Closed Intramedullary Pinning of Displaced Radial Neck Fracture (Metaizeau Technique).

BACKGROUND

Radial neck fractures account for 1% of all pediatric fractures and 5% to 10% of pediatric elbow fractures. The mechanism of injury is typically a fall with the elbow in hyperextension and the forearm in supination. A valgus force compresses the radial head against the capitellum, causing a radial neck fracture. Displaced radial neck fractures are difficult to treat and account for a disproportionate number of bad outcomes, including malunion, nonunion, and osteonecrosis. The preferred treatment is closed reduction and fixation, as open reduction is associated with an inordinately high rate of osteonecrosis. Closed intramedullary pinning is an effective technique to achieve and maintain reduction. The procedure relies on an intact periosteum and requires attention to detail. The present video article will demonstrate the technique of closed intramedullary pinning (the Metaizeau technique). Metaizeau et al. previously described their technique of closed reduction and intramedullary pinning of radial neck fractures. A Kirschner wire is inserted retrograde from the distal radius into the posterolateral radial neck with the forearm pronated to avoid injury to the posterior interosseous nerve. Reduction is achieved by rotating the wire 180°. This technique relies on intact periosteum, with care taken to preserve the tenuous blood supply of the radial head and to achieve adequate reduction.

DESCRIPTION

General anesthesia is administered, and the patient is positioned supine with use of an arm table or with an image intensifier utilized as an arm table. A tourniquet is applied to the operative limb. Fluoroscopy is utilized to identify the distal radius physis. A radial approach is performed to access the distal radius, proximal to the growth plate, with care taken to protect the sensory nerves. The cortex of the radial metaphysis is opened with use of a drill bit or a bone awl to allow space for the internal fixation device. Opening in a proximal direction and into the medullary canal facilitates intramedullary passage. A Steinmann pin (1.2 to 2.5 mm), Ilizarov wire (2.0 mm), or elastic nail can be utilized for as an intramedullary device. Place the pre-bent Steinmann pin/Ilizarov wire/elastic nail into the metaphysis and advance it in a proximal direction toward the radial neck fracture. The tip of the intramedullary device is directed into the displaced radial neck fracture, engaging the radial epiphysis. The pin/wire/elastic nail is rotated 180° to reduce the fracture, and reduction is confirmed on radiographs. Once reduction and fixation are confirmed, the pin/wire/elastic nail is cut and the skin is closed over it with use of absorbable sutures. A long arm cast is applied for 4 to 6 weeks.

ALTERNATIVES

Alternatives include cast immobilization for cases of displaced fractures with <20° of angulation, closed reduction by placing the elbow in varus with direct pressure on the radial head, percutaneous reduction with use of a Steinmann pin for leverage, and arthroscopic reduction.

RATIONALE

Retrograde intramedullary reduction and fixation achieves reduction, provides stability, and avoids open reduction.

EXPECTED OUTCOMES

In a study assessing elbow function following treatment of displaced radial neck fractures with use of the Metaizeau technique, Ghonim et al. reported excellent outcomes in 22.2% and good outcomes in 77.8% of patients, as measured with use of the Mayo Elbow Performance Score. The radiographic results were similar. The results were marginally worse than those reported in other similar studies, likely because of the severity of the included radial neck fractures. Klitscher et al. evaluated 28 cases of radial neck fractures treated with the Metaizeau technique. Excellent results were achieved in 23 cases (82%) and good results, in 5 cases (18%), as measured with use of the Mayo Elbow Performance Score. The average score was 97 points, and 3 malunions were reported. Metaizeau et al. reported the use of their technique in 42 radial neck fractures, with 31 fractures having an angulation between 30° and 80° (group 1) and 16 fractures having an angulation of >80° (group 2). Good or excellent results were reported in 30 cases in group 1 and in 11 cases in group 2. Yallapragada and Maripuri assessed the use of the Metaizeau technique in 21 patients with a mean age of 8 years. At 6 weeks after nail removal, 19 patients (90.5%) had excellent or good results and 2 patients (9.5%) had fair results. Zimmerman et al. performed a retrospective analysis of 151 children with surgically treated radial neck fractures. Among the 131 patients with adequate follow-up, 31% had poor outcomes. The suboptimal results were associated with age >10 years, increased fracture severity, and those patients who underwent open reduction. The authors concluded that less invasive reduction methods should be attempted prior to open reduction whenever possible.

IMPORTANT TIPS

Avoid the distal radial growth plate.Utilize a T-handle to hold the wire.The use of fluoroscopy is necessary to aid in placement of the wire and to confirm adequate reduction and fracture fixation.Supplemental arthrography should be performed in young children.Very displaced fractures may require supplemental reduction with use of a percutaneous Kirschner wire prior to final flexible nail fixation.

ACRONYMS AND ABBREVIATIONS

MEPS = Mayo Elbow Performance Score.