Proximal Radius (Radial Neck) Fractures

Key Points:

  • Radial neck fractures are rare
  • Associated injuries are common and should be ruled-out
  • The most common complication is stiffness or loss of motion
  • Treatment should follow a stepwise approach

Description:

Proximal radius fractures include fractures of the proximal portion of the radius including the radial neck and head.  They are often associated with other injuries including olecranon fractures, elbow dislocations, medial epicondyle fractures and ulna shaft fractures. While most fractures are metaphyseal, physeal fractures can occur and place the radial head at high risk of avascular necrosis (AVN).

Epidemiology:

The incidence of radial neck fracture is around 1% of all pediatric fractures and between 5-10% of all pediatric elbow fractures. (Novoth, 2002) Most occur between ages 8 and 12, with equal distribution between males and females. Around 30-50% are associated with other injuries such as ulna, olecranon and distal humerus fractures, elbow dislocation and collateral ligament injury. (Dormans, 1990)

Clinical Findings:

There may be lateral elbow swelling and ecchymosis.  Patients will exhibit pain and limited range of motion.  A careful neurovascular examination is important, particularly the assessment of posterior interosseous nerve function.

Imaging Studies:

Typically, radiographs are the only imaging studies required.  Classification is based on plain radiographs.  There are several classifications described, most taking into consideration the amount of displacement (angulation) and translation of the fragment. Proximal/ head fractures are classified according to the Salter-Harris scheme. The presence of associated injuries or dislocation is also noted.

Understanding the normal ossification pattern of the elbow and proximal radius is essential for correct diagnosis. The radial head ossifies between 3 and 5 years of age. The unique anatomic features that need to be considered while analyzing these injuries include a normal angulation of 15° of valgus, and 5° of anterior apex. Due to the annular ligament stabilizing the distal fragment, translation is often seen at the fracture site. Excessive translation may block forearm rotation by a cam effect. The radial head fuses with the radial shaft around the age of 16 years (Tibone, 1981). 

Etiology:

Radial head and neck fractures generally occur from a fall onto an outstretched arm with an associated valgus force.  

 

Treatment:

The approach to a proximal radial fracture should follow a stepwise approach from closed reduction, to percutaneous assisted reduction, to open treatment. (Basmajian, 2014) The decision is made base on the amount of angulation and translation. (Schmittenbecher, 2005; Zimmerman, 2013)

Fractures with less than 30º (45º for younger children) of angulation and < 2-3 mm translation may be treated closed without need for reduction as long as full pronation and supination is present.

Fractures with angulation >30º and translation >3mm (>50%) should initially be treated with attempted closed reduction under sedation or anesthesia. Several methods of closed reduction have been described.  The Patterson maneuver holds the elbow in extension while applying distal traction and varus stress on a supinated forearm with direct pressure over the radial head.  The Israeli technique involves pronation of a supinate forearm while the elbow is flexed to 90 degrees with direct pressure over the radial head.  Finally, tight application of an elastic bandage or Esmarch beginning at the wrist and working up toward the elbow may spontaneously reduce the fracture. 

If closed reduction is unsuccessful, then percutaneous-assisted reduction should be attempted. This can be performed with direct manipulation of the fragment with a Kirschner wire or Freer elevator. The wire should come from posterior-distal and the forearm should be held in pronation to increase the distance from and protect the posterior interosseous nerve. Another option is the Metaizeau technique which utilizes an elastic nail in a retrograde fashion, engaging the proximal fragment for manipulation and fixation.

Irreducible or unstable fractures should be treated with open reduction and internal fixation or open reduction with percutaneous fixation.  Open reduction and internal fixation should only be used when all other methods have failed.  This can be performed through a lateral approach to the elbow between ECU and anconeus.  Once reduced, these fractures are often stable and do not require further fixation.  Transcapitellar fixation should be avoided.

Outcomes are influenced by factors including patient age, injury mechanism, fracture characteristics, and treatment approach.  Fractures treated with an open surgical approach have worse prognosis and higher complication rate. (Basmajian, 2014)
 

Complications:

Fracture personality contributes to complication rate. Higher complication rates and worse prognosis are associated with increased amount of angulation and translation of the fracture, patient’s age greater than 10 years (Zimmerman, 2013), higher energy of the trauma, presence of associated injuries, and finally a more invasive treatment approach.

The most common complication is loss of motion (Basmajian, 2014).  Loss of forearm pronation occurs more frequently than loss of supination.  This may be a result of prolonged immobilization, open reduction, heterotopic ossification, or radioulnar synostosis.  Avascular necrosis may occur either as a direct result of the injury, or iatrogenic following open reduction.  Other complications include posterior interosseous nerve (PIN) injury (due to trauma or iatrogenic), compartment syndrome, especially for fractures with associated injuries, (Peters, 1995), malunion, nonunion, and radial head overgrowth.  Rates of radial head overgrowth have been cited between 20 and 40% although it does not usually impair function.  Finally, premature physeal closure and resultant cubitus valgus may occur.

Classification:

These fractures can be described based on the Judet classification where Grade 1 has no angulation of the radial head relative to the shaft, Grade 2 has less than 30 degrees of angulation, Grade 3 has 30-60 degrees, Grade 4a has 60-80 degrees, Grade 4b has more than 80 degrees, and Grade 5 is epiphyseal separation.

References:

  1. Basmajian HG, Choi PD, Huh K, Sankar WN, Wells L, Arkader A. Radial neck fractures in children: experience from two level-1 trauma centers. J Pediatr Orthop B. 2014; 23(4): 369-74.
  2. Dormans JP, Rang M. Fractures of the olecranon and radial neck in children. Orthop Clin North Am. 1990; 21: 257–268.
  3. Novoth B. Closed reduction and intramedullary pinning of radial neck fractures in children. Orthopaedics and trauma 2002; 313–322.
  4. Peters CL, Scott SM. Compartment syndrome in the forearm following fractures of the radial head or neck in children. J Bone Joint Surg Am. 1995 Jul; 77(7): 1070-4.
  5. Schmittenbecher PP, Haevernick B, Herold A, Knorr P, Schmid E. Treatment decision, method of osteosynthesis, and outcome in radial neck fractures in children: a multicenter study. J Pediatr Orthop 2005; 25:45–50.
  6. Tibone JE, Stoltz M. Fractures of the radial head and neck in children. J Bone Joint Surg Am. 1981; 63(1): 100-6.
  7. Zimmerman RM, Kalish LA, Hresko MT, Waters PM, Bae DS. Surgical management of pediatric radial neck fractures. J Bone Joint Surg Am. 2013; 95(20): 1825-32.

Top Contributors:

Alexandre Arkader, MD
Jenifer Powers, MD