Fixation of Displaced Medial Epicondylar Fractures in Adolescents.

UNLABELLED

Fractures of the medial epicondyle are often a marker of injury of the medial collateral ligament complex of the elbow, regardless of displacement. The medial epicondyle serves as the origin for the flexor/pronator mass superficially and the medial collateral ligament near the base. These fractures occur most commonly through the apophysis at the base of the epicondyle, making differentiation of muscular versus ligamentous avulsion difficult. Fractures associated with elbow dislocation and fractures with an intra-articular incarcerated medial epicondyle are ligamentous injuries, requiring at least intraoperative examination and most likely fixation of the fracture. Degree of displacement has traditionally been considered the deciding factor for fracture fixation, but this concept has been proven unreliable both in the literature and in our experience. Regardless of the degree of displacement, we recommend examination under anesthesia for all displaced fractures, with fixation of any fractures that render the elbow unstable to valgus stress.

DESCRIPTION

The patient is placed in the supine position, and an examination under anesthesia is performed. If the elbow is stable to valgus load, the patient is placed into a long arm cast and awakened from anesthesia. If the elbow is unstable, the patient is placed in the lateral decubitus position, and the arm is prepared and draped. The fingers and wrist are wrapped with a self-adhesive bandage in flexion to relax the flexor/pronator mass. Under tourniquet control, a curvilinear medial incision is made just dorsal to the medial epicondyle. The ulnar nerve is identified and transposed if necessary. A guidewire is placed through the fracture fragment and used as a joystick. The hand is then positioned on the posterior aspect of the hip to provide varus load to the elbow and assist with reduction. The medial epicondyle is reduced, and the guidewire is advanced unicortically. A 3.0-mm, partially threaded cannulated screw is then advanced over the guidewire. A long arm cast is applied after closure of the wound with buried absorbable sutures.

ALTERNATIVES

Nonoperative treatment in a cast has been suggested. Surgical variations include supine positioning, bicortical screws, and use of washers.

RATIONALE

Lateral decubitus positioning and wrapping of the hand and wrist in flexion facilitate reduction by both applying a varus load and relaxing the flexor/pronator mass. Unicortical fixation is sufficient and does not risk injury to anterolateral structures. Washers have a higher complication rate than screws alone and may not be necessary in most cases.