Supracondylar fractures of the humerus are the most common elbow fractures
in children. These fractures are classified according to Gartland's criteria
as nondisplaced fractures (type I), hinged fractures with the posterior cortex
intact (type II), and completely displaced fractures (type III). The standard
treatment for type-III extension supracondylar fractures is with closed
reduction and percutaneous pin fixation
(Fig. 1).
The operative treatment of a displaced type-III supracondylar fracture in a
well-perfused arm with no neurologic deficit is considered an urgent
procedure. The patient should be taken to the operating room as quickly as
possible, but a delay of eight to twenty-four hours does not increase the rate
of complications or worsen the
outcome1,2.
After the induction of general anesthesia, the patient is placed in the
supine position with the shoulder of the affected extremity at the edge of the
table. The fluoroscopy unit is brought into position with its base at the foot
of the table and the c-arm adjacent to the table so that the image collector
serves as the operating-room table (Fig. 2,
A). For patients weighing <20 kg, we often use a hand
table in order to facilitate fluoroscopy of the limb during surgery since the
size of the arm often does not allow the elbow to lie in the center of the
fluoroscopic beam. The head is secured at the side of the operating-room table
or hand table, and the field is draped in a sterile fashion
(Fig. 2, B and
C).
Closed reduction of the fracture is performed under the guidance of
fluoroscopy. Gentle traction is applied to the forearm, and countertraction is
applied to the proximal aspect of the humerus. An anteroposterior fluoroscopic
image is obtained, and any varus or valgus malalignment is corrected. Rotation
of the distal fragment is also corrected at this time, notably prior to
flexing the elbow, which locks the distal fragment into position through the
intact posterior periosteal hinge. The elbow is then hyperflexed to
approximately 130° with anteriorly directed pressure being placed on the
distal fragment over the olecranon with the surgeon's thumb in order to reduce
the fracture. The forearm is held in neutral or slight pronation, and
fluoroscopy is used to assess the reduction. The Jones view, an
anteroposterior radiograph of the humerus with the elbow flexed
(Fig. 3), as well as internal
and external oblique radiographs help to confirm the reduction. The lateral
radiograph can be made by externally rotating the flexed arm at the shoulder.
The anterior humeral line should pass through the middle third of the
capitellum on the lateral radiograph (Fig.
4).
Once reduction has been accomplished, percutaneous pin fixation of the
fracture can be carried out. Children who weigh =20 kg are treated with
0.062-in (1.6-mm) Kirschner wires, and those who weigh >20 kg are treated
with 2.0-mm Steinmann pins. For the lateral entry technique, two pins are
inserted from the lateral aspect of the elbow across the lateral cortex of the
humerus, engaging the medial cortex. The pins can be inserted in a divergent
or a parallel fashion. We consider fixation satisfactory only if one pin
engages the lateral column of the distal fragment and the other pin engages
the central column (olecranon fossa) of the distal fragment. The pins should
not cross at the fracture site, and both pins should exit at the medial
cortex. Pin entry should be confirmed on the anteroposterior image and, in
some cases, the lateral image (Fig.
5).
For the medial and lateral entry technique, one pin is first inserted from
the lateral entry site with the elbow hyperflexed. This pin must engage the
lateral column in the distal fragment and penetrate the medial cortex. The
elbow is then extended gently to slightly less than 90° of flexion to
avoid injury to a subluxating ulnar nerve. It should be remembered that the
prevalence of a subluxating ulnar nerve is 17.7% in children between birth and
five years of age and 7.7% in children between six and ten years of
age3. A medial
incision of 1.5 to 3.0 cm is made over the medial epicondyle. Blunt
superficial dissection is performed down to the medial epicondyle to ensure
that the ulnar nerve is not in the path of the pin; the nerve, however, does
not have to be visualized. With the soft tissues retracted, the medial pin is
then placed in the medial epicondyle and is driven across to engage the
lateral cortex (Fig. 6). It is
important that the pins not cross at the fracture site in order to avoid
rotational instability of the distal fragment. The wound can then be closed
around the pin.
The reduction and fracture stability are checked in both the
anteroposterior and lateral planes with the image intensifier. If the fracture
remains unstable, a third pin can be added from the lateral side. The Baumann
angle and the carrying angle of the elbow should be the same as that of the
contralateral side (Fig. 7).
The pins are then cut, bent, and left protruding outside the skin. A bivalved
long-arm cast is applied with the elbow in approximately 70° to 90° of
flexion and neutral rotation.
Patients return in one week for postoperative radiographs to check the
fracture reduction and pin fixation. The cast and pins are removed at the
three to four-week appointment, and gentle range-of-motion exercises are
begun. Patients should return for a clinical examination at six weeks and a
final clinical and radiographic examination at three months.
CRITICAL CONCEPTSINDICATIONS:A displaced (type-II or type-III) supracondylar fracture of the humerus
without neurovascular compromise.CONTRAINDICATIONS:Open fracture. The proximal fragment often tents anteriorly through the
brachialis muscle. This situation is best managed with irrigation,
débridement, and open reduction and internal fixation of the
fracture.Neurovascular compromise after reduction. In 90% of elbows in which
vascular compromise is noted at the time of injury, closed reduction and
stabilization of a displaced fracture restores vascular
flow4. If the hand
is perfused prior to reduction and pulses are lost after manipulation, then
open exploration is required.Severe swelling or an irreducible fracture. If swelling is severe or muscle
or periosteum is interposed in the fracture site, closed reduction may not be
possible and open reduction may be required.Late diagnosis. If the fracture is greater than one week old, there is
usually sufficient callus formation to make closed reduction extremely
difficult. In these cases, we advocate open reduction.PITFALLS:Pin placement. When two lateral pins are used, one pin must engage the
lateral column and the other must engage the central column. Placement of
these lateral pins too close to each other can result in poor fixation and
loss of reduction.Ulnar nerve injury. Placement of the medial pin should be performed with
the elbow in <90° of flexion. Direct visualization of the medial
epicondyle ensures that the ulnar nerve is not within the operative field and
that the pin is not placed within the ulnar nerve groove. Nerve injury does
not necessarily result from direct penetration of the ulnar nerve, but it can
also result from stretch over the medial pin, anterior fixation over the
medial epicondyle, or tethering in the cubital tunnel. Blind percutaneous
pinning of the medial side without an incision or without extending the elbow
to <90° of flexion should be avoided.Unstable reduction. Stability of the reduction is assessed with dynamic
fluoroscopy during a full range of motion. A third pin can be added from the
lateral side as needed to enhance stability.Flexion supracondylar fracture of the humerus. The less common pattern of a
flexion supracondylar fracture of the humerus should be recognized
preoperatively. With this fracture pattern, there is a higher incidence of
ulnar nerve injury with a subsequent need for ulnar nerve decompression as
well as open management of the fracture. It is important to note that fracture
reduction is performed in extension rather than in flexion.AUTHOR UPDATE:The techniques have not changed since the publication of this study. Given
the equivalent nature of the two techniques, we prefer percutaneous pin
fixation with two lateral entry pins placed in a divergent fashion. A third
pin can be added for stability as needed.
CRITICAL CONCEPTS
INDICATIONS:
A displaced (type-II or type-III) supracondylar fracture of the humerus
without neurovascular compromise.
CONTRAINDICATIONS:
Open fracture. The proximal fragment often tents anteriorly through the
brachialis muscle. This situation is best managed with irrigation,
débridement, and open reduction and internal fixation of the
fracture.Neurovascular compromise after reduction. In 90% of elbows in which
vascular compromise is noted at the time of injury, closed reduction and
stabilization of a displaced fracture restores vascular
flow4. If the hand
is perfused prior to reduction and pulses are lost after manipulation, then
open exploration is required.Severe swelling or an irreducible fracture. If swelling is severe or muscle
or periosteum is interposed in the fracture site, closed reduction may not be
possible and open reduction may be required.Late diagnosis. If the fracture is greater than one week old, there is
usually sufficient callus formation to make closed reduction extremely
difficult. In these cases, we advocate open reduction.
Open fracture. The proximal fragment often tents anteriorly through the
brachialis muscle. This situation is best managed with irrigation,
débridement, and open reduction and internal fixation of the
fracture.
Neurovascular compromise after reduction. In 90% of elbows in which
vascular compromise is noted at the time of injury, closed reduction and
stabilization of a displaced fracture restores vascular
flow4. If the hand
is perfused prior to reduction and pulses are lost after manipulation, then
open exploration is required.
Severe swelling or an irreducible fracture. If swelling is severe or muscle
or periosteum is interposed in the fracture site, closed reduction may not be
possible and open reduction may be required.
Late diagnosis. If the fracture is greater than one week old, there is
usually sufficient callus formation to make closed reduction extremely
difficult. In these cases, we advocate open reduction.
PITFALLS:
Pin placement. When two lateral pins are used, one pin must engage the
lateral column and the other must engage the central column. Placement of
these lateral pins too close to each other can result in poor fixation and
loss of reduction.Ulnar nerve injury. Placement of the medial pin should be performed with
the elbow in <90° of flexion. Direct visualization of the medial
epicondyle ensures that the ulnar nerve is not within the operative field and
that the pin is not placed within the ulnar nerve groove. Nerve injury does
not necessarily result from direct penetration of the ulnar nerve, but it can
also result from stretch over the medial pin, anterior fixation over the
medial epicondyle, or tethering in the cubital tunnel. Blind percutaneous
pinning of the medial side without an incision or without extending the elbow
to <90° of flexion should be avoided.Unstable reduction. Stability of the reduction is assessed with dynamic
fluoroscopy during a full range of motion. A third pin can be added from the
lateral side as needed to enhance stability.Flexion supracondylar fracture of the humerus. The less common pattern of a
flexion supracondylar fracture of the humerus should be recognized
preoperatively. With this fracture pattern, there is a higher incidence of
ulnar nerve injury with a subsequent need for ulnar nerve decompression as
well as open management of the fracture. It is important to note that fracture
reduction is performed in extension rather than in flexion.
Pin placement. When two lateral pins are used, one pin must engage the
lateral column and the other must engage the central column. Placement of
these lateral pins too close to each other can result in poor fixation and
loss of reduction.
Ulnar nerve injury. Placement of the medial pin should be performed with
the elbow in <90° of flexion. Direct visualization of the medial
epicondyle ensures that the ulnar nerve is not within the operative field and
that the pin is not placed within the ulnar nerve groove. Nerve injury does
not necessarily result from direct penetration of the ulnar nerve, but it can
also result from stretch over the medial pin, anterior fixation over the
medial epicondyle, or tethering in the cubital tunnel. Blind percutaneous
pinning of the medial side without an incision or without extending the elbow
to <90° of flexion should be avoided.
Unstable reduction. Stability of the reduction is assessed with dynamic
fluoroscopy during a full range of motion. A third pin can be added from the
lateral side as needed to enhance stability.
Flexion supracondylar fracture of the humerus. The less common pattern of a
flexion supracondylar fracture of the humerus should be recognized
preoperatively. With this fracture pattern, there is a higher incidence of
ulnar nerve injury with a subsequent need for ulnar nerve decompression as
well as open management of the fracture. It is important to note that fracture
reduction is performed in extension rather than in flexion.
AUTHOR UPDATE:
The techniques have not changed since the publication of this study. Given
the equivalent nature of the two techniques, we prefer percutaneous pin
fixation with two lateral entry pins placed in a divergent fashion. A third
pin can be added for stability as needed.