Epicondylar and transphyseal elbow fractures in children

INTRODUCTION — This topic review addresses epicondylar and transphyseal elbow fractures in children. Supracondylar and condylar elbow fractures are discussed separately. (See "Supracondylar humeral fractures in children" and "Evaluation and management of condylar elbow fractures in children".)

EPIDEMIOLOGY — Medial epicondylar fractures account for approximately 10 percent of elbow fractures in children [1,2]. These fractures are much more common in boys than girls. Age of occurrence ranges from 9 to 14 years. Falls account for most of these fractures [2]. Case reports also describe medial epicondylar fractures occurring after throwing a baseball and arm wrestling in boys [2,3]. Fifty percent of medial epicondyle fractures are associated with a posterior elbow dislocation [4,5]. (See "Elbow injuries in active children or skeletally immature adolescents: Approach", section on 'Posterior elbow dislocation'.)

Fractures of the lateral epicondyle are unusual and typically arise from a fall on an outstretched hand or a direct blow [6].

Transphyseal fractures of the distal humerus are most commonly seen in children younger than six years of age. In two small case series, they were associated with child abuse in 10 of 22 patients, primarily children under two years of age [7,8]. Transphyseal fractures have also been described in neonates who have undergone difficult vaginal delivery [9,10].

PERTINENT ANATOMY — The predisposition for epicondylar or transphyseal fractures varies by age and is determined by the typical bony development of the distal humerus:

●Distal humeral physis – In infants and toddlers younger than two years of age, the physeal line is close to the center of the olecranon fossa. Thus, hyperextension injuries in this age group cause physeal separation rather than a supracondylar humeral fracture (image 1) [11]. Despite proximity to important neurovascular structures, transphyseal fractures rarely cause neurovascular injury because smooth cartilaginous edges in the undeveloped bone are less likely to damage adjacent structures.

●Medial epicondyle – The medial epicondyle begins to ossify between four to six years of age. This apophysis is the last to fuse with the distal humerus (table 1 and figure 1A-B), which makes it prone to injury into adolescence [6]. Soft tissue attachments include the ulnar collateral ligament and the flexor muscles of the forearm. The ulnar collateral ligament is a major contributor to the valgus stability of the elbow. The ulnar nerve travels behind the medial epicondyle and may be injured if the epicondyle is fractured and displaced.

●Lateral epicondyle – The lateral epicondyle is the last elbow apophysis to ossify (table 1 and figure 1A-B). It is the major attachment site for extensor muscles of the forearm and the radial collateral ligament. Lateral epicondylar fracture is not associated with neurovascular compromise.

MECHANISM OF INJURY — Mechanisms of injury differ for epicondylar versus distal transphyseal fractures:

●Epicondylar fracture – A fall on an outstretched hand is the most common cause of both medial and lateral epicondylar fractures (figure 2) [12]. Fractures following direct blows have also been described. Unusual causes of medial epicondylar fractures include the throwing of a baseball and arm wrestling [2,3]. Posterior elbow dislocations, although rare in children, frequently have an associated medial epicondylar fracture [4,5] and rarely lateral epicondylar fracture with entrapment [13].

●Distal transphyseal fractures – Similar to the other distal humeral fractures, these fractures often result from a hyperextension injury mechanism, particularly in children under six years of age [14]. In infants and toddlers, child abuse with intentional rotatory force applied across the elbow is an important etiology [7-10,14]. These fractures are also described following birth trauma in neonates.

CLINICAL MANIFESTATIONS — The child with an epicondylar or transphyseal fracture typically has elbow pain, swelling, and tenderness over the fracture site with limited range of motion. In patients with medial epicondylar fractures, the elbow is held in flexion. About one-half of pediatric medial epicondyle fractures are associated with elbow dislocation with the potential for brachial artery and ulnar nerve injury; ulnar nerve dysfunction occurs in up to 15 percent of patients (table 2) [15] (see 'Pertinent anatomy' above and "Elbow injuries in active children or skeletally immature adolescents: Approach", section on 'Posterior elbow dislocation'). Thus, nerve function must be carefully assessed (picture 1 and figure 3). In patients with fracture but no dislocation, assessment for elbow instability when valgus stress is applied to the elbow is an important consideration for definitive management.

By contrast, neurovascular compromise is uncommon in patients with an isolated lateral epicondylar fracture, and the elbow is typically stable although acute posterolateral elbow instability may rarely occur and should be assessed [16].

Transphyseal fractures present with significant deformity and have physical features that can suggest an elbow dislocation, although neurovascular compromise is rare. Children with transphyseal fractures warrant careful examination for other potentially abusive injuries (table 3 and table 4).

DIAGNOSIS AND IMAGING — The diagnosis of an epicondylar or transphyseal elbow fracture is suspected based upon localized swelling, tenderness over the fracture site, and deformity; and confirmed by plain radiographs. Pain control and, for patients with significant deformity or suspected dislocation, immobilization should occur before imaging. (See 'Analgesia' below and 'Immobilization' below.)

●Epicondylar fractures – Markedly displaced epicondylar fractures are usually obvious radiographically (image 2). In addition to standard anteroposterior (AP) and lateral images, external oblique views should be obtained for suspected medial injuries, and internal oblique views should be obtained for suspected lateral injuries. Obtaining radiographs of the contralateral uninvolved elbow can be useful in equivocal situations when trying to differentiate between normal physes and fractures. In some cases, complete displacement with an intra-articular medial epicondylar fracture fragment may be difficult to see. In these cases, joint space irregularity accompanied by the absence of the medial epicondyle are the major clues to this injury (image 3). In addition, based on the order of ossification (figure 1A), one should suspect an incarcerated medial epicondyle within the joint if the trochlear and lateral epicondyle ossification centers are present but the medial epicondyle is not visualized.

Description of acute medial and lateral epicondylar fractures includes the following:

•Degree of displacement (in mm)

•Presence or absence of an incarcerated fragment in the joint

•Presence or absence of concomitant dislocation (image 4) [17]

Computed tomography (CT) of the elbow is the most precise means of determining degree of displacement for medial epicondylar fractures. However, for initial diagnosis and emergency department management of the fracture, it is usually not necessary [18].

●Transphyseal fractures – These physeal injuries may be classified using the Salter-Harris classification system (figure 4) as well as the degree of displacement. A posterior fat pad sign is typically present. Of note, transphyseal fractures may be difficult to distinguish radiographically from elbow dislocations [14,19]. With transphyseal fractures, the alignment of the radial head and the capitellum is preserved; however, the forearm will appear translated with respect to the humeral shaft (image 5). With a posterior elbow dislocation, the radial head does not point toward the capitellum (image 6).

Transphyseal fractures may be difficult to identify on the standard three-view plain radiograph (AP, lateral, and oblique), especially in children younger than five years of age in whom the involved areas are not ossified. Comparison views with the unaffected elbow may be helpful in this circumstance (image 5).

In addition, ultrasound, magnetic resonance imaging (MRI), or arthrography is frequently employed to better characterize the injury. Consultation with a pediatric radiologist or orthopedic surgeon with pediatric expertise is encouraged to determine the need for further studies and in selecting the most appropriate modality. (See "Elbow anatomy and radiographic diagnosis of elbow fracture in children", section on 'Plain radiographic views'.)

INITIAL TREATMENT — For children with epicondylar or transphyseal fractures, initial therapy consists of pain management, immobilization, and radiographic evaluation [19].

Analgesia — Parenteral analgesia (eg, intranasal or intravenous [IV] fentanyl or IV morphine) is most appropriate for initial pain control in patients with moderate to severe pain and should be given prior to radiographic evaluation. Oral analgesia (eg, ibuprofen 10 mg/kg) may suffice for patients who have suffered a nondisplaced condylar fracture. In most circumstances, pain relief will result in an improved ability to assess and obtain necessary radiographs in the apprehensive child.

Immobilization — Immobilization enhances patient comfort and prevents further fracture displacement. The arm should be splinted with a modified long arm splint "as it lies" (typically with elbow flexed 20 to 30 degrees rather than 90 degrees (figure 5)). Neurovascular status should be checked before and after splinting. (See "Basic techniques for splinting of musculoskeletal injuries", section on 'Long arm splint'.)

Orthopedic consultation — Prompt orthopedic consultation should be obtained in the following circumstances [1]:

●Transphyseal distal humeral fractures (image 5)

●Epicondylar fractures with an incarcerated joint fragment (image 3)

●Epicondylar fractures with elbow dislocation (image 4)

●Epicondylar fractures with ulnar or median nerve deficit

●Open fractures

Epicondylar fractures without an associated elbow dislocation (image 2) are often initially treated with immobilization alone, regardless of displacement. However, discussion with an orthopedist is appropriate prior to discharge, especially in children who have injured their dominant arm and engage in overhead sports activities (eg, baseball, tennis, or volleyball) or upper extremity weightbearing athletes (eg, gymnasts).

Child protection — Diagnosis of a transphyseal elbow fracture in a child with no plausible mechanism of injury should prompt involvement of an experienced child protection team (eg, social worker, nurse, physician with more extensive experience in the management of child abuse), if available. In many parts of the world (including the United States, United Kingdom, and Australia), a mandatory report to appropriate governmental agencies is also required when child abuse is suspected. (See "Child abuse: Social and medicolegal issues", section on 'Reporting suspected abuse'.)

In addition, children with suspected child abuse should undergo further evaluation for additional injuries, and the safety of other children in the home must be ensured by local child protective services as discussed in detail separately. (See "Physical child abuse: Diagnostic evaluation and management" and "Child abuse: Eye findings in children with abusive head trauma (AHT)".)

DEFINITIVE CARE — All children with epicondylar or transphyseal fractures warrant referral to an orthopedic surgeon with pediatric expertise. Whether definitive care is operative or nonoperative varies according to the type of fracture and associated injuries.

Medial epicondylar fractures — Absolute indications for open reduction and internal fixation include [1,15]:

●Open fractures

●Neurologic deficit (eg, complete deficit of the ulnar nerve or, rarely, the median nerve)

●Incarcerated fragments

●Irreducible dislocations (typically due to incarcerated bony fractures)

●Elbow instability

Minimally displaced fractures on plain radiographs (eg, <2 mm) are typically managed nonoperatively with a long arm splint or cast immobilization and orthopedic follow-up within seven to ten days [1,18]. Early active motion (three to seven days postinjury) is recommended for patients who are treated nonoperatively. (See "Basic techniques for splinting of musculoskeletal injuries", section on 'Long arm splint' and "Patient education: Cast and splint care (Beyond the Basics)".)

The degree of displacement beyond 2 mm that warrants operative intervention is debated. Although 5 mm of displacement is a common cutoff, values from 3 to >9 mm have been used [15,20]. Furthermore, there is large interobserver variability regarding the measurement of displacement on plain radiographs. As a result, there is a wide variability in practice regarding the use of nonoperative or operative treatment among orthopedic surgeons [1,15,18]. Some orthopedic surgeons advocate closed, nonoperative treatment of all such medial epicondyle fractures, noting that nonunions are mostly asymptomatic [15,18,20]. Other surgeons recommend operative stabilization of displaced fractures, especially in overhead adolescent athletes or upper extremity weightbearing athletes (eg, gymnasts), citing the mild persistent valgus instability of the elbow if the fragment is left unreduced.

Lateral epicondylar fractures — Nondisplaced lateral epicondylar fractures are treated by cast immobilization followed by early motion (three to seven days postinjury) when tolerated [2,12]. Close radiographic follow-up for the first two weeks after injury is indicated to identify displacement, which most commonly occurs with fractures that extend into the joint. Displaced fractures warrant open reduction and internal fixation [2].

Transphyseal fracture — A pediatric orthopedic consultation is recommended to determine appropriate intervention. The treatment of displaced transphyseal fractures typically involves closed reduction and percutaneous pinning [14]. Diagnosis of a transphyseal elbow fracture in a child with no plausible mechanism of injury should prompt involvement of an experienced child protection team. (See 'Child protection' above.)

FOLLOW-UP — Splinted patients with displaced epicondylar fractures should be discharged with instructions for splint removal and early active motion as tolerated. They should follow up with an orthopedic surgeon in seven to ten days. Although early active motion is encouraged, formal physical therapy is rarely needed.

Depending upon the orthopedic surgeon's level of concern, children who have received acute operative care (closed reduction with percutaneous pinning or open reduction with internal fixation or fragment removal) may be admitted for 24- to 48-hour observation of neurovascular status and soft tissue compartments or discharged home with careful instructions to caregivers regarding the signs and symptoms of acute compartment syndrome. Once discharged, these patients are followed closely and may require weekly orthopedic evaluation with radiographs to determine the optimal timing for subsequent hardware removal.

Most ulnar nerve deficits associated with medial epicondylar elbow fractures are neurapraxic injuries that resolve with observation. Surgical exploration should be considered for nerve deficits that persist beyond three months [21-23].

COMPLICATIONS — Complications vary by the specific fractures:

●Epicondylar fractures – The most common complications of medial epicondylar fractures include stiffness and ulnar nerve injury. The occurrence of stiffness may be prevented by limiting immobilization to three weeks and initiating early range-of-motion exercise within a few days of injury. Although nonoperative care frequently results in nonunion, patients with this result typically have normal range of motion without pain [2,20]. (See 'Follow-up' above.)

Ulnar nerve injuries occur in 10 to 16 percent of medial epicondylar fractures and are more likely if the fracture fragment is trapped in the joint [5,19,24]. Ulnar nerve function typically recovers in most children who have prompt recognition of their injury and minimal manipulation of the incarcerated fragment prior to operative care [25]. Delayed ulnar palsy may occur due to postsurgical swelling and ulnar nerve compression or traumatic scarring and entrapment [26].

Joint stiffness is the main complication of lateral epicondylar fracture. Less commonly, malunion [27], nonunion, spur formation, or interference in normal growth resulting in cubitus valgus may occur.

●Distal humerus transphyseal fractures – Given the frequency with which these fractures result from nonaccidental trauma, failure to recognize child abuse and intervene is considered a serious complication. In older children, the mechanism and complications of transphyseal fractures are similar to that of supracondylar fractures, including compartment syndrome, neurovascular injury, and cubitus varus. However, neurovascular injury is less common [19,28]. (See 'Child protection' above and "Supracondylar humeral fractures in children", section on 'Complications'.)

OUTCOMES — Most children with medial epicondylar fractures recover fully. However, a significant minority have pain at the final orthopedic follow-up visit (up to 15 percent), ulnar nerve symptoms (3 to 5 percent), decreased range of motion, and/or loss of strength [18]. Cubitus valgus or varus has been described but is rare. These outcomes do not seem to be determined by whether the initial treatment was operative or nonoperative [20].

Lateral epicondylar fractures do not typically have long-term functional significance for the patient [2].

Distal transphyseal humeral fractures may result in cubitus varus, growth arrest, or medial condyle osteonecrosis [2].

ADDITIONAL INFORMATION — Several UpToDate topics provide additional information about fractures, including the physiology of fracture healing, how to describe radiographs of fractures to consultants, acute and definitive fracture care (including how to make a cast), and the complications associated with fractures. These topics can be accessed using the links below:

●(See "General principles of fracture management: Bone healing and fracture description".)

●(See "General principles of fracture management: Fracture patterns and description in children".)

●(See "General principles of acute fracture management".)

●(See "General principles of definitive fracture management".)

●(See "General principles of fracture management: Early and late complications".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: General management of pediatric fractures" and "Society guideline links: Upper extremity, thoracic, and facial fractures in children" and "Society guideline links: Acute pain management".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Elbow fracture (The Basics)" and "Patient education: How to care for your child's cast (The Basics)")

●Beyond the Basics topic (see "Patient education: Cast and splint care (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●Epicondylar elbow fractures most commonly occur in older boys after a fall on an outstretched arm. Medial epicondylar fractures comprise 10 percent of all elbow fractures in children. Because of its anatomical location next to the medial epicondyle, ulnar nerve deficits occur in up to 15 percent of patients. Lateral epicondylar fractures are less common. (See 'Epidemiology' above and 'Pertinent anatomy' above and 'Mechanism of injury' above.)

●Transphyseal fractures are uncommon distal humeral fractures seen in neonates, infants, and young children. They are usually associated with child abuse and birth trauma. (See 'Epidemiology' above and 'Mechanism of injury' above.)

●The child with an epicondylar or transphyseal fracture typically has elbow pain, swelling, and tenderness over the fracture site with limited range of motion. Medical epicondylar fractures frequently occur in association with an elbow dislocation. Transphyseal fractures present with significant deformity and have physical features that can suggest an elbow dislocation, although neurovascular compromise is rare. Children with transphyseal fractures warrant careful examination for signs of other potentially abusive injuries (table 3 and table 4). (See 'Clinical manifestations' above.)

●The diagnosis of an epicondylar or transphyseal elbow fracture is suspected based on clinical findings and confirmed by plain radiographs (image 2 and image 4 and image 5). Pain control and, for patients with significant deformity or suspected dislocation, immobilization should occur before imaging. (See 'Diagnosis and imaging' above.)

●In some cases, complete displacement with an intra-articular medial epicondylar fracture fragment may be difficult to see. In these cases, joint space irregularity accompanied by the absence of the medial epicondyle are the major clues to this injury (image 3).

●Transphyseal fractures may be difficult to distinguish radiographically from elbow dislocations. With transphyseal fractures, the alignment of the radial head and the capitellum is preserved (image 5). With a posterior elbow dislocation, the radial head does not point toward the capitellum (image 6).

●For children with epicondylar or transphyseal fractures, initial therapy consists of pain management, immobilization, and radiographic evaluation (see 'Initial treatment' above). Prompt orthopedic consultation should be obtained for patients with the following diagnoses circumstances (see 'Orthopedic consultation' above):

•Transphyseal distal humeral fractures (image 5)

•Epicondylar fractures with an incarcerated joint fragment (image 3)

•Epicondylar fractures with elbow dislocation (image 4)

•Epicondylar fractures with ulnar or median nerve deficit

•Open fractures

●All children with epicondylar or transphyseal fractures warrant referral to an orthopedic surgeon with pediatric expertise. Whether definitive care is operative or nonoperative varies according to the type of fracture and associated injuries. (See 'Definitive care' above.)