Open Reduction and Internal Fixation of Pediatric Medial Epicondylar Humeral Fractures in the Prone Position.

Abstract

Fracture of the medial epicondyle is a common pediatric injury, with an estimated annual incidence of 40 to 60 per 100,000 people per year1-3. Medial epicondylar fractures are associated with elbow dislocation in about 60% of cases, and ulnar nerve dysfunction is reported to occur nearly 10% of the time2,4. No standard of care for medial epicondylar fracture exists, as similar outcomes have been demonstrated in observational studies with both operative and nonoperative treatment5,6. Increasingly, however, these injuries are being treated with surgical intervention, which in most cases consists of a single screw affixing the osseous piece back to its donor site on the humerus7-9. There is broad consensus on the absolute indications for operative treatment, including an open fracture and an incarcerated epicondylar fragment1,10-13. The relative indications are more controversial and include ulnar nerve dysfunction, elbow instability, increased fragment displacement, and high-level throwing or upper-extremity weight-bearing athletes2,9,14-16. The patient is placed in the prone position with the operative arm on a radiolucent arm board. A milking maneuver with an Esmarch bandage is utilized. A posteromedial incision is made over the medial epicondyle. The ulnar nerve is protected posteriorly. The fracture is easily reduced under minimal tension, and then 1 or 2 guidewires from the 4.0-mm cannulated screw kit are placed to fix the fragment. The central guidewire is overreamed, and then a partially threaded 4.0-mm screw is placed in a relative posterior-to-anterior trajectory within the medial column of the elbow. Nonoperative treatment includes immobilization in a long arm cast until fragment healing. Complications associated with nonoperative treatment include nonunion and late instability. Supine positioning is a reasonable alternative to the prone position described here. In that case, the fracture is fixed with the arm in external rotation of the shoulder and with the elbow extended. Prone positioning for operative treatment of medial epicondylar fractures is preferred because the tension from the flexor pronator mass associated with supine positioning is negated, facilitating an easier fracture reduction and improved anatomic reduction. To our knowledge, there are currently no Level-I or Level-II prospective studies reporting on the outcomes of operative versus nonoperative treatment of medial epicondylar fractures. A systematic review of retrospective results suggested no difference in pain or clinical outcomes, but >9-times greater odds of union with operative treatment5,6. Expectations following operative treatment of a medial epicondylar fracture have been explored in multiple studies. Generally, return to full levels of activity and near-normal range of motion of the elbow have been demonstrated by most. Minor rates of range-of-motion limitation, including extension deficit (4% with deficit up to 20°) are reported in some studies8. In the setting of preoperative instability, the expectation is that elbow stability will be achieved by operative treatment7,8. Perform and document an accurate preoperative neurovascular examination of the arm.Test the shoulder in internal rotation prior to prone positioning.Protect the ulnar nerve during surgical fixation and drilling.Confirm that the screw trajectory is relatively posterior to anterior and only in the medial column of the elbow.