Objective Analysis of Lateral Elbow Exposure with the Extensor Digitorum Communis Split Compared with the Kocher Interval

Abstract

The most widely used surgical approach to treat radial head fractures is through the Kocher interval. However, the extensor digitorum communis (EDC) splitting approach is thought to allow easier access to the anterior half of the radial head, which is more commonly fractured. The aim of this cadaveric study was to compare the osseous and articular surface areas visible through the EDC split and the Kocher interval. Four approaches were used in fresh frozen cadaveric upper extremities: EDC splitting (n = 6), modified Kocher (n = 6), extended EDC splitting (n = 6), and extended modified Kocher (n = 4). For each approach, the osseous and articular surface areas visualized were outlined with use of a burr. Each elbow was then stripped of soft tissue and a digitized three-dimensional model was created with use of a surface scanning system. The visible surface area obtained with each approach was mapped and quantified with use of the markings created with the burr. The EDC splitting approach provided greater exposure of the anterior half of the radial head (median, 100%) compared with the modified Kocher approach (68%, p < 0.05). The extended modified Kocher and extended EDC splitting approaches provided comparable visualization of the distal aspect of the humerus, capitellum, radial head, and coronoid process. The results suggest that the EDC splitting approach provides more reliable visualization of the anterior half of the radial head while minimizing soft-tissue dissection and reducing the risk of iatrogenic injury to the lateral ulnar collateral ligament.