Pediatric Annals

Fractures of the Elbow in Children

William Zink, MD

Abstract

Few childhood injuries are seen with more frequency than those involving the elbow, and none is more troublesome for the average practitioner. These injuries are often difficult to diagnose, and subtle findings must be appreciated to avoid misdiagnosis and serious complications. Diagnosis is especially difficult in young children because of the radiolucent cartilage and the numerous ossification centers (Figure 1 A-F). The importance of a radiograph of the normal elbow or an oblique film cannot be overemphasized as an aid in diagnosis. If the elbow is immobilized in full flexion for more than three weeks, the chance of stiffness is greater.

Here we will review the literature and relate our experience at LSU-affiliated hospitals in dealing with elbow injuries in children and young adults. Our discussion will include: fractures of the distal humerus, fractures of the proximal radius and ulna, dislocations about the elbow, and complications of elbow injuries. These categories may be broken down in the following manner:

1. Fractures of the distal humerus

Supracondylar

Lateral condylar

Medial condylar

Lateral epicondylar

Medial epicondylar

2. Fractures of the proximal radius and ulna

Radial neck fracture

Olecranon fractures

Monteggia fractures

3. Dislocations

Radial head dislocation

Subluxation of the elbow

Elbow dislocation

4. Complications of elbow injuries

Loss of motion

Myositis ossificans

Nerve injury

Vascular injury

FRACTURES OF THE DISTAL HUMERUS

Supracondylar Fractures

In children, the most frequent elbow injury requiring hospitalization is supracondylar fractures of the humerus, which accounted for 67% of such hospital admissions at the LSU-affiliated hospitals and 60% of all elbow injuries in children as reported by Blount, ' The average age of our patients having supracondylar fractures was seven years. In our series, the ratio of left- over right-extremity injury was 2: 1, and the ratio of male to female patients was also 2:1.

Classically, there are two groups of supracondylar fractures- hyperextension and flexion. The most common (95 to 99% of all supracondylar fractures1"3) is the hyperextension type of fracture caused by an indirect hyperextension force to the elbow, generated by a fall onto an outstretched hand. To produce a supracondylar fracture experimentally, one would have to hyperextend the elbow to nearly 90°. With the colateral ligaments, the olecranon forms a fulcrum at the supracondylar region, preventing dislocation. The fracture is transverse, which is typical of an angulatory deformity rather than a rotatory one. The hyperextension group can be further subdivided into posterolateral and posteromedial supracondylar fractures. The vast majority are posteromedial, with a medial periosteal hinge being left on the medial side of the elbow. To produce such a fracture experimentally, one would, in addition to forcing the elbow fracture in hyperextension, have a rotatory force that will cause a rent in the periosteum at this level. Usually only about one third of the periosteum is torn and the rest can be used as a periosteal hinge in closed-reduction techniques.

1. Blouni WP: Fractures in Children · Injury About the Elbow. Baltimore, Williams and Wilkins. 1955, pp 26-75.

2. Cameron SM: The aetiology and prevention of cubitus varus from supracondylar fractures in children. J Bone Joint Surg 57B:255, 1975.

3. Fowles JV, Kassab MT: Displaced supracondylar fracture of the elbow in children. J Bone Joint Surg 56-B:490-500. 1974.

4. Griffin PP: Fractures in children, part 1. Instructional Course Lectures. The American Academy of Orthopaedic Surgeons. 1970, Vol 19, pp 150-159.

5. Baumann E: Knochenbruche am Ellbogengelenk. Beiir klin Chir 146:48, 1929.

6. Baumann E: Spezielle Frakturen am Luxai ionslehre Thieme, Stuttgart. Ellbogen. 1965, Vol ?/ 1. ? 13.

7. Keon-Cohen BT: Fractures at the elbow. J Bone Joint Surg 48-?:?6231639. 1966.

8. Flynn JC. Mathews…

Few childhood injuries are seen with more frequency than those involving the elbow, and none is more troublesome for the average practitioner. These injuries are often difficult to diagnose, and subtle findings must be appreciated to avoid misdiagnosis and serious complications. Diagnosis is especially difficult in young children because of the radiolucent cartilage and the numerous ossification centers (Figure 1 A-F). The importance of a radiograph of the normal elbow or an oblique film cannot be overemphasized as an aid in diagnosis. If the elbow is immobilized in full flexion for more than three weeks, the chance of stiffness is greater.

Here we will review the literature and relate our experience at LSU-affiliated hospitals in dealing with elbow injuries in children and young adults. Our discussion will include: fractures of the distal humerus, fractures of the proximal radius and ulna, dislocations about the elbow, and complications of elbow injuries. These categories may be broken down in the following manner:

1. Fractures of the distal humerus

Supracondylar

Lateral condylar

Medial condylar

Lateral epicondylar

Medial epicondylar

2. Fractures of the proximal radius and ulna

Radial neck fracture

Olecranon fractures

Monteggia fractures

3. Dislocations

Radial head dislocation

Subluxation of the elbow

Elbow dislocation

4. Complications of elbow injuries

Loss of motion

Myositis ossificans

Nerve injury

Vascular injury

FRACTURES OF THE DISTAL HUMERUS

Supracondylar Fractures

In children, the most frequent elbow injury requiring hospitalization is supracondylar fractures of the humerus, which accounted for 67% of such hospital admissions at the LSU-affiliated hospitals and 60% of all elbow injuries in children as reported by Blount, ' The average age of our patients having supracondylar fractures was seven years. In our series, the ratio of left- over right-extremity injury was 2: 1, and the ratio of male to female patients was also 2:1.

Classically, there are two groups of supracondylar fractures- hyperextension and flexion. The most common (95 to 99% of all supracondylar fractures1"3) is the hyperextension type of fracture caused by an indirect hyperextension force to the elbow, generated by a fall onto an outstretched hand. To produce a supracondylar fracture experimentally, one would have to hyperextend the elbow to nearly 90°. With the colateral ligaments, the olecranon forms a fulcrum at the supracondylar region, preventing dislocation. The fracture is transverse, which is typical of an angulatory deformity rather than a rotatory one. The hyperextension group can be further subdivided into posterolateral and posteromedial supracondylar fractures. The vast majority are posteromedial, with a medial periosteal hinge being left on the medial side of the elbow. To produce such a fracture experimentally, one would, in addition to forcing the elbow fracture in hyperextension, have a rotatory force that will cause a rent in the periosteum at this level. Usually only about one third of the periosteum is torn and the rest can be used as a periosteal hinge in closed-reduction techniques.

Figure 1.(A) A fracture separation of the distal humeral epiphysis of a three-month-old infant who fell out of his crib. Involved right elbow (on left); uninvolved left elbow (on right). (B) Close-up showing the improper relationship of the radius and ulna with the humerus. Anteroposterior (C) view.

Figure 1.(A) A fracture separation of the distal humeral epiphysis of a three-month-old infant who fell out of his crib. Involved right elbow (on left); uninvolved left elbow (on right). (B) Close-up showing the improper relationship of the radius and ulna with the humerus. Anteroposterior (C) view.

The flexion type of supracondylar fracture, which is sustained as a result of a direct force applied to the posterior and distal surfaces of the humerus, is seen only rarely.4

To understand the mechanism of the supracondylar fracture, one must be thoroughly familiar with the anatomy of the distal aspect of the humerus. The fracture occurs in a thin, flat area of the humerus at the point in which the olecranon impinges. The two parts of the fracture can be likened to a see-saw. If the thin, flat surface is not accurately reduced, it can tilt under compression and result in an angulatory deformity in the frontal plane producing cubitus varus. The best means of determining whether reduction is accurate is to evaluate Baumann's angle (Figure 2). A constant relationship exists between the angle formed by the humerus and the lateral condylar growth plate, and the carrying angle. A child with a Baumann's angle of 75° will have a carrying angle of I0° valgus. Correspondingly, a Baumann's angle of 100° is equivalent to a cubitus varus of 20°. A simple formula5'6 for arriving at this conclusion is: 90° - Baumann's angle = carrying angle+5°.

The fracture should be treated promptly after a careful examination so that if any neurovascular changes occur during the course of the treatment, they will be recognized. Reduction should be a single, accurate manipulation, not repeated.1 Many different qualified orthopedists have espoused a variety of techniques, including, among the more popular procedures, percutaneous pinning,8"11 Dunlop's skin traction,4'12 Dunlop's pin traction, overhead pin traction,13"15 open reduction,16'17 closed reduction, collar and cuff reduction and plaster casts.1'7

Closed Reduction and Collar and Cuff or Cast - If patients and their parents are reliable, then closed reduction, followed by collar and cuff or a long arm cast, with use of the periosteal hinge to hold the reduced fracture, is certainly acceptable treatment. In the case of an extension type of supracondylar fracture, the fracture can be held reduced in flexion by means of the posterior periosteal hinge. If the fracture is a posteromedial displaced one, then a medial periosteal hinge with flexion in pronation will lock the fracture fragments in place.18 The rare posterolateral displaced supracondylar fracture with a lateral periosteal hinge is held in place with supination. The flexion type of supracondylar fracture is usually a green stick and is simply reduced with longitudinal traction. It does not need immobilization in extension, and can be maintained by means of a posterior splint with the elbow at 90° of flexion.19

The method of reduction for the common extension type of supracondylar fracture is fairly standard. After the child is anesthetized, his elbow is fully extended with traction on the wrist and with the forearm in supination; the assistant controls the rotation of the proximal fragment.7 The medial and lateral displacement of this fragment can be corrected by slightly hyperextending the fracture site and manipulating the distal fragment. After this part of the deformity has been corrected, the posterior displacement is corrected while, simultaneously, the elbow is flexed to allow the periosteal hinge to lock the fragments in place. After reduction of the fracture, the elbow must be immobilized in at least 90° of flexion for the periosteal hinge to be effective. The immobilization can be accomplished by a collar and cuff, posterior splint, or cast. The dangers of this type of treatment are primarily neurovascular. Often, acute flexion of the elbow results in a loss of circulation to the hand and concern for Volkman's ischemic contracture. The neurovascular status must be carefully evaluated before, during, and after reduction. If there is any question of neurovascular compromise, then the treatment should be changed to another technique. This technique is a difficult one to use in a county indigent hospital setting because of the poor patient compliance and concern for observing subtle changes. The danger of a resultant Volkman's ischemic contracture is high.

Figure 1. Lateral (D) view. Arthrography of the elbow confirmed the epiphyseal separation. Anteroposterior (E) and lateral (F) roentgenograms at six weeks postinjury, with healing.

Figure 1. Lateral (D) view. Arthrography of the elbow confirmed the epiphyseal separation. Anteroposterior (E) and lateral (F) roentgenograms at six weeks postinjury, with healing.

Because of this concern for neurovascular complications, other techniques to decrease these complications have become popular in the United States. They include percutaneous wire fixation of the fracture, side arm or Dunlop's traction, and overhead pin traction.

Percutaneous Kirschman-wire (K-wire) Fixation - Percutaneous K-wire fixation can be technically difficult and demanding without power equipment, and a good technique of getting the pins across the fracture site. The technique that works best for us is to have a K-wire drilled through a large-bore needle to prevent sliding of the K-wire after reduction of the fracture. The fracture must be accurately reduced before the K-wires are put across the fracture site; if the fracture is not accurately reduced, you will pin the fracture in a malunited position.

Dunlop's Traction - Dunlop's traction is mentioned only as a technique that is not recommended by the authors. Although it is easy to apply and enables an easy access to taking anteroposterior radiographs of the elbow, the disadvantages far outweigh the advantages. We have shown in a previous study that Dunlop's traction places the forearm in a supinated position, a position in which the supracondylar fracture is unstable, with more likelihood of rotation and tilting of the fracture fragments.13 The supinated forearm position of Dunlop's traction leads to high instance of cubitus varus deformity (35% in the cases that we have evaluated). Dunlop's traction also requires an extensive apparatus that extends over the side of the bed and makes the elbow vulnerable to repeated injury from visitors in the room. It also is barely elevated and does not decrease edema of the elbow. The vertical sling on the anterior portion often slides in the elbow crease, thus creating pressure areas and, as we have observed, skin sloughs from the traction.

Overhead Pin Traction - Overhead pin traction is our preferred method of treatment of supracondylar fractures, especially in a county indigent hospital setting (Figure 3). In a resident-training situation, more consistent good results are obtained from this technique than from any other. The technique is especially valuable for treating difficult forearm fractures in which other methods of treatment have failed. With overhead pin traction, the joint position of acute flexion is unnecessary and therefore the risk of vascular impairment is greatly decreased. There are no constricting dressing or bandages around the patient, and the elevation allows for rapid decrease in swelling around the elbow. It also allows for early active elbow motion.

The problem with overhead pin traction is the prevailing misconception that simply putting a pin through the olecranon and hanging the arm overhead automatically produces reduction. That assumption is not true; if reduction is incomplete, the position will be lost no matter what technique you use to maintain reduction. The fact that must be remembered is that rotation of the distal fracture in relation to the proximal fracture plays an important part in subsequent cubitus varus deformity. The advantage of an olecranon pin is that even when rotational displacement persists, the overhead pin traction will prevent tilting and subsequent cubitus varus deformity.

Open Reduction - In our experience, open reduction and internal fixation of supracondylar fractures of the elbow have led to loss of motion at the elbow. The technique is, however, indicated in two instances - for the patient who has a vascular problem or one whose supracondylar fracture cannot be reduced because of an unrecognized "T" type fracture into the joint.20 When a T-type fracture is a part of this deformity, olecranon pin traction causes further displacement of the fracture and prevents reduction (Figure 4 A-C).

Figure 2. Baumann's angle, that angle subtended between the axis of the humerus and the capitellum (lateral condylar) growth plates (A). In a supracondylar fracture with a posterior medial tilt, this angle may approach 90° or higher (B).

Figure 2. Baumann's angle, that angle subtended between the axis of the humerus and the capitellum (lateral condylar) growth plates (A). In a supracondylar fracture with a posterior medial tilt, this angle may approach 90° or higher (B).

Figure 3. (A) Anteroposterior and lateral roentgenograms of the elbow of an eight-year-old boy who fell from a tree and sustained a hyperextension-type supracondylar fracture of the distal humerus. He was treated in overhead pin traction for two weeks before casting. (B) Anteroposterior and lateral roentgenograms at six weeks postinjury, showing normal carrying angle and bony healing.

Figure 3. (A) Anteroposterior and lateral roentgenograms of the elbow of an eight-year-old boy who fell from a tree and sustained a hyperextension-type supracondylar fracture of the distal humerus. He was treated in overhead pin traction for two weeks before casting. (B) Anteroposterior and lateral roentgenograms at six weeks postinjury, showing normal carrying angle and bony healing.

Regardless of the type of fracture and the treatment method used, any child with a supracondylar fracture requiring reduction should be admitted to the hospital for at least a 24-hour period to allow assessment of the neurovascular status of the extremity. Immobilization should be continued from three to six weeks, and the child should be allowed to regain elbow motion without the benefit of physical therapy. All too often, passive range of motion by the physical therapist leads to loss of motion in the elbow.

Lateral Condylar Fractures

Lateral condylar fractures are second only to supracondylar fractures in frequency (7.5% of all elbow fractures in children admitted to LSU-affiliated hospitals and 1 8.5% of those reported by Blount).1 The mechanism of injury has never been completely understood, although it is clearly indirect stress.' It is usually caused by a fall on an outstretched hand with the elbow extended. The stress producing the fracture is thought by some to be valgus1'19 and by others to be varus.7'14'21 A varus force applied to the elbow causes an avulsion force by way of the lateral collateral ligaments and an upward compressive force via the ulna and radial head. The trochlear ridge on the ulna behaves as a fulcrum for avulsion of the lateral condyle by the lateral ligament. Such fractures are notoriously difficult to diagnose from roentgenographs views, especially in patients below the age of five, in whom the distal humerus is cartilaginous and the only x-ray finding is a flake of bone avulsed from the lateral humoral metaphysis.'9 Comparison roentgenograms are extremely useful in the diagnosis of this type of fracture; they may show only a shift in the position of the ossification center of the capitellum or a change in the shape of this center." This is a transepiphysial injury of the type IV and is intra-articular.19 Growth arrest always remains a potential risk because of epiphysial growth damage.

Figure 4. Anteroposterior (A) and lateral (B) roentgenograms of a "T" type supracondylar fracture in which overhead pin traction caused further displacement of the fracture (B). An open reduction was necessary with K -wire fixation (C) to reduce the fracture.

Figure 4. Anteroposterior (A) and lateral (B) roentgenograms of a "T" type supracondylar fracture in which overhead pin traction caused further displacement of the fracture (B). An open reduction was necessary with K -wire fixation (C) to reduce the fracture.

Bohler classifies lateral condylar fractures into four groups.14 The least severe group comprises those with minimal displacement of the fracture condyle laterally and cranially. The second type is characterized by rotation around a frontal axis, with the articular surface oriented anteriorly and the fracture surface of the distal fragment posteriorly. In the third group, rotation is longitudinal around a sagittal axis by the extensor muscles. In this situation the fracture surface of the distal fragment is subcutaneous laterally and the articular surface of this fragment is adjacent to the fracture surface of the shaft of the humerus. The final degree of severity is the fracture in which the elbow is also laterally dislocated, as described by Kocher in 1896. Any of these last three groups has a bony surface of the shaft and the articular surface of the distal fragment touching one another; without further reduction, the expected outcome is therefore pseudoarthrosis.22 An intact hinge of cartilage may be present preserving the articular alignment.21 The first fracture group, with minimal displacement, can be treated in a long arm cast at 90° flexion; greater than 90° flexion may displace the fragment.

If nonoperative therapy is elected, the patients must be followed up closely for detection of unacceptable displacement of the fracture fragment. Flinn and associates23 found that if less than 2 mm of initial displacement was present and no further displacement was detected on followup, the fracture site could be expected to heal, although the process often required as long as 12 weeks of immobilization.

The treatment for all but the most minimally displaced fractures is to reduce them anatomically and stabilize them with smooth pins (Figure 5A-F).19 Immediate open reduction and internal fixation consistently improved results. Delay in open reduction makes the procedure more difficult and the outcome less certain.' If open reduction is not done within three weeks of injury, then the results are no better than when the fracture is left untreated.21 Some believe that open reduction can be done up to three months after the fracture with a fair chance of improved function.14 We disagree because avascular necrosis and poor elbow motion are the usual sequelae of late open reduction. We believe that some lateral displacement and instability is preferable to stiffness and avascular necrosis. Some believe that if the patient complains of symptoms suggesting ulnar nerve compromise, the nerve should be transferred anteriorly; others recommend that the procedure be done prophylactically before any symptoms occur.21 Flinn and associates23 recommend that a bone graft be done if a pseudoarthrosis develops and the fracture fragment is in good position; if in poor position, the fragment is better left alone until symptoms of tardy ulnar nerve palsy require transfer of the nerve or until the epiphysis closes. In the adult, if the condylar fragment is the source of pain, it can be excised. In the growing child, however, that procedure should never be done.

Until the fracture is completely united, the patient's progress should be followed. Growth disturbance secondary to non-union, manifested as lack of motion and poor function, may not become evident for up to four years, and tardy ulnar nerve palsy may appear even later.

Figure 5. Anteroposterior (A) and lateral (B) roentgenograms of the elbow of a nine-year-old girl who fell while roller skating, sustaining a lateral condylar fracture of the humerus. Anteroposterior (C) and lateral (D) roentgenograms after open reduction and internal fixation. The pins were removed at four weeks. Anteroposterior (E) and lateral (F) roentgenograms taken at six weeks show bony union.

Figure 5. Anteroposterior (A) and lateral (B) roentgenograms of the elbow of a nine-year-old girl who fell while roller skating, sustaining a lateral condylar fracture of the humerus. Anteroposterior (C) and lateral (D) roentgenograms after open reduction and internal fixation. The pins were removed at four weeks. Anteroposterior (E) and lateral (F) roentgenograms taken at six weeks show bony union.

Medial Epicondylar Fracture

The third most common elbow fracture seen in children (8% as reported by Blount' and 5% at LSUaffiliated hospitals) is the medial epicondylar fracture, an extra-articular fracture occurring most frequently in the second decade (average age: 11.3 years). The fracture results either from a valgus stress avulsing the medial collateral ligament and common flexor origin on the medial epicondyle of the humerus24 or, possibly even more commonly, from an elbow dislocation.25

Watson- J ones26 subdivided this type of fracture into four classifications: (1) minimally displaced; (2) displaced, but not beyond the joint line; (3) severely displaced, with the epicondyle within the joint and the joint unstable; and (4) full lateral dislocation of the elbow, which, when reduced, may resemble one of the other classifications.

Fractures that are displaced or minimally displaced may be treated in a cast. Many have recommended that the decision for open reduction be based on the distance of epicondyle displacement, with those greater than 0.5 cm to 1 cm being internally fixed after open reduction (Figure 6A-E). Attempts at manipulating those fragments that are lodged within the joint are usually futile. Rang27 recommended that valgus instability manifested under general anesthesia should be the indication for open reduction. Schwab and associates28 described the gravity stress test, in which the child is assessed under general anesthesia for a functionally lengthened medial collateral ligament.

Figure 6. Anteroposterior (A) roentgenogram of the elbow of a 14-year-old boy who sustained a medial epicondylar fracture when he fell while running to a bus. He had gross valgus instability. Open reduction and internal fixation was accomplished with two K-wires, as shown in anteroposterior (B) and lateral (C) roentgenograms. Anteroposterior (D) and lateral (E) roentgenograms taken at eight weeks show healing; patient at that time had full range of motion.

Figure 6. Anteroposterior (A) roentgenogram of the elbow of a 14-year-old boy who sustained a medial epicondylar fracture when he fell while running to a bus. He had gross valgus instability. Open reduction and internal fixation was accomplished with two K-wires, as shown in anteroposterior (B) and lateral (C) roentgenograms. Anteroposterior (D) and lateral (E) roentgenograms taken at eight weeks show healing; patient at that time had full range of motion.

If the fracture is more than four weeks old, it is probably best not to operate. If it is more than two weeks old, a better result than with open reduction may be obtained by simple excision of the fragment and reattachment of the aponeurosis. ' If fibrous union occurs in a minimally displaced position, there is frequently no disability. Generally the disability encountered because of this injury is secondary to shortening of the flexor mass, limiting extension at the elbow. Parents should always be warned in advance of the potential for loss of extension. Because of this problem, some have recommended immobilization short of 90° flexion.

Fractures of the Lateral Epicondyle

The lateral epicondyle is probably never actually fractured, but its appearance is often confusing to the uninitiated, who may interpret its irregular ossification center as a fracture. Its ossification center appears at age 12 and fuses with the lateral condyle at age 14.

Fractures of the Medial Condyle

Medial condylar fractures, which occur in the older child, are extremely rare. If displaced, they require open reduction in the same manner as lateral condylar fractures.30"33

FRACTURES OF THE PROXIMAL RADIUS AND ULNA

Radial Neck Fractures

Radial neck fractures are fairly common fractures around the elbow, but in our survey of the LSU-affiliated hospitals, none required the patients to be hospitalized. (In Blount's study,1 radial neck fractures accounted for 4.5% of elbow fractures in children.) The mechanism of injury is a fall on an outstretched hand, with the elbow extended, causing a pure valgus stress to fracture the radial neck.19'35 Because the normal carrying angle of the elbow is in a valgus position, a fall on an outstretched hand makes a radial neck fracture likely.

The radial head is cartilaginous and fits like a bottletop within the annular ligament. It usually fractures at the metaphysis (only rarely through the epiphysis) and crushes the lateral portion of the metaphysis. Because this fracture usually occurs in the metaphysis and distal to the entry of blood vessels, avascular necrosis of the radial head is indeed rare. In displaced fractures with less than 20° angulation, closed reduction is not even necessary and remodelling will obviate the deformity. Closed reduction should be attempted if the fracture is displaced more than 30°.

Some authors believe that anatomic reduction is needed,35 but others think that some residual angulation can yield a good result. Pollen lv stated that 25° is the upper limit of acceptability in patients less than eight years old, and 15° in those patients who are older than eight years. Blount suggested that 30° to 45° is acceptable. Wedge and Robertson36 recently reported that technically satisfactory open reduction had worse results than unsuccessful reduction, and suggested that angulation up to 60° be accepted if gentle closed reduction does not improve the fracture.

If seen early, a fracture of less than 60° angulation can be manipulated by pronating and supinating the forearm with direct pressure over the radial head.1 Once reduced, the fracture site is stable on pronation and supination if the elbow is flexed. If an open reduction is necessary, the sooner it is done after injury, the easier it is accomplished. One must be careful to avoid damaging the posterior interosseous nerve. Generally no internal fixation is required, but if the fracture remains unstable, place a Kirschner wire obliquely, avoiding the humerus, or if that position is too difficult, through the capitellum, and remove it at two to three weeks. Even if it is extremely comminuted, a radial head should never be excised in a child.

In followup, the only deficit commonly encountered is a limitation of pronation and supination and occasionally a loss of full extension.37 When possible, keep the hand free from casting so that free supination and pronation can occur. If the fracture is unstable, remove the hand portion of the cast at three weeks, and let pronation and supination occur in the final three weeks of treatment. On x-ray film, the radial neck usually looks enlarged. Avascular necrosis, premature epiphyseal fusion, and cubitus valgus are rarely seen. Because problems with radial head fracture may manifest late, the patient should be followed up until growth is complete.12

Olecranon Fractures

Olecranon fractures are rare in children under the age of 1 0; the average age of patients with such fractures seen at the LSU-affiliated hospitals was 16 years. When seen alone, they are the result of direct violence,37 but more often they are seen in association with radial neck fractures,27 occurring in one out of four of such fractures. The valgus force that fractures the radial neck in full extension will often cause an oblique fracture of the olecranon. Torg and Moyer38 described an avulsion lesion in a baseball pitcher.

Olecranon fractures can be classified7 as subaponeurotic, transverse, or comminuted. Subaponeurotic fractures need no fixation; treatment is simply immobilization in extension, which constitutes the treatment for the bulk of childhood fractures. In the child, transverse fractures may require open reduction but frequently can be adequately reduced by extension. If the fracture is not reduced by extending the elbow, then some form of internal fixation is required. We prefer two Kirschner wires with figure-8 tension wire according to the ASIF (Swiss Association for the Study of Internal Fixation) technique.

Diagnosis may be confused by the olecranon epiphysis, which appears between 8 and 10 years of age and begins to fuse at its anterior border between 16 and 20 years of age.7 A second anomaly is patella cubiti, which fortunately is usually bilateral.'

Monteggia Fractures

Monteggia fractures, or fractures of the proximal ulna in association with dislocation of the radial head, are frequently seen in children. They are believed to arise from both rotation and angular stresses.19 It is because of this injury that the radial head must be assessed in any fracture of the ulna, even with minimal displacement.39

Monteggia fractures are most simply divided into three groups.19 The most common is the extension injury, in which the ulna is angulated anteriorly and the radial head is displaced anteriorly. Less common is the flexion injury in which ulnar angulation and radial head displacement are both posterior. The third group is an adduction type injury in which ulnar angulation and radial head displacement are both lateral.

These fractures can be treated with a good chance of success in plaster without internal fixation. The case must be followed extremely carefully, however, to detect and prevent any dislocation of the radial head.40 We usually immobilize the radial head with a K-wire through the capitellum. The wire is removed at two weeks. Angulation is acceptable in the fracture as long as the radial head remains reduced and the child is less than 10 years old. If the fracture is found to be grossly unstable with the patient under general anesthesia, it may be necessary to plate the ulna;1 one must also resort to internal fixation if reduction is lost after the fracture has been treated by immobilization.19 If the radial head has been dislocated for longer than three months; it should be left alone.1 Even though the dislocation is unsightly, the child will have a functional forearm and a good range of motion in the elbow. As previously mentioned, the radial head should never be excised until after full growth has been reached.

The position for reduction and immobilization varies with the type of fracture. In the common extension injury, the forearm is treated in neutral rotation with the elbow flexed. For the less common flexion and adduction types of fractures, the fracture is reduced with the forearm in extension; before immobilization in plaster, the forearm is kept extended in the case of the flexion fracture and is flexed and supinated in the case of the adduction fracture.19

DISLOCATIONS

Radial Head Dislocations

Radial head dislocations are frequent in children from age four to puberty.19 They are seen in association with ulnar fractures of the Monteggia variety with damage to the annular ligament or with a fracture through the olecranon or coronoid, which allows the radial head to dislocate, leaving the radioulnar joint and annular ligament intact. Adduction and pronation cause the head to dislocate anteriorly and laterally. The patient is unable to flex the elbow fully or to pronate or supínate the forearm. Extension of the elbow and supination of the forearm reduce the fracture and allow full flexion of the elbow. The arm should be immobilized in a flexed, supinated position. Solitary radial head dislocation has been described,41 but one should look for a bent ulna, which will show such cases to be Monteggia injuries.

The diagnosis is most easily made from lateral x-ray images, which show that the radial head is displaced from its articulation with the capitellum. Congenital dislocation of the radial head can occur. This anomaly is generally lateral and associated with a small, misshapen radial head.19

If the radial head has been dislocated for three months or more, it should not be reduced.'

Subluxation of the Elbow

Pulled elbow, nursemaid's elbow, or pronatio dolorosa infantum is an extremely common injury in children between the ages of two and six years, and is probably the most common elbow injury.1 Its mechanism of injury is longitudinal traction on the elbow with the joint in extension and the forearm in pronation. The annular ligament tears, the radial head moves distally, and when traction is released, the ligament is carried up and becomes impacted between the radius and capitellum. The child appears extremely irritable and holds his arm in moderate flexion with the forearm in midpronation. The child does not spontaneously use the arm and supination is limited.' X-ray views of the area appear normal.

Reduction is accomplished by supination of the child's flexed elbow, an action that is accompanied by a palpable click as the radial head reduces. Sometimes the forearm must be pronated for the fracture to be reduced. Reduction immediately relieves the child's pain; however, the elbow should be protected with a sling or asplit cast for several days.1"1'19

Elbow Dislocation

True elbow dislocations without any fracturing of the adjoining bones are not uncommon in children. Fractures of adjoining bones are less common in children. However when an elbow dislocation without apparent fracture is seen, one should look for an occult bony fragment that may be trapped in the joint. The bone most often fractured in conjunction with elbow dislocation is the medial epicondyle, but one may also see a fracture of the coronoid process, radial neck, or a sheer fracture of the lateral or medial condyle.

A dislocated elbow is easily reduced if the procedure is done soon after injury. If reduction is delayed beyond two hours, general anesthesia may be required.42 Complete reduction allows full flexion of the elbow. Some authors recommend flexing the elbow to 90° before applying traction; others use less flexion.

After reduction, fracture of the medial epicondyle, which was previously covered by the humerus, can often be seen. This type of fracture is usually stable. Fractures of the lateral condyle, olecranon, and radial neck may also be seen with elbow dislocation. If treatment is delayed for longer than one week, open reduction may be required. If the elbow remains dislocated for several months, it is usually better to leave it dislocated.42

After reduction, the elbow should be immobilized for three weeks (if the dislocation was acute), followed by one week in a sling with exercise to increase the range of motion.

COMPLICATIONS

Loss of Motion

Probably the most common temporary complication of fracture around the elbow is limitation of motion. Although limited motion is often a result of the initial injury, it can also result from injudicious treatment,7 most often as a complication after open reduction of the supracondylar fracture as opposed to the other noninvasive procedures. There is no justification for a physical therapy program involving passive motion and stretching. Particularly in instances of elbow fracture, stretch produces inflammation that leads to fibrosis and further decrease in motion.7 Use of weights to stretch the elbow out should also be prohibited. Fortunately, if the child's elbow is not molested by well-meaning adults, motion in the elbow will gradually improve. Interestingly, few authors with long-term follow-up studies emphasize this problem. Both surgery and braces have been used effectively in treating iatrogenic loss of motion.43'44

Myositis Ossificans

In close association with the problem described above is myositis ossificans, which is caused by forceful or delayed reduction, most often of elbow dislocation.45 The ankylosing extreme is almost unique to those children subjected to forceful mobilization oftheelbow.14 This new bone formation emerges most often in the brachialis muscle,19 as a result of periosteal stripping of hematoma.7 It appears more commonly in the elbow than in any other joint.

The initial treatment recommended varies from immobilization for three to four additional weeks19 to simple neglect.7 If it is severe, operative intervention may be needed, but the procedure should be delayed for 6 to 1 2 months until all activity is quiescent and danger of irritation is gone. 14 When this new bone is excised, it must be removed with its periosteum to prevent rapid recurrence.14

Nerve Injury

Acute nerve injury is a frequent complication of elbow fractures. Spitzen and Patterson46 reported associated nerve injury in 25% of the supracondylar fractures in children who required hospitalization for greater than 24 hours. Rang27 noted nerve injury in 14% of his patients with supracondylar fractures. These injuries are rarely severe, frequently causing only numbness, but the damage is occasionally permanent.19 Our incidence at LSUaffiliated hospitals has been less than 10%.

In addition to the entire median radial, or ulnar nerve at the elbow, other nerves may be injured. When the anterior interosseous nerve is injured, weakness is evident in the profundus to the index fìnger and the flexor pollucis longus, leading to an inability to flex the distal phalanx of these two fingers. The posterior fasiculus of the median nerve, if injured, involves the pronator teres, the flexor digitorum superficialis, the anterior interosseous fibers, and the sensory fibers to the forearm. Injury to a branch of the radial nerve, the posterior interosseous nerve, leaves one unable to extend his fingers although he can extend his wrist.47

The site of fracture is reported to be closely associated with the nerve injury encountered.47 Radial nerve injury, which is one of the most common (6.5%, as reported by Rang27), is associated with subsequent gun stock deformities in supracondylar fractures.46 It is also reported as frequently accompanying the Monteggia fracture and is seen in association with displaced fractures of the capitellum. Posterior interosseous nerve injury is also seen with Monteggia fracture and occasionally accompanies radial neck fractures and radial head dislocations.

Median nerve injury is associated with supracondylar fractures and also with posterior dislocation of the elbow. According to Rang,27 ulnar nerve injury was the least frequent nerve injury encountered (3.5%). Although it is the most common injury at the LSU-affiliated hospitals, it is associated with posterior lateral dislocation of the elbow, with medial epicondyle avulsion, with anterior laterally displaced supracondylar fracture, and with Monteggia fracture. Immediate surgical exploration is said to be indicated if a nerve that was previously functional is nonfunctional after the fracture or dislocation has been reduced. In other injury, nerve exploration is indicated if recovery is not evident within three months.47 In our experience, most of the nerve palsies are transitory and do not require exploration because they usually resolve.

Mouchet's Syndrome (Tardy Ulnar Palsy) - A special form of nerve injury seen after elbow trauma is Mouchet's syndrome, or tardy ulnar nerve palsy. The condition was defined by Broca and Mouchet in 1899 to include those palsies that can develop from one to more than 50 years after injury.48 It is differentiated from both the acute nerve injury and also the secondary nerve injury, which can occur up to three months after injury when the healing process may compromise the nerve. In Mouchet's syndrome, the average duration between injury and onset of symptoms is 20 years. Because of the long delay between injury and symptoms, Mouchet's syndrome is of course rarely seen in children; however, the injury that precipitates this syndrome most often occurs in childhood.

The usual cause is cubitus valgus. This angular deformity is most often a complication of supracondylar fracture, although it can also occur in any situation in which the lateral epiphyseal plate of the distal humerus is compromised. It has also been reported to arise from the valgus deformity that follows the excision of the radial head or capitellum in an immature person. A less common cause of this syndrome is a displaced medial epicondyle fracture that, because of its irregularity, irritates the ulnar nerve. (Personal communication with K.E. Wilkins).

VASCULAR INJURY

Circulatory compromise is the most dreaded complication of elbow injury, and can be seen with both fractures and dislocations. If it is not rapidly recognized, it may become irreversible within two to four hours. '

Absence of the radial pulse is not a dependable sign of vascular compromise. Better signs include severe pain in the forearm and hand, numbness and coolness of the fingers, pallor or cyanosis of the fingers, and, especially, inability to extend the fingers. 19 The most constant sign is pain. ' Ischemia over a few hours can produce Volkman's ischemic contracture; if it is prolonged for 24 hours or more, gangrene may occur.7

Injury to the brachial artery is the most common cause of circulatory compromise.19 It can be direct, through kinking, contusion or laceration of the vessel, or it may be indirect, secondary to swelling within a closed space.19 The degree of ischemia produced is compounded by arterial spasm that constricts both the brachial artery and its collaterals.7

If this problem is encountered in an unreduced fracture, reduction should be done without delay.19 Any constricting dressing or cast should be removed. The degree of flexion should be reduced. Ice applied to the elbow and sympathetic ganglion block are also useful. ' If these measures are unsuccessful, one should explore the cubital fossa and expose the brachial artery. Irrigation with warm saline frequently will interrupt the reflex spasm, and if that treatment does not succeed, an antispasmotic such as papaverine can be injected around the artery.19 If these measures fail to restore circulation, then the artery should be grafted or simply ligated. Either measure reduces the reflex spasm. Now where microsurgical techniques are accessible, ligation is probably no longer necessary.

If the blood supply to the forearm is interrupted for several hours, muscle infarction and fibrous degeneration of muscle produces a progressive flexion contracture, as described by Volkman.'9 Ischemic nerve changes may be associated with the contracture. If the contracture is not too severe, splinting may restore adequate function. In some cases, however, excision of necrotic muscle and distal advancement of the flexor muscle origin may be required.

REFERENCES

1. Blouni WP: Fractures in Children · Injury About the Elbow. Baltimore, Williams and Wilkins. 1955, pp 26-75.

2. Cameron SM: The aetiology and prevention of cubitus varus from supracondylar fractures in children. J Bone Joint Surg 57B:255, 1975.

3. Fowles JV, Kassab MT: Displaced supracondylar fracture of the elbow in children. J Bone Joint Surg 56-B:490-500. 1974.

4. Griffin PP: Fractures in children, part 1. Instructional Course Lectures. The American Academy of Orthopaedic Surgeons. 1970, Vol 19, pp 150-159.

5. Baumann E: Knochenbruche am Ellbogengelenk. Beiir klin Chir 146:48, 1929.

6. Baumann E: Spezielle Frakturen am Luxai ionslehre Thieme, Stuttgart. Ellbogen. 1965, Vol ?/ 1. ? 13.

7. Keon-Cohen BT: Fractures at the elbow. J Bone Joint Surg 48-?:?6231639. 1966.

8. Flynn JC. Mathews JG, Benoit RL: Blind pinning of supracondylar fracture of the humerus in children. J Bone Joint Surg 56:263-272, 1974.

9. Bongers KJ, Ponsen RJG: Use of Kirschner wires for percutaneous stabilization of supracondylar fractures of the humerus in children. Arch Chir Neerl 31:204-211. 1979.

10. PriettoCA: Supracondylar fractures of the humerus -A comparative study of Dunlop's traction vs. percutaneous pinning. J Bone Joint Surg 6 1 -A :425428. 1979.

11. Arino VL, et al: Percutaneous fixation of supracondylar fracture of the humerus in children. J Bone Joint Surg 59-A:9l4-9l6, 1977.

12. Salama R. Golomb Y, Weismann SL: Fractures of the neck of the radius in children. J Bone Joint Surg 58-B:381, 1976.

13. D'Ambrosia RD: Supracondylar fracture of the humerus and prevention of cubitus varus. J Bone Joint Surg 54-A: 1408- 1418, 1972.

14. Bohler L: The Treatment of Fractures. Supplement to the 5th ed, pp 24722501.

15. Palmer EE, Niemann KMW, Vesely D, et al: Supracondylar fractures of the humerus in children. J Bone Joint Surg 60-A:653-656. 1978.

16. Nassar A, Chater E: Open reduction and Kirschner wire fixation for supracondylar fracture of the humerus. J Bone Joint Surg 58-B: 135-136, 1976.

17. Weiland AJ, et al: Surgical treatment of displaced supracondylar fractures of the humerus in children. J Bone Joint Surg 60-A:657-661, 1978.

18. Arnold JA, Nasca RJ, Nelson C: Supracondylar fractures of the humerus. J Bone Joint Surg 59-A:589-595, 1977.

19. Pollen A: Fractures and Dislocations in Children. Baltimore, Williams and Wilkins, 1973.

20. McLearie M, Merson RD: Injury to the lateral condyle epiphysis of the humerus in children. J Bone Joint Surg 36-B:84-89, 1954.

21. Jakob R, Fowles JV, Rang M, et al: Observations concerning fractures of the lateral humeral condyle in children. J Bone Joint Surg 57-B:430-436, 1975.

22. Wilson PD: Fracture of the lateral condyle of the humerus in childhood. J Bone Joint Surg 18:301-318, 1936.

23. Flynn JC, Richards JF Jr, Saltzman Rl: Prevention and treatment of nonunion of slightly displaced fractures of the lateral humeral condyle in children. J Bone Joint Surg 57-A:l087-l092. 1975.

24. Patrick J: Fracture of the medial epicondyle with displacement into the elbow joint. J Bone Joint Surg 28:143-147, 1946.

25. Smith FM: Medical epicondyle injuries. JAMA 142:346-402, 1950.

26. Watson-Jones R: Fractures and Joint Injuries, ed 4. Baltimore, Williams and Wilkins. 1955.

27. Rang M: Elbow - Children's Fractures. Toronto, JB Lippincott Co, 1974, pp 93-123.

28. Schwab GH, Bennett JB, Woods GW, et al: Biomechanics of elbow instability: The role of the medial collateral ligament. Clin Orthop 145:4252, 1980.

29. Wilson JN: The treatment of fractures of the medial epicondyle of the humerus. J Bone Joint Surg 42-B:778-781, I960.

30. Chacha PB: Fractures of the medial condyle of the humerus with rotational displacement. J Bone Joint Surg 52-A: 1453- 1458, 1970.

31. Faney JJ, O'Brien ET: Fracture separation of the medial humeral condyle in a child confined with fracture of the medial epicondyle. J Bone Joint Surg 53-A: 1 102-1104. 1971.

32. El Ghawabi MH: Fracture of the medial condyle of the humerus. J Bone Joint Surg 57-A:677-68l, 1975.

33. Varma BP, Srivastava TP: Fracture of the medial condyle of the humerus in children: A report of cases including the late sequelae. Injury 4:171-174, 1972.

34. Jeffery CC: Fractures of the neck of the radius in children. J Bone Joint Surg 54-B:7l7-7l9, 1972.

35. Jones ERL, Esha M: Displaced fractures of the neck of the radius in children. J Bone Joint Surg 53-B:429-439, 1971.

36. Wedge JH, Robertson DE: Displaced radial neck fractures in children. Presented at the American Academy of Orthopaedic Surgeons, January 2116, 1982, New Orleans, LA.

37. Ellman H: Anterior angulation deformity of the radial head. J Bone Joint Surg 57-A:776-778, 1975.

38. Torg JS, Moyer R: Non-union of a stress fracture through the olecranon epiphyseal plate observed in an adolescent baseball pitcher. J Bone Joint Surg 59-A:264-265, 1977.

39. Theodorou SD: Dislocation of the head of the radius associated with fractures of the upper end of the ulna in children. J Bone Joint Surg 51B: 700- 706, 1969.

40. Godfrey JD: Trauma in children. J Bone Joint Surg 46-A:422-447, 1964.

41. Stören G: Traumatic dislocation of the radial head as an isolated lesion in children. Acta Chir Scand 1 16:144-147, 1958-59.

42. Hamilton CM: Fracture in children, part H. Instructional Course Lectures, The American Academy of Orthopaedic Surgeons, 1970, pp 160-171.

43. Glynn JJ, Niebauer JJ: Flexion and extension contracture of the elbowsurgical management. Clin Orthop 117:284-291, 1976.

44. Green DP, McCoy H: Turbuckle orthotic correction of elbow flexion contractures after acute injury J Bone Joint Surg 61 -A: 1092-1095, 1979.

45. Thompson HC, Garcia A: Myositis ossificans aftermath of elbow injuries. Clin Or ihop 50:129-134, 1967.

46. Spitzer AG, Patternson D: Acute nerve involvement in supracondylar fractures of the humerus in children. J Bone Joint Surg 55-B:227, 1973.

47. Galbraith KA. McCullough CJ: Acute nerve injury as a complication of closed fractures or dislocations of the elbow. Injury 11:159-164, 1979.

48. Holmes JC, Hall J: Tardy ulnar nerve palsy in children. Clin Orthop 135:128-131, 1978.

10.3928/0090-4481-19820601-12

Sign up to receive

Journal E-contents