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Pediatric Elbow

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Ovid: Handbook of Fractures

Authors: Koval, Kenneth J.; Zuckerman, Joseph D.
Title: Handbook of Fractures, 3rd Edition
> Table of Contents > V – Pediatric Fractures and Dislocations > 44 – Pediatric Elbow

44
Pediatric Elbow
EPIDEMIOLOGY
  • Elbow fractures represent 8% to 9% of all upper extremity fractures in children.
  • Of all elbow fractures, 86% occur at the distal humerus; 55% to 75% of these are supracondylar.
  • Most occur in patients 5 to 10 years of age, more commonly in boys.
  • There is a seasonal distribution for
    elbow fractures in children, with the most occurring during the summer
    and the fewest during the winter.
ANATOMY
  • The elbow consists of three joints: the ulnohumeral, radiocapitellar, and proximal radioulnar.
  • The vascularity to the elbow is a broad anastomotic network that forms the intraosseous and extraosseous blood supplies.
    • The capitellum is supplied by a posterior branch of the brachial artery that enters the lateral crista.
    • The trochlea is supplied by a medial
      branch that enters along the nonarticular medial crista and a lateral
      branch that crosses the physis.
    • There is no anastomotic connection between these two vessels.
  • The articulating surface of the
    capitellum and trochlea projects distally and anteriorly at an angle of
    approximately 30 to 45 degrees. The center of rotation of the articular
    surface of each condyle lies on the same horizontal axis; thus,
    malalignment of the relationships of the condyles to each other changes
    their arcs of rotation, limiting flexion and extension.
  • The carrying angle is influenced by the
    obliquity of the distal humeral physis; this averages 6 degrees in
    girls and 5 degrees in boys and is important in the assessment of
    angular growth disturbances.
  • In addition to anterior distal humeral
    angulation, there is horizontal rotation of the humeral condyles in
    relation to the diaphysis, with the lateral condyle rotated 5 degrees
    medially. This medial rotation is often significantly increased with
    displaced supracondylar fractures.
  • The elbow accounts for only 20% of the longitudinal growth of the upper extremity.
  • Ossification: With the exception of the
    capitellum, ossification centers appear approximately 2 years earlier
    in girls compared with boys
  • CRMTOL: The following is a mnemonic for the appearance of the ossification centers around the elbow (Fig. 44.1):

Capitellum: 6 months to 2 years; includes the lateral crista of the trochlea
Radial head: 4 years
Medial epicondyle: 6 to 7 years

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Trochlea: 8 years
Olecranon: 8 to 10 years; often multiple centers, which ultimately fuse
Lateral epicondyle: 12 years
Figure
44.1. Ossification and fusion of the secondary centers of the distal
humerus. (A) The average ages of the onset of ossification of the
various ossification centers are shown for both boys and girls. (B) The
ages at which these centers fuse with each other are shown for both
boys and girls. (C) The contribution of each secondary center to the
overall architecture of the distal humerus is represented by the stippled areas.

(From Rockwood CA, Wilkins KE, Beaty JH. Fractures and Dislocations in Children. Philadelphia: Lippincott-Raven, 1999:662.)
MECHANISM OF INJURY
  • Indirect: This is most commonly a result of a fall onto an outstretched upper extremity.
  • Direct: Direct trauma to the elbow may
    occur from a fall onto a flexed elbow or from an object striking the
    elbow (e.g., baseball bat, automobile).
CLINICAL EVALUATION
  • Patients typically present with varying
    degrees of gross deformity, usually accompanied by pain, swelling,
    tenderness, irritability, and refusal to use the injured extremity.
  • The ipsilateral shoulder, humeral shaft, forearm, wrist, and hand should be examined for associated injuries.
  • A careful neurovascular examination
    should be performed, with documentation of the integrity of the median,
    radial, and ulnar nerves, as well as distal pulses and capillary
    refill. Massive swelling in the antecubital fossa should alert the
    examiner to evaluate for compartment syndrome of the forearm. Flexion
    of

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    the
    elbow in the presence of antecubital swelling may cause neurovascular
    embarrassment; repeat evaluation of neurovascular integrity is
    essential following any manipulation or treatment.

  • All aspects of the elbow should be
    examined for possible open lesions; clinical suspicion may be followed
    with intraarticular injection of saline into the elbow to evaluate
    possible intraarticular communication of a laceration.
RADIOGRAPHIC EVALUATION
  • Standard anteroposterior (AP) and lateral
    views of the elbow should be obtained. On the AP view, the following
    angular relationships may be determined (Fig. 44.2):
    • Baumann angle: This is the angulation of
      the lateral condylar physeal line with respect to the long axis of the
      humerus; normal is 15 to 20 degrees and equal to the opposite side.
    • Humeral-ulnar angle: This angle is
      subtended by the intersection of the diaphyseal bisectors of the
      humerus and ulna; this best reflects the true carrying angle.
    • Metaphyseal-diaphyseal angle: This angle
      is formed by a bisector of the humeral shaft with respect to a line
      delineated by the widest points of the distal humeral metaphysic.
  • On a true lateral radiograph of the elbow flexed to 90 degrees, the following landmarks should be observed (Fig. 44.3):
    • Teardrop: This radiographic shadow is
      formed by the posterior margin of the coronoid fossa anteriorly, the
      anterior margin of the olecranon fossa posteriorly, and the superior
      margin of the capitellar ossification center inferiorly.
    • Diaphyseal-condylar angle: This projects
      30 to 45 degrees anteriorly; the posterior capitellar physis is
      typically wider than the anterior physis.
    • Anterior humeral line: When extended
      distally, this line should intersect the middle third of the capitellar
      ossification center.
    • Coronoid line: A proximally directed line
      along the anterior border of the coronoid process should be tangent to
      the anterior aspect of the lateral condyle.
  • Special views
    • Jones view: Pain may limit an AP
      radiograph of the elbow in extension; in these cases, a radiograph may
      be taken with the elbow hyperflexed and the beam directed at the elbow
      through the overlying forearm with the arm flat on the cassette in
      neutral rotation.
    • Internal and external rotation views may
      be obtained in cases in which a fracture is suspected but not clearly
      demonstrated on routine views. These may be particularly useful in the
      identification of coronoid process or radial head fractures.
    Figure
    44.2. Anteroposterior x-ray angles for the elbow. (A) The Baumann angle
    (α). (B) The humeral-ulnar angle. (C) The metaphyseal-diaphyseal angle.

    (From O’Brien
    WR, Eilert RE, Chang FM, et al. The metaphyseal-diaphyseal angle as a
    guide to treating supracondylar fractures of the humerus in children,
    1999, unpublished data.    )
    Figure
    44.3. Intraosseous blood supply of the distal humerus. (A) The vessels
    supplying the lateral condylar epiphysis enter on the posterior aspect
    and course for a considerable distance before reaching the ossific
    nucleus. (B) Two definite vessels supply the ossification center of the
    medial crista of the trochlea. The lateral one enters by crossing the
    physis. The medial one enters by way of the nonarticular edge of the
    medial crista.

    (From Rockwood CA, Wilkins KE, Beaty JH. Fractures and Dislocations in Children. Philadelphia: Lippincott-Raven, 1999:663.)

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  • The contralateral elbow should be obtained for comparison as well as identification of ossification centers. A pseudofracture
    of an ossification center may exist, in which apparent fragmentation of
    an ossification center may represent a developmental variant rather
    than a true fracture. This may be clarified with comparison views of
    the uninjured contralateral elbow.
    Figure 44.4. Elevated anterior and posterior fat pads.

    (Adapted from The Journal of Bone and Joint Surgery, in Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)
  • Fat pad signs: Three fat pads overlie the major structures of the elbow (Fig. 44.4):
    • Anterior (coronoid) fat pad: This
      triangular lucency seen anterior to the distal humerus may represent
      displacement of the fat pad owing to underlying joint effusion. The
      coronoid fossa is shallow; therefore, anterior displacement of the fat
      pad is sensitive to small effusions. However, an exuberant fat pad may
      be seen without associated trauma, diminishing the specificity of the
      anterior fat pad sign.
    • Posterior (olecranon) fat pad: The deep
      olecranon fossa normally completely contains the posterior fat pad.
      Thus, only moderate to large effusions cause posterior displacement,
      resulting in a high specificity of the posterior fat pad sign for
      intraarticular disorders (a fracture is present >70% of the time
      when the posterior fat pad is seen).
    • Supinator fat pad: This represents a
      layer of fat on the anterior aspect of the supinator muscle as it wraps
      around the proximal radius. Anterior displacement of this fat pad may
      represent a fracture of the radial neck; however, this sign has been
      reported to be positive in only 50% of cases.
    • Anterior and posterior fat pads may not
      be seen following elbow dislocation owing to disruption of the joint
      capsule, which decompresses the joint effusion.

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SPECIFIC FRACTURES
Supracondylar Humerus Fractures
Epidemiology
  • These comprise 55% to 75% of all elbow fractures.
  • The male-to-female ratio is 3:2.
  • The peak incidence is from 5 to 8 years, after which dislocations become more frequent.
  • The left, or nondominant side, is most frequently injured.
Anatomy
  • Remodeling of bone in the 5- to 8-year
    old causes a decreased anteroposterior diameter in the supracondylar
    region, making this area susceptible to injury.
  • Ligamentous laxity in this age range increases the likelihood of hyperextension injury.
  • The anterior capsule is thickened and
    stronger than the posterior capsule. In extension, the fibers of the
    anterior capsule are taut, serving as a fulcrum by which the olecranon
    becomes firmly engaged in the olecranon fossa. With extreme force,
    hyperextension may cause the olecranon process to impinge on the
    superior olecranon fossa and supracondylar region.
  • The periosteal hinge remains intact on the side of the displacement.
Mechanism of Injury
  • Extension type: Hyperextension occurs
    during fall onto an outstretched hand with or without varus/valgus
    force. If the hand is pronated, posteromedial displacement occurs. If
    the hand is supinated posterolateral displacement occurs. Posteromedial
    displacement is more common.
  • Flexion type: The cause is direct trauma or a fall onto a flexed elbow.
Clinical Evaluation
  • Patients typically present with a swollen, tender elbow with painful range of motion.
  • S-shaped angulation at the elbow: a complete (Type III) fracture results in two points of angulation to give it an S shape.
  • Pucker sign: This is dimpling of the skin
    anteriorly secondary to penetration of the proximal fragment into the
    brachialis muscle; it should alert the examiner that reduction of the
    fracture may be difficult with simple manipulation.
  • Neurovascular examination: A careful
    neurovascular examination should be performed with documentation of the
    integrity of the median, radial, and ulnar nerves as well as their
    terminal branches. Capillary refill and distal pulses should be
    documented. The examination should be repeated following splinting or
    manipulation.
Classification
EXTENSION TYPE
This represents 98% of supracondylar humerus fractures in children.
Gartland
This is based on the degree of displacement.

Type I: Nondisplaced
Type II: Displaced with intact posterior cortex; may be angulated or rotated
Type III: Complete displacement; posteromedial or posterolateral

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FLEXION TYPE
This comprises 2% of supracondylar humerus fractures in children.
Gartland

Type I: Nondisplaced
Type II: Displaced with intact anterior cortex
Type III: Complete displacement; usually anterolateral
Treatment
EXTENSION TYPE

Type I: Immobilization in a long arm cast or splint at 60 to 90 degrees of flexion is indicated for 2 to 3 weeks.
Type II: This is usually reducible by
closed methods followed by casting; it may require pinning if unstable
(crossed pins versus two lateral pins) or if reduction cannot be
maintained without excessive flexion that may place neurovascular
structures at risk.
Type III: Attempt closed reduction and
pinning; traction (olecranon skeletal traction) may be needed for
comminuted fractures with marked soft tissue swelling or damage.
Open reduction and internal fixation may be necessary for rotationally
unstable fractures, open fractures, and those with neurovascular injury
(crossed pins versus two lateral pins).
  • Concepts involved in reduction
    • Displacement is corrected in the coronal and horizontal planes before the sagittal plane.
    • Hyperextension of the elbow with longitudinal traction is used to obtain apposition.
    • Flexion of the elbow is done while applying a posterior force to the distal fragment.
    • Stabilization with control of displacement in the coronal, sagittal, and horizontal planes is recommended.
    • Lateral pins are placed first to obtain
      provisional stabilization, and if a medial pin is needed, the elbow can
      be extended before pin placement to help protect the ulnar nerve.
FLEXION TYPE

Type I: Immobilization in a long arm cast in near extension is indicated for 2 to 3 weeks.
Type II: Closed reduction is followed by percutaneous pinning with two lateral pins or crossed pins.
Type III: Reduction is often difficult; most require open reduction and internal fixation with crossed pins.
  • Immobilization in a long arm cast (or
    posterior splint if swelling is an issue) with the elbow flexed to 90
    degrees and the forearm in neutral should be undertaken for 2 to 3
    weeks postoperatively, at which time the cast may be discontinued and
    the pins

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    removed.
    The patient should then be maintained in a sling with range-of-motion
    exercises and restricted activity for an additional 4 to 6 weeks.

Complications
  • Neurologic injury (7% to 10%): This may
    be caused by a traction injury during reduction owing to tenting or
    entrapment at the fracture site. It also may occur as a result of
    Volkmann ischemic contracture, angular deformity, or incorporation into
    the callus or scar. Most are neurapraxias requiring no treatment.
    • Median nerve/anterior interosseous nerve (most common)
    • Radial nerve
    • Ulnar nerve: This is most common in
      flexion-type supracondylar fractures; early injury may result from
      tenting over the medial spike of the proximal fragment; late injury may
      represent progressive valgus deformity of the elbow. It is frequently
      iatrogenic in extension-type supracondylar fractures following medial
      pinning.
  • Vascular injury (0.5%): This may
    represent direct injury to the brachial artery or may be secondary to
    antecubital swelling. This emphasizes the need for a careful
    neurovascular examination both on initial presentation and following
    manipulation or splinting, especially after elbow flexion is performed.
    Observation may be warranted if the pulse is absent, yet the hand is
    still well perfused.
  • Loss of motion: A >5-degree loss of elbow motion occurs in 5% secondary to poor reduction or soft tissue contracture.
  • Myositis ossificans: Rare and is seen after vigorous manipulation.
  • Angular deformity (varus more frequently
    than valgus): Significant in 10% to 20%; the occurrence is decreased
    with percutaneous pinning (3%) compared with reduction and casting
    alone (14%).
  • Compartment syndrome (<1%): This rare
    complication can be exacerbated by elbow hyperflexion when excessive
    swelling is present in the cubital fossa.
Lateral Condylar Physeal Fractures
Epidemiology
  • These comprise 17% of all distal humerus fractures.
  • Peak age is 6 years.
  • Often result in less satisfactory outcomes than supracondylar fractures because:
    • Diagnosis less obvious and may be missed in subtle cases.
    • Loss of motion is more severe due to intraarticular nature.
    • The incidence of growth disturbance is higher.
Anatomy
  • The ossification center of the lateral condyle extends to the lateral crista of the trochlea.
  • Lateral condylar physeal fractures are
    typically accompanied by a soft tissue disruption between the origins
    of the extensor carpi radialis longus and the brachioradialis muscles;
    these origins remain attached to the free distal fragment, accounting
    for initial and late displacement of the fracture.

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  • Disruption of the lateral crista of the
    trochlea (Milch Type II fractures) results in posterolateral
    subluxation of the proximal radius and ulna with consequent cubitus
    valgus; severe posterolateral translocation may lead to the erroneous
    diagnosis of primary elbow dislocation.
Mechanism of Injury
  • “Pull-off” theory: Avulsion injury occurs by the common extensor origin owing to a varus stress exerted on the extended elbow.
  • “Push-off” theory: A fall onto an
    extended upper extremity results in axial load transmitted through the
    forearm, causing the radial head to impinge on the lateral condyle.
Clinical Evaluation
  • Unlike the patient with a supracondylar
    fracture of the elbow, patients with lateral condylar fractures
    typically present with little gross distortion of the elbow, other than
    mild swelling from fracture hematoma most prominent over the lateral
    aspect of the distal humerus.
  • Crepitus may be elicited associated with supination-pronation motions of the elbow.
  • Pain, swelling, tenderness to palpation, painful range of motion, and pain on resisted wrist extension may be observed.
Radiographic Evaluation
  • AP, lateral, and oblique views of the elbow should be obtained.
  • Varus stress views may accentuate displacement of the fracture.
  • In a young child whose lateral condyle is
    not ossified, it may be difficult to distinguish between a lateral
    condylar physeal fracture and a complete distal humeral physeal
    fracture. In such cases, an arthrogram may be helpful, and the
    relationship of the lateral condyle to the proximal radius is critical:
    • Lateral condyle physeal fracture: This
      disrupts the normal relationship with displacement of the proximal
      radius laterally owing to loss of stability provided by the lateral
      crista of the distal humerus.
    • Fracture of the entire distal humeral
      physis: The relationship of the lateral condyle to the proximal radius
      is intact, often accompanied by posteromedial displacement of the
      proximal radius and ulna.
  • Magnetic resonance imaging (MRI) may help to appreciate the direction of the fracture line and the pattern of fracture.
Classification
MILCH (FIG. 44.5)

Type I: The fracture line courses
lateral to the trochlea and into the capitulotrochlear groove. It
represents a Salter-Harris Type IV fracture: the elbow is stable
because the trochlea is intact; this is less common.
Type II: The fracture line extends into
the apex of the trochlea. It represents a Salter-Harris Type II
fracture: the elbow is unstable because the trochlea is disrupted; this
is more common (Fig. 44.5).

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JAKOB
Figure
44.5. Physeal fractures of the lateral condyle. (A) Salter-Harris Type
IV physeal injury (Milch Type I). (B) Salter-Harris Type II physeal
injury (Milch Type II).

(From Rockwood CA, Wilkins KE, Beaty JH. Fractures and Dislocations in Children. Philadelphia: Lippincott-Raven, 1999:753.)

Stage I: Fracture nondisplaced with an intact articular surface
Stage II: Fracture with moderate displacement
Stage III: Complete displacement and rotation with elbow instability
Treatment
NONOPERATIVE
  • Nondisplaced or minimally displaced
    fractures (Jakob stage I; <2 mm) (40% of fractures) may be treated
    with simple immobilization in a posterior splint or long arm cast with
    the forearm in neutral position and the elbow flexed to 90 degrees.
    This is maintained for 3 to 4 weeks, after which range-of-motion
    exercises are instituted.

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  • Closed reduction of fractures (Jakob
    stage II) may be performed with the elbow extended and the forearm
    supinated. Further room for manipulation may be provided by exerting
    varus stress on the elbow. If the reduction is unable to be held,
    percutaneous pins may be placed. Closed reduction is unsuccessful in
    50% owing to rotation. Late displacement is a frequent complication.
OPERATIVE
  • Open reduction is required for unstable Jakobs stage II and stage III fractures (60%).
    • The fragment may be secured with two crossed, smooth Kirschner wires that diverge in the metaphysis.
    • The passage of smooth pins through the physis does not typically result in growth disturbance.
    • Care must be taken when dissecting near
      the posterior aspect of the lateral condylar fragment because the sole
      vascular supply is provided through soft tissues in this region.
    • Postoperatively, the elbow is maintained
      in a long arm cast at 60 to 90 degrees of flexion with the forearm in
      neutral rotation. The cast is discontinued 3 to 4 weeks postoperatively
      with pin removal. Active range-of-motion exercises are instituted.
  • If treatment is delayed (>3 weeks),
    closed treatment should be strongly considered, regardless of
    displacement, owing to the high incidence of osteonecrosis of the
    condylar fragment with late open reduction.
Complications
  • Lateral condylar overgrowth with spur
    formation: This usually results from an ossified periosteal flap raised
    from the distal fragment at the time of injury or surgery. It may
    represent a cosmetic problem (cubitus pseudovarus) as the elbow gains
    the appearance of varus owing to a lateral prominence but is generally
    not a functional problem.
  • Delayed union or nonunion (>12 weeks):
    This is caused by pull of extensors and poor metaphyseal circulation of
    the lateral condylar fragment, most commonly in patients treated
    nonoperatively. It may result in cubitus valgus necessitating ulnar
    nerve transposition for tardy ulnar nerve palsy. Treatment ranges from
    benign neglect to osteotomy and compressive fixation late or at
    skeletal maturity.
  • Angular deformity: Cubitus valgus occurs
    more frequently than varus owing to lateral physeal arrest. Tardy ulnar
    nerve palsy may develop necessitating transposition.
  • Neurologic compromise: This is rare in the acute setting. Tardy ulnar nerve palsy may develop as a result of cubitus valgus.
  • Osteonecrosis: This is usually
    iatrogenic, especially when surgical intervention was delayed. It may
    result in a “fishtail” deformity with a persistent gap between the
    lateral physeal ossification center and the medial ossification of the
    trochlea.
Medial Condylar Physeal Fractures
Epidemiology
  • Represent <1% of distal humerus fractures.
  • Typical age range is 8 to 14 years.
Anatomy
  • Medial condylar fractures are
    Salter-Harris Type IV fractures with an intraarticular component
    involving the trochlea and an extraarticular component involving the
    medial metaphysis and the medial epicondyle (common flexor origin).
  • Only the medial crista is ossified by the secondary ossification centers of the medial condylar epiphysis.
  • The vascular supply to the medial
    epicondyle and metaphysis is derived from the flexor muscle group. The
    vascular supply to the lateral aspect of the medial crista of the
    trochlea traverses the surface of the medial condylar physis, rendering
    it vulnerable in medial physeal disruptions with possible avascular
    complications and “fishtail” deformity.
Mechanism of Injury
  • Direct: Trauma to the point of the elbow,
    such as a fall onto a flexed elbow, results in the semilunar notch of
    the olecranon traumatically impinging on the trochlea, splitting it
    with the fracture line extending proximally to metaphyseal region.

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  • Indirect: A fall onto an outstretched
    hand with valgus strain on the elbow results in an avulsion injury with
    the fracture line starting in the metaphysis and propagating distally
    through the articular surface.
  • These are considered the mirror image of lateral condylar physeal fractures.
  • Once dissociated from the elbow, the powerful forearm flexor muscles produce sagittal anterior rotation of the fragment.
Clinical Evaluation
  • Patients typically present with pain,
    swelling, and tenderness to palpation over the medial aspect of the
    distal humerus. Range of motion is painful, especially with resisted
    flexion of the wrist.
  • A careful neurovascular examination is important, because ulnar nerve symptoms may be present.
  • A common mistake is to diagnose a medial
    condylar physeal fracture erroneously as an isolated medial epicondylar
    fracture. This occurs based on tenderness and swelling medially in
    conjunction with radiographs demonstrating a medial epicondylar
    fracture only resulting from the absence of a medial condylar
    ossification center in younger patients.
  • Medial epicondylar fractures are often
    associated with elbow dislocations, usually posterolateral; elbow
    dislocations are extremely rare before ossification of the medial
    condylar epiphysis begins. With medial condylar physeal fractures,
    subluxation of the elbow posteromedially is often observed. A positive
    fat pad sign indicates an intraarticular fracture, whereas a medial
    epicondyle fracture is typically extraarticular with no fat pad sign
    seen on radiographs.
Radiographic Evaluation
  • AP, lateral, and oblique views of the elbow should be obtained.
  • In young children whose medial condylar
    ossification center is not yet present, radiographs may demonstrate a
    fracture in the epicondylar region; in such cases, an arthrogram may
    delineate the course of the fracture through the articular surface,
    indicating a medial condylar physeal fracture.
  • Stress views may help to distinguish
    epicondylar fractures (valgus laxity) from condylar fractures (both
    varus and valgus laxity).
  • MRI may help to appreciate the direction of the fracture line and the pattern of fracture.
Classification
MILCH (FIG. 44.6)

Type I: Fracture line traversing through the apex of the trochlea: Salter-Harris Type II; more common presentation
Type II: Fracture line through capitulotrochlear groove: Salter-Harris Type IV; infrequent presentation
KILFOYLE

Stage I: Nondisplaced, articular surface intact
Stage II: Fracture line complete with minimal displacement
Stage III: Complete displacement with rotation of fragment from pull of flexor mass

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Treatment
Figure 44.6. Fracture patterns. Left: In the Milch Type I injury, the fracture line terminates in the trochlea notch (arrow). Right: In the Milch Type II injury, the fracture line terminates in the capitulotrochlear groove (arrow).

(From Rockwood CA, Wilkins KE, Beaty JH. Fractures and Dislocations in Children. Philadelphia: Lippincott-Raven, 1999:786.)
NONOPERATIVE
  • Nondisplaced or minimally displaced
    fractures (Kilfoyle stage I) may be treated with immobilization in a
    long arm cast or posterior splint with the forearm in neutral rotation
    and the elbow flexed to

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    90 degrees for 3 to 4 weeks, followed by range-of-motion and strengthening exercises.

  • Closed reduction may be performed with
    the elbow extended and the forearm pronated to relieve tension on the
    flexor origin, with placement of a posterior splint or long arm cast.
    Unstable reductions may require percutaneous pinning with two parallel
    metaphyseal pins.
  • Closed reduction is often difficult
    because of medial soft tissue swelling, and open reduction is usually
    required for stage II and III fractures.
OPERATIVE
  • Unreducible or unstable Kilfoyle stage II
    or stage III fractures of the medial condylar physis may require open
    reduction and internal fixation. Rotation of the condylar fragment may
    preclude successful closed treatment.
    • A medial approach may be used with identification and protection of the ulnar nerve.
    • The posterior surface of the condylar
      fragment and the medial aspect of the medial crista of the trochlea
      should be avoided in the dissection because these provide the vascular
      supply to the trochlea.
    • Smooth Kirschner wires placed in a
      parallel configuration extending to the metaphysis may be used for
      fixation, or cancellous screw fixation may be used in adolescents near
      skeletal maturity.
    • Postoperative immobilization consists of
      long arm casting with the forearm in neutral rotation and the elbow
      flexed to 90 degrees for 3 to 4 weeks, at which time the pins and the
      cast may be discontinued and active range-of-motion exercises
      instituted.
  • If treatment is delayed (>3 weeks),
    closed treatment should be strongly considered, regardless of
    displacement, owing to the high incidence of osteonecrosis of the
    trochlea and lateral condylar fragment from extensive dissection with
    late open reduction.
Complications
  • Missed diagnosis: The most common is a
    medial epicondylar fracture owing to the absence of ossification of the
    medial condylar ossification center. Late diagnosis of medial condylar
    physeal fracture should be treated nonoperatively.
  • Nonunion: Uncommon and usually represent
    untreated, displaced medial condylar physeal fractures secondary to
    pull of flexors with rotation. They tend to demonstrate varus
    deformity. After ossification, the lateral edge of the fragment may be
    observed to extend to the capitulotrochlear groove.
  • Angular deformity: Untreated or treated
    medial condylar physeal fractures may demonstrate angular deformity,
    usually varus, either secondary to angular displacement or from medial
    physeal arrest. Cubitus valgus may result from overgrowth of the medial
    condyle.
  • Osteonecrosis: This may result after open reduction and internal fixation, especially when extensive dissection is undertaken.
  • Ulnar neuropathy: This may be early,
    related to trauma, or more commonly, late, related to the development
    of angular deformities or scarring. Recalcitrant symptoms may be
    addressed with ulnar nerve transposition.
Transphyseal Fractures
Epidemiology
  • Most occur in patients younger than age 6 to 7 years.
  • These were originally thought to be
    extremely rare injuries. It now appears that with advanced imaging
    (e.g., MRI), they occur fairly frequently, although the exact incidence
    is not known owing to misdiagnoses.
Anatomy
  • The epiphysis includes the medial
    epicondyle until age 6 to 7 years in girls and 8 to 9 years in boys, at
    which time ossification occurs. Fractures before this time thus include
    medial epicondyle.
  • The younger the child, the greater the
    volume of the distal humerus that is occupied by the distal epiphysis;
    as the child matures, the physeal line progresses distally, with a
    V-shaped cleft forming between the medial and lateral condylar
    physes—this cleft protects the distal humeral epiphysis from fracture
    in the mature child, because fracture lines tend to exit through the
    cleft.
  • The joint surface is not involved in this injury, and the relationship between the radius and capitellum is maintained.

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  • The anteroposterior diameter of the bone
    in this region is wider than in the supracondylar region, and
    consequently there is not as much tilting or rotation.
  • The vascular supply to the medial crista
    of the trochlea courses directly through the physis; in cases of
    fracture, this may lead to avascular changes.
  • The physeal line is in a more proximal
    location in younger patients, therefore, hyperextension injuries to the
    elbow tend to result in physeal separations instead of supracondylar
    fractures through bone.
Mechanism of Injury
  • Birth injuries: Rotatory forces coupled
    with hyperextension injury to the elbow during delivery may result in
    traumatic distal humeral physeal separation.
  • Child abuse: Bright demonstrated that the
    physis fails most often in shear rather than pure bending or tension.
    Therefore, in young infants or children, child abuse must be suspected,
    because a high incidence of transphyseal fracture is associated with
    abuse.
  • Trauma: This may result from hyperextension injuries with posterior displacement, coupled with a rotation moment.
Clinical Evaluation
  • Young infants or newborns may present
    with pseudoparalysis of the affected extremity, minimal swelling, and
    “muffled crepitus,” because the fracture involves softer cartilage
    rather than firm, osseous tissue.
  • Older children may present with
    pronounced swelling, refusal to use the affected extremity, and pain
    that precludes a useful clinical examination or palpation of bony
    landmarks. In general, because of the large, wide fracture surface
    there is less tendency for tilting or rotation of the distal fragment,
    resulting in less deformity than seen in supracondylar fractures. The
    bony relationship between the humeral epicondyles and the olecranon is
    maintained.
  • A careful neurovascular examination
    should be performed, because swelling in the cubital fossa may result
    in neurovascular compromise.
Radiographic Evaluation
  • AP, lateral, oblique radiographs should be obtained.
  • The proximal radius and ulna maintain
    normal, anatomic relationships to each other, but they are displaced
    posteromedially with respect to the distal humerus. This is considered
    diagnostic of transphyseal fracture.
  • Comparison views of the contralateral elbow may be used to identify posteromedial displacement.
  • In the child whose lateral condylar
    epiphysis is ossified, the diagnosis is much more obvious. There is
    maintenance of the lateral condylar epiphysis to radial head
    relationship and posteromedial displacement of the distal humeral
    epiphysis with respect to the humeral shaft.
  • Transphyseal fractures with large metaphyseal components may be mistaken for a low supracondylar fracture or a fracture

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    of the lateral condylar physis. These may be differentiated by the
    presence of a smooth outline of the distal metaphysis in fractures
    involving the entire distal physis as compared with the irregular
    border of the distal aspect of the distal fragment seen in
    supracondylar fractures.

  • Elbow dislocations in children are rare,
    but they may be differentiated from transphyseal fractures by primarily
    posterolateral displacement and a disrupted relationship between the
    lateral condylar epiphysis and the proximal radius.
  • An arthrogram may be useful for clarification of the fracture pattern and differentiation from an intraarticular fracture.
  • MRI may be helpful in appreciating the direction of the fracture line and the pattern of fracture.
  • Ultrasound may be useful in evaluating neonates and infants in whom ossification has not yet begun.
Classification
DELEE
This is based on ossification of the lateral condyle.

Group A: Infant, before the appearance
of the lateral condylar ossification center (birth to 7 months);
diagnosis easily missed; Salter-Harris type I
Group B: Lateral condyle ossified (7 months to 3 years); Salter-Harris type I or II (fleck of metaphysis)
Group C: Large metaphyseal fragment, usually exiting laterally (age 3 to 7 years)
Treatment
Because many of these injuries in infants and toddlers
represent child abuse injuries, it is not uncommon for parents to delay
seeking treatment.
NONOPERATIVE
  • Closed reduction with immobilization is
    performed with the forearm pronated and the elbow in 90 degrees of
    flexion if the injury is recognized early (within 4 to 5 days). This is
    maintained for 3 weeks, at which time the patient is allowed to resume
    active range of motion.
  • Severe swelling of the elbow may necessitate Dunlop-type sidearm traction. Skeletal traction is typically not necessary.
  • When treatment is delayed beyond 6 to 7
    days of injury, the fracture should not be manipulated regardless of
    displacement, because the epiphyseal fragment is no longer mobile and
    other injuries may be precipitated; rather, splinting for comfort
    should be undertaken. Most fractures eventually completely remodel by
    maturity.
OPERATIVE
  • DeLee Type C fracture patterns or
    unstable injuries may necessitate percutaneous pinning for fixation. An
    arthrogram is usually performed to determine the adequacy of reduction.
  • Angulation and rotational deformities
    that cannot be reduced by closed methods may require open reduction and
    internal fixation with pinning for fixation.
  • Postoperatively, the patient may be immobilized with the forearm in pronation and the elbow flexed to 90 degrees. The pins

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    and cast are discontinued at 3 weeks, at which time active range of motion is permitted.

Complications
  • Malunion: Cubitus varus is most common,
    although the incidence is lower than with supracondylar fractures of
    the humerus because of the wider fracture surface of transphyseal
    fractures that do not allow as much angulation compared with
    supracondylar fractures.
  • Neurovascular injury: Extremely rare
    because the fracture surfaces are covered with cartilage. Closed
    reduction and immobilization should be followed by repeat neurovascular
    assessment, given that swelling in the antecubital fossa may result in
    neurovascular compromise.
  • Nonunion: Extremely rare because the vascular supply to this region is good.
  • Osteonecrosis: May be related to severe
    displacement of the distal fragment or iatrogenic injury, especially
    with late exploration.
Medial Epicondylar Apophyseal Fractures
Epidemiology
  • Comprise 14% of distal humerus fractures.
  • 50% are associated with elbow dislocations.
  • The peak age is 11 to 12 years.
  • The male-to-female ratio is 4:1.
Anatomy
  • The medial epicondyle is a traction
    apophysis for the medial collateral ligament and wrist flexors. It does
    not contribute to humeral length. The forces across this physis are
    tensile rather than compressive.
  • Ossification begins at 4 to 6 years of
    age; it is the last ossification center to fuse with the metaphysis (15
    years) and does so independently of the other ossification centers.
  • The fragment is usually displaced distally and may be incarcerated in the joint 15% to 18% of the time.
  • It is often associated with fractures of the proximal radius, olecranon and coronoid.
  • In younger children, a medial epicondylar
    apophyseal fracture may have an intracapsular component, because the
    elbow capsule may attach as proximally as the physeal line of the
    epicondyle. In the older child, these fractures are generally
    extracapsular given that the capsular attachment is more distal, to the
    medial crista of the trochlea.
Mechanism of Injury
  • Direct: Trauma to the posterior or
    posteromedial aspect of the medial epicondyle may result in fracture,
    although these are rare and tend to produce fragmentation of the medial
    epicondylar fragment.
  • Indirect:
    • Secondary to elbow dislocation: The ulnar collateral ligament provides avulsion force.

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    • Avulsion injury by flexor muscles results
      from valgus and extension force during a fall onto an outstretched hand
      or secondary to an isolated muscle avulsion from throwing a ball or arm
      wrestling, for example.
  • Chronic: Related to overuse injuries from repetitive throwing, as seen in skeletally immature baseball pitchers.
Clinical Evaluation
  • Patients typically present with pain, tenderness, and swelling medially.
  • Symptoms may be exacerbated by resisted wrist flexion.
  • A careful neurovascular examination is
    essential, because the injury occurs in proximity to the ulnar nerve,
    which can be injured during the index trauma or from swelling about the
    elbow.
  • Decreased range of motion is usually
    elicited and may be secondary to pain. Occasionally, a mechanical block
    to range of motion may result from incarceration of the epicondylar
    fragment within the elbow joint.
  • Valgus instability can be appreciated on
    stress testing with the elbow flexed to 15 degrees to eliminate the
    stabilizing effect of the olecranon.
Radiographic Evaluation
  • AP, lateral, and oblique radiographs of the elbow should be obtained.
  • Because of the posteromedial location of
    the medial epicondylar apophysis, the ossification center may be
    difficult to visualize on the AP radiograph if it is even slightly
    oblique.
  • The medial epicondylar apophysis is
    frequently confused with fracture because of the occasionally
    fragmented appearance of the ossification center as well as the
    superimposition on the distal medial metaphysis. Better visualization
    may be obtained by a slight oblique of the lateral radiograph, which
    demonstrates the posteromedial location of the apophysis.
  • A gravity stress test may be performed, demonstrating medial opening on stress radiographs.
  • Complete absence of the apophysis on
    standard elbow views should prompt a search for the displaced fragment
    after comparison views of the contralateral, normal elbow are obtained.
    Specifically, incarceration within the joint must be sought, because
    the epicondylar fragment may be obscured by the distal humerus.
  • Fat pad signs are unreliable, given that
    epicondylar fractures are extracapsular in older children and capsular
    rupture associated with elbow dislocation may compromise its ability to
    confine the hemarthrosis.
  • It is important to differentiate this
    fracture from a medial condylar physeal fracture; MRI or arthrogram may
    delineate the fracture pattern, especially when the medial condylar
    ossification center is not yet present.
Classification
  • Acute
    • Nondisplaced
    • Minimally displaced

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    • Significantly displaced (>5 mm) with a fragment proximal to the joint
    • Incarcerated fragment within the olecranon-trochlea articulation
    • Fracture through or fragmentation of the epicondylar apophysis, typically from direct trauma
  • Chronic
    • Tension stress injuries (“Little League elbow”)
Treatment
NONOPERATIVE
  • Most medial epicondylar fractures may be
    managed nonoperatively with immobilization. Studies demonstrate that
    although 60% may establish only fibrous union, 96% have good or
    excellent functional results.
  • Nonoperative treatment is indicated for
    nondisplaced or minimally displaced fractures and for significantly
    displaced fractures in older or low-demand patients.
  • The patient is initially placed in a
    posterior splint with the elbow flexed to 90 degrees with the forearm
    in neutral or pronation.
  • The splint is discontinued 3 to 4 days after injury and early active range of motion is instituted. A sling is worn for comfort.
  • Aggressive physical therapy is generally not necessary unless the patient is unable to perform active range-of-motion exercises.
OPERATIVE
  • An absolute indication for operative
    intervention is an irreducible, incarcerated fragment within the elbow
    joint. Closed manipulation may be used to attempt to extract the
    incarcerated fragment from the joint as described by Roberts. The
    forearm is supinated, and valgus stress is applied to the elbow,
    followed by dorsiflexion of the wrist and fingers to put the flexors on
    stretch. This maneuver is successful approximately 40% of the time.
  • Relative indications for surgery include
    ulnar nerve dysfunction owing to scar or callus formation, valgus
    instability in an athlete, or significantly displaced fractures in
    younger or high-demand patients.
  • Acute fractures of the medial epicondyle
    may be approached through a longitudinal incision just anterior to the
    medial epicondyle. Ulnar nerve identification is important, but
    extensive dissection or transposition is generally unnecessary. After
    reduction and provisional fixation with Kirschner wires, fixation may
    be achieved with a lag-screw technique. A washer may be used in cases
    of poor bone stock or fragmentation.
  • Postoperatively, the patient is placed in
    a posterior splint or long arm cast with the elbow flexed to 90 degrees
    and the forearm pronated. This may be converted to a removable
    posterior splint or sling at 7 to 10 days postoperatively, at which
    time active range-of-motion exercises are instituted. Formal physical
    therapy is generally unnecessary if the patient is able to perform
    active exercises.

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Complications
  • Unrecognized intraarticular
    incarceration: An incarcerated fragment tends to adhere and form a
    fibrous union to the coronoid process, resulting in significant loss of
    elbow range of motion. Although earlier recommendations were to manage
    this nonoperatively, recent recommendations are to explore the joint
    with excision of the fragment.
  • Ulnar nerve dysfunction: The incidence is
    10% to 16%, although cases associated with fragment incarceration may
    have up to a 50% incidence of ulnar nerve dysfunction. Tardy ulnar
    neuritis may develop in cases involving reduction of the elbow or
    manipulation in which scar tissue may be exuberant. Surgical
    exploration and release may be warranted for symptomatic relief.
  • Nonunion: May occur in up to 60% of cases
    with significant displacement treated nonoperatively, although it
    rarely represents a functional problem.
  • Loss of extension: A 5% to 10% loss of
    extension is seen in up to 20% of cases, although this rarely
    represents a functional problem. This emphasizes the need for early
    active range-of-motion exercises.
  • Myositis ossificans: Rare, related to
    repeated and vigorous manipulation of the fracture. It may result in
    functional block to motion and must be differentiated from ectopic
    calcification of the collateral ligaments related to microtrauma, which
    does not result in functional limitation.
Lateral Epicondylar Apophyseal Fractures
Epidemiology
  • Extremely rare in children.
Anatomy
  • The lateral epicondylar ossification
    center appears at 10 to 11 years of age; however, ossification is not
    completed until the second decade of life.
  • The lateral epicondyle represents the
    origin of many of the wrist and forearm extensors; therefore, avulsion
    injuries account for a proportion of the fractures, as well as
    displacement once the fracture has occurred.
Mechanism of Injury
  • Direct trauma to the lateral epicondyle may result in fracture; these may be comminuted.
  • Indirect trauma may occur with forced
    volarflexion of an extended wrist, causing avulsion of the extensor
    origin, often with significant displacement as the fragment is pulled
    distally by the extensor musculature.
Clinical Evaluation
  • Patients typically present with lateral
    swelling and painful range of motion of the elbow and wrist, with
    tenderness to palpation of the lateral epicondyle.
  • Loss of extensor strength may be appreciated.

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Radiographic Evaluation
  • The diagnosis is typically made on the AP
    radiograph, although a lateral view should be obtained to rule out
    associated injuries.
  • The lateral epicondylar physis represents
    a linear radiolucency on the lateral aspect of the distal humerus and
    is commonly mistaken for a fracture. Overlying soft tissue swelling,
    cortical discontinuity, and clinical examination should assist the
    examiner in the diagnosis of lateral epicondylar apophyseal injury.
Classification
DESCRIPTIVE
  • Avulsion
  • Comminution
  • Displacement
Treatment
NONOPERATIVE
  • With the exception of an incarcerated
    fragment within the joint, almost all lateral epicondylar apophyseal
    fractures may be treated with immobilization with the elbow in the
    flexed, supinated position until comfortable, usually by 2 to 3 weeks.
OPERATIVE
  • Incarcerated fragments within the elbow
    joint may be simply excised. Large fragments with associated tendinous
    origins may be reattached with screws or Kirschner wire fixation and
    postoperative immobilization for 2 to 3 weeks until comfortable.
Complications
  • Nonunion: Commonly occurs with
    established fibrous union of the lateral epicondylar fragment, although
    it rarely represents a functional or symptomatic problem.
  • Incarcerated fragments: May result in
    limited range of motion, most commonly in the radiocapitellar
    articulation, although free fragments may migrate to the olecranon
    fossa and limit terminal extension.
Capitellum Fractures
Epidemiology
  • Of these fractures, 31% are associated with injuries to the proximal radius.
  • Rare in children, representing 1:2,000 fractures about the elbow.
  • No verified, isolated fractures of the capitellum have ever been described in children younger than 12 years of age.
Anatomy
  • The fracture fragment is composed mainly
    of pure articular surface from the capitellum and essentially
    nonossified cartilage from the secondary ossification center of the
    lateral condyle.

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Mechanism of Injury
  • Indirect force from axial load
    transmission from the hand through the radial head causes the radial
    head to strike the capitellum.
  • The presence of recurvatum or cubitus valgus predisposes the elbow to this fracture pattern.
Clinical Evaluation
  • Patients typically present with minimal swelling with painful range of motion. Flexion is often limited by the fragment.
  • Valgus stress tends to reproduce the pain over the lateral aspect of the elbow.
  • Supination and pronation may accentuate the pain.
Radiographic Evaluation
  • AP and lateral views of the elbow should be obtained.
  • Radiographs of the normal, contralateral elbow may be obtained for comparison.
  • If the fragment is large and encompasses
    ossified portions of the capitellum, it is most readily appreciated on
    the lateral radiograph.
  • Oblique views of the elbow may be
    obtained if radiographic abnormality is not appreciated on standard AP
    and lateral views, especially because a small fragment may be obscured
    by the density of the overlying distal metaphysis on the AP view.
  • Arthrography or MRI may be helpful when a
    fracture is not apparent but is suspected to involve purely
    cartilaginous portions of the capitellum.
Classification

Type I: Hahn-Steinthal fragment: large osseous component of capitellum, often involving the lateral crista of the trochlea
Type II: Kocher-Lorenz fragment: articular cartilage with minimal subchondral bone attached; “uncapping of the condyle”
Treatment
NONOPERATIVE
  • Nondisplaced or minimally displaced fractures may be treated with casting with the elbow in hyperflexion.

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  • Immobilization should be maintained until
    2 to 4 weeks or evidence of radiographic healing, at which time active
    exercises should be instituted.
OPERATIVE
  • Adequate reduction of displaced fractures
    is difficult with closed manipulation. Modified closed reduction
    involving placement of a Steinmann pin into the fracture fragment with
    manipulation into the reduced position may be undertaken, with
    postoperative immobilization consisting of casting with the elbow in
    hyperflexion.
  • Excision of the fragment is indicated for
    fractures in which the fragment is small, comminuted, old (>2
    weeks), or not amenable to anatomic reduction without significant
    dissection of the elbow.
  • Open reduction and internal fixation may
    be achieved by the use of two lag screws, headless screws, or Kirschner
    wires placed posterior to anterior or anterior to posterior. The heads
    of the screws must be countersunk to avoid intraarticular impingement.
  • Postoperative immobilization should
    consist of casting with the elbow in hyperflexion for 2 to 4 weeks
    depending on stability, with serial radiographic evaluation.
Complications
  • Osteonecrosis of the capitellar fragment:
    This is uncommon; synovial fluid can typically sustain the fragment
    until healing occurs.
  • Posttraumatic osteoarthritis: This may
    occur with secondary incongruity from malunion or particularly after a
    large fragment is excised.
  • Stiffness: Loss of extension is most
    common, especially with healing of the fragment in a flexed position.
    This is typically not significant, because it usually represents the
    terminal few degrees of extension.
T-Condylar Fractures
Epidemiology
  • Rare, especially in young children,
    although this rarity may represent misdiagnosis because purely
    cartilaginous fractures would not be demonstrated on routine
    radiographs.
  • Peak incidence is in patients 12 to 13 years of age.
Anatomy
  • Because of the muscular origin of the
    flexor and extensor muscles of the forearm, fragment displacement is
    related not only to the inciting trauma but also to the tendinous
    attachments. Displacement therefore includes rotational deformities in
    both the sagittal and coronal planes.
  • Fractures in the young child may have a
    relatively intact distal humeral articular surface despite osseous
    displacement of the overlying condylar fragments because of the
    elasticity of the cartilage in the skeletally immature patient.
Mechanism of Injury
  • Flexion: Most represent wedge-type
    fractures as the anterior margin of the semilunar notch is driven into
    the trochlea by a fall onto the posterior aspect of the elbow in >90
    degrees of flexion. The condylar fragments are usually anteriorly
    displaced with respect to the humeral shaft.
  • Extension: In this uncommon mechanism, a
    fall onto an outstretched upper extremity results in a wedge-type
    fracture as the coronoid process of the ulna is driven into the
    trochlea. The condylar fragments are typically posteriorly displaced
    with respect to the humeral shaft.

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Clinical Evaluation
  • The diagnosis is most often confused with
    extension-type supracondylar fractures because the patient typically
    presents with the elbow extended, with pain, limited range of motion,
    variable gross deformity, and massive swelling about the elbow.
  • The ipsilateral shoulder, humeral shaft, forearm, wrist, and hand should be examined for associated injuries.
  • A careful neurovascular examination is
    essential, with documentation of the integrity of the median, radial,
    and ulnar nerves, as well as distal pulses and capillary refill.
    Massive swelling in the antecubital fossa should alert the examiner to
    evaluate for compartment syndrome of the forearm. Flexion of the elbow
    in the presence of antecubital swelling may cause neurovascular
    embarrassment; repeat evaluation of neurovascular integrity is thus
    essential following any manipulation or treatment.
  • All aspects of the elbow should be
    examined for possible open lesions; clinical suspicion may be followed
    with intraarticular injection of saline into the elbow to evaluate
    possible intraarticular communication of a laceration.
Radiographic Evaluation
  • Standard AP and lateral views of the injured elbow should be obtained.
  • Comparison views of the normal,
    contralateral elbow may be obtained in which the diagnosis is not
    readily apparent. Oblique views may aid in further fracture definition.
  • In younger patients, the vertical,
    intercondylar component may involve only cartilaginous elements of the
    distal humerus; the fracture may thus appear to be purely
    supracondylar, although differentiation of the two fracture patterns is
    important because of the potential for articular disruption and
    incongruency with T-type fractures. An arthrogram should be obtained
    when intraarticular extension is suspected.
  • Computed tomography and MRI are of
    limited value and are not typically used in the acute diagnosis of
    T-type fractures. In younger patients, these modalities often require
    heavy sedation or anesthesia outside of the operating room, in which
    case an arthrogram is preferred because it allows for evaluation of the
    articular involvement as well as treatment in the operating room
    setting.
Classification

Type I: Nondisplaced or minimally displaced
Type II: Displaced, with no metaphyseal comminution
Type III: Displaced, with metaphyseal comminution
Treatment
NONOPERATIVE
  • This is reserved only for truly
    nondisplaced Type I fractures. Thick periosteum may provide sufficient
    intrinsic stability such that the elbow may be immobilized in flexion
    with a posterior splint. Mobilization is continued for 1 to 4 weeks
    after injury.

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  • Skeletal olecranon traction with the
    elbow flexed to 90 degrees may be used for patients with extreme
    swelling, soft tissue compromise, or delayed cases with extensive skin
    injury that precludes immediate operative intervention. If used as
    definitive treatment, skeletal traction is usually continued for 2 to 3
    weeks, at which time sufficient stability exists for the patient to be
    converted to a hinged brace for an additional 2 to 3 weeks.
OPERATIVE
  • Closed reduction and percutaneous pinning
    are used with increasing frequency for minimally displaced Type I
    injuries, in accord with the current philosophy that the articular
    damage, which cannot be appreciated on standard radiography, may be
    worse than the apparent osseous involvement.
    • Rotational displacement is corrected
      using a percutaneous joystick in the fracture fragment, with placement
      of multiple, oblique Kirschner wires for definitive fixation.
    • The elbow is then protected in a posterior splint, with removal of pins at 3 to 4 weeks postoperatively.
  • Open reduction and internal fixation are
    undertaken for Type II and Type III fractures using either a posterior,
    triceps splitting approach, or the triceps-sparing approach as
    described by Bryan and Morrey. Olecranon osteotomy is generally not
    necessary for exposure and should be avoided.
    • The articular surface is first
      anatomically reduced and provisionally stabilized with Kirschner wires,
      followed by metaphyseal reconstruction with definitive fixation using a
      combination of Kirschner wires, compression screws, and plates.
    • Semitubular plates are usually
      inadequate; pelvic reconstruction plates and specifically designed
      pediatric J-type plates have been used with success, often with two
      plates placed 90 degrees offset from one another.
    • Postoperatively, the elbow is placed in a
      flexed position for 5 to 7 days, at which time active range of motion
      is initiated and a removable cast brace is provided.
Complications
  • Loss of range of motion: T-type condylar
    fractures are invariably associated with residual stiffness, especially
    to elbow extension, owing to the often significant soft tissue injury
    as well as articular disruption. This can be minimized by ensuring
    anatomic reduction of the articular surface, employing arthrographic
    visualization if necessary, as well as stable internal fixation to
    decrease soft tissue scarring.
  • Neurovascular injury: Rare but is related
    to significant antecubital soft tissue swelling. Nerve injury to the
    median, radial, or ulnar nerves may result from the initial fracture
    displacement or intraoperative traction, although these typically
    represent neurapraxias that resolve without intervention.
  • Growth arrest: Partial or total growth
    arrest may occur in the distal humeral physis, although it is rarely
    clinically significant because T-type fractures tend to occur in older
    children. Similarly, the degree of remodeling is limited, and anatomic
    reduction should be obtained at the time of initial treatment.

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  • Osteonecrosis of the trochlea: This may
    occur especially in association with comminuted fracture patterns in
    which the vascular supply to the trochlea may be disrupted.
Radial Head and Neck Fractures
Epidemiology
  • Of these fractures, 90% involve either physis or neck; the radial head is rarely involved because of the thick cartilage cap.
  • Represent 5% to 8.5% of elbow fractures.
  • The peak age of incidence is 9 to 10 years.
  • Commonly associated fractures include the olecranon, coronoid, and medial epicondyle.
Anatomy
  • Ossification of the proximal radial
    epiphysis begins at 4 to 6 years of age as a small, flat nucleus. It
    may be spheric or may present as a bipartite structure; these anatomic
    variants may be appreciated by their smooth, rounded borders without
    cortical discontinuity.
  • Normal angulation of the radial head with
    respect to the neck ranges between 0 and 15 degrees laterally, and from
    10 degrees anterior to 5 degrees posterior angulation.
  • Most of the radial neck is extracapsular;
    therefore, fractures in this region may not result in a significant
    effusion or a positive fat pad sign.
  • No ligaments attach directly to the
    radial head or neck; the radial collateral ligament attaches to the
    orbicular ligament, which originates from the radial aspect of the ulna.
Mechanism of Injury
  • Acute:
    • Indirect: This is most common, usually
      from a fall onto an outstretched hand with axial load transmission
      through the proximal radius with trauma against the capitellum.
    • Direct: This is uncommon because of the overlying soft tissue mass.
  • Chronic:
    • Repetitive stress injuries may occur,
      most commonly from overhead throwing activities. Although most “Little
      League elbow” injuries represent tension injuries to the medial
      epicondyle, compressive injuries from valgus stress may result in an
      osteochondrotic-type disorder of the radial head or an angular
      deformity of the radial neck.
Clinical Evaluation
  • Patients typically present with lateral
    swelling of the elbow, with pain exacerbated by range of motion,
    especially supination and pronation.
  • Crepitus may be elicited on supination and pronation.
  • In a young child, the primary complaint
    may be wrist pain; pressure over the proximal radius may accentuate the
    referred wrist pain.

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Radiographic Evaluation
Figure
44.7. Radiocapitellar view. The center of the x-ray beam is directed at
45 degrees to separate the proximal radius and ulna on the x-ray.

(From Long BW. Orthopaedic Radiography. Philadelphia: WB Saunders; 1995:152).
  • AP and lateral views of the elbow should be obtained. Oblique views may aid in further definition of the fracture line.
  • Special views
    • Perpendicular views: With an acutely
      painful, flexed elbow, AP evaluation of the elbow may be obtained by
      taking one radiograph perpendicular to the humeral shaft, and a second
      view perpendicular to the proximal radius.
    • Radiocapitellar (Greenspan) view: This
      oblique lateral radiograph is obtained with the beam directed 45
      degrees in a proximal direction, resulting in a projection of the
      radial head anterior to the coronoid process of the anterior ulna (Fig. 44.7).
  • A positive supinator fat pad sign may be present, indicating injury to the proximal radius.
  • Comparison views of the contralateral elbow may help identify subtle abnormalities.
  • When a fracture is suspected through
    nonossified regions of the radial head, an arthrogram may be performed
    to determine displacement.
  • MRI may be helpful in appreciating the direction of the fracture line and the pattern of fracture.

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Classification
Figure
44.8. Types of valgus injuries. Left: Type A: Salter-Harris type I or
II physeal injury. Center: Type B: Salter-Harris type IV injury. Right:
Type C: Total metaphyseal fracture pattern.

(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)
O’BRIEN
  • This is based on the degree of angulation.

Type I: <30 degrees
Type II: 30 to 60 degrees
Type III: >60 degrees
WILKINS
  • This is based on the mechanism of injury.
  • Valgus injuries are caused by a fall onto an outstretched hand (compression); angular deformity of the head is usually seen (Fig. 44.8).

    Type A: Salter-Harris Type I or II physeal injury
    Type B: Salter-Harris Type III or IV intraarticular injury
    Type C: Fracture line completely within the metaphysis
  • Fracture associated with elbow dislocation
    • Reduction injury
    • Dislocation injury
Treatment
NONOPERATIVE
  • Simple immobilization is indicated for
    O’Brien Type I fractures with <30-degree angulation. This can be
    accomplished with the use of a collar and cuff, a posterior splint, or
    a long arm cast for 7 to 10 days with early range of motion.
  • Type II fractures with 30- to 60-degree angulation should be managed with manipulative closed reduction.
    • This may be accomplished by distal
      traction with the elbow in extension and the forearm in supination;
      varus stress is applied to overcome the ulnar deviation of the distal
      fragment and open up the lateral aspect of the joint, allowing for

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      disengagement of the fragments for manipulation (Patterson) (Fig. 44.9).

      Figure
      44.9. Patterson’s manipulative technique. Left: An assistant grabs the
      patient’s arm proximally with one hand placed medially against the
      distal humerus. The surgeon applies distal traction with the forearm
      supinated and pulls the forearm into varus. Right: Digital pressure
      applied directly over the tilted radial head completes the reduction.

      (Adapted from Patterson RF. Treatment of displaced transverse fractures of the neck of the radius in children. J Bone Joint Surg 1934;16:696×2013;698; in Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)
    • Israeli described a technique in which
      the elbow is placed in flexion, and the surgeon’s thumb is used to
      apply pressure over the radial head while the forearm is forced into a
      pronated position (Fig. 44.10).
    • Chambers reported another technique for
      reduction in which an Esmarch wrap is applied distally to proximally,
      and the radius is reduced by the circumferential pressure.
    • Following reduction, the elbow should be
      immobilized in a long arm cast in pronation with 90 degrees of flexion.
      This should be maintained for 10 to 14 days, at which time
      range-of-motion exercises should be initiated.
OPERATIVE
  • O’Brien Type II fractures (30- to
    60-degree angulation) that are unstable following closed reduction may
    require the use of percutaneous Kirschner wire fixation. This is best
    accomplished

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    by
    the use of a Steinmann pin placed in the fracture fragment under image
    intensification for manipulation, followed by oblique Kirschner wire
    fixation after reduction is achieved. The patient is then placed in a
    long arm cast in pronation with 90-degree elbow flexion for 3 weeks, at
    which time the pins and cast are discontinued and active range of
    motion is initiated.

    Figure
    44.10. Flexion-pronation (Israeli) reduction technique. (A) With the
    elbow in 90 degrees of flexion, the thumb stabilizes the displaced
    radial head. Usually the distal radius is in a position of supination.
    The forearm is pronated to swing the shaft up into alignment with the
    neck (arrow). (B) Movement is continued to full pronation for reduction (arrow).

    (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)
  • Indications for open reduction and
    internal fixation include fractures that are irreducible by closed
    means, Type III fractures (>60-degree angulation), fractures with
    >4 mm translation, and medial displacement fractures (these are
    notoriously difficult to reduce by closed methods). Open reduction with
    oblique Kirschner wire fixation is recommended; transcapitellar pins
    are contraindicated because of a high rate of breakage, as well as
    articular destruction from even slight postoperative motion.
  • The results of open treatment are not
    significantly different from those of closed treatment; therefore,
    closed treatment should be performed when possible.
  • Radial head excision gives poor results
    in children owing to the high incidence of cubitus valgus and radial
    deviation at the wrist due to the continued growth of the child.
Prognosis
  • From 15% to 23% will have a poor result regardless of treatment.
  • Predictors of a favorable prognosis include:
    • <10 years of age.
    • Isolated injury.

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    • Minimal soft tissue injury.
    • Good fracture reduction.
    • <30-degree initial angulation.
    • <3-mm initial displacement.
    • Closed treatment.
    • Early treatment.
Complications
  • Decreased range of motion occurs in (in
    order of decreasing frequency) pronation, supination, extension,
    flexion. The reason is loss of joint congruity and fibrous adhesions.
    Additionally, enlargement of the radial head following fracture may
    contribute to loss of motion.
  • Radial head overgrowth: From 20% to 40%
    of cases will experience posttraumatic overgrowth of the radial head,
    owing to increased vascularity from the injury that stimulates
    epiphyseal growth.
  • Premature physeal closure: Rarely results in shortening >5 mm, although it may accentuate cubitus valgus.
  • Osteonecrosis of the radial head: Occurs
    in 10% to 20%, related to amount of displacement; 70% of cases of
    osteonecrosis are associated with open reduction.
  • Neurologic: Usually posterior
    interosseous nerve neurapraxia; during surgical exposure, pronating the
    forearm causes the posterior interosseous nerve to move ulnarly, out of
    the surgical field.
  • Radioulnar synostosis: The most serious
    complication, usually occurring following open reduction with extensive
    dissection, but it has been reported with closed manipulations and is
    associated with a delay in treatment of >5 days. It may require
    exostectomy to improve function.
  • Myositis ossificans: May complicate up to 32% of cases, mostly involving the supinator.
Radial Head Subluxation
Epidemiology
  • Referred to as “nursemaid’s elbow” or “pulled elbow.”
  • Male-to-female ratio is 1:2.
  • Occurs in the left elbow 70% of the time.
  • Occurs at ages 6 months to 6 years, with a peak at ages 2 to 3 years.
  • Recurrence rate is 5% to 30%.
Anatomy
  • Primary stability of the proximal
    radioulnar joint is conferred by the annular ligament, which closely
    apposes the radial head within the radial notch of the proximal ulna.
  • The annular ligament becomes taut in supination of the forearm owing to the shape of the radial head.
  • The substance of the annular ligament is reinforced by the radial collateral ligament at the elbow joint.
  • After age 5 years, the distal attachment
    of the annular ligament to the neck of the radius strengthens
    significantly to prevent tearing or subsequent displacement.

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Mechanism of Injury
  • Longitudinal traction force on extended
    elbow is the cause, although it remains controversial whether the
    lesion is produced in forearm supination or pronation (it is more
    widely accepted that the forearm must be in pronation for the injury to
    occur).
Clinical Evaluation
  • Patients typically present with an
    appropriate history of sudden, longitudinal traction applied to the
    extended upper extremity (such as a child “jerked” back from crossing
    the street), often with an audible snap. The initial pain subsides
    rapidly, and the patient allows the upper extremity to hang in the
    dependent position with the forearm pronated and elbow slightly flexed
    and refuses to use the ipsilateral hand (pseudoparalysis).
  • A history of a longitudinal pull may be absent in 33% to 50% of cases.
  • Effusion is rare, although tenderness can usually be elicited over the anterior and lateral aspects of the elbow.
  • A neurovascular examination should be
    performed, although the presence of neurovascular compromise should
    alert the physician to consider other diagnostic possibilities because
    neurovascular injury is not associated with simple radial head
    subluxation.
Radiographic Evaluation
  • Radiographs are not necessary if there is
    a classic history, the child is 5 years old or younger, and the
    clinical examination is strongly supportive. Otherwise, standard AP and
    lateral views of the elbow should be obtained.
  • Radiographic abnormalities are not
    typically appreciated, although some authors have suggested that on the
    AP radiograph >3 mm lateral displacement of the radial head with
    respect to the capitellum is indicative of radial head subluxation.
    However, disruption of the radiocapitellar axis is subtle and often
    obscured by even slight rotation; therefore, even with a high index of
    suspicion, appreciation of this sign is generally present in only 25%
    of cases.
  • Ultrasound is not routinely used in the
    evaluation of radial head subluxation, but it may demonstrate an
    increase in the echonegative area between the radial head and the
    capitellum (radiocapitellar distance typically about 7.2 mm; a
    difference of >3 mm between the normal and injured elbow suggests of
    radial head subluxation).
Classification
  • A classification scheme for radial head subluxation does not exist.
  • It is important to rule out other
    diagnostic possibilities, such as early septic arthritis or proximal
    radius fracture, which may present in a similar fashion, especially if
    a history of a longitudinal pull is absent.

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Treatment
  • Closed reduction
    • The forearm is supinated with thumb pressure on the radial head.
    • The elbow is then brought into maximum flexion with the forearm still in supination.
    • Hyperpronation may also be used to reduce the subluxation.
  • A palpable “click” may be felt on reduction.
  • The child typically experiences a brief
    moment of pain with the reduction maneuver, followed by the absence of
    pain and normal use of the upper extremity 5 to 10 minutes later.
  • Postreduction films are generally
    unnecessary. A child who remains irritable may require further workup
    for other disorders or a repeat attempt at reduction. If the
    subluxation injury occurred 12 to 24 hours before evaluation, reactive
    synovitis may be present that may account for elbow tenderness and a
    reluctance to move the joint.
  • Sling immobilization is generally unnecessary if the child is able to use the upper extremity without complaint.
Complications
  • Chronically unreduced subluxation:
    Unrecognized subluxation of the radial head generally reduces
    spontaneously with relief of painful symptoms. In these cases, the
    subluxation is realized retrospectively.
  • Recurrence: Affects 5% to 39% of cases,
    but generally ceases after 4 to 5 years when the annular ligament
    strengthens, especially at its distal attachment to the radius.
  • Irreducible subluxation: Rare owing to
    interposition of the annular ligament. Open reduction may be necessary
    with transection and repair of the annular ligament to obtain stable
    reduction.
Elbow Dislocations
Epidemiology
  • Represent 3% to 6% of all elbow injuries.
  • The peak age is 13 to 14 years, after physes are closed.
  • There is a high incidence of associated fractures: medial epicondyle, coronoid, and radial head and neck.
Anatomy
  • This is a “modified hinge” joint
    (ginglymotrochoid) with a high degree of intrinsic stability owing to
    joint congruity, opposing tension of triceps and flexors, and
    ligamentous constraints. Of these, the anterior bundle of the medial
    collateral ligament is the most important.
  • Three separate articulations
    • Ulnohumeral (hinge)
    • Radiohumeral (rotation)
    • Proximal radioulnar (rotation)
  • Stability
    • AP: trochlea/olecranon fossa (extension); coronoid fossa, radiocapitellar joint, biceps/triceps/brachialis (flexion)

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    • Valgus: Medial collateral ligament
      complex (anterior bundle the primary stabilizer (flexion and
      extension)) anterior capsule and radiocapitellar joint (extension)
    • Varus: Ulnohumeral articulation, lateral ulnar collateral ligament (static); anconeus muscle (dynamic)
  • Range of motion is 0 to 150 degrees of flexion, 85 degrees of supination, and 80 degrees of pronation.
  • Functionally, range of motion requires 30 to 130 degrees of flexion, 50 degrees of supination, and 50 degrees of pronation.
  • Extension and pronation are the positions of relative instability.
Mechanism of Injury
  • Most commonly, the cause is a fall onto
    an outstretched hand or elbow, resulting in a levering force to unlock
    the olecranon from the trochlea combined with translation of the
    articular surfaces to produce the dislocation.
  • Posterior dislocation: This is a
    combination of elbow hyperextension, valgus stress, arm abduction, and
    forearm supination with resultant soft tissue injuries to the capsule,
    collateral ligaments (especially medial), and musculature.
  • Anterior dislocation: A direct force strikes the posterior aspect of the flexed elbow.
Clinical Evaluation
  • Patients typically present guarding the injured upper extremity with variable gross instability and massive swelling.
  • A careful neurovascular examination is
    crucial and should be performed before radiographs or manipulation. At
    significant risk of injury are the median, ulnar, radial, and anterior
    interosseous nerves and the brachial artery.
  • Serial neurovascular examinations should
    be performed when massive antecubital swelling exists or the patient is
    believed to be at risk for compartment syndrome.
  • Following manipulation or reduction, repeat neurovascular examinations should be performed to monitor neurovascular status.
  • Angiography may be necessary to identify
    vascular compromise. The radial pulse may be present with brachial
    artery compromise as a result of collateral circulation.
Radiographic Evaluation
  • Standard AP and lateral radiographs of the elbow should be obtained.
  • Radiographs should be scrutinized for
    associated fractures about the elbow, most commonly disruption of the
    apophysis of the medial epicondyle, or fractures involving the coronoid
    process and radial neck.
Classification
  • Chronologic: Acute, chronic (unreduced), or recurrent.
  • Descriptive: Based on the relationship of the proximal radioulnar joint to the distal humerus.
  • Posterior
    • Posterolateral: >90% dislocations
    • Posteromedial

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  • Anterior: Represents only 1% of pediatric elbow dislocations.
  • Divergent: This is rare.
  • Medial and lateral dislocations: These are not described in the pediatric population.
  • Fracture dislocation: Most associated
    osseous injuries involve the coronoid process of the olecranon, the
    radial neck, or the medial epicondylar apophysis of the distal humerus.
    Rarely, shear fractures of the capitellum or trochlea may occur.
Treatment
POSTERIOR DISLOCATION
Nonoperative
  • Acute posterior elbow dislocations should
    be initially managed with closed reduction using sedation and
    analgesia. Alternatively, general or regional anesthesia may be used.
  • Young children (0 to 8 years old): With
    the patient prone and the affected forearm hanging off the edge of the
    table, anteriorly directed pressure is applied to the olecranon tip,
    effecting reduction.
  • Older children (>8 years old): With
    the patient supine, reduction should be performed with the forearm
    supinated and the elbow flexed while providing distal traction
    (Parvin). Reduction with the elbow hyperextended is associated with
    median nerve entrapment and increased soft tissue trauma.
  • Neurovascular status should be reassessed, followed by evaluation of stable range of motion.
  • Postreduction radiographs are essential.
  • Postreduction management should consist
    of a posterior splint at 90 degrees with loose circumferential wraps
    and elevation. Attention should be paid to antecubital and forearm
    swelling.
  • Early, gentle, active range of motion 5
    to 7 days after reduction is associated with better long-term results.
    Forced, passive range of motion should be avoided because redislocation
    may occur. Prolonged immobilization is associated with unsatisfactory
    results and greater flexion contractures.
  • A hinged elbow brace through a stable arc of motion may be indicated in cases of instability without associated fractures.
  • Full recovery of motion and strength requires 3 to 6 months.
Operative
  • Indicated for cases of soft tissue and/or bony entrapment in which closed reduction is not possible.
  • A large, displaced coronoid fragment
    requires open reduction and internal fixation to prevent recurrent
    instability. Medial epicondylar apophyseal disruptions with entrapped
    fragments must be addressed.
  • Lateral ligamentous reconstruction in cases of recurrent instability and dislocation is usually unnecessary.
  • An external fixator for grossly unstable
    dislocations (with disruption of the medial collateral ligament) may be
    required as a salvage procedure.
ANTERIOR DISLOCATION
  • Acute anterior dislocation of the elbow may be managed initially with closed reduction using sedation and analgesia.

    • P.536


  • Initial distal traction is applied to the
    flexed forearm to relax the forearm musculature, followed by dorsally
    directed pressure on the volar forearm coupled with anteriorly directed
    pressure on the distal humerus.
  • Triceps function should be assessed
    following reduction, because stripping of the triceps tendon from its
    olecranon insertion may occur.
  • Associated olecranon fractures usually require open reduction and internal fixation.
DIVERGENT DISLOCATION
  • This is a rare injury, with two types:
    • Anterior-posterior type (ulna
      posteriorly, radial head anteriorly): This is more common; reduction is
      achieved in the same manner as for a posterior dislocation concomitant
      with posteriorly directed pressure over the anterior radial head
      prominence.
    • Mediolateral (transverse) type (distal
      humerus wedged between radius laterally and ulna medially): This is
      extremely rare; reduction is by direct distal traction on extended
      elbow with pressure on the proximal radius and ulna, converging them.
Complications
  • Loss of motion (extension): This is
    associated with prolonged immobilization with initially unstable
    injuries. Some authors recommend posterior splint immobilization for 3
    to 4 weeks, although recent trends have been to begin early (1 week),
    supervised range of motion. Patients typically experience a loss of the
    terminal 10 to 15 degrees of extension, which is usually not
    functionally significant.
  • Neurologic compromise: Neurologic
    deficits occur in 10% of cases. Most complications occur with
    entrapment of the median nerve. Ulnar nerve injuries are most commonly
    associated with disruptions of the medial epicondylar apophysis. Radial
    nerve injuries occur rarely.
    • Spontaneous recovery is usually expected;
      a decline in nerve function (especially after manipulation) or severe
      pain in nerve distribution is an indication for exploration and
      decompression.
    • Exploration is recommended if no recovery is seen after 3 months following electromyography and serial clinical examinations.
  • Vascular injury (rare): The brachial artery is most commonly disrupted during injury.
    • Prompt recognition of vascular injury is essential, with closed reduction to reestablish perfusion.
    • If, after reduction, perfusion is not
      reestablished, angiography is indicated to identify the lesion, with
      arterial reconstruction with reverse saphenous vein graft when
      indicated.
  • Compartment syndrome (Volkmann
    contracture): May result from massive swelling from soft tissue injury.
    Postreduction care must include aggressive elevation and avoidance of
    hyperflexion of the elbow. Serial neurovascular examinations and

    P.537



    compartment pressure monitoring may be necessary, with forearm fasciotomy when indicated.

  • Instability/redislocation: Rare (<1%)
    after isolated, traumatic posterior elbow dislocation; the incidence is
    increased in the presence of associated coronoid process and radial
    head fracture (combined with elbow dislocation, this completes the terrible triad of the elbow).
    It may necessitate hinged external fixation, capsuloligamentous
    reconstruction, internal fixation, or prosthetic replacement of the
    radial head.
  • Heterotopic bone/myositis ossificans:
    This occurs in 3% of pure dislocations, 18% when associated with
    fractures, most commonly caused by vigorous attempts at reduction.
    • Anteriorly, it forms between the
      brachialis muscle and the capsule; posteriorly, it may form medially or
      laterally between the triceps and the capsule.
    • The risk is increased with a greater degree of soft tissue trauma or the presence of associated fractures.
    • It may result in significant loss of function.
    • Forcible manipulation or passive stretching increases soft tissue trauma and should be avoided.
    • Indomethacin or local radiation therapy
      is recommended for prophylaxis postoperatively and in the presence of
      significant soft tissue injury and/or associated fractures. Radiation
      therapy is contraindicated in the presence of open physes.
  • Osteochondral fractures: Anterior shear
    fractures of the capitellum or trochlea may occur with anterior
    dislocations of the elbow. The presence of an unrecognized
    osteochondral fragment in the joint may be the cause of an
    unsatisfactory result of what initially appeared to be an uncomplicated
    elbow dislocation.
  • Radioulnar synostosis: The incidence is increased with an associated radial neck fracture.
  • Cubitus recurvatum: With significant
    disruption of the anterior capsule, hyperextension of the elbow may
    occur late, although this is rarely of any functional or symptomatic
    significance.
Olecranon Fractures
Epidemiology
  • These account for 5% of all elbow fractures.
  • The peak age is 5 to 10 years.
  • Twenty percent have an associated fracture or dislocation; the proximal radius is the most common.
Anatomy
  • The olecranon is metaphyseal and has a relatively thin cortex, which may predispose the area to greenstick-type fractures.
  • The periosteum is thick, which may prevent the degree of separation seen in adult olecranon fractures.
  • The larger amount of epiphyseal cartilage may also serve as a cushion to lessen the effects of a direct blow.
Mechanism of Injury
  • Flexion injuries: With the elbow in a
    semiflexed postion, the pull of the triceps and brachialis muscles
    places the posterior cortex in tension; this force alone, or in
    combination with a direct

    P.538



    blow, may cause the olecranon to fail. The fracture is typically transverse.

  • Extension injuries: With the arm
    extended, the olecranon becomes locked in the olecranon fossa; if a
    varus or valgus force is then applied, stress is concentrated in the
    distal aspect of the olecranon; resultant fractures are typically
    greenstick fractures that remain extraarticular and may extend proximal
    to the coronoid process.
  • Shear injuries: A direct force is applied
    to the posterior olecranon, resulting in tension failure of the
    anterior cortex; the distal fragment is displaced anteriorly by the
    pull of the brachialis and biceps; this is differentiated from the
    flexion-type injury by an intact posterior periosteum.
Clinical Evaluation
  • Soft tissue swelling is typically present over the olecranon.
  • An abrasion or contusion directly over the olecranon may indicate a flexion-type injury.
  • The patient may lack active extension,
    although this is frequently difficult to evaluate in an anxious child
    with a swollen elbow.
Radiographic Evaluation
  • Standard AP and lateral x-rays of the elbow should be obtained.
  • Fracture lines associated with a flexion
    injury are perpendicular to the long axis of the olecranon; these
    differentiate the fracture from the residual physeal line, which is
    oblique and directed proximal and anterior.
  • The longitudinal fracture lines associated with extension injuries may be difficult to appreciate.
  • The radiographs should be scrutinized to detect associated fractures, especially proximal radius fractures.
Classification
  • Group A: Flexion injuries
  • Group B: Extension injuries
    • Valgus pattern
    • Varus pattern
  • Group C: Shear injuries
Treatment
NONOPERATIVE
  • Nondisplaced flexion injuries are treated
    with splint immobilization in 5 to 10 degrees of flexion for 3 weeks;
    radiographs should be checked in 5 to 7 days to evaluate for early
    displacement.
  • Extension injuries generally need
    correction of the varus or valgus deformity; this may be accomplished
    by locking the olecranon in the olecranon fossa with extension and
    applying a varus or valgus force to reverse the deformity;
    overcorrection may help to prevent recurrence of the deformity.
  • Shear injuries can be treated with immobilization in a hyperflexed position if the posterior periosteum remains intact,

    P.539



    with the posterior periosteum functioning as a tension band; operative
    intervention should be considered if excessive swelling is present that
    may result in neurovascular compromise in a hyperflexed position.

OPERATIVE
  • Displaced or comminuted fractures may require surgical stabilization.
  • Determining whether the posterior
    periosteum is intact is key to determining the stability of a fracture;
    if a palpable defect is present, or if the fragments separate with
    flexion of the elbow, internal fixation may be needed.
  • Fixation may be achieved with Kirschner
    wires and a tension band, tension band alone, cancellous screws alone,
    or cancellous screws and tension band.
  • Removal of hardware is frequently
    required and should be considered when deciding on a fixation technique
    (i.e., tension band with wire versus tension band with suture).
  • Postoperatively, the elbow is immobilized
    in a cast at 70 to 80 degrees of flexion for 3 weeks, after which
    active motion is initiated.
Complications
  • Delayed union: Rare (<1%) and is usually asymptomatic, even if it progresses to a nonunion.
  • Nerve injury: Rare at the time of injury;
    ulnar neurapraxia has been reported after development of a
    pseudarthrosis of the olecranon when inadequate fixation was used.
  • Elongation: Elongation of the tip of the
    olecranon may occur after fracture; the apophysis may elongate to the
    point that it limits elbow extension.
  • Loss of reduction: Associated with
    fractures treated nonoperatively that subsequently displace; it may
    result in significant loss of elbow function if it is not identified
    early in the course of treatment.

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