What is Proximal Humeral Epiphysiolysis (Little League Shoulder)?
Proximal humeral epiphysiolysis, also known as Little League shoulder, involves an injury to the soft, growing part of the upper arm bone near the shoulder. It specifically relates to the stress or damage to the cartilage of this part of the bone, which is near the growth plate. This condition is also known by other medical names such as osteochondrosis of the proximal humeral epiphysis and rotation stress fracture of the proximal humeral growth plate.
This condition only affects young athletes whose bones are still growing and who haven’t yet reached the stage where their growth plates close. It’s most commonly seen in young people who play baseball, especially pitchers. This closure of the growth plate usually happens between the ages of 18 and 21, so theoretically, these injuries can happen until then. But, typically, this condition is seen in those aged between 11 and 16 years old.
Though Little League shoulder is usually linked with young baseball players and throwing athletes, it has also been seen in competitive gymnasts and tennis players.
What Causes Proximal Humeral Epiphysiolysis (Little League Shoulder)?
‘Little League shoulder’ is a condition typically seen in those who frequently throw overhead, such as young athletes. It happens when too much force from repeatedly twisting and stretching the arm damages the cartilage in the upper arm bone.
The reason young people are more prone to this injury is that a part of the bone called the ‘growth plate’ is weaker than the nearby tendons and ligaments. This growth plate, made of cartilage, is more likely to get injured, particularly from repeated actions.
During adolescence, when bones are growing rapidly, there can be imbalances in strength and flexibility, making injuries more likely. Moreover, the growth plate is particularly sensitive to twisting forces.
Some experts believe that a change in the angle of an arm bone’s twist, known as ‘humeral retrotorsion’, might increase the risk of damage to the growth plate. However, research on this is not consistent, with some studies suggesting that this does not necessarily lead to symptoms.
Risk Factors and Frequency for Proximal Humeral Epiphysiolysis (Little League Shoulder)
Little League shoulder is a condition often seen in young baseball players. One research studied 2055 baseball players between the ages of 9 and 12. They discovered that slightly over 13% had pain in the arm they use for throwing. Among those with pain, 41 agreed to get x-rays of their shoulder. Out of these 41, over a third (36.6%) showed signs of Little League shoulder on x-ray. We need to note that this is a small group, but it suggests that around 5% of all baseball players in this research, with or without pain, had Little League shoulder.
A different study with 1563 young baseball players found that nearly 16% had shoulder pain, though it wasn’t specifically linked to Little League shoulder.
Signs and Symptoms of Proximal Humeral Epiphysiolysis (Little League Shoulder)
If a child is suspected of having Little League shoulder, it’s crucial to ask about any previous shoulder or elbow injuries. Past injuries might cause the child to unintentionally alter their throwing technique to reduce pain, which can lead to an increased risk of further injury. A recent growth spurt might also increase their risk for this condition as it affects the top growth plate of the upper-arm bone.
The typical symptoms include gradual shoulder pain when throwing, which may progress to pain even when just lifting the arm, and in some cases, at rest. Despite this, in the early stages, most patients find that their symptoms lessen with rest. Other signs can include throws becoming less accurate or slower, with up to 13% of patients experiencing both shoulder and elbow pain.
During a physical examination, patients often show tenderness when the growth plate of the upper arm, near the shoulder, is pressed. Swelling might be minimal and other visual and touch inspections are usually normal. Depending on the severity of the condition, there could also be a decreased range of motion and muscle weakness, often as a result of the child trying to avoid pain.
- Gradual shoulder pain during throwing
- Pain when lifting the arm
- Pain at rest in some cases
- Symptoms lessen with rest in early stages
- Decreased accuracy or slower throwing speed
- A small portion of patients also experience elbow pain
Testing for Proximal Humeral Epiphysiolysis (Little League Shoulder)
Diagnosis for this issue mostly involves a doctor guessing what might be wrong based on the patient’s symptoms and medical history. Most athletes will have normal looking growth plates, or areas where new bone grows, in their arm bones when examined via an x-ray. But, a different type of x-ray, taken from the front while the arm is rotated outward, might show a widened area where new bone grows in the upper arm.
This widening could be a sign that something is wrong. Other signs in the x-ray could include areas of hardening (sclerosis), loss of minerals (demineralization), or breaking up (fragmentation) in the area where the bone grows.
Besides x-rays, doctors can also use ultrasound, a technique that uses sound waves to produce images, to diagnose the issue. Here, ultrasound images of the affected shoulder might show areas with increased swelling that doesn’t appear on the unaffected shoulder. The use of ultrasound, however, should be done by an experienced practitioner.
Although not often needed, Magnetic Resonance Imaging (MRI) scans, which use strong magnetic fields to generate detailed images, can be used to confirm the diagnosis if x-rays do not show the issue. An MRI would show an area of swelling called edema around the growth plate.
Treatment Options for Proximal Humeral Epiphysiolysis (Little League Shoulder)
If you start feeling pain at the start, stopping the activities that cause the pain can prevent a complete stress fracture in the growth plate of the upper arm bone. Before a stress fracture happens, taking a break usually eases the pain. But once a stress fracture has occurred, the pain won’t go away with rest, and your throwing ability might decrease.
The treatment for an injury often called “Little League shoulder” involves resting and avoiding overhead activities for 3 to 6 months. Once you don’t feel any pain while resting, your treatment can move onto strengthening exercises for your core muscles and rotator cuff, often under the guidance of a physical therapist. When your movement range, strength, and shoulder blade motion are back to normal, you can gradually start throwing again through a guided throwing program and eventually return to your sport.
Surgery is not required for an injury to the part of your upper arm bone where growth occurs, known as proximal humeral epiphysiolysis.
What else can Proximal Humeral Epiphysiolysis (Little League Shoulder) be?
When doctors are diagnosing your symptoms, they consider several other conditions that may have similar signs. These commonly include:
- Impingement syndrome
- Rotator cuff injury
- Biceps tendonitis
- Labral tear
- Subdeltoid bursitis
They also consider some less common conditions, which include:
- Tumors of the upper arm
- C5 radiculopathy
- Thoracic outlet syndrome
What to expect with Proximal Humeral Epiphysiolysis (Little League Shoulder)
Most children with this condition can go back to their normal activities if they take enough rest from throwing activities and gradually return to playing. One research found out that having good shoulder flexibility may be connected to a pain-free return to baseball.
Along the same lines, another research discovered that children with ‘Little League shoulder’, who also have a condition called glenohumeral internal rotation deficit (GIRD) – which means a reduced ability to rotate their shoulder – have a tripled risk of experiencing the condition again.
Possible Complications When Diagnosed with Proximal Humeral Epiphysiolysis (Little League Shoulder)
Though uncommon, possible complications involving abnormalities in the growth plate can occur. These may include:
- Partial dislocation of the shoulder joint or glenohumeral joint
- Death of bone tissue in the upper arm or humeral head due to lack of blood supply, known as osteonecrosis
- Early sealing of the growth plate, also known as ‘physis,’ that can lead to differences in limb length
Preventing Proximal Humeral Epiphysiolysis (Little League Shoulder)
This type of injury can happen because of repeated stress on the shoulder from too much throwing. So, it’s advised to take steps to prevent this by not throwing too much. Some studies suggest that limiting the number of pitches can help prevent this injury from happening in the first place or coming back. It’s also a good idea to stretch before and after any sports activity and apply ice to the shoulder after throwing. Additionally, taking a break from throwing for one season each year can help keep the shoulder healthy.
The United States Baseball and Major League Baseball suggest guidelines for young players which include limiting the number of pitches based on the player’s age and ensuring they get enough rest between games. Paying attention to the right way to throw can also help lessen the stress on the shoulder. One study recommended specific shoulder movements for throwing that reduced the stress on the shoulder.
Other factors that can put more strain on the shoulder and elbow and increase the risk of injury include things like bending the knee differently when throwing, turning the trunk of the body too soon, having difficulty moving the shoulder fully, bending the elbow more when throwing, throwing the ball very fast, and fatigue from pitching.
When a child starts throwing again, doctors discourage the use of painkillers like NSAIDs before throwing because they can mask pain that may indicate inflammation in the shoulder.
