ASSESSMENT OF INJURY

The entire extremity should be thoroughly examined for open wounds, other injuries, and neurovascular impairment. A fall on the outstretched hand can result in injury at multiple levels. As in adults, injury about the wrist must be specifically excluded, and fracture of the scaphoid has been reported.^10,11

Anteroposterior and lateral radiographs of both the elbow and the entire forearm should be examined for other injuries, particularly about the elbow. An estimate should also be made of the degree of angulation of the radial head and the amount of displacement.

The precise degree of angulation can be accurately determined only by an anteroposterior radiograph with the forearm in the position of rotation at the moment of impact. Jeffery¹⁰ demonstrated that this is best achieved by taking radiographs in varying degrees of forearm rotation so that the radial head will cast shadows of different shapes. When the radial head forms as nearly perfect a rectangle as possible, the real degree of angulation can be determined. Oval shapes indicate that the radiographs have not been taken at a right angle to the plane of maximal angulation (Fig. 17-7). Although ob-taining these multiple views is not practical or necessary for the majority of fractures, in cases in which it is unclear whether or not fracture reduction is indicated, performing multiple radiographs as described can be very helpful. Comparison views of the uninjured forearm in the same degree of rotation are helpful in assessing the degree of angulation. Also, in children, normal variations in the radiographic appearance of the proximal radius must be considered when assessing injury.³⁰ Again it is a basic principle of treating elbow fractures in children that radiographs of the injury may be compared with films of the opposite (uninjured) side.

FIGURE 17-7 Diagram of the radiographic appearance of the head of the radius in varying degrees of rotation, where A = a and E = e. When the film is taken at right angles to the plane of maximum angulation, the radial head is rectangular in shape as in Ee (shaded epiphysis).

INDICATIONS FOR REDUCTION

It is generally agreed that a radial neck fracture with angulation of more than 60 degrees or more than 3 mm of displacement will likely produce problems if it is not corrected.^2,6,23,24,39 It is also agreed that in radial neck fractures, less than 30 degrees’ angulation can safely be accepted,^10,25,33 and there is some support for the position that fractures less than 45 degrees’ angulation do not require open reduction.^{2,23,24,32,35,39} The proper treatment approach should be individualized based on the clinical circumstances of each patient when angulation is between 30 and 60 degrees. There is support both for and against open reduction of these fractures.^{6,18,25,26,32,39} Advocates of open reduction believe that, without it, significant loss of forearm rotation will ensue. Those who prefer closed reduction or acceptance of deformity believe that the complications of open reduction do not justify the risks, considering the minimal disability that is the legacy of fractures left with even 50 to 55 degrees of angulation.

Recently, two techniques have been developed that provide the benefits of improved fracture alignment yet have not caused the problems associated with open reduction. In several series, percutaneous reduction of radial neck fractures has been associated with fewer complications and less elbow stiffness as compared with open reduction (Fig. 17-8).^1,20,31 Originally described using a Steinmann pin, we have also used a small elevator to percutaneously reduce the fracture with excellent success. After percutaneous reduction, fracture stability should be assessed by bringing the elbow through full range of motion including pronation and supination under fluoroscopic imaging. Frequently, the fracture is stable enough that internal fixation is not necessary and casting alone is sufficient. In situations in which redisplacement or angulation occurs, percutaneous pinning or intramedullary stabilization using the Metaizeau technique may be employed.

FIGURE 17-8 A, Fracture of the radial neck angulated approximately 45 degrees. B, A Steinmann pin is inserted percutaneously. C, Using fluoroscopic guidance, the Steinmann pin is used to reduce the fracture. D, Normal anatomy is restored without open reduction, and the fracture is stable without internal fixation.

(From Green N. E., and Swiontkowski, M. F.: Skeletal Trauma in Children, 2nd ed. Philadelphia, W. B. Saunders, 1998.)

Metaizeau and colleagues²⁰ described a method of reducing and stabilizing displaced or angulated radial neck fractures using an intramedullary K-wire. An intramedullary pin or small-diameter flexible intramedullary nail is used to enter the radius in a retrograde fashion just proximal to the distal radial physis. Before insertion, a 30- to 45-degree bend is placed in the pin approximately 1 cm from the tip. Advancing the intramedullary pin proximally to the fracture site, the intramedullary pin is used to elevate the depressed or angulated fracture (Fig. 17-9). Rotation of the bent tip is then used to correct displacement. The intramedullary pin is cut proximally where it lies beneath the skin, along the surface of the radius. Often, the pin becomes symptomatic at the insertion site and may be removed after the fracture has completely healed, 3 to 9 months following surgery. Occasionally, radial neck fractures cannot be reduced by use of an intramedullary pin alone. Employment of an intramedullary pin in combination with percutaneous reduction techniques described earlier is a very effective means of reducing and stabilizing severely displaced or angulated fractures by minimally invasive methods. Percutaneous and intramedullary reduction and fixation techniques represent a significant advance in the treatment of radial neck fractures, providing the benefits of improved fracture reduction with minimal risk of avascular necrosis (AVN) and stiffness associated with open techniques.^8,20

FIGURE 17-9 A, Radial neck fracture angulated greater than 45 degrees. B, A 2-mm diameter pin with a slight bend 1 cm from the tip is advanced retrograde to the fracture within the intramedullary canal and used to elevate the depressed and angulated fracture. C, Rotating the intramedullary pin reduces fracture displacement. D, One year postoperatively, immediately before hardware removal, the fracture has completely healed with full elbow motion in all planes E.

Displacement, rather than angulation, often leads to loss of forearm rotation. Angulation produces a defect at the joint surface and, therefore, does not obstruct rotation. Incomplete contact between articular surfaces is, theoretically, harmful, but enough remodeling usually occurs so that the incomplete contact appears to improve. Displacement, on the other hand, results in radial neck deformity and abutment on the edges of the radial notch (Fig. 17-10). This produces a cam effect during rotation, confirmed in cadaver studies.³⁹ The radial neck was divided with a saw and fixed with Kirschner wires without angulation but with varying degrees of displacement. The observed effect on forearm rotation was that displacement greater than 3 mm resulted in loss of forearm rotation because of abutment of the radial head against the ulna.

FIGURE 17-10 Diagram illustrates the effect of union with displacement of the fracture. The white circle represents the shaft of the radius just distal to the fracture, and the gray circle represents the head of the radius. The black area represents the radial notch on the ulna. Rotation of the radius after union with persistent displacement results in abutment on the margin of the radial notch of the ulna. The degree of limitation of pronation and supination is proportional to the degree of displacement.

Because closed or open reduction performed more than 5 to 7 days after injury leads to loss of forearm rotation and radioulnar synostosis,^18,23,32,39 a fracture more than 1 week old is a relative contraindication to reduction. It is better to accept deformity.

PRINCIPLES OF TREATMENT

Review of the literature indicates that, regardless of the severity of the injury, closed treatment gives better results than open treatment. In addition, fractures treated with internal fixation tend to have poor results compared with those treated without internal fixation. In particular, transcapitellar fixation with a Kirschner wire passed through the capitellum of the humerus and across the joint into the head and medullary canal of the radius is associated with significant complications including septic arthritis, breakage of the wire within the joint, and nonunion (see Figs. 17-4 and 17-11).^7,19 Thus, as little internal fixation as possible is recommended.^2,39 When necessary, intramedullary fixaton using the Metaizeau technique seems to avoid the undesirable consequences associated with other internal fixation techniques. Finally, immobilization of the elbow for more than 3 to 4 weeks leads to stiffness, even in children.

FIGURE 17-11 Nonunion of the neck of the radius 4 years after open reduction and fixation with a transcapitellar wire in a 12-year-old boy.

Thus, the following principles apply to treating radial neck fractures:

COMPLICATIONS RELATED TO THE INJURY

Radioulnar Synostosis

The dreaded complication of radioulnar synostosis (see Fig. 17-2)^{1,18,23,24,25,39} is associated with widely displaced fractures and is often associated with dislocation of the elbow.

Premature Fusion of the Epiphyseal Plate

Premature fusion is common but of little consequence.^4,9,10,18,26

Avascular Necrosis

AVN is most common (Fig. 17-12)^{12,18,23,32,39} after open reduction but can occur with widely displaced fractures treated by closed reduction. Although this complication probably occurs to a certain extent in many of these serious injuries, the eventual effect is determined by the degree of loss of blood supply.

FIGURE 17-12 A, Irreducible fracture angulated 90 degrees. B, Open reduction was performed with two K-wires place at the periphery of the articular surface angled obliquely across the fracture site. C and D, Three years postoperatively, the patient shows signs of avascular necrosis, but the fracture has united and the patient has excellent motion in all planes.

Enlargement of the Head of the Neck of the Radius and Increase in Diameter of the Neck of the Radius

This complication, which is often seen, is accompanied by compensatory enlargement of the capitellum of the humerus.^23,24,26 Because growth is stimulated by the increased vascularity during the healing phase, the event is of little significance.

Ectopic Calcification

Ectopic calcification is also frequent, but it is usually limited and has little effect on the outcome.^{23,25,26,33,39}

Vascular and Peripheral Nerve Injury

Injuries to vessels and to peripheral nerves are unusual after this injury. When vascular injury occurs, it is usually related to dislocation of the elbow. Nerve injury may occur, but permanent paralysis is unusual.

Impaction or Shear Injury to the Articular Surface of the Radial Head

This complication is difficult to diagnose because it occurs in fractures that produce less angulation and because the joint injury is not directly visualized,²⁴ but it can lead to elbow stiffness and premature physeal closure. A shear injury to the head of the radius can produce an intra-articular free osteochondral fragment containing articular cartilage and a “variable amount” of epiphysis.

COMPLICATIONS RELATED TO TREATMENT

Avascular Necrosis

AVN can complicate not only widely displaced fractures but also those with lesser degrees of displacement treated by open reduction (see Fig. 17-12).^{12,16,18,23,39} The risk of AVN can be reduced by carefully preserving the soft tissue attachments. It is seldom seen with closed treatment.

Radioulnar Synostosis

Radioulnar synostosis also may result from less severe injuries that have undergone the trauma of open reduction or late closed reduction (see Fig. 17-2).^3,10 If complete dislocation of the radial head or a dislocation of the elbow is initially unrecognized, reduction should probably be attempted up to 3 months after the injury (see Fig. 17-3). In this setting, the parents must be warned that significant stiffness will result.

FIGURE 17-3 A, Radiograph of the elbow of an 8-year-old girl who had fallen 6 weeks earlier. The radial head is tilted 90 degrees posteriorly and is not articulating with the joint surface of the capitellum. The presumed mechanism of this fracture pattern is that (spontaneous or manipulative) reduction of a posteriorly dislocated elbow reduces the dislocation but leaves the radial head displaced. B, In the same patient 22 years after open reduction, note the enlargement and irregularity of the radial head. She had a full range of motion and no pain. This is the only exception in our experience to the rule that stiffness usually follows late open reduction.

Infection

Postoperative infection³⁹ is always a concern with open procedures and can result in dissolution of the articular surface and ankylosis.

Nonunion

Nonunion is rare, but when it occurs, it is almost always after open reduction (see Fig. 17-11).³⁷ Poor results are inevitable,^4,26,39 but there may be surprisingly little pain, and excision should be deferred until skeletal maturity. Bone grafting should be considered with caution because radioulnar synostosis frequently develops. Healing of the nonunion has not necessarily led to improvement of clinical symptoms.

A rare cause of nonunion may be complete reversal of the head of the radius when the fracture surface faces the capitellum of the humerus and the articular surface faces the distal fragment.²⁵ The radial head should be returned to its proper orientation, even if it has lost all its soft tissue attachments. It should not be excised.

Damage to the Articular Surface

Such damage can result from injury or from breakage of wires inserted across the joint to fix the fracture. This technique also is associated with stiffness, so it should be avoided.

Loss of Motion

Stiffness has been associated with open treatment, internal fixation, delayed treatment more than 1 week after the injury, and immobilization longer than 4 weeks.

AUTHOR’S PREFERRED METHOD OF TREATMENT

Selection of the treatment technique depends on the nature of the injury. The sequence and method of treatment preferred by the author is based on his personal zeal for treating these injuries “closed” whenever that is at all possible.

FIGURE 17-13 A and B, The author’s daughter fell from a couch, sustaining this radial neck fracture angulated 40 degrees, and an associated, nondisplaced olecranon fracture. C and D, Two years following cast immobilization without reduction, the fracture alignment has completely remodeled and the patient has full motion in all planes with unlimited function.

With the patient under general anesthesia, the forearm is rotated while the operator palpates for the position of maximal prominence of the head of the radius at different degrees of flexion and pronation/supination. An assistant applies varus stress to the elbow to open the joint laterally and to increase the prominence of the radial head. Firm pressure is applied to the radial head in mediad and craniad directions. Successful reduction is confirmed by radiographs (several views may be necessary).

If the elbow region is too swollen to palpate the radial head, an assistant should stabilize the humerus and flex the elbow to 90 degrees. The forearm is rotated to full supination without applying varus strain to the elbow. Thumb pressure is applied to the anterolateral aspect of the head of the radius just lateral and distal to the cubital fossa. At the same time, the forearm is gradually rotated to the neutral position and then into full pronation. A variation on this technique has been recently described by Neher.²² The reduction is verified radiographically, preferably with a C-arm fluoroscope. The patient’s arm is placed in an above-elbow splint or cast for 3 weeks, and a follow-up radiograph is taken after 1 week.¹³

If this maneuver fails to achieve reduction, an Esmarch bandage is wrapped snugly around the elbow and the radiographic studies are repeated. Occasionally, this results in reduction.

If reduction is still inadequate, the arm is prepared and draped, and an attempt is made to achieve a percutaneous reduction.^1,5,31,34 Under fluoroscopic control, a Steinmann pin or small elevator is introduced through the skin, and the radial head is pushed into proper position (see Fig. 17-8). If reduction is achieved and is stable, with the elbow flexed 90 degrees and the forearm in a natural position, a long arm cast is applied. Radiographs confirm the maintenance of reduction. If the radial neck fracture reduction cannot be achieved, cannot be maintained, or is unstable, then an intramedullary pin is placed using the Metaizeau technique (see Fig. 17-9).

Only in the rare situation in which percutaneous reduction and the Metaizeau technique are not successful should open reduction be performed. A 5-cm incision is made, commencing on the lateral aspect of the capitellum and angling posteriorly over the radial head. This is the central portion of Kocher’s posterolateral incision at the interval between the extensor carpi ulnaris and the anconeus muscles. To avoid damaging the posterior interosseous nerve, no incision should be made distal to the bicipital tuberosity of the radius. The elbow joint is entered anterior to the anconeus muscle. Do not interfere with the orbicular ligament even if torn, or stiffness may result. The radial head is reduced into its proper position and is often sufficiently stable to make internal fixation unnecessary. If the radial head is unstable, the child’s bone is often soft enough to allow use of a heavy absorbable suture on a stout cutting needle to hold it in place, introducing the needle at the articular margin of the radial head and passing it across the fracture into the neck of the radius and through the cortex. If this does not seem feasible, one or two fine, smooth Kirschner wires are inserted at the articular margin of the radial head, across the fracture, and just through the cortex of the radial neck (see Fig. 17-12). They should be bent external to the skin, cut external to the skin, and a dressing sponge or gauze placed beneath the pins to facilitate removal in 3 weeks.

A growing child’s radial head must never be excised. Excision results in pain, increased carrying angle, radioulnar synostosis, or distal radioulnar dysfunction (see Fig. 17-5).^2,3,15 If stable reduction cannot be achieved, less than optimal reduction should be accepted. Delayed radial head resection is not usually necessary but can be performed at skeletal maturity.

FIGURE 17-5 A, A type IV fracture of the radial head and a dislocation of the elbow in an 8-year-old boy. B, The free fragment was excised, along with the radial head (left). Seven years later (right), that patient had very little forearm rotation, limited extension, irregularity of the articular surface, and valgus deformity.

The rare Salter-Harris type III or IV injury produces a dilemma. The fracture fragment should be fixed whenever possible, but if the fragment is too small, the fragment should be excised. The prognosis for Salter-Harris type III or IV fractures is guarded. Loss of motion after this fracture may be due to other factors, because the injury is usually produced by considerable forces.

Immobilization following open reduction is as described for closed treatment and should be continued for no more than 3 to 4 weeks. If Kirschner wires have been used, they should be removed at this time. Reha bilitation and follow-up are exactly as described for closed treatment.