Monteggia Fracture Treatment & Management

Pain should be managed as needed in the immediate period. If the fracture is open, the status of the patient's tetanus immunization should be determined and addressed as indicated. Intravenous antibiotics should be administered to patients with open fractures. Open wounds should be irrigated with sterile saline solution and dressed with sterile, moist gauze. The radial head should be reduced in the emergency department if possible. Pediatric patients should undergo closed reduction and splint application emergently. Closed reduction in children is easiest when performed under procedural sedation or general anesthesia. Ketamine 1-2 mg/kg IV or 3-4 mg/kg IM is a very useful drug for sedation. An image intensifier should be available with real-time and static images to verify anatomic reduction of the fracture and congruent relationship of the radiohumeroulnar joint. The position of the elbow when immobilized depends on the fracture pattern as described earlier.

Nonoperative treatment is successful for most Monteggia injuries in children because (1) the majority of the fractures are inherently stable, (2) they require a shorter time for both the osseous and the ligamentous injuries to heal, (3) children have little trouble regaining motion lost through stiffness, despite immobilization of the fractures for the duration of the initial healing period (3-6 wk), and (4) the potential may exist for remodeling of mild, residual angular deformities (< 10°).

Open fractures require emergent surgical consultation. The initial treating physician may reduce the radial head dislocation and splint this fracture. Otherwise, an orthopedic surgeon should be consulted immediately to reduce the radial head. Anatomic reduction of the ulna is usually required prior to radial head reduction. Unless the fracture is open, surgical treatment is performed on an elective basis. While most adults require operative treatment, most pediatric fractures are treated closed.

Operative fixation of complete fractures of the ulna with proximal radioulnar joint dislocation is recommended in children. The complete disruption of bone continuity is likely to be associated with substantial soft-tissue trauma in these injuries. Shortening and angulation of complete fractures after cast immobilization is not uncommon. Anatomic reduction of the ulnar fracture and radial head often requires operative treatment. In the past, transverse and short oblique fractures were adequately treated with intramedullary wire fixation. Intramedullary wires, however, cannot be relied on to maintain reduction of complete fractures that are either long oblique in pattern or comminuted; the wires therefore are not used anymore. These fractures are likely to displace or even shorten and, consequently, should be fixed with a plate and screws.

As a result of the rapidity of osseous repair and the tolerance of cast immobilization in children, the use of plate-and-screw constructs that are smaller (typically a one-third tubular or semitubular plate) and shorter (2 or 3 holes [4 or 6 cortices] proximal and distal to the fracture) than those recommended for adults are usually adequate.

Patients with fracture-dislocations of the forearm should initially be stabilized if more serious injuries are present. Adequate pain control should be provided in the preoperative period, and the affected arm should be placed in a long arm splint to reduce further injury and pain.

After adequate analgesia and sedation, a closed reduction of the radial head can be performed with distal traction and direct pressure over the radial head. This can be done in the emergency department or in the operating room. An open technique should be considered if the radius is fractured or irreducible.

Once the radius has been reduced, the ulnar fracture is addressed with rigid internal fixation. In adult Monteggia fracture, fixation with a 3.5-mm dynamic compression (DC) plate or a limited contact – dynamic compression (LC-DC) plate is recommended. If the fracture is comminuted, purchase should be obtained, if possible, with 3-4 screws or 6-8 cortices proximal and distal to the fracture.

Once the ulna is stabilized, the stability of the radial head is assessed using intraoperative fluoroscopy. Permanent radiographs should be taken, and a posterior long arm splint should be placed with the elbow immobilized in 90° of flexion and full supination for types I, III, and IV. Type II is best splinted in the same manner, but in 70° flexion at the elbow to prevent radial head subluxation. If the radial head is unable to reduce, the reduction and alignment of the ulna should be checked. If the radial head is unstable after ulnar fixation, then the elbow should be splinted in supination, which is the position of stability.

Follow-up appointments are scheduled for wound checks and suture removal based on the nature of the soft-tissue injury and operative treatment. If rigid fixation is achieved and the radiocapitellar joint remains stable, the patient is referred to begin range-of-motion exercises under the close supervision of a qualified physical therapist.

Patients with stable injuries may be placed in range-of-motion braces for 6-8 weeks. Unstable injuries should remain in cast immobilization until stability is achieved at 4-6 weeks.

Significant concern exists regarding loss of elbow motion with prolonged immobilization. Chronic radiocapitellar instability is unusual and may be addressed surgically.

The patient should be evaluated with the dressing and splint changed at 5-7 days. A posterior long arm cast in 90° flexion should be placed at that time. Follow-up radiography at 2, 4, and 6 weeks is recommended to monitor healing and union of the fracture. After this point, if the patient is reliable and stability is present, the above-described therapy can be continued.

If the hardware is causing significant problems, the provider may consider removing it. However, unless infection is present, waiting at least 1 year is recommended.

Complications include infection, bleeding, malunion, nonunion, nerve injury, redislocation of the radial head, radioulnar synostosis, and chronic pain.

Many of the complications listed are significantly reduced with timely diagnosis, adequate reduction, stable surgical fixation, and appropriate postoperative care.

Most nerve injuries are neurapraxias, and function usually returns within 1 to 6 months. Baseline electrodiagnostic studies are obtained early. If nerve function does not return within 2 to 3 months, surgical exploration may be indicated. If the nerve injury results from reduction or operative treatment, it should be addressed immediately. Prolonged or complete nerve dysfunction requires early splinting and therapy and may result in the need for tendon transfers.

If the radial head dislocates after surgery, improper ulnar reduction must be considered. If this is the case, the hardware should be removed and a proper reduction of the ulna should take place. If dislocation of the radial head is recognized more than 6 weeks after the surgery, a radial head excision should be performed.

A nonunion or malunion complication can be considered for bone grafting.

Chronic pain may be the result of hardware or improper reduction. If all mechanical causes have been excluded, consulting a pain management specialist should be considered.

In 1991, Anderson and Meyer used criteria to evaluate forearm fractures and their prognosis, as follows^[12] :

• Excellent - Union with less than 10° loss of elbow and wrist flexion/extension and less than 25% loss of forearm rotation
• Satisfactory - Union with less than 20° loss of elbow and wrist flexion/extension and less than 50% loss of forearm rotation
• Unsatisfactory - Union with greater than 30° loss of elbow and wrist flexion/extension and greater than 50% loss of forearm rotation
• Failure - Malunion, nonunion, or chronic osteomyelitis

Pain, nerve dysfunction, and cosmetic deformity are other factors to consider when evaluating the outcome of treatment in Monteggia fracture-dislocations. Type II lesions that are associated with ulnohumeral dislocation have been noted to have outcome scores with greater disability than those without ulnohumeral dislocation.^[4]

Future research will help to identify appropriate treatment protocols to achieve optimum long-term outcome. The most important step is to educate the specialist, emergency physician, and primary care physician to correctly diagnose and treat these injuries.