Pediatric Shoulder

These account for <5% of fractures in children.

Incidence ranges from 1.2 to 4.4 per 10,000 per year.

They are most common in adolescents owing to increased sports participation and are often metaphyseal, physeal, or both.

Neonates may sustain birth trauma to the proximal humeral physis, representing 1.9% to 6.7% of physeal injuries (Fig. 43.1).

Eighty percent of humeral growth occurs at the proximal physis, giving this region great remodeling potential.

There are three centers of ossification in the proximal humerus:

The joint capsule extends to the metaphysis, rendering some fractures of the metaphysis intracapsular (Fig. 43.2).

The primary vascular supply is via the
anterolateral ascending branch of the anterior circumflex artery, with
a small portion of the greater tuberosity and inferior humeral head
supplied by branches from the posterior circumflex artery.

The physis closes at age 14 to 17 years in girls and at age 16 to 18 years in boys.

The physeal apex is posteromedial and is associated with a strong, thick periosteum.

Type I physeal fractures occur through
the hypertrophic zone adjacent to the zone of provisional
calcification. The layer of embryonal cartilage is preserved, leading
to normal growth.

Muscular deforming forces: The
subscapularis attaches to lesser tuberosity. The remainder of the
rotator cuff (teres minor, supraspinatus, and infraspinatus) attaches
to posterior epiphysis and greater tuberosity. The pectoralis major
attaches to anterior medial metaphysis, and the deltoid connects to the
lateral shaft.

Indirect: This results from a fall
backward onto an outstretched hand with the elbow extended and the
wrist dorsiflexed. Birth injuries may occur as the arm is hyperextended
or rotated as the infant is being delivered. Shoulder dystocia is
strongly associated with macrosomia from maternal diabetes.

Direct: Direct trauma to the posterolateral aspect of the shoulder can occur.

Newborns present with pseudoparalysis
with the arm held in extension. A history of birth trauma may be
elicited. A fever is variably present. Infection, clavicle fracture,
shoulder dislocation, and brachial plexus injury must be ruled out.

Older children present with pain,
dysfunction, swelling, and ecchymosis, and the humeral shaft fragment
may be palpable anteriorly. The shoulder is tender to palpation, with a
painful range of motion that may reveal crepitus.

Typically, the arm is held in internal rotation to prevent pull of the pectoralis major on the distal fragment.

A careful neurovascular examination is required, including the axillary, musculocutaneous, radial, ulnar, and median nerves.

Anteroposterior (AP), lateral (in the
plane of the scapula; “Y” view), and axillary views should be obtained,
with comparison views of the opposite side if necessary.

Ultrasound: This may be necessary in the newborn because the epiphysis is not yet ossified.

Computed tomography may be useful to help diagnose and classify posterior dislocations and complex fractures.

Magnetic resonance imaging is more useful
than bone scan to detect occult fractures because the physis normally
has increased radionuclide uptake, making a bone scan difficult to
interpret.

Neer-Horowitz grade I and II fractures do well because of the remodeling potential of the proximal humeral physis.

Neer-Horowitz grade III and IV fractures
may be left with up to 3 mm of shortening or residual angulation. This
is well tolerated by the patient and is often clinically insignificant.

As a rule, the younger the patient, the higher the potential for remodeling and the greater the acceptable initial deformity.

Proximal humerus varus: Rare, usually
affecting patients less than 1 year of age, but it may complicate
fractures in patients as old as 5 years of age. It may result in a
decrease of the neck-shaft angle to 90 degrees with humeral shortening
and mild to moderate loss of glenohumeral abduction. Remodeling
potential is great in this age group, however, so observation alone may
result in improvement. Proximal humeral osteotomy may be performed in
cases of extreme functional limitation.

Limb length inequality: Rarely
significant and tends to occur more commonly in surgically treated
patients as opposed to those treated nonoperatively.

Loss of motion: Rare and tends to occur
more commonly in surgically treated patients. Older children tend to
have more postfracture difficulties with shoulder stiffness than
younger children.

Inferior glenohumeral subluxation: May
complicate patients with Salter-Harris Type II fractures of the
proximal humerus secondary to a loss of deltoid and rotator cuff tone.
It may be addressed by a period of immobilization followed by rotator
cuff strengthening exercises.

Osteonecrosis: May occur with associated
disruption of the anterolateral ascending branch of the anterior
circumflex artery, especially in fractures or dislocations that are not
acutely reduced.

Nerve injury: Most commonly axillary
nerve injury in fracture-dislocations. Lesions that do not show signs
of recovery in 4 months should be explored.

Growth arrest: May occur when the physis
is crushed or significantly displaced or when a physeal bar forms. It
may require excision of the physeal bar. Limb lengthening may be
required for functional deficits or severe cosmetic deformity.

Most frequent fracture in children (8% to 15% of all pediatric fractures).

It occurs in 0.5% of normal deliveries and in 1.6% of breech deliveries (accounts for 90% of obstetric fractures).

In macrosomic infants (>4,000 g), the incidence is 13%.

Eighty percent of clavicle fractures
occur in the shaft, most frequently just lateral to the insertion of
the subclavius muscle, which protects the underlying neurovascular
structures.

Ten to 15% of clavicle fractures involve the lateral aspect, with the remainder representing medial fractures.

The clavicle is the first bone to ossify; this occurs by intramembranous ossification.

The secondary centers develop via endochondral ossification:

Clavicular range of motion involves
rotation about its long axis (approximately 50 degrees) accompanied by
elevation of 30 degrees with full shoulder abduction and 35 degrees of
anterior-posterior angulation with shoulder protraction and retraction.

The periosteal sleeve always remains in the anatomic position. Therefore, remodeling is ensured.

Indirect: Fall onto an outstretched hand.

Direct: This is the most common
mechanism, resulting from direct trauma to the clavicle or acromion; it
carries the highest incidence of injury to the underlying neurovascular
and pulmonary structures.

Birth injury: Occurs during delivery of
the shoulders through a narrow pelvis with direct pressure from the
symphysis pubis or from obstetric pressure directly applied to the
clavicle during delivery.

Medial clavicle fractures or dislocations
usually represent Salter-Harris type I or II fractures. True
sternoclavicular joint dislocations are rare. The inferomedial
periosteal sleeve remains intact and provides a scaffold for
remodeling. Because 80% of the growth occurs at the medial physis,
there is great potential for remodeling.

Lateral clavicle fractures occur as a
result of direct trauma to the acromion. The coracoclavicular ligaments
always remain intact and are attached to the inferior periosteal tube.
The acromioclavicular ligament is always intact and is attached to the
distal fragment.

Birth fractures of the clavicle are
usually obvious, with an asymmetric, palpable mass overlying the
fractured clavicle. An asymmetric Moro reflex is usually present.
Nonobvious injuries may be misdiagnosed as congenital muscular
torticollis because the patient will often turn his or her head toward
the fracture to relax the sternocleidomastoid muscle.

Children with clavicle fractures
typically present with a painful, palpable mass along the clavicle.
Tenderness is usually discrete over the site of injury, but it may be
diffuse in cases of plastic bowing. There may be tenting of the skin,
crepitus, and ecchymosis.

Neurovascular status must be carefully
evaluated because injuries to the brachial plexus and upper extremity
vasculature may result.

Pulmonary status must be assessed,
especially if direct trauma is the mechanism of injury. Medial
clavicular fractures may be associated with tracheal compression,
especially with severe posterior displacement.

Differential diagnosis

Ultrasound evaluation may be used in the diagnosis of clavicular fracture in neonates.

Because of the S-shape of the clavicle,
an AP view is usually sufficient for diagnostic purposes; however,
special views have been described in cases in which a fracture is
suspected but not well visualized on a standard AP view (Fig. 43.5):

Patients with difficulty breathing should
have an AP radiograph of the chest to evaluate possible pneumothorax or
associated rib fractures.

Computed tomography may be useful for the
evaluation of medial clavicular fractures or suspected dislocation,
because most represent Salter-Harris Type I or II fractures rather than
true dislocations.

Neurovascular compromise: Rare in
children because of the thick periosteum that protects the underlying
structures, although brachial plexus and vascular injury (subclavian
vessels) may occur with severe displacement.

Malunion: Rare because of the high
remodeling potential; it is well tolerated when present, and cosmetic
issues of the bony prominence are the only long-term issue.

Nonunion: Rare (1% to 3%); it is probably associated with a congenital pseudoarthrosis; it never occurs <12 years of age.

Pulmonary injury: Rare injuries to the
apical pulmonary parenchyma with pneumothorax may occur, especially
with severe, direct trauma in an anterosuperior to posteroinferior
direction.

Rare in children less than 16 years of age.

The true incidence is unknown because
many of these injuries actually represent pseudodislocation of the
acromioclavicular joint.

The acromioclavicular joint is a diarthrodial joint; in mature individuals, an intraarticular disc is present.

The distal clavicle is surrounded by a thick periosteal sleeve that extends to the acromioclavicular joint.

Athletic injuries and falls comprise the majority of acromioclavicular injuries, with direct trauma to the acromion.

Unlike acromioclavicular injuries in
adults, in children the coracoclavicular (conoid and trapezoid)
ligaments remain intact. Because of the tight approximation of the
coracoclavicular ligaments to the periosteum of the distal clavicle,
true dislocation of the acromioclavicular joint is rare.

The defect is a longitudinal split in the
superior portion of the periosteal sleeve through which the clavicle is
delivered, much like a banana being peeled from its skin.

The patient should be examined while in
the standing or sitting position to allow the upper extremity to be
dependent, thus stressing the acromioclavicular joint and emphasizing
deformity.

A thorough shoulder examination should be
performed, including assessment of neurovascular status and possible
associated upper extremity injuries. Inspection may reveal an apparent
step-off deformity of the injured acromioclavicular joint, with
possible tenting of the skin overlying the distal clavicle. Range of
motion may be limited by pain. Tenderness may be elicited over the
acromioclavicular joint.

A standard trauma series of the shoulder
(AP, scapular-Y, and axillary views) is usually sufficient for the
recognition of acromioclavicular injury, although closer evaluation
includes targeted views of the AC joint, which requires one-third to
one-half the radiation to avoid overpenetration.

Ligamentous injury may be assessed via
stress radiographs, in which weights (5 to 10 lb) are strapped to the
wrists and an AP radiograph is taken of both shoulders for comparison.

For Types I to III, nonoperative
treatment is indicated, with sling immobilization, ice, and early
range-of-motion exercises as pain subsides. Remodeling is expected.
Complete healing generally takes place in 4 to 6 weeks.

Treatment for Types IV to VI is
operative, with reduction of the clavicle and repair of the periosteal
sleeve. Internal fixation may be needed.

Neurovascular injury: This is rare and is associated with posteroinferior displacement. The intact periosteal sleeve is thick

and usually provides protection to neurovascular structures underlying the distal clavicle.

Open lesion: Severe displacement of the
distal clavicle, such as with Type V acromioclavicular dislocation, may
result in tenting of the skin, with possible laceration necessitating
irrigation and debridement.

These constitute only 1% of all fractures
and 5% of shoulder fractures in the general population and are even
less common in children.

The scapula forms from intramembranous ossification. The body and spine are ossified at birth.

The center of the coracoid is ossified at
1 year. The base of the coracoid and the upper one-fourth of the
glenoid ossify by 10 years. A third center at the tip of the coracoid
ossifies at a variable time. All three structures fuse by age 15 to 16
years.

The acromion fuses by age 22 years via two to five centers, which begin to form at puberty.

Centers for the vertebral border and
inferior angle appear at puberty and fuse by age 22 years. The center
for the lower three-fourths of the glenoid appears at puberty and fuses
by age 22 years.

The suprascapular nerve traverses the
suprascapular notch on the superior aspect of the scapula, medial to
the base of the coracoid process, thus rendering it vulnerable to
fractures in this region.

The superior shoulder suspensory complex
(SSSC) is a circular group of both bony and ligamentous attachments
(acromion, glenoid, coracoid, coracoclavicular ligament, and distal
clavicle). The integrity of the ring is breached only after more than
one violation. This can dictate the treatment approach (Fig. 43.8).

In children, most scapula fractures
represent avulsion fractures associated with glenohumeral joint
injuries. Other fractures are usually the result of high-energy trauma.

Isolated scapula fractures are extremely
uncommon, particularly in children; child abuse should be suspected
unless a clear and consistent mechanism of injury exists.

The presence of a scapula fracture should
raise suspicion of associated injuries, because 35% to 98% of scapula
fractures occur in the presence of other injuries including:

Rate of mortality in setting of scapula fractures may approach 14%.

Full trauma evaluation, with attention to
airway, breathing, circulation, disability, and exposure should be
performed, if indicated.

Patients typically present with the upper
extremity supported by the contralateral hand in an adducted and
immobile positions, with painful range of shoulder motion, especially
with abduction.

A careful examination for associated
injures should be pursued, with a comprehensive assessment of
neurovascular status and an evaluation of breath sounds.

Initial radiographs should include a
trauma series of the shoulder, consisting of true AP, axillary, and
scapular-Y (true scapular lateral) views; these generally are able to
demonstrate most glenoid, neck, body, and acromion fractures.

A 45-degree cephalic tilt (Stryker notch) radiograph is helpful to identify coracoid fractures.

Computed tomography may be useful for further characterizing intraarticular glenoid fractures.

Because of the high incidence of
associated injuries, especially to thoracic structures, a chest
radiograph is an essential part of the evaluation.

Scapula body fractures in children are
treated nonoperatively, with the surrounding musculature maintaining
reasonable proximity of fracture fragments. Operative treatment is
indicated for fractures that fail to unite, which may benefit from
partial body excision.

Scapula neck fractures that are
nondisplaced and not associated with clavicle fractures may be treated
nonoperatively. Significantly displaced fractures may be treated in a
thoracobrachial

cast.
Associated clavicular disruption, either by fracture or ligamentous
instability (i.e., multiple disruptions in the SSSC) are generally
treated operatively with open reduction and internal fixation of the
clavicle alone or include open reduction and internal fixation of the
scapula fracture though a separate incision.

Coracoid fractures that are nondisplaced
may be treated with sling immobilization. Displaced fractures are
usually accompanied by acromioclavicular dislocation or lateral
clavicular injury and should be treated with open reduction and
internal fixation.

Acromial fractures that are nondisplaced
may be treated with sling immobilization. Displaced acromial fractures
with associated subacromial impingement should be reduced and
stabilized with screw or plate fixation.

Glenoid fractures in children, if not
associated with glenohumeral instability, are rarely symptomatic when
healed and can generally be treated nonoperatively if they are
nondisplaced.

Posttraumatic osteoarthritis: This may result from a failure to restore articular congruity.

Associated injuries: These account for most serious complications because of the high-energy nature of these injuries.

Decreased shoulder motion: Secondary to subacromial impingement from acromial fracture.

Malunion: Fractures of the scapula body
generally unite with nonoperative treatment; when malunion occurs, it
is generally well tolerated but may result in painful scapulothoracic
crepitus.

Nonunion: Extremely rare, but when present and symptomatic it may require open reduction and plate fixation for adequate relief.

Suprascapular nerve injury: May occur in
association with scapula body, scapula neck, or coracoid fractures that
involve the suprascapular notch.

Rare in children; Rowe reported that only
1.6% of shoulder dislocations occurred in patients <10 years of age,
whereas 10% occurred in patients 10 to 20 years of age.

Ninety percent are anterior dislocations.

The glenohumeral articulation, with its
large convex humeral head and correspondingly flat glenoid, is ideally
suited to accommodate a wide range of shoulder motion. The articular
surface and radius of curvature of the humeral head are about three
times those of the glenoid fossa.

Numerous static and dynamic stabilizers of the shoulder exist; these are covered in detail in Chapter 14.

The humeral attachment of the
glenohumeral joint capsule is along the anatomic neck of the humerus
except medially, where the attachment is more distal along the shaft.
The proximal humeral physis is therefore extraarticular except along
its medial aspect.

As in most pediatric joint injuries, the
capsular attachment to the epiphysis renders failure through the physis
much more common than true capsuloligamentous injury; therefore,
fracture through the physis is more common than a shoulder dislocation
in a skeletally immature patient.

In neonates, an apparent dislocation may actually represent a physeal injury.

Neonates: Pseudodislocation may occur
with traumatic epiphyseal separation of the proximal humerus. This is
much more common than a true shoulder dislocation, which may occur in
neonates with underlying birth trauma to the brachial plexus or central
nervous system.

Anterior glenohumeral dislocation may occur as a result of trauma, either direct or indirect.

Posterior glenohumeral dislocation (2% to 4%):

Atraumatic dislocations: Recurrent
instability related to congenital or acquired laxity or volitional
mechanisms may result in anterior dislocation with minimal trauma.

Patient presentation varies according to the type of dislocation encountered.

A trauma series of the affected shoulder is indicated: AP, scapular-Y, and axillary views.

Velpeau axillary view: Compliance is
frequently an issue in the irritable, injured child in pain. If a
standard axillary view cannot be obtained, the patient may be left in a
sling and leaned obliquely backward 45 degrees over the cassette. The
beam is directed caudally, orthogonal to the cassette, resulting in an
axillary view with magnification.

Special views (See Chapter 14):

Computed tomography may be useful in
defining humeral head or glenoid impression fractures, loose bodies,
and anterior labral bony injuries (bony Bankart lesion).

Single- or double-contrast arthrography
may be utilized in cases in which the diagnosis may be unclear; it may
demonstrate pseudosubluxation, or traumatic epiphyseal separation of
the proximal humerus, in a neonate with an apparent glenohumeral
dislocation.

Magnetic resonance imaging may be used to identify rotator cuff, capsular, and glenoid labral (Bankart lesion) pathology.

Atraumatic dislocations may demonstrate congenital aplasia or absence of the glenoid on radiographic evaluation.

Closed reduction should be performed
after adequate clinical evaluation and administration of analgesics and
or sedation. Described techniques include (see the figures in Chapter 14):

Following reduction, acute anterior
dislocations are treated with sling immobilization. Total time in sling
is controversial but may be up to 4 weeks, after which an aggressive
program of rehabilitation for rotator cuff strengthening is instituted.
Posterior dislocations are treated for 4 weeks in a commercial splint
or shoulder spica cast with the shoulder in neutral rotation, followed
by physical therapy.

Recurrent dislocation or associated
glenoid rim avulsion fractures (bony Bankart lesion) may necessitate
operative management, including reduction and internal fixation of the
anterior glenoid margin, repair of a Bankart lesion (anterior labral
tear), capsular shift, or capsulorraphy. Postoperatively, the child is
placed in sling immobilization for 4 to 6 weeks with gradual increases
in range-of-motion and strengthening exercises.

Atraumatic dislocations rarely require
reduction maneuvers as spontaneous reduction is the rule. Only after an
aggressive, supervised rehabilitation program for rotator cuff and
deltoid strengthening has been completed should surgical intervention
be considered. Vigorous rehabilitation may obviate the need for
operative intervention in up to 85% of cases.

Psychiatric evaluation may be necessary in the management of voluntary dislocators.

Recurrent dislocation: The incidence is
50% to 90%, with decreasing rates of recurrence with increasing patient
age (up to 100% in children less than 10 years old). It may necessitate
operative intervention, with >90% success rate in preventing future
dislocation.

Shoulder stiffness: Procedures aimed at
tightening static and dynamic constraints (subscapularis
tendon-shortening, capsular shift, etc.) may result in
“overtightening,” resulting in a loss of range of motion, as well as
possible subluxation in the opposing direction with subsequent
accelerated glenohumeral arthritis.

Neurologic injury: Neurapraxic injury may
occur to nerves in proximity to the glenohumeral articulation,
especially the axillary nerve and less commonly the musculocutaneous
nerve. These typically resolve with time; a lack of neurologic recovery
by 3 months may warrant surgical exploration.

Vascular injury: Traction injury to the
axillary artery has been reported in conjunction with nerve injury to
the brachial plexus.