Medial Epicondyle Apophysitis (Little League Elbow)

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Medial Epicondyle Apophysitis (Little League Elbow)

Medial Epicondyle Apophysitis, commonly referred to as Little League Elbow, is characterized as an apophysitis of the medial epicondyle among athletes aged 6 to 15 who participate in sports that involve repetitive actions such as overhead throwing, racket use, or other overhead arm movements. Apophysitis is an inflammation or stress injury to the areas on or around growth plates in children and adolescents.

The medial epicondyle possesses its own ossification center (apophysis). The apophysis develops between the age of 6 and 7 and usually fuses by the time the individual reaches 15 years of age. The medial epicondyle serves as the point of origin for both the medial (ulnar) collateral ligament and the flexor-pronator muscle group. These structures play a vital role in stabilizing the elbow against valgus stress. The flexor-pronator muscle group include the pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis, and flexor carpi ulnaris.

The elbow’s static stabilizers consist of bony articulations, a joint capsule, and various ligament groups. The medial collateral ligament complex, consisting of the anterior and posterior oblique bundles and the transverse ligament, serves as the main medial support during valgus stress.

The elbow’s dynamic stabilizers consist of the muscles that cross the elbow. These include the triceps, biceps, and brachioradialis muscles, as well as the flexor-pronator and extensor-supinator muscle groups. The flexor-pronator group stabilizes the elbow to resist valgus stress.

Sports such as softball, volleyball, tennis, swimming, javelin throwing, and particularly baseball pitching may all lead to medial epicondyle apophysitis. In young athletes, these activities subject their elbow apophysis to recurrent valgus stress before its fusion.

The persistent strain from these actions leads to repetitive microtrauma to the apophysis and ossification center of the medial epicondyle, resulting in an abnormal widening and inflammation of the apophysis. In more severe cases, this can lead to an avulsion fracture.

Training errors, such as sudden shifts in the intensity, duration, or frequency of a sports activity (e.g., overhead throwing), are often linked to sports-related injuries. For example, Medial Epicondyle Apophysitis arising in baseball is often attributed to inadequate coaching, lack of preseason conditioning, and poor throwing technique.

Most cases of Medial Epicondyle Apophysitis resolve with conservative management, and patients can eventually return to their desired level of athletic activity.

• Medial elbow pain commonly localized to the medial epicondyle
• Age of onset between 6 and 15 years
• History of involvement in a sporting activity that requires repetitive overhead motions
• Pain onset is typically insidious but may be acute and may be accompanied by a ‘popping’ sensation if an avulsion occurs
• Pain during the cocking and/or acceleration phases of throwing

• Medial epicondyle point tenderness
• May have medial elbow swelling
• Pain aggravated by valgus stress (e.g., when performing the Moving Valgus Stress Test and Modified Milking Maneuver)
• Pain that is aggravated by contraction of the wrist flexors (e.g., when performing the Resisted Wrist Flexion test)
• May present with elbow instability, reduced elbow range of motion, and ulnar nerve deficiencies in cases of avulsion fractures

Moving Valgus Stress Test

The Moving Valgus Stress Test specifically targets structures on the medial side of the elbow, particularly the medial collateral ligament. The aggravation of the patient’s pain during this test strengthens the likelihood of medial collateral ligament involvement or suggests that the pain may stem from stress on the medial epicondyle apophysis.

For a demonstration of how to perform the Moving Valgus Stress Test, please watch the video below.

Modified Milking Maneuver

The Modified Milking Maneuver is specifically designed to assess medial elbow instability by applying stress to the medial elbow structures, particularly the medial collateral ligament (MCL). This test may also be useful in suspected cases of medial epicondyle apophysitis (Little League Elbow).

To see a demonstration of how the Modified Milking Maneuver is performed, please refer to the video below.

Resisted Wrist Flexion Test

The Resisted Wrist Flexion test is designed to identify the involvement of the flexor-pronator muscle group. The exacerbation of the patient’s pain during this test suggests either the involvement of the flexor-pronator muscle group or that the pain results from the loading of the medial epicondyle apophysis.

Please watch the video below if you wish to see how the Resisted Wrist Flexion test is performed.

Medial Epicondyle Apophysitis is often a clinical assessment. However, plain radiography may demonstrate hypertrophy of the medial epicondyle, a bony fragmentation, or an apophyseal widening. Radiographs may also help to detect medial epicondyle avulsion, loose cartilaginous bodies, osteochondral lesions, or serious pathologies such as tumors.

When plain radiography is inconclusive, MRI may be used to confirm the diagnosis or to help rule out other conditions.

Ultrasonography is also beneficial for visualizing the soft tissues around the elbow, especially when there is suspicion of medial collateral ligament injury.

The following are examples of red flags for patients presenting with elbow pain:

• A history of significant injury
• Severe pain
• Unrelenting pain
• Nocturnal pain
• Unexplained weight loss
• Fever
• Deformity
• Significant swelling
• Presence of tingling, numbness, burning, or other neurological impairment
• Loss of distal pulses
• Significant loss of range of motion
• Severe tenderness on palpation or severe pain with any examination procedure

If any red flags are identified during history taking and clinical examination, referral for urgent medical evaluation and further investigation is warranted.

Differential Diagnosis of Medial Elbow Pain

The differential diagnosis of medial elbow pain should include conditions such as:

• Medial epicondyle apophysitis
• Medial elbow tendinopathy
• Apophyseal avulsion fracture (as described below)
• Medial collateral ligament tear (as described below)
• Ulnar neuropathy (as described below)
• Flexor-pronator injury
• Valgus extension overload syndrome (as described below)
• Myofascial pain syndrome (e.g., the pectoralis major and the triceps brachii muscles, as described below)
  
• Elbow joint dysfunction
• Cubital tunnel syndrome
• Inflammatory arthritis
• Cervical radiculopathy

Apophyseal Avulsion Fracture – Sudden onset or worsening of pain together with a ‘popping’ sensation suggests an avulsion fracture. Plain radiography should demonstrate widening with a displacement of the medial epicondyle apophysis.

Partial or Full Thickness Medial Collateral Ligament Tear – Medial collateral ligament tear presents with similar signs and symptoms to Medial Epicondyle Apophysitis. However, this condition typically occurs in individuals older than 15 years of age.

Ulnar Neuropathy – Ulnar Neuropathy may present with pain around the medial elbow where the ulnar nerve traverses the cubital tunnel. However, rather than pain, the most prominent clinical findings are numbness and muscular weakness due to ulnar nerve involvement. Nerve conduction studies may be required when Ulnar Neuropathy is suspected.

Flexor-Pronator Muscle Injury – Injuries of the flexor-pronator muscle group can present with muscle weakness and elbow pain that is aggravated by wrist flexion. Depending on the severity of the injury, swelling and bruising may also be present.

Valgus Extension Overload Syndrome – Valgus Extension Overload Syndrome may manifest in athletes engaged in overhead throwing activities. It is characterized by discomfort in the posterior and medial aspects of the elbow. This condition is often accompanied by episodes of elbow locking and the presence of crepitus.

Medial Elbow Pain Caused by Myofascial Pain Syndrome

In patients presenting with medial elbow pain, a complete clinical examination should include checking for the presence of myofascial pain syndrome as the concomitant or primary cause of the patient’s pain. The main muscles to examine for myofascial trigger points are the triceps brachii (medial head) and pectoralis major. As illustrated below, when the pectoralis major muscle is involved, it produces chest and shoulder pain as well as pain in the medial elbow.

The trigger points associated with myofascial pain syndrome may be located anywhere within a muscle and its fascia. Therefore, the entire muscle should be examined thoroughly. However, based on our clinical experience, the common locations for trigger points are presented in the images below.