eMedicine Specialties > Sports Medicine > Upper Limb

Little League Elbow Syndrome

Author: Holly J Benjamin, MD, FACSM, FAAP, Assistant Professor of Clinical Pediatrics and Surgery, Section of Orthopedic Surgery and Rehabilitation Medicine, The University of Chicago and The University of Chicago Physicians Group; Appointed Director of Primary Care Sports Medicine, The University of Chicago
Coauthor(s): Igor Boyarsky, DO, Director of Triage, Assistant Professor, Department of Emergency Medicine, King-Drew Medical Center, University of California at Los Angeles; Christian Rank, MD, Staff Physician, Department of Emergency Medicine, Martin Luther King/Charles R Drew Medical Center; Eleby R Washington III, MD, FACS, Associate Professor, Department of Surgery, Division of Orthopedics, Charles R Drew University of Medicine and Science
Contributor Information and Disclosures

Updated: Jan 5, 2009

Introduction

Background

Little league elbow (LLE) syndrome is a valgus overload or overstress injury to the medial elbow that occurs as a result of repetitive throwing motions. Over the past several decades, the number of organized sports for children has grown significantly, with millions of children participating in organized athletics each year. This increase in participation has been paralleled by an increase in sports-related injuries in the pediatric population.^{1,2,3,4,5,6,7,8,9,10,11}

Increased single-sport participation with year-round training, higher intensities at young ages, and longer competitive seasons are contributing factors to the increased injury rates seen in pediatric athletes. Conditioning and training errors also contribute significantly to the risk and frequency of injury. Although briefly discussed below, injuries to the lateral, posterior, and anterior elbow are separate entities and should not be confused with the medial injuries referred to as little league elbow syndrome.
 
During the throwing motion, valgus stress is placed on the elbow. This valgus stress results in tension on the medial structures (ie, medial epicondyle, medial epicondylar apophysis, medial collateral ligament complex) and compression of the lateral structures (ie, radial head, capitellum). Repeated stress results in overuse injury when tissue breakdown exceeds tissue repair. Recurrent microtrauma of the elbow joint can lead to little league elbow, a syndrome that encompasses (1) delayed or accelerated growth of the medial epicondyle (medial epicondylar apophysitis), (2) traction apophysitis (medial epicondylar fragmentation), and (3) medial epicondylitis.^{1,8,12,13,14,15}
 
Medial epicondylar apophysitis and stress fractures through the medial epicondylar epiphyses caused by repetitive valgus stress generally manifest with progressive medial pain, decreased throwing effectiveness, and decreased throwing distance.
 
Other causes of medial elbow pain include avulsion fractures of the medial epicondyle and ulnar collateral ligament (UCL) sprains or tears. Although a fracture is usually an acute traumatic event, a preceding history of medial elbow pain is common and is thought to be a risk factor for progression to acute fracture. Therefore, any thrower who is experiencing medial elbow pain should refrain from pitching until he or she has had a thorough evaluation.^1,3,5,8,16

A medial epicondyle fracture manifests as point tenderness and swelling over the medial epicondyle, often with an elbow flexion contracture greater than 15°. Repetitive medial stress can also cause attenuation and microstretching of the UCL complex, causing mild instability over time.¹
 
UCL injuries can manifest as acute ligament tears following a single valgus stress or as overuse sprains following repetitive valgus overloads. The clinical presentation is similar to little league elbow; however, the typical age range of the athlete is the older teenager who is skeletally mature. Suspected UCL injuries should be referred for further evaluation by a sports medicine specialist. Athletes with UCL injuries should not be allowed to pitch until they have been evaluated.
 
Although uncommon in children, neurologic injuries such as C8-T1 radiculopathy and ulnar neuritis can manifest as medial elbow pain and should be included in the differential diagnosis (see Differentials and Other Problems to Be Considered).
 
Lateral compression of the elbow most frequently results in injuries to the capitellum and radial head. Osteochondrosis of the capitellum (known as Panner disease) generally occurs in children aged 7-12 years and manifests as dull, achy, activity-related lateral elbow pain. Swelling, clicking, and decreased range of motion are uncommon associated symptoms. Panner disease tends to be a benign self-limited condition that does well over time and is treated with complete rest from inciting activities such as throwing and weight bearing on the elbow. Osteochondral injuries can also be observed in the radial head.
 
Osteochondritis dissecans (OCD) of the capitellum occurs in adolescents aged 13-17 years. This is a localized injury to subchondral bone that results from repetitive lateral compression of the elbow during overhead motions. These patients report a general dull elbow pain that worsens with activity, often have a flexion contracture of 15° or greater, and may have mechanical symptoms of clicking or popping. Loose body formation, residual capitellum deformity, and elbow degenerative joint disease are potential sequelae. Different treatment options are used based on the age and skeletal maturity of the patient and the type of lesion present. 

Osteochondritis dissecans lesions can be separated into type I, which has no displacement and no articular cartilage fracture; type II, which has evidence of articular cartilage fracture or partial displacement; and type III, which is completely displaced with loose bodies in the joint.

Posterior elbow injuries also occur as a result of throwing. During the follow-through stage of throwing, extension overload and valgus stress can result in injury of the olecranon. These athletes present with posterior elbow pain, clicking, and possible loss of elbow extension. Loose bodies and olecranon nonunion can occur in younger athletes. Older athletes may experience olecranon fractures or secondary osteophyte formation. These injuries are sometimes treated surgically.^{1,3,4,5,6,7,9,10,11,17}

For excellent patient education resources, visit eMedicine's Hand, Wrist, Elbow, and Shoulder Center and Sports Injury Center. Also, see eMedicine's patient education article Repetitive Motion Injuries.

Related eMedicine topics:
Floating Elbow
Tendonitis
Ulnar Nerve Entrapment

Frequency

United States

Annually, an estimated 4.8 million children aged 5-14 years participate in baseball and softball. The incidence of all baseball-related overuse injuries is 2-8% per year. The incidence of overuse injuries in the 9- to 12-year-old range for baseball is 20-40%, and in the adolescent age group is 30-50%. The true incidence of sports-related injuries is unknown because a large number of athletes never seek medical care. Early recognition of little league elbow syndrome is important, because it leads to better outcomes and decreases the risk of persistent functional disabilities in the athletes.

International

No data are available for the annual incidence of little league elbow syndrome in the international community.

Functional Anatomy

Evaluation of the young adolescent elbow presents some anatomic challenges to the healthcare provider in that the elbow consists of numerous ossification centers and cartilaginous physes. Becoming familiar with the chronologic order of appearance and ossification of these growth centers is important. Consider the mnemonic CRITOE (ie, capitellum, radius, internal epicondyle, trochlea, olecranon, external epicondyle).

Each of the ossification centers appears at a relatively predictable time starting around age 1-2 years, with 2-year intervals between the next center's appearance. Closure of each of the apophyses occurs from age 14 to 16 years, with the medial epicondyle specifically closing at approximately age 15 years. The elbow likely reaches full skeletal maturity by the late teen years, at which time injuries to the UCL are far more common. Until then, the young thrower is at risk for little league elbow syndrome.^1,4,12,16,18

The static stabilizers around the elbow include the bony articulations, the joint capsule, and the various ligament bundles. The medial (ulnar) collateral ligamentous complex consists of the anterior oblique bundle, posterior oblique bundle, and transverse ligament. These structures are the primary medial support of the elbow during valgus stress. The lateral (radial) ligamentous complex, composed of the lateral collateral, lateral ulnar collateral, and accessory lateral collateral ligaments, provides support during varus stress.

The dynamic stabilizers primarily include the muscles that cross the elbow joint, such as the triceps, biceps, and brachioradialis. The flexor-pronator group stabilizes against valgus stress, and the extensor-supinator group stabilizes against varus stress.

Elbow biomechanics include flexion/extension range of motion and pronation/supination. Slight hyperextension 5-15° through flexion of approximately 150° is within normal limits. Baseball pitchers with years of throwing experience often have relative 5-10° flexion contractures on their dominant side; however, in the young thrower, a flexion contracture can be a sign of injury. Pronation of 75° and supination of 85° is normal. Varus-valgus laxity of 3-4° is normal.

Sport-Specific Biomechanics

One should be familiar with the stages of throwing to understand the complexities of the biomechanical forces that contribute to the young thrower's risk of injury, such as in little league elbow syndrome. The pitching or throwing motion can be divided into 6 stages. Medial elbow injuries are the most common type seen in throwers and occur most commonly in the cocking and acceleration phases of throwing, owing to the presence of maximum valgus extension or distraction forces.^{1,12,13,14,15}

1. Windup begins with the pitcher balancing his weight over his rear leg, with the elbow flexed and the forward leg flexed at least 90°.
2. Stride starts with the lead leg beginning to descend toward the plate, and the 2 arms separate. The elbow moves from extension into flexion of 80-100°.
3. Cocking occurs when the humerus is in extreme abduction and external rotation and the elbow is flexed. The lead foots contacts the ground, the pelvis and trunk rotate, and elbow torque transfers valgus force across the elbow joint. During this phase, medial tension and lateral compression forces are applied to the elbow.
4. Acceleration is the shortest pitching phase, lasting from maximal external shoulder rotation to ball release. In this phase, the trunk rotates as the elbow extends. Maximum elbow angular velocity is comparable during fastballs, sliders, and curveballs, but it less during the change-up pitch. Velocity comes from rotation of the trunk, shoulder, and hips. Varus torque forces during this phase act to resist the valgus extension "overload" phenomenon and can contribute to posterior elbow (olecranon) impingement.
5. Deceleration is initiated at ball release and ends when the shoulder has reached full internal rotation. The body must decelerate the arm and dissipate forces in the elbow and shoulder.
6. Follow-through is the final phase of the baseball pitch and ends with the pitcher reaching a balanced fielding position with full-trunk rotation and the body weight fully transferred from the rear leg to the forward leg. During follow-through, the elbow flexes into a relaxed position and crosses the body.

Clinical

History

• Little league elbow syndrome occurs most commonly in pitchers, but it is also seen in infielders, catchers, and outfielders. This condition can also occur in other overhead or throwing sports, such as tennis and football (quarterback position). It is important to identify the player's position on the sports team during history taking, because this makes determining the magnitude of the stress placed on the elbow and the subsequent risk of injury easier.
• Skeletal age is an indicator of the stage of skeletal maturity and is a major determining factor in regard to these potential types of injuries. Little league elbow injuries during childhood are usually due to repetitive microtrauma to the apophysis and ossification center of the medial epicondyle. During adolescence, increased throwing force and valgus stress result in avulsion, delayed union, or nonunion of the medial epicondyle. In young adulthood, the medial epicondyle is fused, and injuries to the UCL are more common.
• Throwing history is important. Types of pitches, an accurate pitch count of approximate numbers of competitive pitches per game per week and/or season is necessary information. (See the 2008 USA Baseball Medical & Safety Advisory Committee recommendations for youth pitch counts.¹¹ )The level of play and time of season should be noted. Recent changes in pitch types, counts, or other alterations in training should be carefully noted. For example, fastballs and change-up pitches result in less medial elbow stress than curveballs and sliders. Curveballs thrown at a young age, regardless of previous pitching experience, are associated with an increased risk of little league elbow syndrome and more serious injuries such as medial epicondylar avulsion fractures due to shear forces over a immature growth plate.
• It is vital to obtain the location, timing, and duration of symptoms (usually pain). Elbow pain in a thrower is usually a chronic overuse injury. However, an acute inciting event that changes or worsens the symptoms may prompt an athlete to seek an evaluation. Pain is most commonly localized to the medial epicondyle, although patients may also present with lateral or posterior elbow pain. Medial elbow pain during the cocking and/or acceleration phases of throwing is typical. Pain during the deceleration phase is more likely to be associated with posterior elbow injuries. Radiation of symptoms is important to note, because patterns such as radiation of symptoms into the forearm with flexor-pronator tendinitis are common, as are paresthesias into the ring and little fingers with ulnar neuritis.
• Handedness is important only because symptoms usually manifest in the dominant extremity.
• Past history of injuries such as shoulder, back, or knee injuries that can easily alter the biomechanics of throwing may place the elbow at increased risk for overuse injuries. A general health assessment is also important.

Physical

• Inspection is important to note the carrying angle and any flexion contractures that may be present relative to the opposite side. During the initial examination, evaluate for muscle atrophy or hypertrophy, bony deformities, or the presence of swelling and ecchymosis.^1,18,19  
• Palpation of bony structures should include both epicondyles, the olecranon process, the capitellum, and the radial head. Soft-tissue palpation should include the UCL (felt best with the patient's elbow in 50-70° of flexion), the biceps tendon, the triceps tendon, and the flexor-pronator and extensor-supinator muscle complexes. 
• Strength testing of the various muscles should be performed.
• Neurologic testing should include evaluation of the ulnar nerve. Palpation for tenderness, stability testing, and a Tinel test via percussion over the ulnar groove for paresthesias consistent with ulnar neuritis constitute a thorough examination.
• Special tests include valgus stress testing to evaluate injury to the UCL. The patient may be prone, supine, or upright. The stress test should be performed with the elbow in 20-30° of flexion with a valgus force exerted on the elbow. Opening up on the injured side, compared with the opposite uninjured side, is most reflective of an injury to the UCL. Pain without instability during valgus stress testing is more commonly seen with little league elbow syndrome.
• Two special tests to note are the milking maneuver , which is performed with the patient seated, and the valgus extension overload test.
  • For the milking maneuver, the examiner grasps the thrower's thumb with the arm in the cocked position of 90° of shoulder abduction and 90° of elbow flexion. Then the examiner applies a valgus stress by pulling down on the thumb.
  • For the valgus extension overload test, the examiner stabilizes the humerus from the outside and then pronates the forearm during extension while applying valgus stress. Pain is more likely associated with posterior impingement if this test result is positive. 
• Conduct a complete examination of the neck, shoulders, wrist, and hand. A general inspection should include an assessment of height and weight, because a larger body habitus is associated with an increased risk of elbow injury. 
• Perform a complete neurologic and vascular examination of the neck and upper extremity.

Causes

• Training errors, such as abrupt changes in intensity, duration, or frequency of throwing activity are frequently associated with sports injuries. Poor coaching and lack of preseason conditioning can also contribute to an increased risk of injury.
• Strength and flexibility imbalances can indirectly cause elbow injuries, as can injuries to other areas of the body (current and/or previous injuries).
• Anatomic malalignment of the lower extremities can cause little league elbow syndrome.
• Improper footwear or playing surface can result in an insecure platform for stability in throwing activities.
• Associated disease states or preexistent injury can be causative.
• Growth patterns are sometimes implicated as the cause of little league elbow syndrome. Physeal or growth cartilage at the epiphysis or apophysis is less resistant to repetitive trauma than fused adult bone at ligamentous and tendinous insertions; thus, skeletally immature athletes more commonly develop growth plate (apophyseal) injuries. In addition, rapid growth (growth spurts) causes increased muscle and tendon tightness around a joint, resulting in loss of flexibility, biomechanical imbalance, and an increased risk of injury.

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