Approach Considerations
Assess and document the neurologic and vascular status of the arm. Further evaluate the arm on the basis of the type of injury (see below).
Monteggia injuries were once treated nonoperatively in adults. However, surgical treatment of these injuries results in decreased pain, less restricted motion, decreased valgus, and less late neuropathy. [49, 50, 51, 52, 53] Once the ulna is fixed, often by means of operative compression plating, [54, 55] the radial head often self-reduces. If orthopedic or surgical care is not immediately available, the practitioner who provides initial treatment may splint the fracture and perform reduction as instructed below, with prompt referral to a specialist.
Although operative repair is recommended in adults, [56] a conservative approach is often used in children with Monteggia injuries. [42, 43, 57] Children may be treated with closed reduction of both bones and immobilization in a long arm cast. [58] It is important to consider the Monteggia-equivalent injury associated with plastic bowing of the ulna; the radial head might continue to redislocate with pronation after reduction. [30]
The key to reduction in children is to obtain normal length and alignment of the ulna, after which the radial head typically falls into place. When necessary, open reduction with internal fixation (ORIF) is performed. [59] Delayed recognition of these injuries in children can lead to more complex reconstructions and less predictable outcomes. [60]
Some advocate primary operative care in complete ulnar fractures because of the shortening and angulation that may occur without fixation. In general, surgical repair of ulnar fractures in children may involve relatively smaller plates and screws than those used in adults because of rapid osseous repair. In transverse and short oblique fractures, an intramedullary wire may be used.
Pearls
Be wary of other serious associated injuries, especially to the head and chest.
Carefully evaluate the bones and joints above and below the injury.
Always assess and document the neurologic and vascular status of the arm both before and after reduction.
Before discharging a patient with a forearm or elbow injury, always use the radiocapitellar line to check any misalignment of the radial head. [61] This is especially important in the case of an ulnar fracture.
Delayed treatment
Many radial head dislocations are missed on initial presentation and may not be diagnosed until years later. [62] Previously undiagnosed radial head dislocations are fixed operatively in adults and are usually fixed operatively in children. [63, 64, 65] After 3 years of dislocation, deformities develop in the radial head (dome-shape deformity) and the radial notch of the ulna. [66]
A retrospective review showed a high success rate with surgical management of chronic posttraumatic anterior dislocation of the radial head in children. [67]
The triceps tendon can be used to reconstruct the anular ligament through techniques described by Bell Tawse, [68, 69] Lloyd-Roberts, and Bucknill. [70] DeBoeck described a procedure without anular ligament reconstruction. [71]
In some cases, the nonreducible radial head may have to be excised. [72] Seel, Peterson, and Papandera have also described alternative reduction techniques.
Reduction of Monteggia Injury
Type I (anterior dislocation)
Closed reduction
Nonsurgical treatment may be considered in children. [73] The key to success is proper reduction of the ulnar fracture. Reestablish the proper length of the ulna, and correct any angulation. Once the ulna is reduced, the radial head is easily replaced. With the elbow flexed 115° to relax the biceps, provide longitudinal traction and fully supinate the arm while applying posterior manual pressure to the proximal radius anteriorly. Splint the arm in 90° flexion and supination, using three-point molding to counteract the forearm musculature.
Confirm reduction with radiographs. Repeat radiographs in 1 week to assess continued proper reduction. A long-arm cast may be used for 3 weeks, followed by 3 weeks in a short-arm cast.
Open reduction
Open reduction is indicated in cases of failure to maintain ulnar or radial anatomic position. Ulnar osteotomy with elongation and reduction of the angulation is performed along with open reduction of the radial head. [74]
Type II (posterior dislocation)
Closed reduction
Reduction is accomplished with longitudinal traction with the elbow in extension because the ulna is most stable with the arm extended. The radial head is reduced with pressure directed anteriorly onto the radial head. Once reduction has been accomplished, three-point cast molding is placed with the elbow in extension and pronation (70° of flexion).
This metaphyseal fracture heals quickly, and the cast can usually be removed in 3 weeks. However, immobilization must continue until union of the ulna occurs, which may take as long as 10 weeks in older patients. Flexion may return slowly.
Open reduction
Operative indications are the same as those for type I Monteggia injuries.
Type III (lateral dislocation)
Closed reduction
The incidence of posterior interosseous nerve injury is high with this lesion [75] ; however, such injury typically resolves spontaneously and rapidly. Reduction is accomplished by hyperextension and stabilization of the olecranon followed by a valgus force to the olecranon. This force corrects the greenstick fracture, and the radial head often spontaneously reduces. If necessary, direct medial pressure to the radial head facilitates reduction.
Controversy exists concerning the best type of immobilization for a type III injury. Some advocate splinting, as in type I Monteggia injuries (115° of flexion), and some recommend immobilization in a long arm cast in extension with valgus stress applied to the ulna. [76] The cast should be maintained for 4-6 weeks.
Open reduction
This type of injury is most commonly irreducible because of anular ligament interposition.
Type IV (fracture of both forearm bones)
Closed reduction
Nonoperative methods for this unstable fracture are difficult and often unsuccessful.
Open reduction
Unlike the other three types of Monteggia injury, type IV lesions usually necessitate initial surgical stabilization of the radius and ulna fractures. The elbow is immobilized in supination and hyperflexion (115°) in a long arm cast for 3 weeks. A short arm cast is applied for an additional 3-4 weeks.
Reduction of Isolated Radial Head Dislocation
Anterior
Supinate the arm, and flex the elbow to 115° to relax the biceps. An assistant holds the humerus distally for stabilization while the practitioner applies distal traction to the wrist and direct posterior pressure to the radial head. [77, 78, 79, 80, 81, 82] (See the video below.)
Posterior
The arm is held supinated in extension at the patient’s side, and the humerus is stabilized distally. [83] With care taken not to hyperextend the arm, distal traction is placed at the wrist, and anterior pressure is applied to the radial head. (See the video below.)
Lateral
As with the technique used in a posterior reduction, provide stabilization to the distal humerus and place distal traction at the wrist while applying medial pressure to the radial head. (See the video below.)
Failure to reduce
In some instances, the elbow is not reducible with closed reduction techniques, and operative repair is necessary. Possible reasons for this include delayed treatment, [84] presence of interposed tissues that impede reduction, "buttonholing" of the radial head through the joint capsule, and an extremely unstable elbow. [85] In rare cases, osteosynthesis or resection of the radial head may be necessary.
Reduction of Chronic Radial Head Dislocation
Chronic dislocation of the radial head is rare and often goes undiagnosed. These dislocations may be of either congenital or traumatic origin. [86] Although they might be initially asymptomatic, arthritic changes may restrict movement as time goes on. [87] Long-term dislocations often result in valgus deformity of the elbow, which may subsequently give rise to ulnar and interosseous nerve disturbance. [86] Furthermore, when the radial head is left dislocated for an extended period, anatomic changes begin to occur to the radial head and the radial notch of the ulna. [66]
Treatment of chronic radial head dislocation is controversial, ranging from neglect to ORIF. Three-dimensional (3D) computed tomography (CT) and 3D-printed bone models have proved useful in the approach to surgical correction. [40]
Closed reduction is based on the direction of dislocation, as outlined above.
Surgical intervention is recommended to restore function, relieve pain, and improve cosmetic appearance. [86] Open repair of the ulna is carried out if necessary. For the chronically dislocated radius, two surgical options are available: resect or preserve the radial head.
Advocates of radial head–sparing reconstructions have touted the advantages of fewer complications and substantial pain relief; however, improvement of range of motion (ROM) is limited, and additional surgery is needed 25% of the time. [86, 88] Radial head–sparing techniques include reconstruction and reattachment of the anular ligament and osteotomy of the radius or ulna. [89, 86, 90, 91]
Postprocedural Care
Once reduction is complete, reassess and document the neurologic and vascular status of the arm. Evaluate the elbow in its full ROM (varus, valgus, pronation, supination) and check for soft tissue, bony blocks, or other instability. Apply a posterior splint in 90° flexion, and supinate for isolated dislocations.
Obtain postreduction radiographs, and reevaluate the radiocapitellar line. If reduction is performed in the operating room, the stability of the radial head may be checked with fluoroscopy. Patients are generally admitted for 24 hours to observe for possible complications (eg, compartment syndrome).
The ROM exercises can be initiated when pain and swelling permit. Frequent radiographs should be taken to confirm that the elbow remains reduced during early rehabilitation. In isolated radial head dislocations, ROM is instituted within a few days, and the splint is generally discontinued after 1-2 weeks if the elbow is deemed stable. Unstable elbows require longer immobilization.
After such an injury, a loss of 5-10° of extension in comparison with the contralateral elbow can be expected; however, uncomplicated radial head dislocations have a favorable prognosis. [92]
Follow-up with an orthopedist is mandatory.
Complications
Complications include the following:
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Osteomyelitis - Carefully evaluate for signs of an open fracture and treat appropriately to avoid serious infection [93]
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Compartment syndrome - Elevated compartment pressures are not uncommon after serious forearm injuries; for this reason, hospital admission for observation is advocated
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Neurologic injury - Although this is uncommon, it may occur as a consequence of the injury or as a result of the reduction [94, 95] ; the posterior interosseous nerve is the most commonly injured nerve, with injury resulting in weakness of finger or thumb extension [96, 97, 98, 99, 100] ; sensory involvement is rare; postreduction neurapraxia is often a temporary problem that resolves spontaneously [101] ; paralysis that does not improve may necessitate further surgery; ulnar nerve compression may occur as result of the radial head dislocation [6]
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Chronic pain - Long-term disability and chronic pain can result from missed radial head dislocations, which occur in as many as 50% of cases
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Loss of motion - Reduced ability to pronate and supinate or flex and extend the elbow is common immediately after cast removal; if loss of motion is promptly treated, function usually returns completely within 3 months [103] ; stiffness may be avoided with early ROM exercises or surgical capsulectomies [104]
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Periarticular ossification - Periarticular ossification can occur in cases of chronic dislocations but tends to reabsorb after reduction; heterotopic ossification should be excised more than 6 months after injury or treated with indomethacin or radiation
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Posttraumatic proximal radioulnar synostosis - This complication occurs in a minority of injuries and may be treated with anti-inflammatory medications, radiation, or surgery [105, 106]
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Nonunion of fracture
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Osteochondritis dissecans - This can occur in chronic and recurrent dislocations and subluxtions of the radial head [107]
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Osteonecrosis [104]
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Landmarks on lateral elbow radiograph: radial head (R), ulna (U), capitellum (C), and humerus (H).
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Normal radiocapitellar line drawn down through middle of neck of radius should intersect capitellum.
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Abnormal radiocapitellar line due to dislocation of radial head. Line does not bisect capitellum. Apex of ulnar fracture points in direction of radial head dislocation (anteriorly, in this case).
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Isolated posterior radial head dislocation.
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Reduced isolated posterior radial head dislocation.
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Technique for reduction of anterior radial head dislocation.
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Technique for reduction of posterior radial head dislocation.
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Technique for reduction of lateral radial head dislocation.
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Swollen elbow from radial head dislocation.
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Elbow anatomy.
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Abnormal maximum ulnar bow is present when maximum perpendicular distance (red arrow) drawn from the dorsal ulnar border (dashed line) exceeds 1 mm.
Tables
Classification |
Incidence |
Description |
Type I |
60% |
Fracture of the proximal or middle third of the ulna with anterior angulation and anterior dislocation of the radial head |
Type II |
15% |
Fracture of the proximal or middle third of the ulna with posterior angulation and posterior dislocation of the radial head |
Type III |
20% |
Fracture of the ulnar metaphysis distal to the coronoid process with lateral dislocation of the radial head |
Type IV |
5% |
Fracture of the proximal or middle third of the ulna and fracture of the proximal third of the radius with anterior dislocation of the radial head |
