Introduction

Since radial head fractures are very rare in children¹ this chapter will concentrate on paediatric fractures of the radial neck and their management.

Radial neck fractures account for 1% of all fractures and 5–14% of elbow fractures. They involve all age groups from childhood to prepuberty, with a peak incidence at around 9–10 years of age. They occur at a younger age in girls than in boys (approximately 2 years earlier).²

Most often the injury is a Salter–Harris type II, or complete fracture of the neck itself. Some of these fractures are very difficult to treat, with many possible complications, all of which have a significant, deleterious effect on joint function. The degree of initial anatomical disruption, especially if associated with a vascular lesion, has a major effect on outcome. However, the inadequacies of difficult primary treatment are equally responsible. Open reduction with a condyloradial Steinmann pin is usually associated with a high incidence of complications and, whenever possible, closed treatments are preferred by most paediatric orthopaedic surgeons. To avoid open reduction, two closed methods are helpful and will be described: intramedullary pinning as proposed by JP Métaizeau et al,^3–8 and percutaneous pinning.^9–11 In our experience, open reduction only becomes necessary when the above methods cannot obtain reduction. Even in these circumstances, osteosynthesis may require intramedullary pinning.

Aetiology

The mechanism of injury is usually an indirect force. It results from a fall onto the outstretched hand in which the elbow is extended or slightly flexed and a valgus force is applied to the elbow joint. According to the Jeffery classification, which is based on the mechanism of injury, it is a type I injury.¹² The head of the radius is driven against the capitulum. As the radial head is essentially cartilaginous, it is more resistant to trauma, which is why isolated radial head fractures and epiphyseal separations are so rare. Typically, the proximal radial metaphysis cannot withstand the sudden axial compression forces to which it is subjected, and breaks. Radial neck fractures may also occur in association with dislocation of the elbow: Jeffery type II injury.¹³ If this occurs during a posterior dislocation of the elbow the radial head remains in an anterior position.¹⁴ If, however, it occurs during reduction of the dislocation the radial head will remain posteriorly dislocated (posterior to the capitulum). This form of fracture adversely affects the prognosis because there is an associated vascular risk and because reduction of the fracture is significantly more challenging.

Clinical Pearl 11.2

An 8-year-old child fell on their elbow. Initial X-rays, and more particularly the lateral view, showed a Jeffery type II radial head fracture (A, B). It was treated by closed reduction and FIN. On the fluoroscopic image, note the 180° rotation of the radial head (C). Open surgery was necessary to perform reduction and FIN (again) using a 1.5 mm nail (D, E) The implant was removed in the 4th postoperative month. At 10-month follow-up function was excellent with full range of motion, but the X-ray showed significant remodelling of the radial head (F). Still, viability of the epiphysis was confirmed by MRI.

Note: this unusual fracture needs to be better known.

Other forms of radial neck fracture can also occur. The most common by far is the pure metaphyseal fracture of the radial neck with subsequent Salter II epiphyseal separation. The other types of epiphyseal separation, particularly those with intra-articular fracture extension (Salter types III and IV), are exceptional.

Associated injuries are frequent, from fracture of the olecranon that occurs in an extended elbow, to dislocation of the elbow joint with or without avulsion of the medial epicondyle in an elbow that is slightly flexed on impact.^15,16 Skin lesions and neurovascular injuries are, however, rare.

During displacement, a metaphyseal periosteal flap often remains attached to the radial head. Preservation of this sleeve, which contributes to the vascular supply of the radial head, is critically important for two reasons: first, to preserve the blood vessels it contains; and second, because once tensioned this piece of tissue will assist in maintaining the reduction.

Presentation, investigation and treatment options

The child usually presents having fallen onto the outstretched hand. The injury most frequently occurs during sport, play or after a simple fall. Clinical examination reveals a swollen elbow that must be carefully evaluated. In addition to assessing the bony anatomy of the joint it is also essential to examine the neurovascular status of the forearm and hand. Anteroposterior (AP) and lateral radiographs of the elbow should routinely be undertaken, the fracture configuration studied and displacement of the radial head measured. Accurate classification of the injury enables appropriate treatment to be instituted. Although many radial neck fracture classifications have been developed,^1,12,17 that described by Métaizeau et al⁴ is perhaps the most useful. This classifies radial neck fractures based on translation and is useful because of its influence on prognosis (Table 11.1):⁴

In 30–50% of severe displaced radial neck fractures another fracture of the elbow joint will have occurred. Most often there is a fracture of the olecranon, lateral condyle, medial epicondyle or ulna, all of which may require an additional procedure with appropriate osteosynthesis.¹⁶

Preoperative complications of radial neck fractures are seldom seen but occasionally protrusion of the fractured end of the bone through the skin may occur in association with a fracture of the olecranon. Vascular lesions are hardly ever seen. A careful assessment of the radial nerve is essential at the time of presentation because of its close proximity to the fracture. It should also be re-examined after any intervention, particularly if a punch is used to achieve fracture reduction.

Early postoperative complications are those of any surgically treated fracture and include compartment syndrome, early infection and redisplacement of the fracture.

Surgical techniques and rehabilitation

Surgical treatment

Percutaneous pinning

A small stab wound is made on the lateral side of the elbow, 2–5 cm below the level of the radial fracture, depending on the amount of displacement. The more displaced the fracture, the lower the entrance of the wire. This approach must be posterior to the extensor radial muscles and with the forearm in pronation so that the deep branch of the radial nerve is protected by being displaced anteriorly. A smooth 2 or 2.5 mm K-wire is inserted through the wound, the subcutaneous tissues and the muscles to reach the radial head and neck (Fig. 11.1).

Figure 11.1 Use of a punch: the forearm is pronated to allow forward shift of the radial nerve and thus protect it from injury. The punch is placed on the epiphysis, not on the radial neck, in order to avoid potential damage to the precarious vascularization.

The radial head is then gradually pushed back into place. To avoid injury to the growth plate, the head itself must be pushed, or in some circumstances the wire should be introduced into the fracture to help the reduction. As these fractures are impacted, reduction can be difficult to obtain and the same wire may need to be redirected through the same stab wound several times before an appropriate reduction is achieved. This should then be verified by standard radiographs.

Although Lenggenhager originally left the pin in place in the cast, it is nowadays considered unnecessary as sufficient stability can be obtained with a long-arm cast with the elbow flexed at 90° and the forearm in neutral rotation for 3–6 weeks.¹⁹ The period of immobilization is determined by the age of the child and is shorter for younger children, whose fractures heal more rapidly.⁹

Clinical Pearl 11.5

Percutaneous pinning involves the use of a 2 or 2.5 mm K-wire and begins 2–5 cm below the level of the radial fracture.

Elastic stable intramedullary nailing (ESIN) technique

Published by Métaizeau et al in 1980,³ this method is very simple but requires perfect knowledge of the elastic stable intramedullary nailing technique, which is used in fractures of the forearm.²⁰

Surgical preparation

As is often the case in trauma surgery, retrograde ESIN is preferably performed under general anaesthesia instead of regional block anaesthesia in order to facilitate postoperative monitoring. Furthermore, reduction is best achieved with the patient under general anaesthesia as it permits complete relaxation of the muscles.

The child is positioned supine on the operating table with the injured upper limb on an attached radiolucent arm table. A tourniquet is placed around the upper arm. It is not systematically inflated but it may prove useful should open reduction be required.

An image intensifier is usually placed parallel to the operating table and perpendicular to the arm table, at the level of the child’s axilla. In this position, the surgeon can face the image intensifier and the posterolateral compartment of the elbow, and has a straight-shot access to the radial head and easy access to the distal radial metaphysis. Reduction is performed under fluoroscopic guidance. For the AP projection the elbow is extended in a mid-pronation position. For the lateral projection it is flexed 90° in a mid-pronation position, and the shoulder is positioned in full external rotation.

The entire upper limb is prepped. A sterile upper extremity drape is used which extends down to the tourniquet, and covers the child’s body including the trunk and the lower limbs.

Closed reduction

A closed reduction is attempted. The ESIN technique is used either to stabilize the reduced fracture or (and this is the most common) to reduce and stabilize the radial neck.

Two different reduction manoeuvres can be used but, prior to anything else, the surgeon must determine the plane of maximal displacement of the radial head. This is achieved using image intensification at progressively larger angles, from supination to full pronation. The plane of maximal displacement is found when the radial head forms an almost perfect rectangle, with a clearly and entirely visible physis. It is generally translated in the posterolateral direction, so that the plane of maximal displacement is best visualized in 20° to 40° of pronation (with reference to a full supination position).

The first reduction manoeuvre involves the assistant placing a varus stress on the extended elbow and applying traction to restore the joint space, while the surgeon places his/her thumb on the assumed position of the radial head (i.e. in the plane of maximal displacement) and gives a firm push in an upward and medial direction to return the radial head to its normal position. In this method the forearm is supinated, but many variants have been described. According to other authors, the elbow should be slightly flexed for better muscle relaxation. Jeffery recommends a small amount of pronation of the forearm to ensure that the push is applied in the plane of maximal displacement.

An alternative reduction manoeuvre involves replacing the thumb with a punch as described above.

Clinical Pearl 11.6

Before attempting ESIN the plane of maximal displacement of the radial head must be determined.

Surgical procedure: retrograde radial intramedullary nailing

Sharp or tapered stainless or titanium steel nails are used as they literally pin the epiphyseal–metaphyseal fragment, and provide a firm anchorage during the reduction manoeuvres.

The diameter of the nail must satisfy the relationship; nail diameter = 0.4 × diameter of the medullary canal. This corresponds to a 1.5–2.5 mm diameter range.

The sharp leading end of the nail may be slightly bent to anchor in the fractured fragment. Mild contouring is performed in the same plane and direction as the tip to match the natural curve of the radius at the end of the procedure.

The skin incision is made on the lateral aspect of the metaphysis of the distal radius, 1.5 cm distal to the anticipated entry point. This avoids the risk of skin impingement during oblique insertion of the nail.

Identification of the distal physis with fluoroscopy assists in accurately positioning the 1.5–2 cm longitudinal incision. Blunt dissection using scissors is then performed. The radial vein and the sensory branch of the radial nerve are successively retracted posteriorly and protected with a mini retractor. Dissection continues anterior to the insertion of the brachioradialis tendon to avoid potential damage to the extensor pollicis brevis and abductor pollicis longus tendons, and is carried down to the bone (Fig. 11.2).

Figure 11.2 Entry hole is created in the distal radial metaphysis. A 10–20 mm longitudinal incision is made anterior to the cephalic vein and the sensory branch of the radial nerve. (A) The hole is made in an anterior–posterior direction to avoid injury to the radial artery. (B) Position of the entry hole: 10–15 mm above physis, on the anterolateral aspect of the distal radius, anterior to insertion of the brachioradialis tendon and anterior to extensor pollicis tendons. (C) Transverse section through incision.

The entry hole is made with an awl in the same anterior–posterior oblique direction, 10–15 mm above the distal physis. Care should be taken not to slip anteriorly to avoid injury to the radial artery. The chief advantage of this anterolateral approach to the distal radius is safety, since there are no critical superficial neurovascular structures in the vicinity. Furthermore, if the metaphysis is firmly held in mid pronation with the thumb and index finger, the awl can be safely directed posteriorly away from the radial artery (Fig. 11.3).

Figure 11.3 FIN technique for radius. (A) Entry hole is created with the awl. (B) Nail insertion.

The nail is attached to a T-handle and inserted into the medullary canal. Advancement of a sharp-tipped implant through such a narrow path may be somewhat difficult, and slight rotation movements or even light mallet blows may be necessary. Following the natural curve of the radius facilitates initial advancement of the nail.

Once the nail has reached the fracture site, it must be rotated so that its tip is positioned in the plane of maximal displacement of the radial head. The nail is firmly impacted into the radial head under fluoroscopic guidance using heavy mallet blows. Reduction of translation and tilt is then obtained by rotating the nail 180° anteriorly. The direction of rotation clearly depends on the position of the radial head but, as the radial head is most often translated posterolaterally, rotation is performed in an anteromedial direction. Therefore, with the surgeon facing the distal end of the radius, rotational movement will be clockwise in a right elbow and counterclockwise in a left elbow. Gentle rotation is mandatory, otherwise the tip of the nail may cut out into the epiphysis. It is also recommended to combine rotation of the nail and pronation of the forearm. In fractures with grade 4 displacement, it may be necessary to use a punch as previously described to gently move the radial head towards the nail until it is positioned right in front of the nail tip (Fig. 11.4).

Figure 11.4 ESIN for radial neck fracture. (A) Intramedullary nail is slowly advanced with a slight twist and to-and-fro motion of the T-handle. The tip of the nail reaches the fracture site laterally (B) and posteriorly (C). During this time, the surgeon tries to reduce the radial head as much as possible by applying digital pressure. (D, E) The nail is then impacted into the radial epiphysis using a mallet. (F, G) Finally, reduction is performed by combining rotation of the T-handle and pronation of the forearm. (H) Reduction and stabilization are now achieved.

Once closed reduction is completed, the tip of the nail should be directed medially and follow the natural curve of the radius. This means that after reduction and stabilization have been achieved, further manipulation will result in secondary displacement.

Owing to the remodelling capacity of the radial neck and depending on the child’s age at the time of surgery, under-reduction (lateral tilt) of up to 20° and even 30° is acceptable.¹⁸ For this reason one should not try at all costs to achieve a perfect reduction at the risk of damaging the lateral periosteum or making multiple perforations in the radial head.

The distal end of the nail is then slightly bent and carefully trimmed so that it is just proud of the bone surface. This may make later removal more difficult, but it eliminates the risk of irritating the sensory branch of the radial nerve, damaging the extensor pollicis tendons and causing skin injury.

Alternatively, the distal end can be left unbent and cut close to the bone. The elastic properties in the nail will result in it springing back to lie flush against the metaphysis, thus avoiding impingement of local critical structures.

The wound is closed in two layers without drainage.

Clinical Pearl 11.7

The anterolateral approach to the distal radius is used for radial intramedullary nailing as this avoids the superficial neurovascular structures and protects the radial artery.

Difficult injuries

Grade 4 radial neck fractures

These fractures cannot initially be managed with ESIN as the severe radial head tilt precludes impaction of the nail. The first technical option is to use a punch to partially reduce the radial head and allow insertion of the nail.¹⁰

Clinical Pearl 11.8

An 11-year-old child presented with a Grade 4 radial neck fracture associated with an olecranon fracture (A, B). Treatment consisted in reduction of the radial head fracture with a punch and FIN using a 2 mm nail, and open reduction and fixation of the olecranon fracture with K-wires. At 45 days post treatment, range of motion had not yet been restored: there was a flexion and extension lag, and a loss of pronation–supination of about 40° in each range (C, D). The implant was removed, but at 1-year follow-up no improvement was noted. CT showed small calcifications, particularly along the medial border of the radial head, which might explain this loss of motion (E). Eighteen months after the initial treatment, arthrolysis was performed and calcifications removed, and an intensive rehabilitation programme was initiated. At the 3-year follow-up the X-ray showed remodelling of the radial head and medial epicondylar groove. There was a loss of 5° both in flexion and extension as compared to the contralateral side, full supination, and a loss of 30° in pronation (as compared to the contralateral elbow) (F, G).

Note: the severity of this case is attributable to the associated lesions.

The second option is to perform a step-by-step reduction: first, the nail is impacted into the radial head and reduction is attempted by rotating the nail. If reduction is insufficient, the nail is freed by applying a firm mallet blow to avoid the risk of secondary displacement, and the impaction/rotation procedure is repeated to complete the reduction.

A third option consists of inserting a provisional nail to both partially reduce and stabilize the fracture. Then, a second nail is inserted in the same way, which anchors in the partially reduced epiphysis. The provisional nail can then be removed and reduction is completed using the second nail. The main drawback of this method is the creation of two distal holes, and its major limitation is the small diameter of the intramedullary canal, which may not accommodate both nails.³

Radial head dislocation

Dislocation of the radial head anterior to the capitulum is not a big problem and the ESIN technique can still be used. The main hazard is misdirection of the nail, which may cause injury to the anterior structures. We strongly advise surgeons against the use of a punch in anterior dislocations because of the high risk of injury to the radial nerve. The main difficulty lies in evaluation of the plane of maximal displacement to correctly perform the reduction manoeuvres.

Dislocation of the radial head posterior to the capitulum may be a contraindication to percutaneous reduction because of the risk of 180° rotation of the radial head, which would result in avulsion of the periosteal flap (if present) and, as a consequence, to necrosis of the epiphysis. Nevertheless, a subluxation manoeuvre of the joint may help the reduction with a K-wire.²¹ When an open approach is required, a posterolateral approach is used between the extensor carpi radialis anteriorly, and the extensor digitorum posteriorly. A technical trick from JD Métaizeau’s personal experience involves using a lateral approach through a superolateral arthrotomy that will afford access to the radial head from above and will reduce the potential risk of injury to an already compromised periosteal flap. Caution must be exercised when mobilizing the radial head, in order to preserve integrity of the few blood vessels that remain. Once reduction has been achieved, stabilization is provided by intramedullary pinning as previously described, or sometimes sutures are placed through capsuloperiosteal tissue.

Outcome

With the percutaneous technique, Kohler et al¹⁰ used a Rocher punch in a ‘tyre lever manoeuvre’ in 19 patients and had 18 satisfactory reductions. His results in 15 patients were nine excellent, three good and three poor with, among these, one case of partial necrosis of the radial head.

Bernstein et al⁹ used percutaneous pinning for fracture reduction and had success in 15 out of 18 patients. The three patients in whom this method failed comprised two who had comminuted radial head and neck fractures and one with a completely rotated and displaced radial head.

Rodriguez-Merchan¹¹ obtained successful reduction in 20 patients with 70% good, 15% fair and 15% poor results.

Métaizeau et al published their experience of the ESIN method in 47 patients.⁴ Twenty patients’ radial neck fractures were grade 3, 11 grade 4a and 16 grade 4b. The reduction quality was excellent in 16 grade 3, eight grade 4a and nine grade 4b. In this latter group, three patients underwent reduction with percutaneous pinning. All these cases had excellent results with no loss of motion and no radiological change of the radial head. Residual tilt of the radial head after reduction was measured at less than 20° in three grade 3, two grade 4a and one grade 4b. Their functional results were also excellent. One grade 3 had an overcorrection of 25° with progressive remodelling and excellent function. One grade 4a had residual displacement of more then 20° and a loss of motion of more than 20°. Six grade 4b had loss of motion with five poor results. Four of these had open reduction and suffered complications of non-union of the neck (one case), necroses of the radial head (two cases) and articular calcifications (two cases). Other authors have had similar results. Gonzalez-Herranz et al⁵ reported 16 excellent results in 17 cases. In three cases, an overgrowth of the radial head was observed without any functional impairment. Tollet et al²² reported 15 cases with a mean age of 9 years, all of whom had full functional recovery at 6 weeks without any complications. Marchiodi et al²³ described 12 cases with excellent results. Keller et al²⁴ reported this method in the treatment of six adult patients with displaced fractures of the radial neck. All patients had good results 9 months after intramedullary reduction and stabilization. They had little or no pain, complete healing and no significant periarticular calcifications. Ursei et al⁸ and Nawabi et al⁶ reported comparable favourable results.

Complications

Summary

Indications (Table 11.3)

Non-operative treatment of radial neck fractures is indicated for grade 1 fractures, which can be successfully managed with immobilization without reduction (long-arm cast with the forearm slightly pronated for 3–4 weeks). It is also indicated in grade 2 fractures after manipulative reduction, if adequate stability is achieved.

Table 11.3 Indications of ESIN in radial neck fracture

However, in cases where reduction is insufficient or unstable, and in grade 3 fractures, intramedullary nailing is the treatment of choice as it provides both reduction and stabilization of the fracture. Immobilization in a plaster cast for 3 weeks is highly recommended following the reduction.

In grade 4 fractures, reduction can be achieved with ESIN and reduction manoeuvres alone or in association with punching. Open procedures should be avoided if at all possible. Stabilization is provided by an intramedullary nail and cast immobilization. There are no indications for radiocapitular pin fixation.

Any associated bone fractures should be treated at the same time and are not a contraindication to ESIN.

Conclusion

Fractures of the radial neck in children must be treated conservatively whenever possible. Allowing for remodelling with growth, conservative treatment is the method of choice in grade l and 2 cases, and some grade 3 fractures with a residual tilt of <30°.¹⁸

In other cases with a displaced radial head, a perfect reduction may be obtained with percutaneous pinning or intramedullary nailing.²⁶ An analysis of the literature indicates that the best long-term results are achieved with intramedullary nailing, in comparison to percutaneous pinning. The main difference in the two techniques is the quality of stability, which is excellent with intramedullary nailing, when compared to the cast used in the percutaneous pinning method. For these reasons, treatment of displaced fractures will give better results with intramedullary nailing, combined in some difficult reductions with percutaneous pinning.

Unfortunately, in some circumstances, reduction with these closed manoeuvres is impossible. In this case, an open reduction through a lateral approach of the elbow is necessary. It is very important to leave the periosteum intact, to reduce the fracture very gently, and to fix it using intramedullary nailing.