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Pediatric Forearm Fractures. J.J. Prosser. Incidence. 3.4% of all children’s fractures Bimodal peak with boys – 9 and 13 years old Girls – 5 years old. 0ssification. Radial and ulnar shafts ossify during the eighth week of gestation Distal radial epiphysis – age 1
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Pediatric Forearm Fractures J.J. Prosser
Incidence • 3.4% of all children’s fractures • Bimodal peak with boys – 9 and 13 years old • Girls – 5 years old
0ssification Radial and ulnar shafts ossify during the eighth week of gestation Distal radial epiphysis – age 1 Distal ulnar epiphysis – age 6 Radial head – age 5-7 Olecranon – age 9-10 They all close between the ages of 16-18
Anatomic Area Distal third – 75% Middle third – 18% Proximal third – 7%
Osteology The periosteum is very strong and thick in a child It is generally disrupted on the convex side, while an intact hinge remains on the concave side This is an important point when considering closed reduction
Biomechanics The radius shortens with pronation and lengthens with supination Malreduction of 10 degrees in the middle third limits rotation by 20-30 degrees Bayonet apposition does not reduce forearm rotation
Deforming Muscle Forces Proximal third Biceps and supinator – flexion and supination of proximal fragment Pronator teres and quadratus – pronate distal fragment Middle third Supinator, biceps, and pronator teres – proximal fragment is neutral Pronator quadratus – pronates distal fragment Distal third Brachioradialis – dorsiflex and radial deviate distal fragment
Mechanism of injury Indirect – fall onto an outstretched hand Direct – blow from an object onto the radial and ulnar shaft Rotation Pronation – flexion injury(posterior angulation) Supination – extension injury(anterior angulation)
Clinical evaluation History – age, mechanism of injury, and other areas of pain Physical exam – skin integrity, neurovascular status, and examination of elbow and wrist joints
Radiographic evaluation AP and lateral of forearm, wrist, and elbow The bicipital tuberosity is the landmark for identifying rotation
Description Location – proximal, middle, distal Type Plastic deformation Incomplete(greenstick) Compression(torus or buckle) Complete
Salter-Harris 75% in children 10-16 years old Uncommon in children < 5 years old Type II most common – Thurston-Holland fragment
Monteggia Proximal ulna fracture with dislocation of the radial head 0.4% of all forearm fractures in children Peak incidence between 4 and 10 years old Ulna fracture usually at junction of proximal/middle thirds
Galeazzi Middle to distal third radius fracture with disruption of the distal radioulnar joint Rare in children Peak incidence between 9 and 12 years old
Initial management Correct gross deformity Perform closed reduction and application of a well molded long arm cast Forearm reduction after rotation Proximal third – supination Middle third – neutral Distal third – pronation Split cast if concerned about swelling(uni-valve, bi-valve)
Acceptable deformity Patients > 10 years old, treat like adult – no deformity accepted Patients < 10 years old; Angular deformities – 1 degree/month - 10 degrees/year Rotational deformities – none Bayonet apposition – 1cm
Undisplaced fractures Long arm cast – 4-6 weeks until nontender Elbow at 110-120 degrees of flexion
Plastic deformation Children < 4 years old or with deformities < 20 degrees, same as undisplaced
Greenstick fractures Complete the fracture to decrease risk of angular deformity Carefully crack the intact cortex while preventing displacement Well molded long arm cast
Complete displacement Attempt closed reduction and long arm cast with pancake molding If the fracture is irreducible, ORIF may be indicated
Operative management IM fixation – Enders nail, K-wires - limited exposure at fracture site may be required for reduction Plate fixation – prime indication is one of refracture in which the intramedullary canal has a high risk of being obstructed
Problems Malunion – over 60% have rotational losses >20 degrees Refracture – incidence of 12% - refrain from sports 1 month after cast removal Nonunion – rare in children - high energy, open, infection - ulnar > radial Neurovascular injuries – posterior interosseous nerve damage with Monteggia Type III
Problems continued Compartment syndrome – pain aggravated by passive motion - pressure > 30mmHg - fasciotomy Infection - > 6 hours before debridement(exponential growth) RSD – rare in children - burning pain, hyperesthesia, and swelling - resolves 6-12 months after injury Overgrowth – 6-8 months after injury - averages 6-7mm