Trauma about the Elbow I: Overview, Supracondylar, and Transphyseal Fractures

Up to 20% of displaced supracondylar fractures present
with an absent pulse. To clarify one’s thinking, consider three
clinical scenarios:

A child with a poorly perfused, pulseless hand requires
urgent treatment. If practical, an immediate attempt at closed
reduction in the operating room is ideal. If this is not practical,
gentle traction and placement of the elbow in 20 to 40 degrees of
flexion should be performed. Note that the this maneuver is not
an attempt to anatomically reduce the fracture, as further injury to
neurovascular structures is possible, and an acceptable reduction is
unlikely without the use of fluoroscopy and K-wires. Vascular
compromise is usually positional, with the proximal fragment often
causing occlusion of the brachial artery. Most frequently a child with
a poorly perfused, pulseless hand, whose arm was splinted in full elbow
extension prior to arrival at the hospital, will have significant
improvement in vascular perfusion by simply flexing the arm to 20 to 30
degrees (Fig. 5-8). Arteriograms generally have
no role in preoperative evaluation of the pulseless supracondylar
fracture, as they delay treatment and most frequently contribute no
useful information.²

Following a closed reduction of the fracture with a
poorly perfused, pulseless hand, perfusion usually returns. If the hand
remains poorly perfused and pulseless, operative exploration is
indicated. An anterior approach is appropriate

when
the purpose of the approach is for arterial exploration. Be aware that
at times the artery itself is not trapped in the fracture site, but
soft tissue adjacent to the artery is trapped, tethering the artery
just enough to stop flow. If the hand is still poorly perfused after
exploration and removal of an entrapped or tethered artery from the
fracture site, a general or vascular surgical consult is wise (Fig. 5-9).

If following closed reduction, the hand is pulseless but
warm and well perfused management is controversial. Some favor arterial
exploration and repair if needed at that time. With such excellent
collateral circulation about the elbow, close in-hospital observation
of at least 48 hours and mild elevation is usually sufficient, with an
understanding that if the hand loses perfusion an urgent return to the
operating room may be necessary.

With proper vigilance, compartment syndrome should be
very infrequent. A great way to minimize the risk of compartment
syndrome is to avoid elbow flexion greater than 90 degrees (Fig. 5-10).
With the predictable efficacy and safety of closed reduction and pin
fixation, elbow hyperflexion should no longer be used to hold a
fracture reduction. As a general rule, if an elbow needs to be held in
more than 90 degrees of flexion to keep the fracture reduced, using
k-wires to maintain the reduction is probably safer. In a child with a
supracondylar fracture, as elbow flexion increases, forearm compartment
pressures increase dramatically³ and brachial artery flow decreases.⁴

There are particular presentations that deserve special
attention. If the elbow is excessively swollen, perhaps with anterior
skin tenting (which suggests significant soft-tissue injuries),
treatment should be urgent to prevent compartment syndrome and
soft-tissue injury. Patients with a concomitant forearm fracture should
be closely watched for compartment syndrome as well. Particularly in
children, soft findings such as paresthesias are difficult to
interpret, and worsening pain is the most valuable sign of developing
compartment syndrome. As in adults, follow the golden rule for staying
out of trouble: if you are thinking about compartment syndrome, you
should probably measure compartment pressures or release the
compartments. One may want to consider avoiding narcotics for pain
management to better follow an examination in children at high risk for
compartment syndrome.

A situation that has resulted in lawsuits is a
compartment syndrome that was initially unrecognized in the setting of
a median nerve injury. Any child with impaired sensation, either from
local nerve injury or decreased mental status, should be closely
evaluated for compartment syndrome.

Posteromedially displaced fractures are associated with
AIN (anterior interosseous nerve) injuries, posterolaterally displaced
fragments with radial nerve damage, and flexion type fractures with
ulnar nerve injury. Nerve damage at the time of injury should be
observed; it usually improves within 3 months. One exception to this is
an open fracture, for which exploration of the nerve should be
considered if it would not require extensive dissection. An ulnar nerve
palsy following fixation with a medial pin most often resolves within 4
months, and removal of the medial pin upon recognition of the nerve
injury is controversial, though probably a good idea.⁵ If the surgeon chooses to remove the medial pin before the fracture is healed, loss of fracture reduction

is a potential pitfall. Thus, medial pin removal in a potentially
unstable fracture should occur in the operating room only after an
additional pin has been placed to ensure maintenance of fracture
reduction after medial pin removal.

Loss of median nerve function after surgical reduction
should raise the concern that the nerve may be trapped or tethered at
the fracture site (see Figure 5-9). If on the lateral x-ray there is a gap at the fracture site, surgical exploration may be indicated.

Often, reduction and pinning of a supracondylar fracture
can safely wait until morning. There are now at least four studies
reporting that mean delays of 8 to 21 hours in the treatment of
supracondylar humerus fractures do not increase the risk of
complications or need for an open reduction. These studies must be
interpreted with a great deal of caution, as they are retrospective.
One interpretation of these studies is that orthopaedic surgeons’
clinical judgment in determining which fractures needed urgent
treatment was correct, and we should therefore continue to have a high
vigilance for fractures at risk. Most Type II and III fractures without
undue swelling, skin puckering from the proximal fragment, significant
vascular impairment or signs of compartment syndrome do not require
urgent surgery. Children awaiting surgery may have their arms splinted
in 20° to 50° of elbow flexion, elevated, and checked every hour or two
by someone capable of recognizing signs of trouble.

A type I fracture may be treated in a long arm cast for
about 3 weeks. It has been recommended that in order to reduce and
maintain reduction of a type II extension supracondylar fracture
without pins, the elbow must be flexed to at least 120 degrees. While
good results are certainly possible with this technique, it is more
predictable to perform a closed reduction and pinning of any displaced
supracondylar fracture (see Figure 5-10).
Anecdotally it appears that more malpractice suits are generated from
malreduction of type II fractures than type III fractures. As there is
relatively little growth in the distal humerus, significant remodeling
can not be relied on, even in the plane of motion. Stay out of trouble
by pinning type II fractures.

One type of supracondylar fracture deserves special
mention—the apparently minimally displaced fracture with medial
comminution or impaction and a change in Baumann’s angle.⁶ This fracture pattern is easy to mistake for a Type I fracture and treat nonoperatively, which would result in cubitus varus (Fig. 5-11).
Operative reduction can usually be achieved by applying a significant
valgus force on a fully extended elbow, followed by flexion, pronation
(to maintain tension across the medial column), and pinning.

Type III fractures should be reduced and pinned.
Particularly in children with preoperative vascular compromise or AIN
palsy, beware of the reduction that feels “rubbery” as the brachial
artery or median nerve may be trapped in the fracture site. The
criteria for accepting a closed reduction are:

Note that a few millimeters of translation is
acceptable. A fair amount of rotation is also acceptable, as the
shoulder joint can make up for it. Open reductions

should
be done to remove interposed tissue, but only after a very patient
effort at closed reduction has failed. The opened elbow may be stiffer
than those treated closed, and the scar can be unsightly.

Cubitus varus is a function of inadequate reduction in
the frontal plane. It does not occur as a result of a medial growth
arrest, as there is too little growth in the distal humerus to cause
this deformity within months of injury. After pinning, full extension
of the arm is often not possible, so the clinical exam may be
unreliable. There is no way to avoid this complication other than being
strict in obtaining and carefully scrutinizing adequate quality
imaging, confirming that the fracture is not in cubitus varus.

Iatrogenic injury of the ulnar nerve has been reported
in 5-6% of the two largest series of operatively treated supracondylar
fractures. This complication is predictably avoided by avoiding the use
of a medial pin.

A review of supracondylar fractures pinned with lateral
pins that lost reduction revealed the cause was always secondary to
errors in pin placement, such as pins crossing or immediately adjacent
to each other at the fracture site (Fig. 5-13). No failures in cases fixed with 3 lateral pins were identified.⁷

If the surgeon chooses to use a medial pin, avoiding
injury to the ulnar nerve is a complex issue. One thing that is certain
is not to place a medial pin when the elbow is flexed. The Boston
Children’s group reported that in children less than five years of age,
when the elbow is flexed more than 90 degrees, the ulnar nerve migrated
over, or even anterior to, the medial epicondyle in 61% of children.⁸
Unfortunately, even making an incision over the medial epicondyle to
make certain the ulnar nerve is not directly injured by a pin does not
ensure protection of the nerve.⁹ In
a series of six cases of iatrogenic ulnar nerve injuries with early
exploration, the nerve was directly penetrated by the pin in only two
cases, with constriction of the cubital tunnel in three cases, and the
nerve fixed anterior to the

medial epicondyle in one case.¹⁰
Thus even if direct penetration of the ulnar nerve is avoided, simply
placing a medial epicondyle entry pin adjacent to the nerve may cause
injury.

As supracondylar humerus fractures are so common and so
predisposed to trouble, a detailed discussion of surgical technique is
warranted. Traction is applied in line with the humerus, with the elbow
in slight flexion. Avoid traction in full extension as this may cause
tethering of neurovascular structures over the proximal fragment. If
there is suspicion that the proximal fragment has pierced through the
brachialis muscle, persistent, gradual traction of the slightly flexed
elbow for a full minute will often reward you with a palpable freeing
of the proximal fragment. Alternatively, the proximal to distal
“milking” maneuver over the brachialis may achieve the same end.¹¹ Freeing the proximal fragment from soft-tissue entrapment is essential for an anatomic reduction, and worth the time invested.

For the reduction maneuver, hyperflex the elbow while
pushing in an anterior direction on the olecranon. Keep the elbow
hyperflexed during fluoroscopic assessment. An AP image is difficult to
interpret with the proximal ulna and radius overlying the fracture
site. However, slightly oblique views allow assessment of the
continuity of the medial and lateral columns and Baumann’s angle.

If there is significant rotation present, repeat the
reduction with two additional maneuvers. If the distal medial column is
still posterior (most commonly internally rotated), press selectively
harder on the medial side during the reduction, and pronate the forearm
during the reduction as well. The opposite applies for an externally
rotated distal fragment. If Baumann’s angle is not clearly at least 10
degrees, or medial comminution remains, repeat the reduction while
stressing the arm in valgus.

When the reduction is acceptable, surgeons who like to
relax, such as the author, may tape the arm with Coban in the
hyperflexed, reduced position to effortlessly maintain reduction.
Lateral entry pins are placed first by the above technique, being
certain to go through the proximal cortex, and pin position is assessed
with AP and lateral imaging. The arm is then straightened and the

carrying
angle is assessed clinically, at which point Baumann’s angle is
assessed again with AP imaging. The arm is then subjected to varus and
valgus, flexionextension and rotational stress under live AP imaging to
assess fixation. If there is any question of stability, place a third
pin, lateral or medial, depending on surgeon preference and fracture
pattern, then reassess stability by stressing the fracture under live
imaging.

Neurovascular status is assessed, and the arm is casted
in about 30 to 70 degrees of elbow flexion depending on swelling, but
certainly no less than 20 degrees of extension greater than the amount
of flexion at which the pulse disappears. Pins should be bent 90
degrees to help prevent subcutaneous migration, with the skin protected
by sterile felt or petroleum jelly-impregnated gauze. Foam padding
placed directly on skin, with no underlying circumferential bandaging,
allows for swelling, and obviates the need for splitting the cast (Fig. 5-14).
Fiberglass casting allows for better postoperative radiographs.
Alternatives such as split casts or splints are used successfully as
well.

Occasionally, there is so little intact periosteum that
the distal fragment can be moved into flexion and extension. A
potential pitfall is to create this situation iatrogenically by an
overenthusiastic reduction, in which the posterior periosteum is torn,
as the hapless surgeon feels the fracture fragment move from extension
to flexion. Using the surgical technique described in the next section
for flexion-type supracondylar fractures, these completely unstable
fractures can often be treated without the need for an open reduction.

While flexion-type supracondylar fractures are
relatively rare injuries, closed reduction and pinning is technically
more challenging than extension type fractures. In order to reduce the
fracture, the elbow is extended. However, in an extended position,
K-wires are more difficult to place. In addition, when

attempting
to view the lateral image of the elbow, fracture reduction can be lost
if the arm is rotated. These difficulties have led to the belief that
open reduction is usually necessary.

These fractures can usually be reduced closed using the
following guidelines. It is helpful to first place two lateral entry
pins in the distal fragment before the fracture is reduced. To confirm
fracture reduction, rotate the image machine between AP and lateral
positions instead of rotating the arm. This can be accomplished by
positioning the fluoroscopy unit parallel to the operating table, and
rotating the c-arm. After fracture reduction is confirmed in both
planes, drive the pins across the fracture site (Fig. 5-15).