Monteggia Fracture - Pediatric - Pediatrics

summary
- Monteggia Fractures in the pediatric population are defined as proximal ulna fractures or plastic deformation of the ulna with an associated radial head dislocation.
- Diagnosis can be made with plain radiographs of the elbow.
- Treatment may be closed reduction and casting for length stable ulna fractures with a stable radiocapitellar joint. Surgical management is indicated for radial heads that are not stable following closed reduction.

Epidemiology
- Demographics
  - 4 to 10 years of age is peak incidence

Etiology
- Definition
  - radial head dislocation plus
  - proximal ulna fracture or
  - plastic deformation of the ulna without obvious fracture

                        Classification
                    
                                            Bado Classification
                                        
                                            Type I
                                        
                                            Apex anterior proximal ulna fracture with anterior dislocation of the radial head
                                        
                                            Type II
                                        
                                            Apex posterior proximal ulna fracture with posterior dislocation of the radial head
                                        
                                            Type III
                                        
                                            Apex lateral proximal ulna fracture with lateral dislocation of the radial head
                                        
                                            Type IV
                                        
                                            Fractures of both the radius and ulna at the same level with ananterior dislocation of the radial head (1-11% of cases)

Presentation
- Symptoms
  - pain, swelling, and deformity about the forearm and elbow
- Physical exam
  - must palpate over radial head with all ulna fractures because spontaneous relocation of radial head is common
  - must examine for plastic deformation of the ulna if there is a presumed isolated radial head dislocation
    
    isolated radial head dislocations almost never occur in pediatric patients

Imaging
- Radiographs
  - obtain elbow radiographs for all forearm fractures to evaluate for radial head dislocation
    
    assess radiocapitellar line on every lateral radiograph of the elbow
    
    a line down the radial shaft should pass through the center of the capitellar ossification center
  - obtain forearm radiographs for all radial head dislocations

Treatment
- Nonoperative
  - closed reduction of ulna and radial head dislocation and long arm casting
    
    indications
    
    Bado Types I-III with
    
    radial head is stable following reduction
    
    length stable ulnar fracture pattern
    
    reduction technique
    
    reduction technique uses traction
    
    radial head will reduce spontaneously with reduction of the ulna and restoration of ulnar length
    
    for Type I, elbow flexion is the main reduction maneuver
    
    immobilization
    
    Type I 110° of flexion and full supination to tighten interosseous membrane and relax biceps tendon
    
    Type II fulll extension.
    
    Type III full extension and valgus mold
- Operative
  - pinning/nailing of ulna + reduction of radial head ± annular ligament repair/reconstruction
    
    indications
    
    Bado Types I-III with
    
    radial head is not stable following reduction
    
    ulnar length is not stable (unable to maintain ulnar length)
    
    acute Bado Type IV
    
    open fractures
    
    older patients ≥ 10y if closed reduction is not stable
    
    technique
    
    annular ligament reconstruction almost never required for acute fractures
    
    open reduction of radial head through a lateral approach if needed in chronic (>2-3 weeks old) Monteggia fractures where radial head still retains concave structure
    
    symptomatic individuals (pain, loss of forearm motion, progressive valgus deformity) who had delayed treatment or missed diagnosis
  - ORIF similar to adult treatment
    
    indications
    
    closed physes

Bado Classification
Type I	Apex anterior proximal ulna fracture with anterior dislocation of the radial head
Type II	Apex posterior proximal ulna fracture with posterior dislocation of the radial head
Type III	Apex lateral proximal ulna fracture with lateral dislocation of the radial head
Type IV	Fractures of both the radius and ulna at the same level with ananterior dislocation of the radial head (1-11% of cases)