Understanding Subluxation and Dislocation of the Radial Head: Causes, Symptoms, and Prevention

The human body is a complex system of joints, ligaments, and muscles designed to move in fluid, coordinated ways. However, under certain forces or movements—especially in young children—these systems can be disrupted. One common but often misunderstood injury in children is the subluxation or dislocation of the radial head, commonly referred to as “nursemaid’s elbow.” This injury occurs when the head of the radius bone slips out from its normal alignment with the annular ligament, often due to sudden pulling on the arm. While it’s usually not a serious or permanent injury, it can be painful and alarming. Understanding how this injury happens, what it looks like, and how to prevent it is essential for parents, caregivers, and healthcare professionals alike.

What Is the Radial Head and Its Function?

The elbow joint is composed of three bones: the humerus (upper arm bone), the ulna, and the radius (both in the forearm). The head of the radius is the top, rounded part that connects to the humerus and is held in place by a strong band of connective tissue called the annular ligament. This ligament allows the radial head to rotate within it, enabling pronation and supination of the forearm (the turning of the palm up or down). The radial head must stay snug within this ligament for smooth, functional motion of the arm. In children, however, the ligament is still developing and is more elastic, making it easier for the radial head to slip out—leading to subluxation or, in more severe cases, dislocation.

What Is Radial Head Subluxation?

Subluxation is a partial dislocation, meaning the radial head is temporarily out of place but not completely detached from the annular ligament. This injury is especially common in children under the age of five because their ligaments are still developing and more prone to stretching. It often happens when a child is pulled suddenly by the hand or wrist, such as during rough play, lifting them by the arms, or when they stumble and are jerked up to prevent a fall. In these moments, the radial head slips out from under the annular ligament. This causes pain, limited movement, and discomfort, although the injury can usually be corrected quickly by a healthcare professional.

What Is Radial Head Dislocation?

Dislocation of the radial head is more severe than subluxation. It involves the complete displacement of the radial head from the annular ligament and joint space. This type of injury is less common in young children and usually occurs due to more traumatic incidents such as falls or forceful twists. A dislocation often presents with a visible deformity, swelling, intense pain, and an inability to move the arm. Unlike a subluxation, which may be subtle in appearance, a full dislocation requires immediate medical attention and sometimes imaging or even surgical intervention to correct.

What Happens During a Subluxation or Dislocation?

When a pulling force is applied to a child’s outstretched or extended arm, the annular ligament may stretch enough to allow the radial head to slip out of place. This displacement can cause a noticeable lump near the elbow where the radial head has moved, and children often hold their arm limp at their side, refusing to use it. As shown in the image, muscle contraction further pulls the radial head superiorly, adding tension and pain. While the injury may not always show visible swelling or bruising, it will almost always result in a limited range of motion and discomfort, especially when the child tries to turn their palm up or down.

Understanding the Stages: Normal to Dislocation

The image depicts a progression from a normal joint to full dislocation. In a normal elbow, the radial head is perfectly aligned with the annular ligament, allowing free movement. A subclinical subluxation involves minimal displacement, which might not cause immediate symptoms but can increase the risk of future injuries. A complete subluxation shows the radial head partially out of its socket, while a dislocation shows total separation from the ligament. This visual progression is critical for understanding the injury’s severity and the importance of early detection and intervention.

Common Causes of Radial Head Subluxation

The majority of radial head subluxations occur from seemingly harmless activities such as:

• Pulling a child up by one or both arms

• Swinging a child by their hands

• Jerking a child’s arm to prevent a fall

• Lifting a child quickly from the ground by their forearms

• Roughhousing or playing games involving pulling or swinging

Parents often report the incident as a simple tug, unaware of the force applied to the delicate structures of the elbow. Because young children’s bones and ligaments are more pliable, even a minor pull can result in subluxation.

Signs and Symptoms of a Subluxed or Dislocated Radial Head

Children with a subluxed or dislocated radial head typically exhibit the following symptoms:

• Sudden crying or distress after being pulled by the arm

• Refusal to use the arm or hand

• Holding the arm slightly bent at the elbow, close to the body

• Refusing to reach out or grasp objects

• No visible bruising or swelling in most cases

• A “click” or pop may be heard or felt at the time of injury

In the case of dislocation, additional signs may include:

• Swelling or deformity near the elbow

• Severe pain and complete lack of mobility

• A bulge or lump where the radial head is displaced

Prompt diagnosis and treatment are key to resolving the condition and avoiding further complications.

How Is Radial Head Subluxation Diagnosed?

Diagnosis is typically clinical and based on the history of the incident and physical examination. Because this is such a common pediatric injury, healthcare providers can often identify it without the need for X-rays. The classic presentation—a child holding their arm in a protective position following a sudden pull—is often sufficient for diagnosis. If a full dislocation or fracture is suspected, imaging may be ordered to confirm the diagnosis and rule out other injuries.

Treatment for Radial Head Subluxation

The treatment is usually a simple manual reduction performed by a healthcare professional. This involves gently manipulating the forearm through a technique known as the supination-flexion method or the hyperpronation method. These methods aim to guide the radial head back into its correct position under the annular ligament. A subtle pop or click is often felt during successful reduction, and the child typically regains full use of the arm within minutes. No surgery, medication, or immobilization is usually required for uncomplicated subluxations. However, if the condition does not resolve or if the child experiences repeated incidents, further evaluation may be necessary.

Treatment for Radial Head Dislocation

Dislocation requires more intensive care. If the radial head cannot be manually repositioned, or if there’s associated injury like a fracture, the child may require sedation, imaging, and even surgery. Immobilization with a splint or cast may be needed to allow the ligaments and tissues to heal properly. Physical therapy might also be necessary to restore full range of motion and strength.

What Is the Prognosis?

For simple subluxations, the prognosis is excellent. Once the radial head is reduced, most children recover quickly with no long-term effects. However, recurrence can happen, especially if the child is repeatedly exposed to the same mechanism of injury. In cases of dislocation, recovery may take longer, and ongoing monitoring may be needed to ensure proper joint alignment and function.

Prevention: How to Avoid Radial Head Subluxation

The most effective way to prevent this injury is through awareness and proper handling of young children. Here are some key prevention tips:

• Avoid pulling or jerking a child by the hands or forearms

• Lift young children by supporting under their arms or around their chest

• Discourage swinging children by their arms, even during playful moments

• Teach older siblings and caregivers the correct way to lift and guide younger children

• Use caution during dressing, especially when putting on jackets or long-sleeved clothing

These simple preventive measures can drastically reduce the likelihood of injury and protect a child’s developing joints.

What to Do If You Suspect Subluxation or Dislocation

If a child suddenly refuses to use their arm, especially after being pulled or swung by the arms, remain calm and observe the signs. Do not attempt to force the arm into movement. Take the child to a healthcare professional or pediatric urgent care. A trained clinician can quickly and safely reposition the joint if needed. Early intervention leads to faster recovery and less distress for the child.

Educational Importance for Parents and Caregivers

Understanding the vulnerability of a child’s joints is essential for anyone who interacts with young children. Accidental injuries are common, but with proper education, many can be prevented. Sharing this knowledge with babysitters, teachers, and family members ensures a safer environment for children and reduces unnecessary visits to emergency departments.

Final Thoughts: Awareness Can Prevent Injury

Radial head subluxation and dislocation are injuries that can happen in an instant—but with proper awareness and handling, they are also highly preventable. These injuries serve as a reminder that children are still developing and that their bodies respond differently to force. By understanding the structure of the elbow, recognizing the signs of injury, and practicing safe lifting and play techniques, we can protect our children from pain and reduce the risk of repeat injuries. As always, when in doubt, consult a medical professional. A gentle approach and informed care go a long way in ensuring healthy, happy development for our children.