Coronal Plane Articular Shear Fractures of the Distal Humerus.

Abstract

Coronal plane articular shear fractures of the distal humerus are a rare injury, comprising 6% of distal humerus fractures. The fracture can be easily missed on initial radiographs; therefore, a high index of suspicion is warranted. Radiographically obvious fractures are often more complex than initially appreciated, with plain radiographs often underestimating the extent of posterior comminution and trochlear involvement. Associated bony and ligamentous injuries are common. Anatomic reduction and internal fixation of displaced fractures is the standard of care because poor results have been described with nonsurgical treatment. However, the regional anatomy and the often-limited bone stock can make open reduction and internal fixation challenging. The lateral approach, with headless compression screws placed from anterior to posterior, is commonly used for simpler fracture patterns, but exposure and fixation of trochlea extension can be difficult. In the absence of posterior comminution, the anterolateral approach can enhance trochlea exposure and allow for a better trajectory for screw placement. Posterior comminution often requires locking plate fixation. Better results and lower complication rates have been reported for fractures with less fragmentation of the articular surface and those without posterior comminution. Contracture and symptomatic implants are the most common reasons for revision surgery.