Elbow injuries in active children or skeletally immature adolescents: Approach

INTRODUCTION — The approach to elbow injuries in children or skeletally immature adolescents is reviewed here.

The radiographic diagnosis of elbow fractures and the evaluation and management of fractures of the elbow, distal humerus, and proximal forearm in children and adolescents are discussed separately:

●(See "Elbow anatomy and radiographic diagnosis of elbow fracture in children".)

●(See "Supracondylar humeral fractures in children".)

●(See "Proximal fractures of the forearm in children".)

●(See "Evaluation and management of condylar elbow fractures in children".)

●(See "Epicondylar and transphyseal elbow fractures in children".)

BACKGROUND — Injuries to the elbow, forearm, and wrist account for more than 25 percent of all sports-related injuries [1]. Acute injuries usually are related to falls, whereas chronic injuries occur with repetitive motion. Individuals who injure their elbows usually are throwers (eg, baseball and javelin), power grippers (eg, weightlifters, racquet athletes, gardeners, and carpenters), or those who use the elbow as a weightbearing joint (eg, gymnasts).

BASIC ANATOMY — The elbow is made up of three interrelated joints (figure 1) and their stabilizing ligaments (table 1 and figure 2) are as follows:

●The radiocapitellar joint is formed laterally by the articulation of the capitellum of the humerus with the radial head.

●The ulnohumeral joint is formed medially by the articulation of the humerus with the coronoid process, trochlear notch, and olecranon of the ulna. The ulnar collateral ligament (UCL) is a triangle-shaped ligament complex that connects the medial epicondyle to the proximal ulna. The anterior band of the UCL is the most clinically important portion that originates at the medial epicondyle and inserts on the sublime tubercle of the ulna.

●The radioulnar joint is formed by the articulation of the radial head with the radial notch of the ulna and is surrounded by the annular ligament.

The medial and lateral epicondyle and olecranon process of the humerus are the bony landmarks that are easily palpated (image 1). The medial epicondyle is the origin of the wrist and finger flexors and pronators. The lateral epicondyle is the origin of the wrist and finger extensors. The olecranon process is the insertion of the elbow extensors (triceps). The olecranon bursa is the most superficial of the 12 bursae surrounding the elbow.

The muscles of the elbow and forearm can be divided according to their major actions: flexion or extension and supination or pronation:

●Muscles of elbow flexion or extension – Flexion or extension of the elbow occurs at the ulnohumeral joint. Elbow flexion is controlled by the biceps brachii and brachialis muscles (figure 3). The biceps brachii has insertions on the radial tuberosity and the forearm flexor fascia through the bicipital aponeurosis or lacertus fibrosis. The brachialis lies deep to the biceps and originates from the distal humerus and inserts on the coronoid process of the ulna.

Elbow extension is primarily controlled by the triceps and some of the anconeus. The normal arc of motion in children and adolescents ranges from -15 to 0 degrees in full extension to 150 degrees in flexion. At least 30 degrees from full extension and 130 degrees of flexion are necessary for the activities of daily living.

●Muscles of supination or pronation – Supination or pronation of the forearm, with the radius rotating over the stationary ulna, occurs at the radiohumeral and proximal radioulnar articulations. The pronator quadratus and the pronator teres pronate the wrist. The pronator quadratus runs obliquely from the distal ulna to the more distal radius. The pronator teres originates from the medial epicondyle and the proximal ulna and inserts on the lateral midshaft of the radius.

The supinators are much stronger than the pronators and include the supinator and the biceps brachii. The supinator originates on the proximal posterior ulna and inserts on the proximal radius. The biceps brachii has insertions on the radial tuberosity and the forearm flexor fascia through the bicipital aponeurosis or lacertus fibrosis. The normal range of motion is approximately 90 degrees for both supination and pronation. At least 50 degrees of pronation and supination are necessary for the activities of daily living.

Sensation and voluntary movement of the elbow and wrist are under control of the median, radial, ulnar, and musculocutaneous nerves (figure 4 and table 2):

●The median nerve crosses the elbow in the antecubital fossa just medial to the biceps tendon and brachial artery and primarily innervates the wrist flexor/pronators, finger flexors, and thenar muscles.

●The ulnar nerve crosses the elbow posteriorly and medially in the cubital tunnel of the humerus and innervates the intrinsic muscles of the hand and the flexor carpi ulnaris.

●The radial nerve crosses the elbow anterior to the lateral epicondyle and innervates the wrist extensors and supinators.

●The musculocutaneous nerve crosses the elbow in the lateral antecubital fossa and innervates the elbow flexors.

The brachial artery is the major artery that transverses the antecubital fossa (figure 4); injury to the brachial artery will cause radiating pain, decreased skin temperature, decreased pulses, and pallor of the distal arm and may result in Volkmann's contracture.

SKELETAL DEVELOPMENT AND OSSIFICATION — Skeletal maturity in children and adolescents is classified according to the appearance and fusion of the secondary ossification centers of the distal humerus and proximal radius and ulna. Childhood, in relation to bone age, ends with the appearance of all the secondary ossification centers; adolescence with the fusion of all secondary ossifications centers; and young adulthood with the completion of all bone growth.

The appearance of these ossification centers proceeds in an orderly fashion, usually occurring approximately one year earlier in girls than in boys (table 3 and figure 5) [2]. One mnemonic aid to remember the order of their appearance is CRITOE, as follows:

●C – Capitellum

●R – Radial head

●I – Inner or medial epicondyle

●T – Trochlea

●O – Olecranon

●E – External or lateral epicondyle

The secondary ossification centers fuse to create the mature bony elbow. The lateral epicondyle, trochlear, and capitellar centers fuse first (figure 6); this unit then fuses with the distal humerus; the last fusion occurs at the medial epicondyle. Similar to the appearance of the ossification centers, fusion proceeds in an orderly fashion and usually occurs earlier in girls than in boys (table 3).

EVALUATION

History — The crucial elements of the history vary depending upon whether the complaints are acute or chronic.

Acute injury — Acute complaints begin with a discrete event. Before focusing on the elbow, the clinician should differentiate shoulder and cervical spine injury with pain radiating to the elbow from true elbow injuries. Patients with trauma to the head or neck and neck pain should have the cervical spine immobilized pending further evaluation. (See "Traumatic causes of acute shoulder pain and injury in children and adolescents" and "Evaluation and acute management of cervical spine injuries in children and adolescents", section on 'History' and "Pediatric cervical spinal motion restriction".)

Once cervical spine injury is excluded or addressed, the mechanism of injury and details of elbow joint mobility and stability and neurovascular symptoms are key components of the history as follows:

●Mechanism of injury – The mechanism of injury helps to indicate the most likely region of the elbow that is injured:

•Contact trauma – Area that was impacted

•Valgus force applied with the hand planted – Medial components of the elbow joint

•Fall on an outstretched hand – Proximal forearm or distal humerus

•Acute pain while throwing – Depending upon the patient's skeletal maturity, medial epicondyle apophysitis, medial epicondyle avulsion fracture, or ulnar collateral ligament injury (table 4 and table 3) (see 'Little League elbow' below)

•Hyperextension – Distal humerus and proximal ulna from posterior dislocation or impingement

•Axial traction on the arm with the elbow in full extension (eg, forcefully pulling on the wrist of a young child) – Radial annular ligament (nursemaid's elbow) (see "Radial head subluxation (pulled elbow): Evaluation and management")

●Joint mobility and stability – In addition to the mechanism of injury the clinician should determine the following:

•Did the patient feel a pop, crack, or snap sensation at the time of the injury? These sensations suggest a fracture, tendon rupture, or ligament tear.

•Does the patient have shifting or instability of the elbow? These symptoms indicate ligament injury causing joint instability.

●Neurovascular complaints – Are there any distal neurovascular complaints (eg, weakness, tingling, paresthesias, coolness)?

Subacute or chronic injury — Chronic complaints have an insidious onset and a longer duration of symptoms. Chronic elbow injuries typically are caused by repetitive activity or start of a new activity. The frequency, intensity, duration, progression, and mechanics of the activity should be determined. This determination is particularly true for throwing because it causes medial traction and lateral compression of the elbow. In addition, the elbow is the weakest link in the kinetic chain, the connection of joints from the foot through the arm that is used to throw an object; biomechanical change especially in the shoulder and scapula caused by an injury can cause abnormal mechanics and stress that will result in secondary injury at the elbow. (See "Throwing injuries of the upper extremity: Clinical presentation and diagnostic approach".)

Additional questions — Questions of importance regardless of the timing of the injury include:

●Pain – The location, quality, radiation, and intensity of pain (eg, on a 10-point scale) as well as aggravating and alleviating factors.

●Mechanical sensations- The elbow may have clicking, popping, and locking sensations especially associated with pain may indicate loose bodies or osteochondritis dissecans.

●Interventions – Any interventions the athlete has tried to improve the symptoms (eg, medications, application of heat or cold, or activity modification) and whether they were successful.

●Functional performance – Has the athlete experienced a change in functional performance? Throwers with medial epicondyle apophysitis, for example, may complain initially of loss of control (eg, the tendency of the ball to sail higher than the intended target), followed by loss of endurance, pain, and finally loss of velocity.

●Recent illnesses – Athletes being treated with quinolone antibiotics have been noted to have an increased risk of tendinitis and tendon rupture. The athlete should also be asked about recent illness because arthritis is a well-recognized and relatively common accompaniment to infection by a number of viruses. (See "Fluoroquinolones", section on 'Tendinopathy' and "Viral arthritis: Causes and approach to evaluation and management".)

●Interventions – Any interventions the athlete has tried to improve the symptoms (eg, medications, application of heat or cold, activity modification, rehabilitation, or surgery) and whether they were successful.

●Age – The age and bone maturity of the patient affect the differential diagnosis (see 'Skeletal development and ossification' above). For example, with medial elbow pain children are more likely to have apophysitis while skeletally immature adolescents are more likely to have a medial epicondyle avulsion fracture (table 4).

Past medical history, family history, and review of systems must be included to evaluate for other causes of joint pain and swelling. Important historical features include the following:

●Presence of fever suggesting infection or inflammation (see "Hematogenous osteomyelitis in children: Evaluation and diagnosis" and "Bacterial arthritis: Clinical features and diagnosis in infants and children")

●Involvement of other joints possibly signifying rheumatologic disease (see "Systemic juvenile idiopathic arthritis: Clinical manifestations and diagnosis", section on 'Extraarticular manifestations')

●History of sickle cell disease suggesting a painful crisis (see "Overview of the clinical manifestations of sickle cell disease", section on 'Acute painful episodes')

●Known hemophilia or other bleeding disorder with a hemarthrosis (see "Clinical manifestations and diagnosis of hemophilia", section on 'Joints and muscle')

Physical examination — Children and adolescents who have elbow complaints must undergo a thorough history and screening examination of the neck and shoulder in addition to the elbow. Neck and shoulder injuries can manifest with symptoms at the elbow. (See "Evaluation and acute management of cervical spine injuries in children and adolescents" and "Physical examination of the shoulder".)

The key components of the physical examination of the elbow are as follows:

●Observation – The physical examination of the elbow includes observation for ecchymosis, swelling, muscular atrophy, and breaks in the skin that may indicate an open fracture or entry point for infection.

Patients with obvious deformity should undergo prompt evaluation of neurovascular status as described below followed by appropriate analgesia, immobilization as indicated by degree of deformity, and imaging. (See 'Imaging' below.)

The clinician should assess for the following normal relationships:

•The angle between the long axes of the humerus and the forearm (the carrying angle) varies between 5 and 20 degrees and usually is greater in girls than in boys [3]. Alterations in the symmetry of this angle when compared with the opposite elbow may indicate previous fractures (figure 7).

•The lateral and medial epicondyle and olecranon process form an isosceles triangle with the elbow in 90 degrees flexion and a straight line with the elbow in full extension (figure 8). This relationship is lost in posterior elbow dislocations or displaced fractures. (See 'Acute injury' below.)

•The radial head, tip of the olecranon, and the medial epicondyle normally form an equilateral triangle with the elbow in 90 degrees flexion. Alterations in this relationship may indicate fracture of the radial head, olecranon, or the medial epicondyle.

●Palpation – The examination of the elbow should include palpation of the following structures in each location:

•Anterior elbow – Biceps muscle and distal tendon (figure 9)

•Posterior elbow – Olecranon process, olecranon bursa, epiphyseal plate and olecranon fossa, triceps brachii muscle and tendon insertion (figure 10)

•Medial elbow – Medial epicondyle (picture 1), medial epicondyle apophysis and epiphyseal plate, flexor pronator mass, ulnar collateral ligament (figure 2), and cubital tunnel (ulnar nerve)

•Lateral elbow – Lateral epicondyle with the common wrist extensors, radial head (best felt with the elbow at 90 degrees and supinating and pronating the forearm), supinator, brachioradialis, and capitellum (figure 11)

●Neurovascular examination – The neurovascular examination of the elbow and distal extremity should include:

•Sensation and strength testing in the distribution of the median, radial, ulnar, and musculocutaneous nerves (table 2)

•Deep tendon reflexes of the biceps (C5), brachioradialis (C6), and triceps (C7)

•Palpation of the brachial, radial, and ulnar pulses

●Range of motion – The range of motion and strength of the elbow and wrist should be examined (table 5A-B).

●Provocative testing – Several confirmatory tests may be warranted in patients with a suspected diagnosis based upon the findings of the history and physical examination. They include varus and valgus testing of the medial complex (figure 12), moving valgus stress test, the pronator compression test, posterior impingement test, and the OK and Tinel signs (table 6).

DIAGNOSTIC APPROACH — The diagnostic approach after an elbow injury varies according to whether the injury is acute or chronic.

Acute injury — Children and young adolescents with acute elbow injuries and elbow pain warrant plain radiographs to evaluate for fractures or dislocation, especially when physical findings show deformity, swelling, focal bony tenderness (eg, tenderness in the supracondylar region of the distal humerus, radial head, medial or lateral epicondyle, or over the olecranon), or any decreased range of motion [4,5].

In patients with evidence of severe fracture (S-shape configuration or pucker sign (image 2 and figure 13)), careful assessment for neurovascular compromise and an open fracture is essential and prompt orthopedic consultation should occur if either are present. (See "Supracondylar humeral fractures in children", section on 'Orthopedic consultation' and "Supracondylar humeral fractures in children", section on 'Inspection and neurovascular examination'.)

In patients with marked deformity, splinting is advisable prior to obtaining radiographs. Alternatively, the clinician and an assistant may accompany the patient and assist with positioning of the obviously deformed extremity while ensuring neurovascular status does not deteriorate. (See 'Imaging' below.)

Further care is determined based upon the radiographic findings and the presence of bony tenderness as follows:

●Patients with positive radiographs are treated according to the specific findings. (See 'Acute injury' below.)

●Skeletally immature patients with normal radiographs but focal bony tenderness may still have an occult fracture (figure 14) and warrant immobilization and repeat evaluation in 7 to 10 days. (See "Proximal fractures of the forearm in children", section on 'Occult fractures of the elbow'.)

●Patients without fracture, effusion, or dislocation on plain radiographs and no focal bony tenderness typically have a soft tissue bruise that can be managed symptomatically with rest, local application of ice packs, and a brief course of nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen.

Evidence suggests that exclusion of a fracture in children with elbow injuries based upon physical examination alone misses a significant number of fractures as follows:

●In a prospective observational study of 332 children (median age 9 years) undergoing evaluation for an elbow injury in a pediatric emergency department, almost 60 percent of the 299 patients with an abnormal examination (decreased extension or bony tenderness at one of five sites) had a fracture or elbow joint effusion (ie, a positive fat pad sign suggesting an occult supracondylar fracture). Of the 33 children with elbow pain but a normal examination, seven (21 percent) had a fracture or effusion [5].

●In another prospective multicenter observational study that included 233 children (median age 10 years) with an elbow injury, 52 percent of children had a fracture or effusion on plain radiographs including 12 percent of children with normal arm extension after analgesia and 2 percent of children with normal arm extension and point tenderness over the radial head [4].

Subacute or chronic injury — Children and young adolescents with subacute or chronic elbow injuries frequently can have a working diagnosis established by an experienced clinician after a careful physical examination. Imaging with plain radiographs and/or magnetic resonance imaging (MRI) may also be indicated depending upon the condition and its severity. (See 'Subacute or chronic injury' below.)

Imaging — The indications for imaging of the elbow depend upon the timing of the injury and, in patients with chronic elbow pain, the history and physical examination. (See 'Acute injury' above and 'Subacute or chronic injury' above.)

In patients with acute elbow injury and selected patients with subacute or chronic injury, plain radiographs should be obtained in three views: anterior-posterior, lateral, and lateral oblique (image 1). The anterior-posterior view shows the epicondyles (medial and lateral) and the articular surfaces (radiocapitellar and ulnotrochlear). The lateral shows the relationship between the bones of the distal humerus and proximal forearm.

The lateral oblique shows the radiocapitellar joint, medial epicondyle, radioulnar joint, and coronoid process. Comparison views do not increase diagnostic accuracy, but they may be helpful for patients who have inconclusive initial radiographic and clinical evaluation [6].

Several anatomic relationships should be evaluated on lateral elbow radiographs to avoid failing to recognize subtle fractures (see "Elbow anatomy and radiographic diagnosis of elbow fracture in children", section on 'Plain radiograph interpretation'):

●The line along the anterior humerus should intersect the middle one-third of the capitellum (anterior humeral line) (image 3).

●The line of the long axis of the radius should extend through the middle of the capitellum (radiocapitellar line) (image 3).

●The fat pad of the elbow usually sits along the anterior border of the coronoid fossa and is concave-shaped. The fat pad is displaced superiorly and ventrally and appears convex if a fracture (sail sign) if a significant effusion (most often resulting from a fracture) is present (figure 15).

MRI is an excellent tool in the evaluation of the soft tissue structures damaged in chronic overuse injuries. Muscles, tendons, ligaments, nerves, and articular cartilage as well as more subtle bone injuries such as occult fracture and osteochondritis dissecans are well-imaged using MRI. Indications for MRI depend upon clinical findings and the likely diagnosis.

DIFFERENTIAL DIAGNOSIS

Acute injury — Children and young adolescents with elbow pain after an acute injury have a high likelihood of fracture or dislocation although radial head subluxation should also be considered in preschool children.

Fracture — Up to 60 percent of children and young adolescents with decreased range of motion or bony tenderness after an elbow injury have a fracture [4,5]. Furthermore, a significant number of patients with elbow pain but a normal examination also have a fracture. Thus, these patients should undergo plain radiographs and receive care according to the findings. (See 'Acute injury' above.)

Patients with a significant deformity warrant careful assessment for neurovascular compromise or an open fracture and prompt orthopedic consultation should occur if either is present.

The most common elbow fractures in children and young adolescents include:

●Supracondylar fracture – Supracondylar fractures account for up to 60 percent of pediatric elbow fractures (image 4 and image 2). They occur most frequently in children between 5 and 10 years of age. Supracondylar fractures result from a fall on an outstretched arm in up to 70 percent of patients. Most fractures in older children result from higher falls from playground equipment (eg, monkey bars, swings) or another high energy mechanism. The child with a supracondylar fracture typically has elbow pain, swelling, and limited to no range of motion at the elbow. Patients with neurovascular compromise or signs of an open fracture warrant prompt consultation with an orthopedic surgeon. (See "Supracondylar humeral fractures in children", section on 'Clinical presentation'.)

The radiographic assessment, classification, and management of supracondylar fractures are discussed separately. (See "Supracondylar humeral fractures in children".)

●Lateral condyle fracture – Lateral condylar fractures account for up to 15 percent of all elbow fractures in children. Lateral condylar fractures occur after a fall on an outstretched hand where lateral force to the forearm puts varus stress on the elbow joint. This stress causes soft tissue structures (eg, extensor muscles and lateral collateral ligaments) to avulse the lateral condyle (figure 16). A lateral condylar fracture may also result from a fall on the palm with the elbow flexed. In this mechanism, the radial head is driven directly into the lateral condyle. The child with a lateral condylar fracture typically has elbow pain and swelling over the lateral elbow with a decreased range of motion including limited extension and supination or pronation. (See "Evaluation and management of condylar elbow fractures in children", section on 'Epidemiology' and "Evaluation and management of condylar elbow fractures in children", section on 'Mechanism of injury' and "Evaluation and management of condylar elbow fractures in children", section on 'Physical findings'.)

The radiographic assessment, classification, and management of lateral condylar fractures are discussed separately. (See "Evaluation and management of condylar elbow fractures in children".)

●Medial epicondyle avulsion fracture – Medial epicondyle avulsion fractures are the most common elbow injury related to throwing in skeletally immature adolescents (between the appearance and the fusion of the secondary ossification centers (table 3)) and are included among the injuries referred to as "Little League elbow" (table 4). Patients may report that they felt a sudden "pop" of the elbow during the throw, followed by acute onset of pain [7]. The physical findings in athletes with medial epicondyle avulsion are similar to those in apophysitis (pain to palpation over the medial epicondyle and pain with resisted wrist flexion (picture 2) and pronation). However, radiographs demonstrate a separation of the medial epicondyle apophysis (image 5 and figure 17).

Treatment for chronic avulsion fractures involves avoiding all throwing and forceful contraction of the wrist flexors/pronators (some patients may need a sling for one to two weeks). Most patients can be limited to activities of daily living. While throwing is restricted, it is important to identify any shoulder or kinetic chain issues that can be rehabilitated to avoid stress on the elbow. After six to eight weeks of no throwing, if the clinical exam is normal, a graduated throwing program can be started in conjunction with proper throwing techniques. Treatment of acute minimally displaced (<2 mm) medial epicondyle avulsion fractures involves splint immobilization for six weeks. Early range of motion exercises out of the splint can be started once the athlete can perform them without pain (usually one to two weeks). Referral to an orthopedic surgeon is advised if greater than 2 mm displacement of the apophysis has occurred or if concomitant ulnar nerve findings are present.

●Radial head or neck fracture – Radial head or neck fractures typically occur after a fall on the outstretched hand with the elbow extended. This mechanism transmits a valgus force to the neck of the radius, pushing the radial head onto the capitellum (figure 14 and image 6). The clinician should suspect a proximal radial fracture if there is tenderness over the radial head, and supination and pronation of the forearm produces pain on the lateral side of the elbow. Approximately half of children with proximal radial fractures will have a second elbow injury such as a ligament rupture, a medial epicondyle fracture, or an olecranon or other ulnar fracture. Radial head and neck fractures and their management are discussed in more detail separately. (See "Proximal fractures of the forearm in children", section on 'Radial head and neck fractures'.)

Posterior elbow dislocation — Posterior elbow dislocations account for approximately 5 percent of all elbow injuries in children; 64 percent have associated fractures, typically a proximal radial fracture through the physis (image 7) [8]. The peak incidence occurs at 12 years of age.

●Clinical findings – Posterior elbow dislocations usually occur after a fall or a twisting injury to the elbow. Pain and obvious deformity aid in the diagnosis. The olecranon is prominent posteriorly, and the normal triangular relationship between the olecranon and the medial and lateral epicondyles is disrupted. Radiographs should be obtained to rule out associated fracture.

Neurovascular complications are relatively uncommon, but they are imperative to diagnose [9]. Transient ulnar neuropathy, with the classic findings of altered sensation involving the ring and little fingers and hypothenar eminence, occurs in approximately 10 percent of cases. Median nerve injury occurs less frequently and is characterized by severe pain that is not relieved by elbow relocation. Brachial artery injuries, a rare complication of posterior elbow dislocation, cause radiating pain, decreased skin temperature, decreased pulse, and pallor in the distal arm. Early microvascular repair of brachial artery injuries decreases the long-term sequelae, including the development of contracture of the flexor muscles and median and ulnar nerve palsies (Volkmann's ischemic contracture) [10,11].

●Management – Unreduced dislocations should be immobilized "as is" pending evaluation and reduction by an experienced practitioner or orthopedic surgeon [12]. Given the high likelihood of an associated fracture, children and young adolescents with an elbow dislocation warrant plain radiographs prior to reduction, which should be obtained promptly in patients with neurovascular compromise. Complicated dislocations associated with neurovascular compromise or fracture with dislocation warrant prompt evaluation and treatment by an orthopedic surgeon.

Analgesia (eg, intravenous morphine) and procedural sedation are important adjuncts to a successful reduction. (See "Pain in children: Approach to pain assessment and overview of management principles", section on 'Pharmacologic therapy' and "Procedural sedation in children: Approach".)

Several techniques are effective in the reduction of the uncomplicated posterior dislocation (ie, dislocation without associated fracture or neurovascular compromise) (figure 18 and figure 19). The common components include [13]:

•Supination of the forearm

•Elbow flexed to 90 degrees

•Counter traction stabilizes the humerus

•Gentle axial traction on the forearm

If not successful, adding more elbow flexion, volar directed pressure on the olecranon process as well as gentle pressure on the proximal forearm in a volar direction may be helpful [14]. However, each attempt risks further injury to the elbow and adjacent structures. Thus, orthopedic consultation is warranted if the dislocation is not successfully reduced in a timely fashion.

After reduction, the forearm should be maintained in pronation to avoid supination that could lose elbow reduction. Joint stability, passive elbow flexion and extension range of motion, and neurovascular examination should be assessed. Evidence of instability, diminished range of motion indicative of intraarticular osteochondral fragments, or neurovascular compromise requires prompt orthopedic consultation for operative treatment [13].

In patients with good joint stability and an intact neurovascular examination after reduction, intermittent immobilization with a posterior splint for 7 to 10 days as needed for pain and during activities when it is difficult to control external stresses to the arm (eg, school) is indicated along, with active early range of motion exercises [13]. Subsequently, the arm may be placed in a hinged brace for two to three weeks while range of motion exercises are continued. Rehabilitation should be supervised by an experienced practitioner until full recovery (approximately six to eight weeks). Long-term functional outcomes are very good [15].

Radial head subluxation (pulled elbow) — Radial head subluxation (RHS) is the most common elbow injury in preschool children (1 to 4 years old). A common history is that the forearm was pulled while it was pronated and the elbow was extended (figure 20). This often occurs as a parent or caregiver grabs the arm to prevent the child from falling or pulling away; RHS also can occur when a child is swung by the forearms or during play. Children with RHS may hold the affected arm close to the body with the elbow either fully extended or slightly flexed and the forearm pronated (figure 21). The child is in little distress unless attempts are made to move the elbow. There is also no focal bony tenderness, bruising, deformity, or swelling suggestion of fracture, especially over the distal humerus and proximal ulna. (See "Radial head subluxation (pulled elbow): Evaluation and management", section on 'Evaluation'.)

The diagnosis of RHS can be made when the characteristic history and examination findings are present. Even in the absence of the classic history, the diagnosis should be considered when the examination is characteristic. The reduction and management of RHS are discussed separately. (See "Radial head subluxation (pulled elbow): Evaluation and management", section on 'Management'.)

Subacute or chronic injury — The differential diagnosis for elbow injury in children and young adolescents is organized according to the location of pain (table 7).

Anterior elbow pain — Causes of subacute or chronic anterior elbow pain include:

●Occult fracture

●Anterior capsule strain (may be associated with posterolateral olecranon impingement)

●Median nerve compression syndromes

●Radiculopathy of C5/6

Occult fracture — Children and young adolescents have incomplete ossification and are more prone to fractures that may not be initially apparent upon plain radiographs, particularly, radial neck or olecranon fractures.

Occult fractures of the radial neck or olecranon may present with anterior elbow pain and limitation of motion. Repeated radiographs one to two weeks after onset of pain or injury may show evidence of bone healing. MRI can also be used to identify occult fractures when plain radiographs are not definitive. Management depends upon the location and type of fracture. (See "Proximal fractures of the forearm in children", section on 'Occult fractures of the elbow'.)

Anterior capsule strain/posterolateral olecranon impingement — Anterior capsule strain occurs after a hyperextension injury from a fall, with repetitive extension motions (eg, the follow-through of a pitcher, gymnastics, and strength training), or during a posterior subluxation injury with spontaneous relocation.

●Clinical findings – Following an acute injury, the patient can experience anterior capsule pain and posterior lateral olecranon pinching when the elbow is passively moved into terminal extension. During more chronic repetitive hyperextension, the pain at terminal extension may be accompanied by fibrotic flexion contracture. The diagnosis is supported by a positive bounce home/arm/posterior elbow impingement test in which the patient’s elbow is flexed and their forearm supinated. The examiner will rapidly move the elbow into full extension which will reproduce the posterior pinching and the anterior stretching sensation [16].

●Diagnosis – The diagnosis is established by clinical findings and exclusion of other conditions that can restrict full extension. Plain radiographs of the elbow are indicated to exclude bony causes of limited extension (eg, olecranon apophysitis or fracture and osteochondritis dissecans).

Other conditions that limit elbow extension include:

•Posteromedial olecranon impingement syndrome – Patients typically have posterior and medial pain which is worsened by valgus stress during physical examination. (See 'Valgus extension overload/posterior medial olecranon impingement syndrome (VEO/OIS)' below.)

•Olecranon apophysitis or stress fracture (especially in throwers and gymnasts) – These patients usually have posterior pain at the end of their range with full extension and with resisted elbow extension testing. (See 'Olecranon apophysitis/stress fracture' below.)

•Distal biceps tendinitis and muscle spasm – These athletes have pain on palpation of the distal biceps tendon, weakness in elbow flexion, and altered accessory motion in the proximal radius.

•Osteochondritis dissecans (osteonecrosis) – The characteristic findings may be apparent on plain radiographs or MRI. (See "Osteochondritis dissecans (OCD): Clinical manifestations, evaluation, and diagnosis", section on 'Imaging'.)

The diagnosis can typically be established by physical findings. Patients with loss of range or motion, catching, locking, or posterior pain warrant plain radiographs. Additional imaging may be indicated based upon the most likely diagnosis.

●Management – Treatment of anterior capsule strain entails protection from repeated injury and passive range of motion exercises to avoid contracture. Splinting in a dynamic, hinged or static, progressive brace is part of nonoperative therapy to treat those patients with loss of range of motion. Patients who do not gain a full range of motion after six months should be referred to an orthopedic surgeon.

In patients with excessive motion, working on eccentric firing of the biceps can avoid getting into the painful terminal elbow extension. It is also important to translate these firing patterns into proper follow-through technique so that patient’s condition will not return when they restart their sports activity (especially pitchers).

Median nerve compression syndromes — Median nerve compression syndromes present with palmar side proximal forearm pain, particularly with repeated pronation, and with numbness and/or weakness in the median nerve distribution.

●Clinical findings – The most common syndromes are the pronator and anterior interosseous nerve (AON) syndromes [17,18]. The pronator syndrome is characterized by compression of the proximal median nerve between the humeral and ulnar head of the pronator teres muscle (common median nerve). Patients typically complain of proximal forearm numbness and pain and have a positive pronator compression test (figure 22). Motor weakness is not a prominent sign, although it is sometimes present and involves opponens pollicis, flexor pollicis brevis, flexor pollicis longus, flexor digitorum profundus of the middle and pointer fingers, the pronator quadratus, and/or the flexor carpi radialis. The pain of pronator syndrome is usually activity-related and not typically present at night.

The AON syndrome follows compression of the anterior interosseous branch of the median nerve by the flexor digitorum superficialis muscle (anterior interosseous branch of median nerve). Patients initially have proximal forearm pain followed by weakness in the hand with no sensory deficits. On physical examination they have a weak "OK sign" and/or a lack of distal interphalangeal flexion in OK sign (more of a pincer grasp than an OK sign) (picture 3).

The diagnosis is typically made based upon clinical findings.

●Differential diagnosis – Median nerve deficits may also arise from a C6 radiculopathy (brachial plexus or cervical spine pathology), carpal tunnel syndrome, occult fracture (eg, Galeazzi fracture), interphalangeal joint pathology, and rupture of the flexor pollicis. The following features typically differentiate these conditions from pronator or AOIN syndrome:

•Carpal tunnel syndrome is rare in children and is associated with night-time paresthesias, paresthesia with wrist compression, and thenar atrophy. (See "Carpal tunnel syndrome: Clinical manifestations and diagnosis".)

•Interphalangeal joint pathology and flexor pollicis rupture typically present with hand pain.

•C6 radiculopathy causes pain that radiates from the brachial plexus or the neck. (See "Brachial plexus syndromes", section on 'Symptoms and signs' and "Clinical features and diagnosis of cervical radiculopathy", section on 'Clinical features' and "Clinical features and diagnosis of cervical radiculopathy", section on 'Examination'.)

When the diagnosis is uncertain, neurodiagnostic evaluation may be helpful in localizing the lesion and degree of nerve injury. (See "Overview of nerve conduction studies".)

Management – The initial treatment for pronator or AOIN syndrome is nonoperative and includes [17,18]:

●Relative rest (avoidance of pain-producing activities: elbow flexion, wrist pronation, and grip activation) for four to six weeks.

●A short course of nonsteroidal anti-inflammatory drugs (NSAIDs, eg, ibuprofen).

●Immobilization with a posterior long arm splint for the initial 10 to 14 days except for gentle range-of-motion exercises.

●Progressive stretching and strengthening of elbow flexors, wrist flexors and pronators, and grip exercises.

If no interval improvement is seen in six to eight weeks, referral to an orthopedic surgeon is warranted. However, AOIN syndrome can recover spontaneously up to 12 months after onset of symptoms [6,18].

Referred nerve pain — Anterior elbow pain may represent referred pain from a brachial plexus (figure 23) or cervical spine (C5/C6) radiculopathy. Patients with these conditions typically describe pain radiation from the primary location that may feel like an electric shock. The clinical features and manifestations of brachial plexus and cervical spinal root syndromes are discussed separately. (See "Overview of upper extremity peripheral nerve syndromes".)

Posterior elbow pain — Subacute or chronic posterior elbow pain can be caused by the following (table 7):

●Olecranon apophysitis/stress fracture

●Olecranon bursitis

●Triceps tendinitis or osteophytic degeneration of the tendon

●Valgus extension overload/posteromedial olecranon impingement syndrome

●Radiculopathy of C7, T1-2

Olecranon apophysitis/stress fracture — The olecranon apophysis begins growth in mid to late childhood and closes in early to mid-adolescence (figure 5 and table 3). During throwing or gymnastic movements in which the arm becomes weight-bearing (eg, tumbling), the triceps muscle applies significant force to the apophysis [19,20]. In throwers with medial instability, the olecranon will experience increased torque stress as the medial olecranon hits the medial olecranon fossa [21]. Over time, these forces can cause chronic injury to the posteromedial olecranon that varies according to the development status of the apophysis as follows [19]:

●Apophysitis – Olecranon apophysis widens and fails to close in prepubertal children

●Avulsion fracture – The partially closed apophysis is avulsed in young adolescents

●Stress fracture – Repeated trauma causes a stress fracture in adolescents with a closed apophysis

●Clinical findings – Patients present with posterior elbow weakness and pain during tumbling exercises or the follow-through phase of throwing. Physical examination demonstrates posterior elbow swelling, tenderness to palpation of the posterior and medial portion of the olecranon, and decreased range of motion. The pain can be reproduced by resisted elbow extension. The following techniques will be normal with apophysitis but positive in olecranon stress fractures (and posterolateral olecranon impingement) [19]:

•Bounce home/posterior elbow impingement test – The examiner takes the fully flexed elbow and, with the patient relaxed, rapidly moves it into extension.

•Arm bar test – The examiner places the fully pronated and extended the elbow on his or her shoulder and applies downward pressure on the proximal forearm and midhumerus (figure 24).

●Diagnosis – Imaging confirms the clinical diagnosis as follows [19,20]:

•In patients with olecranon apophysitis, widening or fragmentation of the olecranon apophysis is seen on plain radiographs. Comparison views with the unaffected elbow can be helpful in identifying minimal changes.

•Olecranon avulsion is typically apparent on plain radiographs as an avulsed fragment off the olecranon.

•Patients with stress fracture may have findings on plain radiographs. When plain radiographs are negative, MRI can confirm the diagnosis in patients with characteristic findings as well as look at the anatomy of the ulnar collateral ligament (associated with olecranon stress fractures).

●Management – The initial management of olecranon apophysitis or stress fracture is nonoperative and consists of the following [19,20]:

•Relative rest (avoidance of pain-producing activities [eg, throwing or gymnastics]) for a minimum of four to six weeks.

•Intermittent application of ice packs and a short course of NSAIDs (eg, ibuprofen) for pain.

•Physical therapy with specific attention to eccentric biceps firing as well as attention to technique (ball release) and training issues.

Patients with persistent symptoms after a period of three months warrant referral to an orthopedic surgeon.

Olecranon bursitis — Olecranon bursitis may be seen in repetitive throwers (eg, darts) or in children and adolescents who have direct contact trauma or friction to the olecranon (eg, a fall on a hard surface, wrestling). A boggy swelling over the olecranon that can be as large as an egg will be present on physical examination (picture 4). Other diagnostic considerations include septic bursitis/arthritis, rheumatologic disease (eg, juvenile idiopathic arthritis), or triceps tendinitis.

Triceps tendon injury — Whereas triceps tendinitis is relatively common [22], rupture is rare in children and young adolescents unless associated with systemic lupus erythematosus, hyperparathyroidism, or xanthomatous degeneration or the athlete is receiving systemic or local corticosteroids, anabolic steroids, or quinolone antibiotics [23,24]. Athletes may experience triceps tendinitis related to excessive strength training that emphasizes elbow extension (eg, dips, bench press, triceps curls, or swimming follow through). (See "Use of androgens and other hormones by athletes", section on 'Other' and "Fluoroquinolones", section on 'Tendinopathy'.)

●Clinical findings – Patients with triceps tendinitis note a snapping sensation along the medial border of the elbow where the triceps snaps over the medial epicondyle when the arm is in greater than 135 degrees of flexion [25]. Similar complaints also may occur in patients who have a subluxating ulnar nerve, but it usually occurs at 90 degrees of flexion. Physical examination may show swelling and pain to palpation over the distal triceps and posterior olecranon, pain with resisted extension, and decreased range of motion in elbow extension.

Patients with triceps ruptures may have a palpable defect, usually at the tendon's insertion on the olecranon, and decreased strength in extension of the elbow [24]. Olecranon impingement (eg, apophysitis or stress fracture) may have similar findings. However, patients with triceps tendinitis have pain over the distal humerus whereas pain over the posteromedial olecranon is more characteristic of olecranon apophysitis or stress fracture. (See 'Olecranon apophysitis/stress fracture' above.)

●Diagnosis – Patients with characteristic findings of triceps tendinitis can be diagnosed clinically. Tendon rupture requires plain radiographs to exclude bony avulsion and also warrants MRI or ultrasound to determine if the tear is partial or complete.

●Management – Tendinitis can be treated with relative rest, intermittent application of ice packs, a short course of NSAIDs and a stretching and strengthening program. Corticosteroid injections should be avoided [22].

Children with suspected triceps rupture warrant referral to an orthopedic surgeon; complete rupture requires surgical repair, whereas partial tears are typically initially treated by splint immobilization for four weeks with 30 degrees of elbow flexion [26].

Valgus extension overload/posterior medial olecranon impingement syndrome (VEO/OIS) — Repetitive valgus stress at the elbow can stretch the ulnar collateral ligament, leading to medial elbow instability. Repetitive valgus extension loads, in the presence of medial instability, cause the medial olecranon to rotate internally and rub against the medial olecranon fossa and/or stretch the ulnar nerve. (See "Throwing injuries of the upper extremity: Clinical presentation and diagnostic approach", section on 'Elbow injuries'.)

●Clinical findings – Patients with VEO/OIS have tenderness to palpation along the medial border of the olecranon fossa, pain with valgus of the elbow in extension, and possible flexion contracture. Children and adolescents who have triceps tendinitis may have similar symptoms, but their pain to palpation is posterior rather than medial, and they do not have pain with passive hyperextension of the elbow (moving stress test of the elbow (movie 1)).

Posteromedial olecranon impingement, which can occur without medial instability, may result in osteophyte formation, loose bodies, and fracture. Insidious onset of posterior medial elbow pain with locking and catching sensation in the elbow is the hallmark complaint. This condition needs to be differentiated from osteochondritis dissecans of the capitellum. (See "Osteochondritis dissecans (OCD): Clinical manifestations, evaluation, and diagnosis", section on 'Clinical presentation'.)

●Diagnosis – Radiographs are indicated to identify olecranon impingement with osteophyte formation and, in patients with locking or catching, to exclude articular foreign bodies or osteochondritis dissecans.

●Management – The treatment of VEO/OIS is discussed separately. (See "Throwing injuries of the upper extremity: Treatment, follow-up care, and prevention", section on 'Valgus extension overload syndrome'.)

Referred nerve pain — Posterior elbow pain may be caused by referred nerve pain from C7, C8, and/or T1 radiculopathies arising from the brachial plexus (figure 23) or low cervical or upper thoracic spinal cord roots. Patients with these conditions typically describe pain radiation from the primary location that may feel like an electric shock. The clinical features and manifestations of brachial plexus and cervical spinal root syndromes are discussed separately. (See "Overview of upper extremity peripheral nerve syndromes".)

Medial elbow pain — Medial elbow pain can be caused by (table 7):

●Little League elbow

•Medial epicondyle avulsion fracture (see 'Fracture' above)

•Medial epicondyle traction apophysitis

•Ulnar collateral ligament tear

●Medial epicondylitis (golfer's elbow)

●Ulnar neuritis

●Radiculopathy of C8, T1

Little League elbow — Little League elbow is the name used to describe a group of elbow problems related to the stress of throwing in children and young adolescents [27]. Throwing can cause medial symptoms as well as lateral and posterior symptoms. A stepwise clinical approach to throwing injuries is provided separately. (See "Throwing injuries of the upper extremity: Clinical presentation and diagnostic approach", section on 'Stepwise clinical approach'.)

In children and young adolescent throwers, the skeletal maturity of the athlete affects the type of medial elbow injury that occurs (table 4) [28]. (See 'Medial epicondyle apophysitis' below and 'Medial epicondyle avulsion fractures' below and 'Ulnar collateral ligament sprain' below.)

The epidemiology, anatomy, and biomechanics of youth throwing athletes is discussed in greater detail separately. (See "Throwing injuries: Biomechanics and mechanism of injury", section on 'Youth throwing athletes'.)

●Prevention – Risk factors for injury requiring surgery on their elbow or shoulder were discerned by comparing the throwing habits of injured and uninjured young pitchers (mean age 18 years) and included [29]:

•Throwing frequently when arm was fatigued (OR = 36, 95% CI 6.0-221.0)

•Throwing more than 80 pitches per appearance (OR = 4.0, 95% CI 1.4-11.0)

•Pitching for more than eight months per year (OR = 5.0, 95% CI 1.4-18.3)

•Fast ball faster than 85 mph (OR = 3, 95% CI 0.9-7.0)

•Additionally, pitchers who also play catcher are more likely to have shoulder or elbow injuries than those who play other positions on their off day [30].

A systematic review added age >12 and pitching on multiple teams to the list of risk factors for elbow and shoulder injuries in adolescent baseball players [31]. In a 10-year prospective study of young pitchers (age 9 to 14), 5 percent required elbow or shoulder surgery or had injuries that caused them to stop playing baseball. Only 2.2 percent were still pitching at the end of the study [32].

The total number of pitches thrown by children in youth baseball (eg, Little League) may be more important than the type of pitch thrown (eg, curveball versus fastball) in predicting elbow injury, given that biomechanical forces required to throw a curveball are actually less than for a fastball [33,34]. However, increased frequencies of elbow and shoulder pain have been described in children who throw breaking pitches (curveballs or sliders) [35].

The Committee on Sports Medicine and Fitness of the American Academy of Pediatrics (AAP) and Little League Baseball recommend that preventive measures should be employed to prevent these injuries in young pitchers [36,37]. These measures include restriction of the amount of pitching (eg, limit pitches per game, months per year spent pitching); instruction in proper throwing techniques; avoidance of pitching when the arm hurts or is fatigued; and the education of coaches, parents or caregivers, and children to facilitate early diagnosis and treatment. Furthermore, injuries may be prevented by warm-up exercises that emphasize stretching, dynamic mobility, and strength. (See "Throwing injuries of the upper extremity: Treatment, follow-up care, and prevention", section on 'Active warm-up program for shoulder, arm, and forearm'.)

Medial epicondyle apophysitis — The medial epicondyle has the longest exposure to medial distraction forces in the elbow because it is the last ossification center to close (figure 5 and table 3).

●Clinical findings – Children with medial epicondyle apophysitis complain of medial elbow pain, initially after throwing, that progresses to persistent pain. Physical examination demonstrates pain to palpation of the medial epicondyle that is exacerbated by resisted wrist flexion (picture 2) and valgus testing of the elbow. Elbow extension may be limited.

●Diagnosis – Radiographs demonstrate an open ossification center without separation.

●Management – Treatment includes no throwing for four to six weeks and pain control with intermittent application of ice packs and a short course of NSAIDs (eg, ibuprofen).

Correction of throwing mechanics and a progressive throwing program over the subsequent six to eight weeks will help the athlete to return to play. In addition, a position change from pitcher (typically 15 to 30 throws per inning) may help the player to avoid overloading the elbow, especially during ages associated with peak height velocity (figure 25A-B).

Medial epicondyle avulsion fractures — Medial epicondyle avulsion occur in young adolescents. The physical findings in patients with medial epicondyle avulsion are similar to those in apophysitis (pain to palpation over the medial epicondyle and pain with resisted wrist flexion (picture 2) and pronation). However, radiographs demonstrate a separation of the medial epicondyle apophysis (image 5 and image 8). Contralateral radiographs may be needed to appreciate the separation. The clinical findings and treatment of these fractures are discussed in greater detail separately. (See 'Fracture' above.)

Ulnar collateral ligament sprain — Ulnar collateral ligament sprain occurs in the skeletally mature thrower, as well as in wrestlers, gymnasts, or football players who sustain traumatic valgus injury from a fall on an outstretched arm or a tackle while the hand is planted. The anterior bundle of the ulnar collateral ligament is the primary restraint to valgus forces at the elbow during the throwing motion. (See "Throwing injuries of the upper extremity: Clinical presentation and diagnostic approach", section on 'Elbow injuries'.)

The clinical findings, approach to imaging, and management of ulnar collateral ligament tears are discussed separately. (See "Throwing injuries of the upper extremity: Clinical presentation and diagnostic approach", section on 'Elbow injuries' and "Throwing injuries of the upper extremity: Treatment, follow-up care, and prevention", section on 'Ulnar collateral ligament sprain'.)

Sublime tubercle avulsion — The sublime tubercle is located on the proximal medial ulna and is the site for insertion of the anterior bundle of the ulnar collateral ligament. Avulsion of the tubercle is an uncommon type of ulnar collateral ligament injury seen after forceful throwing in skeletally mature adolescent athletes [19,20,38]. Patients typically present with medial elbow pain during throwing. Physical examination demonstrates medial elbow tenderness and increased pain with valgus stress.

●Diagnosis – Sublime tubercle avulsion requires confirmation by plain radiographs, which can show avulsion of the tubercle. In patients with clinical features but normal plain radiographs, MRI may can establish the diagnosis.

●Management – Seventy-five percent of nondisplaced sublime tubercle avulsions will fail to recover after two to three months of rest and progressive throwing, so for those that fail to attain full recovery, operative fixation is required. All patients having surgery return to full throwing following rehabilitation [38]. Thus, these patients warrant referral to an orthopedic surgeon [19,20].

Medial epicondylitis — Medial epicondylitis, also known as golfer's elbow, results from improper overuse of the forearm pronators and wrist flexors. It is less common in skeletally immature patients than in older adolescents and adults. Physical examination demonstrates pain to palpation over the medial epicondyle (picture 1) and pain with resisted wrist flexion (picture 2) and pronation.

The clinical findings and management of medial epicondylitis are discussed in greater detail separately. (See "Elbow tendinopathy (tennis and golf elbow)".)

Ulnar neuritis — Ulnar neuritis is the most common nerve injury involving the elbow. It has numerous etiologies, including:

●Direct trauma (from a fall or leaning on the elbows)

●Repetitive traction (eg, the acceleration phase of throwing)

●Exaggerated valgus from medial instability of the elbow [39]

●Prolonged elbow hyperflexion (eg, hyperflexed during sleep or while talking on the phone)

●Compression from muscle hypertrophy (eg, triceps, anconeus muscles in throwers and weightlifters)

●Friction from ulnar nerve subluxation (16 percent of the general population have this hypermobility of the ulnar nerve)

●Upper limb neural tension from abnormal muscle spasm and altered by mechanics [40]

The clinical findings, diagnosis, and management are as follows:

●Clinical findings – Ulnar neuritis presents with pain at the posterior medial elbow that radiates proximally to the medial bicep-triceps interval and distally to the palm and dorsum of the hand and the fifth and ulnar fourth finger. The patient should be asked about clumsiness and lack of dexterity which may represent motor weakness of the lumbrical and interosseous muscles of the hand. Ulnar nerve findings without elbow symptoms require more attention to the ulnar nerve as it crosses the wrist (Guyon’s Canal). (See "Evaluation of the adult with acute wrist pain", section on 'Ulnar neuropathy (Guyon’s canal syndrome)'.)

Additional testing helps to confirm the diagnosis and contributing factors as follows:

•The pain is reproduced with the Tinel maneuver at the cubital tunnel (picture 5) and prolonged (three minutes) elbow flexion and wrist extension.

•Valgus instability at 30 degrees of flexion is an important test to identify whether medial instability is contributing to nerve irritation, particularly in throwers.

•Foraminal loading to stress the C8 nerve root will help to exclude cervical pathology. This test is performed by pushing down on the top of the head with gentle force.

●Diagnosis – A working diagnosis is typically made based upon clinical findings. In patients with medial instability, plain radiographs are indicated to identify the presence of changes consistent with medial instability.

●Management – Management varies according to the presence of medial instability on physical examination as follows:

•Ulnar neuritis without medial instability – Treatment includes avoidance of exacerbating activities, use of elbow pads to decrease incidental trauma, and use of elbow splints or a towel rolled around the elbow to prevent arms from becoming fully flexed during sleep during sleep.

Anti-inflammatory agents and physical therapy may also be helpful. Recalcitrant cases (lasting three to six months), cases in which the ulnar nerve continues to sublux out of the cubital tunnel, or those with motor deficits warrant referral to an orthopedic surgeon.

•Ulnar neuritis with medial instability – The initial management is similar to that of an ulnar collateral ligament sprain. (See "Throwing injuries of the upper extremity: Treatment, follow-up care, and prevention", section on 'Ulnar collateral ligament sprain'.)

Lateral elbow pain — Causes of lateral elbow pain include (table 7):

●Osteochondritis dissecans of the capitellum

●Panner disease

●Lateral epicondylitis

●Radial nerve syndromes

●Musculocutaneous nerve entrapment

●Radiculopathy of C5/6

Osteochondritis dissecans — Osteochondritis dissecans (OCD) is an avascular necrosis of the articular cartilage and underlying subchondral bone that occurs in the capitellum in older athletes (age 13 to 15 years), particularly gymnasts, baseball pitchers, and American football quarterbacks.

●Clinical findings – The symptoms include dull, poorly localized lateral elbow pain with decreased range of motion. Mechanical symptoms of popping, locking, and catching usually are late symptoms. Patients with OCD of the elbow have swelling over the capitellum, limited range of motion (extension much more significant than supination, and pronation) and increased pain when performing pronation and supination in full elbow extension (radiocapitellar compression test). (See "Osteochondritis dissecans (OCD): Clinical manifestations, evaluation, and diagnosis".)

●Diagnosis – The diagnosis of osteochondritis dissecans requires demonstration of the lesion on imaging. Plain radiographs show flattening of the capitellum with a crater and subchondral sclerosis in some patients (image 9) but may be normal initially. MRI is helpful in early detection and staging of the lesion. (See "Osteochondritis dissecans (OCD): Clinical manifestations, evaluation, and diagnosis", section on 'Diagnosis and classification'.)

●Management – The management of OCD of the elbow depends upon fragment stability and is discussed in greater detail separately. (See "Management of osteochondritis dissecans (OCD)".)

Panner disease — Panner disease is an osteochondrosis of the capitellum. Osteochondrosis is a developmental disorder of the growing epiphysis and its secondary ossification centers [19]. It occurs most frequently in boys between 7 and 12 years of age and is almost always unilateral and in the dominant (ie, throwing) arm.

●Clinical findings – The symptoms include lateral elbow tenderness with decreased range of motion in extension. Appreciable swelling with effusion may occur over time.

●Diagnosis – Plain radiographs establish the diagnosis and show fragmentation (areas of sclerosis and rarefaction) of the capitellum with an irregular joint surface. These findings differentiate Panner disease from osteochondritis dissecans (flattening of the capitellum with a crater and subchondral sclerosis).

●Management – Panner disease is self-limited [19]. Initial management consists of pain control with intermittent application of ice packs, a short course of NSAIDs (eg, ibuprofen), and, in selected patients with significant pain or swelling, immobilization in a posterior long arm splint for one to two weeks.

The patient should avoid painful activities until radiographic and physical examination provides evidence of full healing (usually 6 to 12 months). Because of the young athlete's ability to regenerate and recalcify, the capitellum has excellent potential for normal anatomic and functional healing [41,42].

Lateral epicondylitis — Lateral (tennis elbow) can present in the pediatric population but is more commonly seen in adolescents and adults. Lateral epicondylitis presents with pain at the lateral epicondyle where the extensor carpi radialis brevis inserts.

●Clinical findings and diagnosis – Patients complain of sharp pain at the lateral epicondyle that may radiate down the extensor forearm especially during a power grip maneuver (eg, picking up a gallon of milk, shaking hands, strength training), keyboarding, or hitting a backhand stroke in tennis. They may also complain of wrist weakness. Pain to palpation over the lateral epicondyle that worsens with resisted wrist extension (picture 6) or passive wrist flexion with the elbow extended is demonstrated on physical examination. Unlike OCD, epicondylitis is not associated with locking and the capitellum is unaffected. Plain radiographs are typically normal. (See "Elbow tendinopathy (tennis and golf elbow)" and "Elbow tendinopathy (tennis and golf elbow)", section on 'Clinical presentation and examination'.)

●Management – The management of lateral epicondylitis is discussed separately. (See "Elbow tendinopathy (tennis and golf elbow)", section on 'Initial management' and "Elbow tendinopathy (tennis and golf elbow)", section on 'Secondary management'.)

Radial nerve syndromes — As the radial nerve enters the antecubital fossa laterally, it divides into the posterior interosseous branch and the superficial radial nerve. Compression syndromes can affect both branches as follows (see "Overview of upper extremity peripheral nerve syndromes", section on 'Radial nerve syndromes'):

●Posterior interosseous nerve (PIN) syndrome – PIN syndrome occurs from irritation of the nerve typically caused by repetitive pronation and supination, direct trauma, or mass lesion from tumor or previous injury. PIN syndrome coexists in 5 percent of lateral epicondylitis (tennis elbow) cases and may explain lack of response to conservative measures in these patients. (See "Elbow tendinopathy (tennis and golf elbow)".)

Physical examination demonstrates lateral elbow pain, usually distal to the lateral epicondyle, and weakness in the wrist, thumb, and finger extensors (wrist drop) and a weak hitch hiker's thumb up sign (figure 26).

●Radial neuropathy at the spiral groove – Also called "radial tunnel syndrome," this radial nerve syndrome occurs because of compression of the superficial radial nerve by structures in or near the radial tunnel or groove, including the supinator, extensor carpi radialis brevis, and brachioradialis. It may be caused by repetitive pronation and supination, direct trauma, ganglion, or bony lesion of the radial head. Complaints include deep, dull ache distal to the lateral epicondyle that may be worse at night. Weakness and sensory changes are uncommon. Physical examination demonstrates pain to palpation over the extensor mass about four finger breadths distal to lateral epicondyle and pain with resisted forearm supination. Pain may be reproduced by resisted extension of the middle finger with the elbow in extension (long finger extension test) (picture 7).

The diagnosis of radial neuropathy is based upon clinical findings and confirmed by neurodiagnostic testing. The management of radial nerve syndromes is discussed separately. (See "Overview of upper extremity peripheral nerve syndromes", section on 'Overview of diagnostic testing' and "Overview of upper extremity peripheral nerve syndromes", section on 'Treatment'.)

Musculocutaneous nerve entrapment — Isolated musculocutaneous nerve entrapment is rare but has been reported in swimmers, racquet players, weight lifters, and throwers who repeatedly pronate the elbow in full extension [43]. It may also complicate shoulder dislocation. Patients present with vague pain and dysesthesia in the anterior lateral portion of the elbow and forearm. Weakness of elbow flexion may also be noted upon physical examination.

The diagnosis of musculocutaneous nerve entrapment is made clinically. The management of entrapment is discussed separately. (See "Overview of upper extremity peripheral nerve syndromes", section on 'Musculocutaneous neuropathy'.)

Referred nerve pain — Lateral elbow pain may be caused by referred nerve pain from C5/6 radiculopathies arising from the brachial plexus (figure 23) or low cervical or upper thoracic spinal cord roots. Patients with these conditions typically describe pain radiation from the primary location that may feel like an electric shock. The clinical features and manifestations of brachial plexus and cervical spinal root syndromes are discussed separately. (See "Overview of upper extremity peripheral nerve syndromes".)

SUMMARY AND RECOMMENDATIONS

●Anatomy – The elbow is made up of three interrelated joints (the radiocapitellar [radiohumeral], ulnohumeral, and radioulnar) and their stabilizing ligaments (table 1 and figure 2). Skeletal maturity in children and adolescents is classified according to the appearance and fusion of the secondary ossification centers of the distal humerus and proximal radius and ulna (table 3 and figure 5). (See 'Basic anatomy' above.)

●Evaluation – A careful history and physical examination help to narrow the possible causes of an elbow injury. (See 'History' above and 'Physical examination' above.)

●Diagnostic approach – The diagnostic approach after an elbow injury varies according to whether the injury is acute or chronic:

•Acute injury – Children and young adolescents with acute elbow injuries and elbow pain warrant plain radiographs to evaluate for fractures or dislocation, especially when physical findings show deformity, swelling, focal bony tenderness (eg, tenderness in the supracondylar region of the distal humerus, radial head, medial or lateral epicondyle, or over the olecranon), or any decreased range of motion. Further care is determined based upon the radiographic findings and the presence of bony tenderness. (See 'Acute injury' above.)

•Subacute or chronic injury – Subacute or chronic elbow injuries typically are caused by repetitive activity (eg, throwing a baseball). Children and young adolescents with subacute or chronic elbow injuries frequently can have a working diagnosis established by an experienced clinician after a careful physical examination. (See 'Subacute or chronic injury' above.)

●Imaging – In patients with acute elbow injury and selected patients with subacute or chronic injury, plain radiographs should be obtained in three views (image 1):

•Anterior-posterior – The anterior-posterior view shows the epicondyles (medial and lateral) and the articular surfaces (radiocapitellar and ulnotrochlear).

•Lateral – The lateral view shows the relationship between the bones of the distal humerus and proximal forearm.

•Lateral oblique – The lateral oblique view shows the radiocapitellar joint, medial epicondyle, radioulnar joint, and coronoid process. Comparison views do not increase diagnostic accuracy, but they may be helpful for patients who have inconclusive initial radiographic and clinical evaluation.

In addition, several anatomic relationships should be evaluated on lateral elbow radiographs to avoid failing to recognize subtle fractures (see "Elbow anatomy and radiographic diagnosis of elbow fracture in children", section on 'Plain radiograph interpretation'):

•The line along the anterior humerus should intersect the middle one-third of the capitellum (anterior humeral line) (image 3).

•The line of the long axis of the radius should extend through the middle of the capitellum (radiocapitellar line) (image 3).

•The fat pad of the elbow usually sits along the anterior border of the coronoid fossa and is concave-shaped. The fat pad is displaced superiorly and ventrally and appears convex if a fracture (sail sign) if a significant effusion (most often resulting from a fracture) is present (figure 15).

●Differential diagnosis – The differential diagnosis varies according to the acuity of the injury (see 'Differential diagnosis' above):

•Children and young adolescents with elbow pain after an acute injury have a high likelihood of fracture and/or dislocation. Supracondylar fractures account for up to 60 percent of pediatric elbow fractures (image 4 and image 2). Radial head subluxation (pulled elbow) is the most common elbow injury in preschool children (figure 20). (See 'Acute injury' above.)

•Subacute and chronic elbow pain in the young athlete is organized according to the location of pain (table 7). (See 'Differential diagnosis' above.)