*The views expressed in this chapter are those of the author(s) and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense or the United States Government. Nicholas J. Erdle, Dominic L. Van Nielen, and Christopher S. Smith are military service members and this work was prepared as part of their official duties. Title 17 U.S.C. 105 provides that ‘Copyright protection under this title is not available for any work of the United States Government.’ Title 17 U.S.C. 101 defines a United States Government work as a work prepared by a military service member or employee of the United States Government as part of that person’s official duties.
- The elbow is a complex ginglymus, or hinge joint, that permits flexion and extension of the forearm, while the proximal radioulnar articulation is a pivot joint that permits pronation and supination of the forearm.1
- The anterior band of the ulnar collateral ligament and the radial head resist valgus stresses on the elbow.2
- The lateral collateral ligament complex, which includes the ulnohumeral ligament, resists varus stresses.
- The coronoid process and olecranon process of the ulna resist anterior and posterior translation of the ulna at the ulnohumeral joint.1
- The olecranon is subcutaneous on its posterior surface, and its most proximal aspect is the insertion point of the triceps tendon.
- Direct trauma, such as a fall onto the elbow, can result in comminuted fracture of the olecranon.
- Indirect trauma, such as a fall onto an outstretched hand, can result in transverse or short oblique fractures of the olecranon due to forceful triceps contraction.2
- Olecranon fractures are intra-articular, requiring anatomic reduction of the articular surface with more than 2 mm of displacement.1
- A reported 2% to 30% of olecranon fractures are open, due to the very superficial nature of the bone.
- Posterior Monteggia lesions are typically the result of low-energy trauma but can still be associated with coronoid process fractures (25%), ipsilateral humeral shaft fractures (23%), radial shaft fractures (68%), and also ligamentous injury about the elbow.3
Anteroposterior (AP) View
- The AP view is performed with the elbow extended and the arm in supination.
- The AP view demonstrates radiocapitellar alignment as well as congruent articular surfaces of the ulnohumeral joint and the radiocapitellar joint (Fig. 9-1).
- The lateral view is performed with the elbow in 90 degrees of flexion.
- The lateral view demonstrates radiocapitellar alignment, and in intra-articular trauma, it can demonstrate the presence of effusion through displacement of intra-articular fat pads (Fig. 9-2).
- The radiocapitellar view is performed in the same positioning as the lateral view, with 45-degree inclination of the beam.
- The radiocapitellar view is useful in characterizing coronoid process fractures, radial head fractures, and capitellar sheer fractures (Fig. 9-3).
- Obtained by rotating extremity 45 degrees internally or externally in relation to the beam.
- The internal oblique view of the humerus is useful in visualizing medial epicondylar fractures.
- The external oblique view of the humerus is useful in visualizing lateral epicondylar fractures.
- The radiographic indication for operative treatment of an olecranon fracture is >2 mm displacement of the fracture, which causes intra-articular incongruity.
- Due to the strong pull of the triceps attachment, even minimally displaced fractures are likely to need operative fixation to prevent delayed displacement with active or passive range of motion.4
- Standard radiographic views include AP, lateral, and radiocapitellar views to ensure the treating surgeon sees all aspects of the injury pattern.
- In comminuted olecranon fractures, computed tomography (CT) is useful in demonstrating impaction and displacement of fracture fragments and characterizing intra-articular fragments that may contribute to posttraumatic arthritis (Figs. 9-4–9-6).
Supine and 45-Degree Lateral Positioning
- The supine position or semilateral position can be used to easily perform preparatory sterilization and draping of the operative extremity, as well as perform intraoperative imaging. This allows the anesthesiologist direct access to the patient’s airway, allowing for regional anesthesia without the need for intubation. This position is also useful for polytrauma patients with positioning restrictions.
- Intraoperatively, the shoulder can be flexed and internally rotated with the forearm flexed over the chest of the patient to facilitate a posterior approach to the distal humerus and proximal ulna. To support the operative arm, a bump or a well-padded Mayo stand placed from the contralateral side of the patient can be used.
- The operating table can be rotated 90 degrees in the room to facilitate use of fluoroscopy and maximize space for multiple surgeons while still enabling anesthesia staff to have appropriate access to airway and intraoperative monitoring devices.
- The draped C-arm should enter from a 45-degree angle with one of the surgeons positioning the arm appropriately to obtain either true AP or lateral views of the arm on the arm table (Fig. 9-7).