Supracondylar Humerus Fractures• Fractures of the distal humerus just above the

epicondyles• Typically remains extra articular• 55% to 75% of all elbow fractures• Peak incidence 5 to 8 years, after which

dislocations become more frequent• The left, or nondominant side, is most frequently

injured

Supracondylar Fractures• In 5 – 8 year olds, bone remodeling causes a decreased

anteroposterior diameter in the supracondylar region, making this area susceptible to injury

• Ligamentous laxity in this age range increased 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– Hand is pronated posteromedial displacement *More common*Possible radial nerve injury– Hand is supinated posterolateral displacement

*Possible median nerve and vascular compromise• Flexion type: Caused by direct trauma or a fall onto

a flexed elbow

• Typical presentation: 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– Dimpling of the skin anteriorly secondary to penetration of the

proximal fragment into the brachialis muscle– Means reduction of the fracture may be difficult with simple

manipulation• Evaluate integrity of the median, radial, and ulnar nerves plus

their terminal branches• Can be occult on radiographs with only a positive fat pad sign

Lateral radiograph with positive fat pad sign in a patient with a nondisplaced fracture of the radial headAnterior lucency (arrow) elevated anterior fat Posterior lucency (arrowhead) elevated posterior fat pad

Supracondylar Fractures

Type I: NondisplacedType II: Displaced with intact posterior cortex; may

be angulated or rotatedType III: Complete displacement; posteromedial or

posterolateral

Gartland Classification based on the degree of displacement

EXTENSION TYPE (98%)

FLEXION TYPE (2%)

Type I: NondisplacedType II: Displaced with intact anterior cortexType III: Complete displacement; usually

anterolateral

Gartland - Extension Type

type I (undisplaced), II (displaced with an intact posterior cortex), and III (displaced with no cortical contact)

Treatment

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).

EXTENSION TYPE

Treatment

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.

FLEXION TYPE

• Immobilization in a long arm cast (or posterior splint for swelling) with the elbow flexed to 90 degrees and the forearm in neutral for 2 to 3 weeks postoperatively, at which time the cast may be discontinued and the pins 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

Special Characteristics of Pediatric Bones

Anatomy• Less dense and more porous

o More vascular channelso More water and cellular content, less mineral contento Higher collagen to bone ratio

• Periosteum o Stronger, thicker and more fibrous o Loosely attached and easily elevated with trauma (especially diaphysis)o More firmly attached in metaphyseal-epiphyseal region helps stabilize the growth plate allowing more active bone growtho Thickens and is continuous with physis at perichondreal ring (ring of Lacroix) Additional resistance to shear force

Anatomy• Physis (Growth plate) unique cartilaginous structure

o Thickness depends on ageo Weaker than bone in torsion, shear and bending predisposes children to injuryo Facilitates remodelling o Can possibly cause deformity

• Ligaments functionally stronger than bone in childreno More injuries result in fractures rather than sprains

Anatomy

• Blood supply o In growing bone rich metaphyseal

circulation with fine capillary loops ending at the physis

Biomechanics

• More elastic and weaker Injury at lower energy trauma (compression, torsion, bending forces)

Physiology

• More rapid bone healing / metabolismo Increased blood flowo Increased cellular activityo More active periosteum

• High remodeling potential especially near the growth plate

Elbow X Ray (AP)

Elbow X Ray (Oblique)

Elbow X Ray (Lateral)