Evaluation and Initial Management
Monteggia fractures are unstable injuries, and the physical examination is challenging. Patients generally hold the elbow and forearm in a flexed position. Assessing the range of motion is difficult, if not nearly impossible, without adequate pain control or sedation. Distal neurovascular status should be carefully assessed, specifically examining for PIN dysfunction, which is in the direct vicinity of the proximal radius injury. Open skin and compartment swelling are important to document and can determine the urgency of definitive management.
Initial radiographs include anteroposterior and lateral images of the elbow, forearm, and wrist. In a normal elbow, a line drawn down the shaft of the radius and through the center of the radial head should bisect the capitellum in all views. If this is not the case, then a radial head dislocation should be suspected. Owing to the overlying ulna on the lateral view, and frequent oblique projection of the humeral condyles, a radial head dislocation or partial intra-articular fracture are commonly obscured. Cortical shadows and increased opacity in the elbow joint can indicate coronoid or radial head fragments, which can increase the complexity of the surgery. The location of the displaced radial head fragments can be unpredictable, and they can be found distal to the radial neck, torn through the anterior capsule, and can even be underneath the triceps in the olecranon fossa. Preoperative knowledge of the fragment location facilitates intraoperative extraction.
A CT scan can be used to assess the proximal ulna fracture, particularly the size and pattern of the coronoid fragment. A careful analysis of sagittal and coronal cuts can assist the surgeon in determining how to direct the exposure to appropriately capture the anterior cortical fragment and the coronoid from the posterior approach. Understanding the extent of the radial head comminution can prepare the surgeon for the treatment options, generally between ORIF or radial head arthroplasty. Implants for both should be available because intraoperative findings can differ markedly from the preoperative predictions. Although not classically considered a part of the injury spectrum, subtle anterior ulnohumeral joint subluxation may be encountered with severe coronoid fragmentation, and the treating surgeon should remain aware of this possibility.
Initial management involves closed reduction maneuvers to obtain proper ulnar length because this aids in the reduction of the radiocapitellar joint. Monteggia fractures are inherently unstable, and we advise against multiple reduction attempts, which can increase patient discomfort and likely cause soft-tissue damage. A long arm posterior or spiral splint generally provides enough comfort and stability. Once closed reduction is complete, a repeat neurovascular examination should be performed. For closed injuries without concern for excessive forearm swelling and a stable neurovascular examination, patients can be discharged with urgent follow-up within a few days to schedule an elective surgery within 2 weeks. For severely comminuted fractures or if the radial head cannot be adequately reduced, we advocate admission and surgical fixation in a semiurgent fashion, although many patients request discharge if their pain is well controlled.
J Am Acad Orthop Surg. 2020;28(19):e839-e848. © 2020 American Academy of Orthopaedic Surgeons