Fractures of the Coronoid Process of the Ulna: Which Ones to Fix and Which Ones to Leave Alone: A Review.

The coronoid process of the ulna forms the anterior boundary of the trochlear notch and is crucial for elbow stability. Coronoid fractures are uncommon and they occur in aproximately 10% of elbow dislocations. They are mostly associated with ligamentous and capsular disruptions as well as concomitant fractures. Posterior elbow dislocations, combined with fractures of the coronoid and the radial head are known as the terrible-triad of the elbow. These injuries result in instability of the elbowjoint and, if not treated properly, lead to recurrent dislocations that can cause further damage. Depending on the pattern of the injury and the quality of the bone, the surgeon has to choose from a variety of treatment options. Large coronoid fragments and other associated fractures are ideally treated by ORIF (open reduction internal fixation); a prosthetic radial head replacement may be favorable if a comminuted radial head fracture is not reconstructable. Isolated small coronoid process fractures can be treated non-operatively with satisfactory results. Although rough guidelines can bemade, it is important to view each patient's elbow injury individually and then make a specific treatment plan. Data on treatment results are sparse. Improved understanding of coronoid fractures and their management will result in better outcomes and decrease possible complications including a certain degree of stiffness, neuropathy and arthrosis.