Radial Head and Neck Fractures - Pediatric - Pediatrics

Introduction

Overview
- radial neck fractures in children are a relatively common traumatic injury that usually affects the radial neck (metaphysis) in children 9-10 years of age.
  - treatment depends on the degree of angulation and is surgical if angulation remains greater than 30 degrees after closed reduction is attempted.
Epidemiology
- demographics
  - median age is 9-10 years
  - no difference in incidence between sexes
  - 5-10% of all pediatric elbow fractures and 1% of pediatric fractures overall
Pathophysiology
- mechanism
  - usually associated with an extension and valgus loading injury of the elbow
  - elbow dislocation
Associated Conditions
- elbow dislocation
- olecranon fracture
- medial epicondyle fracture
- forearm compartment syndrome
Outcomes
- worse outcomes seen in patients >10 years of age

Anatomy

There are 6 ossification centers around the elbow joint
- age of ossification is variable but occurs in the following order (C-R-I-T-O-E) at an average age of (years)
  - Capitellum (1 yr.)
  - Radius (3 yr.)
  - Internal or medial epicondyle (5 yr.)
  - Trochlea (7 yr.)
  - Olecranon (9 yr.)
  - External or lateral epicondyle (11 yr.)
Ossification center of radial head appears between and 3 and 5 years of age
- may be bipartite
- radial head fuses with radial shaft between ages of 16 and 18 years

Classification

O'Brien Classification
Type I	< 30 degrees
Type II	30-60 degrees
Type III	> 60 degrees

Judet Classification
Type I	Undisplaced
Type II	< 30 degrees
Type III	30-60 degrees
Type IVa	60-80 degrees
Type IVb	More than 80 degrees

Chambers Classification (rarely used)
Group 1: Primary displacement of radial head (most common)	Valgus Injury A: Physeal injury - Salter-Harris I or II B: Intra-articular -Salter-Harris III or IV C: metaphyseal fracture Elbow Dislocation D: reduction injury E: dislocation injury
Group 2: Primary displacement of radial neck	Monteggia variant
Group 3: Stress injury	Osteochondritis dissecans

Presentation

Symptoms
- elbow pain
- refusal to move
Physical exam
- inspection
  - lateral swelling
- motion
  - pain exacerbated by motion, especially supination and pronation.
- must have high suspicion for forearm compartment syndrome
- pain may be referred to the wrist

Imaging

Radiographs
- recommended views
  - AP and lateral of the elbow
  - radiocapitellar (Greenspan) view
    - oblique lateral performed by placing the arm on the radiographic table with the elbow flexed 90 degrees and the thumb pointing upward
    - The beam is directed 45 degrees proximally
- findings
  - nondisplaced fractures may be difficult to visualize
  - look for fat pads signs
    - anterior fat pad may be normal, but a posterior fat pad sign should be treated as an occult fracture
    - a portion of the radial neck is extra-articular and therefore an effusion and fat pads signs may be absent.

Treatment

Nonoperative
- immobilization alone
  - indications
    - <30 degrees of angulation
    - <3mm translation
  - technique
    - immobilize in long arm cast or splint without reduction
  - follow-up
    - 7 days of immobilization followed by early range of motion
- closed reduction and immobilization
  - indications
    - >30 degrees of angulation
    - closed reduction followed by immobilization in long arm cast or splint if an adequate reduction is achieved
Operative
- closed percutaneous reduction
  - indications
    - > 30° of residual angulation following closed reduction
    - 3-4 mm of translation
    - < 45° of pronation and supination
  - outcomes
    - improved outcomes with younger patients, lesser degrees of angulation, and isolated radial neck fractures
- open reduction
  - indications
    - fracture that cannot be adequately reduced to <45 degrees angulation with closed or percutaneous methods
  - outcomes
    - open reduction has been associated with a greater loss of motion, increased rates of osteonecrosis and synostosis compared with closed reduction (though this is controversial as higher rates of open reduction are also seen with worse fractures)

Techniques

Closed reduction
- reduction techniques
  - Patterson maneuver
    - hold the elbow in extension and apply distal traction with the forearm supinated and pull the forearm into varus while applying direct pressure over the radial head
  - Israeli (Kaufman) technique
    - pronate the supinated forearm while the elbow is flexed to 90° and direct pressure stabilizes the radial head
  - Nehar and Torch technique
    - elbow held in extension and supination with distal traction and varus force with assistant pushing laterally on radial shaft and surgeon pushing medially on radial head
  - elastic bandage technique
    - tight application of an elastic bandage (esmarch) beginning at the wrist continuing over the forearm and elbow may lead to spontaneous reduction
Closed Reduction and Percutaneous Pinning
- reduction technique
  - K-wire joystick technique
    - push technique
      - blunt end of a large k-wire is pushed against the posterolateral aspect of the proximal fragment and pushed into place
    - lever technique
      - k-wire is placed into the fracture site and levered proximally
    - if unstable after reduction a pin may be placed to maintain reduction
  - Metaizeau technique
    - involves retrograde insertion of a pin/nail across the fracture site
    - fracture is reduced by rotating the pin/nail
Open reduction
- approach
  - performed with lateral approach (Kocher interval) to radiocapitellar joint
  - pronate to avoid the posterior interosseous nerve (PIN)
- fixation
  - avoid transcapitellar pins
  - internal fixation only used for fractures that are grossly unstable

Complications

Decreased range of motion
- loss of pronation more common than supination
Radial head overgrowth
- 20-40% of fractures
- usually does not affect function
Osteonecrosis
- 10-20% of fractures
- radial head in children is entirely cartilage and blood supply is primarily from the metaphysis
- up to 70% of cases occur with open reduction
Nerve injury
- PIN may be injured
Physeal arrest
- may lead to cubitus valgus deformity
Synostosis
- most serious complication
- occurs in cases of open reduction with extensive dissection or delayed treatment