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Duke Orthopaedics
Wheeless' Textbook of Orthopaedics

Pediatric Radial Neck Fracture

- See:
      - Adult Radial Neck Frx and Radial Head Frx;
      - Pediatric Elbow Injuries

- Discussion:
    - radial neck frx are more common in children, whereas frx of radial head occur primarily in adults;
    - site of frx in childhood is either thru physis w/ metaphyseal fragment (type II physeal injury), or thru neck proper (3-4 mm distal to epiphyseal plate);
          - most cases are Salter-Harris type II fractures (90%);
          - in children, proximal radial epiphysis is cartilaginous & is more prone to fracture than hard articular surface of radial head;
          - may have angulation or lateral translation of radial head to a variable degree (Jeffrey type I);
    - this frx occurs on average at age of 10 yrs, after ossification center of the proximal radial epiphysis appears;
          - ossification center of the upper epiphysis of the radius appears at fifth yr & fuses w/ body between ages of 16 and 18 years; 
    - mechanism:
          - results from a hard fall on an extended & supinated outstretched hand;
          - force is transmitted thru shaft of radius, & momentum of body drives capitellum against lateral half of radial head, tilting & displacing it laterally;
          - direction of tilting of displaced head relative to shaft of radius depends upon the rotational attitude of radius at time of injury;
                 - if the forearm is fully supinated, the displacement is lateral;
                 - if the forearm is in neutral mid position, it is posteiror;
          - total displacement, especially in posterior direction, may occur following spontaneous relocation of an elbow dislocation;
    - associated Injuries:
          - capitulum fracture
          - dislocation of distal RU joint;
          - valgus instability (MCL avulsion);
          - rupture of triceps tendon;
          - fracture of olecranon or upper shaft of the ulna;
          - compression force may frx lateral humeral condyle;

- Physical Exam:
    - carefully assess the function of the posterior interosseous nerve

- Radiographic Features:
    - before age 4, normal lateral (valgus) sloping of radial neck may be misinterpreted as representing an injury;
           - up to 15 deg of valgus may be normal;
    - notch at lateral aspect of proximal radial metaphysis may be seen in older children and should not be confused with injury;
    - note that the radial neck may lie in 15 deg of valgus;
    - note that the physis of the proximal radius is widened on the lateral side; 
    - technique:
           - anteriorposterior, lateral (look for fat pad sign)
           - consider radiocapitellar view;
           - forearm in neutral rotation & the x-ray tube angle 45 deg. cephalad
    - type I frx:
           - may be difficult to identify;
           - posterior fat pad sign should suggest further oblique views, including radial head capitellum view;
    - Salter Harris II:
           - type II frx is most common type of radial head & neck frxs in children;
                  - look for positive posterior fat pad signs, but note that this fracture type can be extra-articular, and therefore a fat pad sign may not be seen;
                  - subtle anterior or posterior displacement of the radial head or shaft, as determined by use of radiocapitellar line;

- Accetable Reduction:
    - younger child:
          - < 10 deg of residual neck angulation will correct w/ growth;
          - up to 30 deg of residual angulation can be accepted;
          - angulation is > 30 deg
                - closed manipulative reduction or percutaneous pin to manipulate frx;
    - age > than 10 yrs:
          - poor results w/ angulation > 30 deg, or translocation > 3 mm;
          - inability to reduce angulation < 45 deg, requires ORIF
                - crossed K-wire fixation of the proximal radius is preferred;
          - inability to pronate and supinate the forearm more than 60 deg, is another sign that that the reduction is not adequate;

- Treatment Algorithm Based on Displacement:
    - minimally displaced frx:
         - immobilize elbow (in 90 deg of flexion & neutral forearm rotation) in posterior splint for 1-2 weeks, then active ROM;
         - child > 10 years: correct tilting of radial head to less than 15 deg by closed reduction;
    - moderately displaced Frx:
         - w/ frx tilting of between 30 & 60 deg perform closed reduction under GEA;
         - 45 deg of angulation is acceptable, if passive supination and pronation is 60-70 deg in both directions;
         - reduction maneuver;
                 - elbow is completely extended & forearm is then fully supinated;
                 - determine direction of displacement of radial head;
                 - firm digital pressure is applied to acheive reduction;
    - displaced frx:
         - may require open reduction;
         - closed manipulative reduction is attempted under GET
                 - manipulation should achieve < 30 deg of angulation to be acceptable;
                 - attempt reduction by applying a valgus stress and simultaneous direct manipulation w/ the surgeon's thumbs;
                 - percutaneous K-wire manipulation may be attempted before resorting to open reduction;
                       - pronating the forearm moves the posterior interosseous nerve away from the radial head; 
         - note that the residual intact periosteum / capsule will provide some intrinsic fracture stability once the fracture is reduced;
         - oblique K-wires offer the best fixation in this age group;
         - w/ residual angulation > 45 deg after reduction, consider ORIF;
         - when frx is diagnosed late, deformity of radial head tilting can be corrected by open up wedge osteotomy with a bone grafting; 
         - references:
               - Percutaneous reduction of displaced radial neck fractures in children.  
               - Reduction and fixation of displaced radial neck fractures by closed intramedullary pinning.  
               - New reduction technique for severely displaced pediatric radial neck fractures.
               - Elastic stable intramedullary nail fixation for severely displaced fractures of the neck of the radius in children.
               - Centromedullary Pinning of Radial Neck Fractures: Length Matters! 
               - Evaluation of Severely Displaced Radial Neck Fractures in Children Treated With Elastic Stable Intramedullary Nailing
               - Angulated radial neck fractures in children. A prospective study of percutaneous reduction 
               - Displaced Radial Neck Fractures in Children: Association of the Metaizeau and Bohler Surgical Techniques 
               - Radial neck fractures in children treated with the centromedullary Métaizeau technique

- Complications:

     - malunion results from failure either to achieve adequate reduction or to maintain reduction;
           - malunion may also result from premature fusion of upper radial epiphysis occurs frequently displaced fractures;
                  - this will cause shortening of the radius and increased cubitus valgus, depending on pt's age & degree of cartilagenous damage;
    - non union:
           - in the study by Waters PM, et al, the authors conducted a retrospective review of 9 cases of radial neck nonunion in an effort to identify
                           risk factors for nonunion and to evaluate treatment options;
                  - 9 patients, average age 8.2 years, sustained displaced Salter-Harris type II fractures of the radial neck, with average angulation of 83
                           deg and average displacement of 83%, and elbow dislocation or additional fracture in eight of nine patients;
                  - initial treatment with open reduction achieved anatomical alignment of the fracture fragments in 7 of the 9 patients;
                  - initial reduction was lost and radial neck nonunion developed in all patients;
                  - nonunion was treated with observation, radial head and neck excision, or ORIF with bone graft, depending on the level of pain, deformity, and functional deficit;
                  - healing of the nonunion did not necessarily lead to improvement of clinical symptoms;
                  - severity of initial fracture displacement and inadequate fixation technique contributed to radial neck nonunion;
                  - ref: Radial Neck Fracture Nonunion in Children
    - avascular necrosis:
           - may occur in up to 10 %, and is more common with operative intervention; 
    - radial head excision in children:
           - in children radial head should not be excised because of resulting growth disturbance & deformity of wrist & elbow;
           - excision of radial head in children is disastrous, w/ uniformly poor results due to cubitus valgus, proximal migration of radius, & synostosis.
           - ref: Radial growth and function of the forearm after excision of the radial head. A study of growing macaque monkeys.

Fractures of the radial head and neck in children.

Fracture-separation of the distal humeral epiphysis in young children.

Management of radial neck fractures in children: a retrospective analysis of one hundred patients.

Observations concerning radial neck fractures in children

Surgical Management of Pediatric Radial Neck Fractures

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Wednesday, October 30, 2013 10:06 am