Anterior Monteggia injuries are frequently complicated by persistent radial head instability and suboptimal outcomes. Using a cadaveric elbow motion simulator, we quantified the contributions of ligaments of the proximal radius on maintaining radial head stability, evaluated the effectiveness of ulnar overcorrection to create an apex dorsal angulation in stabilizing the radiocapitellar joint, and finally compared the stabilizing effect of annular ligament repair to three different reconstruction techniques. Our results showed increased anterior radial head translation with progressive soft tissue sectioning with the annular ligament as the primary stabilizer. Ulnar overcorrection and forearm pronation were shown to decrease anterior translation of the radial head. Finally, our results showed annular ligament repair restored stability closest to the intact state. These findings support the importance of safeguarding the annular ligament and repairing if feasible. Our findings also suggest pronation may be a useful method of postoperative immobilization for patients with anterior radiocapitellar instability.