an
outstretched pronated arm. Skateboarding and bicycling are the most frequent sports
precipitating injury. Recommended treatment for avulsion type and incomplete fractures
is immobilization for 4 to 6 weeks in a thumb spica cast. Most authors recommend 6 to 8
weeks of immobilization for middle third (waist) and transverse fractures. Some authors
recommend a long arm cast initially, followed by short arm cast. Complications are more
common with misdiagnosis and late presentation.
Figure
Grisel’s Syndrome: atlantoaxial rotary subluxation associated with inflammation or
infection. If the subluxation is minimal and < 1 week in duration, no traction is required.
All types show rotary displacement plus a) Type I: no anterior shift of axis; b) Type II:
anterior shift <5mm; c) Type III: anterior shift > 5 mm; and d) Type IV: posterior shift of
the axis. Treatment for Type I: soft cervical collar, analgesics, bed rest. Tx if sx’s 1-4
weeks: Hospitalization with halter traction, c-collar for 4-6 weeks; Tx if sx’s > 4 weeks:
Hospitalization with skeletal traction, C-collar for 4-6 weeks.
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Pseudosubluxation of C2 on C3 may be visible in up to 30% of lateral C-spine x-rays of
children < 8 years old. Swischuk described the spinolaminar line, which is a line
connecting the anterior edges of the spinous processes of C1 and C3. The line should
pass through the cortex of the anterior edge of the spinous process of C2 or be less than
1-2 mm anterior to it. A larger distance warrants further investigation for a fracture.
Fracture of the arch of C2 would be highest on the differential. The malalignment in
pseudosubluxation is accentuated in flexion. The prevertebral soft tissue should be less
than half the width of the adjacent vertebral body.
Sever’s Disease: a calcaneal apophysistis, an overuse injury associated with running and
jumping sports, especially in poorly cushioned cleats. It is seen in skeletally immature
athletes, and may be associated with growth spurts in either gender. Symptoms are
intermittent heel pain, positive squeeze test of heel, a tight Achilles Tendon, and pain
over the calcaneal apophysis. Treatment: Achilles tendon stretching, a heel cup for the
athletic shoe, and icing before and after physical activity.
Iselin’s Disease: A apophysitis at the base of the 5th metatarsal.
Stress fractures are less common in prepubescent athletes.
Monteggia Fracture: a combination of a fracture of the middle or proximal ulna and a
proximal dislocation of the radial head. Radial head alignment is assessed on a lateral
film by the radial-capitellar line—a line drawn through the axis of the radial shaft that
should bisect the capitellum in all views—need to assess elbow!
Galeazzi Fracture: Middle to distal Radial fracture with distal ulna dislocation. These
children will have difficulty with wrist pronation and supination—need to assess wrist!
A Triplane Fracture involves the metaphysis (sagital plane), physis (transverse plane),
and epiphysis (coronal plane). It is a type of SALTER IV fracture. It is more common in
ages 12-15 years with partial closure of the tibial physis. Fibular fractures are often
associated with this injury. Closed reduction may be adequate, but CT scan, to fully
assess the alignment of the articular surfaces, is necessary to determine appropriate
treatment. Those with residual displacement of >2 mm after closed reduction will require
open reduction and fixation (> 50% of patients end up needing this).
Remodeling of fractures in children allows for good outcomes with less than perfect
initial alignment. Fractures that are closer to the growth plate have a better potential for
remodeling with time. Bowing deformities do not remodel well, and often need
reduction. “Acceptable allowances” in angulation and rotation are more conservative in
patients over 10 years of age or who have less than 2 years of growth potential.
Allowances in angulation for distal radius buckle fractures are up to 20 degrees for
children less than 8-10 years old, and up to 10 degrees of angulation for those over 10
years old. In general, shortening of only 1 cm or less is acceptable.
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Little League Elbow: Tenderness of the medial epicondyle from overuse; it precedes a
fracture of the medial epicondylar apophysis. Ulna nerve dysfunction can occur with
widely displaced fractures or when the fragment is impacted in the elbow joint, and
emergent open reduction may be required to restore nerve function. The elbow should
NOT be manipulated in a closed manner with evidence of nerve injury or compression!
Hip dislocations in adolescents are usually the result of high impact trauma, such as high
speed MVC’s, but not so in younger children. A posterior dislocation is much more
common than an anterior dislocation. Under sedation, a posterior dislocation is reduced
with the patient supine; the pelvis is stabilized by an assistant, longitudinal traction is
applied to the thigh with the leg still in adduction and internal rotation, and, when
adequeate muscle relaxation is achieved as evidenced by the return of the leg to normal
length, the hip is flexed to 90 degrees and then gently abducted and externally rotated
while extending the hip. To reduce an anterior hip dislocation, place the child supine,
and pull the leg upward with the knee flexed. Reducing these dislocations within 6 hours
reduces the risk of osteonecrosis.
Sling and swath, with follow-up Ortho visit in 1 week is adequate for uncomplicated
proximal humerus fractures without neurovascular compromise.
Open physeal fractures (Seymour’s Fracture) of the distal phalanx should have the nail
removed, the nail bed repaired and the dorsal nail fold splinted open and oral antibiotics
are adequate.
The ACL is the most commonly torn ligament in the knee. Both the Lachman (preferred)
and the anterior drawer test are abnormal. These are performed with the hip and knee in
20-30 degrees and 90 degrees of flexion, respectively. While stabilizing the knee, the
proximal tibia is anteriorly stressed. Movement of greater than 2 mm compared to the
other knee, a “soft endpoint” or increased pain are considered abnormal. A posterior
drawer test is used to test the integrity of the posterior cruciate ligament. McMurray and
Apley tests are used to diagnose meniscal injuries, which usually present with medial or
lateral joint line pain. The patellar apprehension test is used to evaluate patellar
subluxation.
Avulsion of the apophysis of the iliac crest is common in adolescents. The crest is
attached to the external and internal oblique abdominal muscles. Increasing pain will be
elicited with active flexion of the torso. Treatment consists of bed rest, ice, pain
medications, then non-weight bearing for 2-4 weeks followed by PT. Internal fixation is
considered if the fragment is displaced > 20 mm.
The most common pelvic apophyseal injury in adolescents involves the anterior superior
ileac spine (injured with forceful contraction of the Sartorius), then the anterior inferior
iliac spine (rectus femoris) then the ischial tuberosity (hamstrings), then iliac crest
(abdominal obliques).
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For finger fractures, ANY rotational deformity should be initially corrected with closed
reduction, and, if unsuccessful, with internal fixation.
A skier with tenderness at the base of the ulnar aspect of the thumb after falling who has
normal x-rays should be placed in a thumb spica splint for 3-6 weeks for a possible
avulsion of the ulnar collateral ligament of the proximal phalanx of the thumb—
commonly referred to as “skier’s” or “gamekeeper’s thumb”. You will see adduction
instability of the first MCP joint of the thumb.
Ulnar Nerve: wrist flexion, finger spread, and power grasping; also sensory to the ulnar
aspect of the 4th finger and the entire 5th finger; injured in anterolaterally displaced
supracondylar fractures.
Median Nerve: flexion at the PIP joints, opposition of the thumb and 5th finger; anerior
interosseous branch is tested with OK sign. Sensory to the 1st, 2nd, 3rd, and radial aspect
of 4th; injured in posterolaterally displaced supracondylar fractures.
Radial Nerve: wrist extension, thumbs up sign; sensation to the radial aspect of the
dorsum of the hand; Injured in posteriomedially displaced supracondylar fractures.
Gustilo Classification of open fractures with increased risk of complications with
progressively higher numbers is:
Type I: wound < 2 cm
Type II: wound 2-10 cm
Type III: wound > 10 cm
A: adequate soft tissue coverage
B: inadequate soft tissue coverage
C: associated arterial injury
Patients who have pain in their anterior tibial area out of proportion from what would be
expected from a simple flare of Osgood-Schlatter could have a fracture of the tibial
tubercle (which may be confused with Osgood-Schlatter Disease). It carries an increased
risk of compartment syndrome due to tearing of the anterior tibial compartment vessels.
A patient should be placed in a posterior splint and transferred immediately to a tertiary
care center. Early signs of compartment syndrome are pain disproportionate to the
injury, and increased pain with active flexion and passive extension. A compartment
pressure > 30-40 mm Hg or within 30 mm Hg of the diastolic BP is abnormal.
For Proximal Femur (Head and neck) fractures, the Delbet Classification, unlike other
schemes is worse with a lower number: I-III are intracapsular and have a higher risk of
vascular damage. Type IV (intertrochanteric) is outside the joint capsule and has a
decreased risk of complications.
In a younger child with a twisting knee injury who hears a “pop” and has a hemarthrosis,
the most common cause is patellar dislocation, followed by tibial tubercle avulsion,
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followed by tibial spine avulsion. Tunnel views should be ordered to evaluate the tibial
spines in young children (in addition to standard views).
For evaluating fractures of the metacarpals and phalanges, the physical exam is more
accurate than x-rays in assessing for rotational injuries. When the fingers are flexed to
the palm, all fingers should point to the scaphoid bone, and all the nails should be parallel
with NO overlap of the fingers.
The usual treatment for a boxer’s fracture (metacarpal neck fracture) is ulnar gutter splint
with ortho follow-up in one week. However, closed reduction should be performed
when:
A) > 10 degrees of angulation in the 2nd and 3rd metacarpals
B) > 20 degrees of angulation in the 4th metacarpal
C) > 30 degrees of angulation in the 5th metacarpal
Capitellum articulates with radius; Trochlea articulates with ulna “C-T” on AP view.
Median nerve is the most common nerve injury in supracondylar fractures.
A line drawn along the midshaft of the proximal radius should intersect the capitellum in
all radiographic views.
CRITOE: age at which elbow ossification centers appear: 1,3, 5, 7, 9, 11.
C=capitellum
R=radius
I=internal (medial) epicondyle
T=trochlea
O=olecranon
E=external (lateral) epicondyle
Elbow dislocations: uncommon in children; most are posterior and closed. Nerve
entrapment or a fracture fragment in the joint mandates surgery.
For greenstick fractures, the angulation is overcorrected toward the cortical break, in
essence, completing the fracture to prevent persistent angulation and subsequent
deformity. A splint is then applied.
For subungual hematomas > 25% nail removal and nail bed repair is often advocated but
you can trephinate instead if the nail and nail margin is intact.
Ankle Fractures: Tillaux fracture and Maisonneuve Fracture are at the more severe end
of the injury spectrum.
Tillaux Fracture: A Salter III fracture of the lateral distal tibia (due to asymmetric
closing of the growth plate. CT may be required to see it and open reduction and internal
fixation are usually required.
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Maisonneuve Fracture: is actually 2 fractures—the first is a medial malleolar fracture of
the distal tibia. The second is an oblique fracture of the proximal fibula. There is
consequent disruption in the interosseous membrane between the tibia and fibula and the
ankle joint is unstable—subsequent diastasis of the joint is likely. Require open
reduction and internal fixation; pitfall—focusing the physical exam and x-rays just on the
ankle and missing the proximal fibula.
Ottawa Knee Rules: Obtain knee radiographs if there is a history of acute knee injury and
at least one of the following:
 Inability to walk 4 steps immediately after the injury and in the ED (regardless of
limp)
 Tenderness over the patella
 Tenderness of the head of the fibula
 Inability to flex the knee to 90 degrees
 Age greater than 55 years
Ottawa Ankle Rules: Obtain ankle radiographs if there is acute ankle injury and at least
one of the following:
 Inability to bear weight (4 steps) immediately after the injury and in the ED
(regardless of limp)
 Tenderness to palpation over the posterior edge or tip of the lateral malleolus
 Tenderness to palpation over the posterior edge or tip of the medial malleolus
Ottawa Foot Rules: Obtain foot radiographs if there is a history of acute foot injury and
at least one of the following:
 Inability to bear weight immediately after the injury and in the ED
 Tenderness to palpation over the base of the 5th metatarsal
 Tenderness to palpation over the navicular bone
Displaced fractures of the calcaneus and the midfoot sustained under a high-impact
mechanism require ortho consultation in the ED. Avascular necrosis and compartment
injuries are serious complications of these Lisfranc-type injuries (tarsometatarsal joint
injuries after a midfoot plantar-flexion injury).
Pseudo-Jones Fracture (Dancer’s Fracture): avulsion of the proximal 5th metatarsal—tx—
hard soled shoe for 2 weeks
Jones Fracture: fracture to the neck of the 5th metatarsal (more distal than pseudo-Jones);
higher complication rate due to low vascular area therefore treatment is posterior splint
and non-weight bearing with crutches.
Compartment Syndrome: 6 P’s!! pain, pallor, pulselessness (palpable pulse does NOT
exclude diagnosis!), paresthesia, prolonged capillary refill, and paralysis. Pallor and
pulselessness are late findings. Early findings are disproportionate pain and pain on
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passive stretch. Increased pain and decreased sensation are cardinal signs that a
compartment syndrome is beginning.
The boy described in the vignette has a clenched-fist injury with signs suggestive of
tenosynovitis or early septic arthritis, necessitating inpatient management with parenteral
antibiotics for a likely bacterial infection.
Human bite injuries can be occlusional, in which the upper and lower teeth come together
on a body part, or clenched-fist, in which the dominant hand typically strikes the teeth of
another person. The former are more common in the young preschool child and more
likely to occur on the face, upper extremities, or trunk. Child abuse should be suspected if
the intercanine distance is greater than 3 cm (suggestive of an adult perpetrator) or
occlusional bites are present on the genitals of a young child. Clenched-fist injuries are
the most serious of human bite wounds and are more common in adolescents. Abrasions
or lacerations occur typically on the fourth and fifth metacarpals. In many instances, the
injuries are trivial and ignored by the patients. Clenched-fist injuries are highly prone to
infection because of the proximity of the bone, joint capsule, and tendon to the overlying
skin. In addition, relaxation of the skin and soft tissue after the fist is unclenched allows
the oral microbes to enter a deeper and now effectively closed space, leading to septic
arthritis, osteomyelitis, or tenosynovitis.
Management of lacerations includes copious irrigation with sterile saline and removal of
debris. Surgical evaluation to determine involvement of nerves, muscles, tendons, and
bone is important. In general, lacerations should be left open and re-evaluated in a few
days for delayed primary closure. Very large lacerations may be candidates for primary
closure. Because most human clenched-fist wounds are small, local wound care,
elevation of the injured extremity, and splinting and immobilization are indicated.
Antibiotic prophylaxis is indicated in clenched-fist bites, deep puncture wounds, wounds
requiring surgical repair, and those with associated crush injury. Monotherapy with
amoxicillin-clavulanic acid is the prophylactic measure of choice. Alternatively, a twodrug regimen composed of an antibiotic active against Eikenella (doxycycline,
trimethoprim-sulfamethoxazole, penicillin VK, cefuroxime, ciprofloxacin) and an
antibiotic active against anaerobes (metronidazole or clindamycin) may be used.
Antibiotics that are ineffective against Eikenella, including dicloxacillin, cephalexin, and
erythromycin, should not be prescribed as monotherapy.
Individuals who have infected hand wounds, should be hospitalized for evaluation and
parenteral antibiotic therapy. Empiric antibiotic therapy with a beta-lactam/betalactamase inhibitor combination such as ampicillin-sulbactam, piperacillin-tazobactam,
or ticarcillin-clavulanic acid should be initiated pending culture results. Alternate options
include a third-generation cephalosporin with metronidazole or fluoroquinolones with
metronidazole.
The boy described in the vignette has an exsanguinating external hemorrhage and signs
of compensated shock. The priorities that must be addressed simultaneously are control
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of the hemorrhage and restoration of blood volume. The first step in attempting to control
the hemorrhage is to apply direct pressure, which should be undertaken while
simultaneously obtaining vascular access with at least two large-bore intravenous or
intraosseous catheters.
If bleeding cannot be stopped with direct pressure, use of the Windlass technique may be
helpful. In this technique, a dressing is applied to the wound and held in place by a broad
bandage that is secured by tying a knot directly over the wound. A pen or other
cylindrical object is placed under the knot and rotated several times before being secured
in place. This allows for maximal and sustained pressure directly over the wound. If the
bleeding still cannot be stopped, application of a tourniquet may allow for stabilization
until the patient can be brought to surgery.
Although the use of tourniquets have been discouraged in the past due to concerns for
ischemic injury, including injury to neurovascular structures, military experience in
recent conflicts has shown they can play a safe role in temporarily controlling
hemorrhage, especially in the prehospital setting. It is now accepted that a tourniquet may
be left in place for up to 2 hours without significant risk of permanent ischemic injury.
Multiple commercial tourniquet devices are available, and some trials have compared the
effectiveness of various devices, but results do not conclusively support one device over
another.
Tourniquets that are applied in the prehospital setting should be left in place until the
patient is transported to a site where definitive care is possible. In the emergency
department, use of a tourniquet may allow for stabilization until the patient can be taken
to the operating room. However, if a tourniquet has been in place and bleeding seems to
be controlled, a trial of releasing it may be carefully undertaken. If hemostasis has been
achieved it may sometimes be maintained after release of the tourniquet. In patients who
are awake, the pain produced by ischemia with tourniquet use may require analgesics,
including opioids if the patient is stable.
Obtaining vascular access and attempting to restore blood volume without addressing the
ongoing hemorrhage for this patient would likely be ineffective. Repair of an arterial
laceration, as in this case, without operating room resources would have a small chance
of success. Oversewing or stapling large scalp lacerations to obtain hemostasis can be
efficacious, but this approach usually is not successful in vascular injuries of the limbs.
In a study of nearly 300 children who had acute hip pain, Kocher and
associates developed a clinical evaluation tool to determine the
likelihood of septic arthritis. After retrospectively reviewing all of the
cases, they used univariate analysis and multiple logistic regression
analyses to compare patients who had true or presumed septic
arthritis with those who had other diagnoses. Four predictors were
ultimately identified:
• Fever > 38 (100.4)
• Elevated white blood cell count (>12x103/μL [12x103/L])
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• Elevated inflammatory marker(s) (ESR >40 mm/h)
• Inability to bear weight
The likelihood of septic arthritis based on number of predictors was:
less than 0.2% with zero, 3% with one, 40% with two, 93% with
three, and 99.6% with four predictors. Based on this algorithm, this
girl had one predictor (fever) and a resultant 3% likelihood of having
septic arthritis.
If results of the initial laboratory and radiographic evaluations are
normal and the child is able to bear weight, discharge with outpatient
follow-up is appropriate. Children who have fever and elevated
inflammatory markers or white blood cell counts should receive further
evaluation for possible septic arthritis, osteomyelitis, or tumor. Such
evaluation may include computed tomography scan, magnetic
resonance imaging, bone scintigraphy, or ultrasonography to identify
joint effusion or to guide joint aspiration. Hospitalization should be
considered for patients who are unable to bear weight after
administration of appropriate analgesic agents.
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