Monteggia Fracture 

Updated: Nov 13, 2018
Author: Floriano Putigna, DO, FAAEM; Chief Editor: Murali Poduval, MBBS, MS, DNB 

Overview

Background

The eponym Monteggia fracture is most precisely used to refer to a dislocation of the proximal radioulnar joint (PRUJ) in association with a forearm fracture, most commonly a fracture of the ulna. These injuries are relatively uncommon, accounting for fewer than 5% of all forearm fractures. The mechanism of injury is most often a fall on an outstretched hand.

The ulna fracture is usually clinically and radiographically apparent. Findings associated with the concomitant radial head dislocation are often subtle and can be overlooked. The keys to successful diagnosis of a Monteggia fracture are clinical suspicion and radiographs of the entire forearm and elbow. Properly assessing the nature of this injury in a timely fashion is imperative in order to prevent permanent disability or limb dysfunction.[1]

The first challenge is correctly assessing the extent and nature of the injury. The ulna fracture is usually noted, commonly in the proximal third of the ulna. The olecranon, midshaft, and distal shaft may be involved. In his classic 1943 text, Watson-Jones stated that "no fracture presents so many problems; no injury is beset with greater difficulty; no treatment is characterized by more general failure."[2]

Some injuries associated with radiocapitellar dislocation (such as the transolecranon fracture-dislocation of the elbow) are mislabeled as Monteggia lesions, when in fact the PRUJ remains intact. The Monteggia lesion is most precisely characterized as a forearm fracture in association with dislocation of the PRUJ.

The radial head dislocation may not be apparent and will possibly be missed if the elbow is not included in the radiograph. Whenever a fracture of a long bone is noted, the joints above and below should be evaluated with radiographs in orthogonal planes (planes at 90° angles to each other). If one of the forearm bones is injured, injury should be looked for in the other bone and in associated joints of the forearm, elbow, and wrist. This principle also applies to a Galeazzi fracture, which is a fracture of the distal radius with concomitant dislocation of the distal radioulnar joint (DRUJ).

Separate radiographs should be taken of the elbow. The radial head should point towards the capitellum on all radiographs of the elbow.

Unrecognized dislocations may result from reduction of the dislocated radius prior to presentation. This may occur in the field spontaneously or as a result of manipulation by emergency responders. The treating physician may reduce an unrecognized dislocation while reducing or immobilizing the ulna fracture.[3]

For patient education resources, see the Breaks, Fractures, and Dislocations Center, as well as Broken Arm, Broken Elbow, and Elbow Dislocation.

Anatomy

The annular and radial collateral ligaments stabilize the radial head. These ligaments stretch or rupture during radial head dislocation.[4] The radial head articulates with the humeral capitellum and the radial notch of the proximal ulna. The radius and ulna are closely invested by the interosseous membrane, which accounts for the increased risk of displacement or injury to the radius when the ulna fractures.

The distal ulna and radius also articulate at the DRUJ.[5] The ulna provides a stable platform for rotation of the radius and forearm. The ulna and interosseous membrane also may provide stable platforms for dislocation of the proximal radius, leading to the Monteggia fracture.

The posterior interosseous nerve travels around the neck of the radius and dives under the supinator as it courses into the forearm. The median and ulnar nerves enter the antecubital fossa just distal to the elbow. The close proximity of these nerves may lead to injuries when a Monteggia fracture occurs. Neural injuries are generally traction injuries and result from stretching around the displaced bone or from energy dispersed during the initial injury.

Pathophysiology

The forearm structures are intricately related, and any disruption to one of the bones affects the other. The ulna and radius are in direct contact with each other only at the PRUJ and the DRUJ; however, they are unified along their entire length by the interosseous membrane. This allows the radius to rotate around the ulna. When the ulna is fractured, energy is transmitted along the interosseous membrane, displacing the proximal radius. The end result is a disrupted interosseous membrane proximal to the fracture, a dislocated PRUJ, and a dislocated radiocapitellar joint.

Radial head dislocation may lead to radial nerve injury. The posterior interosseous branch of the radial nerve, which courses around the neck of the radius, is especially at risk, particularly in Bado type II injuries.[6] Injuries to the anterior interosseous branch of the median nerve and the ulnar nerve also have been reported. Most nerve injuries are neurapraxias and typically resolve over a period of 4-6 months. Splinting of the wrist in extension and finger range-of-motion (ROM) exercises help prevent contractures from developing while the patient awaits resolution of the nerve injury.

Classification

In 1814, Giovanni Battista Monteggia of Milan first described this injury as a fracture to the proximal third of the ulna with associated anterior dislocation of the radial head.[7]  Interestingly, he described this injury pattern in the pre-Roentgen era solely on the basis of the history of injury and the physical examination findings. However, this particular fracture pattern only accounts for about 60% of these types of injuries.

More than 150 years later, in 1967, Bado coined the term Monteggia lesion and classified the injury into the following four types[8] :

  • Type I - Fracture of the proximal or middle third of the ulna with anterior dislocation of the radial head (see the first and second images below)
  • Type II - Fracture of the proximal or middle third of the ulna with posterior dislocation of the radial head (see the third and fourth images below)
  • Type III - Fracture of the ulnar metaphysis with lateral dislocation of the radial head (see the fifth and sixth images below)
  • Type IV - Fracture of the proximal or middle third of the ulna and radius with anterior dislocation of the radial head (see the seventh image below)
Bado type I lesion. This is the most common type o Bado type I lesion. This is the most common type of Monteggia fracture.
Bado type I lesion. Bado type I lesion.
Bado type II lesion. Bado type II lesion.
Bado type II lesion after open reduction and inter Bado type II lesion after open reduction and internal fixation.
Bado type III lesion with lateral displacement of Bado type III lesion with lateral displacement of the radial head.
Bado type III lesion with lateral displacement of Bado type III lesion with lateral displacement of the radial head.
Bado type IV lesion. Bado type IV lesion.

The Bado classification is based on the recognition that the apex of the fracture is in the same direction as the radial head dislocation.

Etiology

Monteggia fractures are primarily associated with falls on an outstretched hand with forced pronation. If the elbow is flexed, the chance of a type II or III lesion is greater. In some cases, a direct blow to the forearm can produce similar injuries.

Evans in 1949[9] and Penrose in 1951[10] studied the etiology of Monteggia fractures on cadavers by stabilizing the humerus in a vise and subjecting different forces to the forearm. Penrose considered type II lesions a variation of posterior elbow dislocation. Bado believed that the type III lesion, the result of a direct lateral force on the elbow, was primarily observed in children.

In essence, high-energy trauma (eg, a motor vehicle collision) and low-energy trauma (eg, a fall from a standing position) can result in the described injuries. A high index of suspicion, therefore, should be maintained with any ulna fracture.

Epidemiology

Monteggia fractures account for fewer than 5% of forearm fractures, with published literature supporting figures in the range of 1-2%.[11, 12] Of the Monteggia fractures, Bado type I is the most common (59%), followed by type III (26%), type II (5%), and type IV (1%). Monteggia fractures are one third as common as the more familiar Galeazzi fractures.

Prognosis

In 1991, Anderson and Meyer used the following criteria to evaluate forearm fractures and their prognosis[13] :

  • 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 in 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.[14]

In a retrospective study on the functional and radiologic long-term outcome of open reduction and internal fixation (ORIF) in 11 skeletally mature patients with Bado type 1 Monteggia fractures, Guitton et al found that the mean arc of elbow flexion increased from 110º at early follow-up to 120º at late follow-up.[5]  The mean arc of forearm rotation increased from 145º to 149º. The mean Broberg and Morrey score increased from 89 points to 94 points, and the median Disabilities of the Arm, Shoulder, and Hand (DASH) score was 7 points at long-term follow-up.

In a study evaluating long-term clinical and radiographic outcomes after open reduction for missed Monteggia fracture-dislocations in 22 children (14 boys, 8 girls; age range, 4 years to 15 years 11 months), Nakamura et al noted that the postoperative Mayo Elbow Performance Index (MEPI) at follow-up ranged from 65 to 100, with 19 excellent results, two good results, one fair result, and zero poor results.[14]

In 17 of the 22 patients, the radial head remained in a completely reduced position, and it was subluxated in five patients.[14]  Osteoarthritic changes were seen at the radiohumeral joint in four patients. Radiographically, there were 15 good results, seven fair results, and zero poor results. A good radiographic result was seen in all patients who underwent open reduction within 3 years after injury or before reaching 12 years of age.

Datta et al conducted a prospective, longitudinal study of 21 children with Monteggia fracture with dislocation (18 type I, three type III), all of whom were treated by modified Hirayama corrective osteotomy of the ulna with wedge bone grafting, restoration of bone length, reconstruction of the annular ligament using the Bell Tawse method, and fixation of the radial head with transcapitellar Kirschner wire (K-wire).[15]  The average follow-up period was 5.5 years.

The investigators evaluated outcomes on the basis of the 100-point MEPI, radiology, and questionnaire.[15]  The mean postoperative increase in MEPI score was 30. ROM increased by an average of 30º. Subluxation of the radial head occurred in three patients; one patient experienced transient palsy of the posterior interosseous nerve; and distortion of the radial head (which had no bearing on function) occurred in three.

 

Presentation

History

Following the mechanism previously described (see Pathophysiology), patients present with elbow pain. Depending on the type of fracture and severity, they may experience elbow swelling, deformity, crepitus, and paresthesia or numbness. Some patients may not have severe pain at rest, but elbow flexion and forearm rotation are limited and painful.

Physical Examination

The dislocated radial head may be palpable in the anterior, posterior, or anterolateral position. In Bado type I and IV lesions, the radial head can be palpated in the antecubital fossa. The radial head can be palpated posteriorly in type II lesions and laterally in type III lesions.

The skin should be closely inspected to ensure that an open fracture is not present. Pulses and capillary refill should be documented. A negligible hematoma may be present at the site if no direct trauma is associated.

Motor function must be thoroughly tested because the branches of the radial nerve can become entrapped, causing weakness or paralysis of finger or thumb extension. The sensory branch is not usually involved but also should be checked. Bado indicated that spontaneous recovery is the usual course, and exploration is appropriate if function does not begin to return within 2-3 months.

Monteggia fractures in the pediatric population typically manifest with unique features that have led to a decreased emphasis on the direction of the radial head dislocation and an increased focus on the character of the fracture of the ulna. When the various fracture types occur in the immature bone of children, distinct patterns result and influence treatment considerations.

Monteggia fractures in children may be categorized according to the type of ulnar injury, as follows:

  • Plastic deformation
  • Incomplete (greenstick or buckle) fracture
  • Complete transverse or short oblique fracture
  • Comminuted or long oblique fracture

Plastic deformation of the ulna in association with anterior radial head dislocation represents up to 31% of anterior Monteggia lesions. Poor recognition of this injury pattern can lead to recurrent or persistent dislocation because the radial head reduction remains unstable until the plastic deformity is corrected. Incomplete fractures of the ulna and greenstick fractures represent other variants that must be corrected along with the radial head dislocation.

 

Workup

Laboratory Studies

Laboratory studies may be obtained as indicated by the patient's medical history, to assist with anesthesia and perioperative management.

Imaging Studies

Plain radiography is indicated. Views of the forearm in orthogonal planes (planes at 90° to each other) are needed with the wrist and elbow joints included. The evaluating physician should also obtain separate radiographs of the elbow to assess the proximal radioulnar joint (PRUJ), the ulnohumeral articulation, and the radiocapitellar joint.

On radiographs, the ulna fracture is usually obvious, but the findings associated with the radial head dislocation may be subtle and overlooked. In order to assess the radiocapitellar joint, a line should be drawn parallel to the long axis of the radius. This line should point directly at the capitellum on any projection of the elbow. The radial head dislocation almost always points in the same direction as the apex of the ulna fracture. In children, recognizing a plastic deformation of the ulna, which may also lead to radial head dislocation, is important.

 

Treatment

Approach Considerations

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 (IV) 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 (ED) if possible.

Pediatric patients should undergo emergency closed reduction and splint application. Closed reduction in children is easiest when performed with procedural sedation or general anesthesia. Ketamine 1-2 mg/kg IV or 3-4 mg/kg intramuscularly (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, for the following reasons[16] :

  • The majority of the fractures are inherently stable
  • Children require a shorter time for both the osseous and the ligamentous injuries to heal
  • Children have little trouble regaining motion lost through stiffness, despite immobilization of the fractures for the duration of the initial healing period (3-6 weeks)
  • The potential may exist for remodeling of mild residual angular deformities (< 10°)

Indications for treatment of Monteggia fractures are based on the specific fracture pattern and the age of the patient (ie, pediatric or adult).[17, 18]  Although most pediatric fracture patterns can be managed conservatively with closed reduction and long arm casting, most adult fractures require open reduction and internal fixation (ORIF). Few contraindications for surgery exist. Once the radial head is reduced in closed injuries, surgical treatment may be delayed until the patient is stable and the surgery may be performed in a more elective fashion.

Closed reduction of the radial head dislocation under sedation should be performed on an emergency basis within 6-8 hours of the injury. This is usually achieved with supination of the forearm, but it may require traction and direct pressure on the radial head. If closed reduction is unsuccessful, the patient should be taken to the operating room (OR) within this same time frame for open reduction. Delay in reduction of the radius may lead to permanent articular damage, further nerve injury, or both.

The stability of the reduction depends on the fracture pattern. Greenstick fractures have plastic deformation that may resist maintenance of reduction and necessitate completion of the fracture to keep the radial head reduced. However, completing the fracture may make it more difficult to maintain rotational alignment of the ulna. This difficulty can be alleviated with appropriate reduction techniques. Greenstick proximal ulna fractures require appropriate reduction using supination in addition to flexion and extension maneuvers.[19]   

An open fracture requires immediate operative intervention. In closed injuries, once the radial head is reduced, the forearm is splinted, and operative fixation of the ulna fracture may then be carried out electively. Whereas adults usually require operative internal fixation to stabilize the ulna and prevent further displacement forces on the radiocapitellar joint, children with closed Monteggia fractures are generally treated in a closed fashion. A posterior long arm splint with the elbow in 90° of flexion and full supination is the immobilization method of choice for types I, III, and IV. Type II injuries (posterior lesions) are best splinted in 70° elbow flexion with supination.

If the wound is open and heavily contaminated, serial debridement may be indicated before plate fixation. In medically unstable patients, emergency treatment of the open wound is still necessary. The procedure can be limited to irrigation and debridement of the open wound and closed reduction at the bedside, performed with regional anesthesia or, if absolutely necessary, with local anesthesia and sedation. If the patient is unable to tolerate operative treatment, the fracture-dislocation may be treated with cast immobilization after reduction of the radius and irrigation and debridement if the fracture is open.

Future research will help identify appropriate treatment protocols for achieving optimum long-term outcomes. The most important step is to educate the specialist, emergency physician, and primary care physician regarding correct diagnosis and treatment of these injuries.

Surgical Therapy

Open fractures require emergency 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 before radial head reduction. Unless the fracture is open, surgical treatment is performed on an elective basis. Whereas most adults require operative treatment, most pediatric fractures are treated with closed reduction.

Operative fixation of complete fractures of the ulna with proximal radioulnar joint (PRUJ) 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; consequently, they 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 (two or three holes [four or six cortices] proximal and distal to the fracture) than those recommended for adults are usually adequate.

Operative details

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 ED or in the OR. 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 three or four screws (six or eight cortices) proximal and distal to the fracture.

Once the ulna is stabilized, the stability of the radial head is assessed by means of 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 cannot be reduced, 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.

If the radial head remains unstable despite confirming anatomic reduction of the ulna surgical repair of the annular ligament and lateral ligaments should be considered.  Chronic radial head dislocation may require surgical reconstruction of the annular ligament.[20]

Postoperative Care

Follow-up appointments are scheduled for wound checks and suture removal according to 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 (ROM) exercises under the close supervision of a qualified physical therapist.

Patients with stable injuries may be placed in ROM 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.

Complications

Complications can be divided into two broad categories: acute and chronic. Acute complications include the following:

  • Bleeding
  • Nerve damage
  • Swelling
  • Compartment syndrome
  • Loss of initial reduction
  • Failure to diagnose the correct pathology

Chronic complications include the following:

  • Malunion
  • Nonunion
  • Radioulnar synostosis
  • Elbow stiffness
  • Myositis ossificans
  • Infection
  • 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 of the radial and median nerves, and function usually returns within 1-6 months. Baseline electrodiagnostic studies are obtained early. If nerve function does not return within 2-3 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.

Li et al conducted a study of the pathology of posterior interosseous nerve injury associated with Monteggia fracture-dislocation in children.[21] For all eight patients, closed reduction was attempted before exploration of the posterior interosseous nerve. The nerve was found to be trapped acutely posterior to the radiocapitellar joint in four of five patients with Bado type III Monteggia fractures. In the remaining patients, chronic compressive changes and epineural fibrosis of radial nerve were observed, related to the time between injury and operation.

After microsurgical neurolysis, complete recovery of nerve function was obtained for all eight patients.[21] The authors concluded that immediate surgical exploration of the posterior interosseous nerve should be performed for all children with Bado type III Monteggia fracture-dislocation in whom there is decreased or absent function of muscles innervated by the posterior interosseous nerve in the presence of an irreducible radial head.

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. Treatment of chronic radial head dislocation in children with Monteggia fracture has been controversial, but some suggest that surgical treatment may be warranted.[22, 23]

In the case of nonunion or malunion, bone grafting and revision internal fixation may be considered.

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.

Long-Term Monitoring

The patient should be evaluated at 5-7 days. If nonsurgical management has been employed, consideration should be given to leaving the splint or cast on and overwrapping to avoid loss of reduction by removing the immobilization. Follow-up radiography at 2, 4, and 6 weeks and then every 3 months thereafter is recommended to monitor healing and union of the fracture.

The average duration of casting is 6 weeks for pediatric patients and 8-12 weeks for adults. A posterior long arm cast in 90-110° flexion and supination should be used to maintain reduction based on fracture type. If surgery was performed, a wound check is necessary, with suture removal 5-7 days after the operative procedure. Surgical repair should allow for a shorter period of cast immobilization and early ROM in a brace, beginning 2-4 weeks after the procedure.

In pediatric patients, hardware removal commonly takes place 6-12 months after healing to prevent growth disturbance. In adults, hardware removal is optional; it may be considered in cases of pain, infection, or malunion/nonunion. For this reason, these patients should be followed for at least 1 year.[24]